Category Archives: Discoveries

Increased Ovarian Cancer Metastases Identified In Women With BRCA Gene Mutations; May Shed Light on New Treatment Approach

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U.K. researchers have found that patients with hereditary ovarian cancer – whose tumors are caused by faulty BRCA1 or BRCA2 genes – are more likely to experience metastases of the liver, lung, spleen, and viscera. … [T]he researchers suggest that ovarian cancer patients whose tumors spread to the solid organs … should be tested for the faulty genes – BRCA1 and BRCA2 – to ensure they are given the most appropriate treatment.

Dr. Charlie Gourley, Acting Head, Medical Oncology, University of Edinburgh Cancer Research Centre

U.K. researchers have found that patients with hereditary ovarian cancer – whose tumors are caused by faulty BRCA1 or BRCA2 genes – are more likely to experience metastases of the liver, lungs, spleen, and viscera. This is despite the fact that their overall prognosis is better than other ovarian cancer patients.  The research is published in the April 20th online edition of the Journal of Clinical Oncology.

In the study, researchers discovered that the percentage of women with BRCA1 or BRCA2 gene mutations who experienced visceral, liver, lung, and splenic metastases were 58%, 42%, 16%, and 32% , respectively, as compared with 5%, 0%, 0%, and 3%, respectively, in non-BRCA gene deficient women.  The researchers note that sporadic (i.e., non-hereditary) ovarian tumors tend to remain within the lining of the abdomen and pelvis.

Based upon the study findings, the researchers suggest that ovarian cancer patients whose tumors spread to the solid organs such as the liver, lungs, and spleen should be tested for the faulty genes – BRCA1 and BRCA2 – to ensure they are given the most appropriate treatment.  For example, patients with hereditary tumors, which account for 10 per cent of ovarian cancers, may be suitable for trials of a new drug called olaparib [AZD2281], which has fewer side-effects than normal cancer treatments. Olaparib belongs to a class of drugs known as “PARP” (Poly (ADP-ribose) polymerase) inhibitors.

Researchers say the study findings will improve the detection of faulty BRCA genes, as current criteria for genetic testing may miss as many as two-thirds of ovarian cancer patients carrying the mutated genes.  Improving the identification of BRCA mutations will help relatives of ovarian cancer patients, who may themselves be at increased risk of developing hereditary ovarian cancer.

Dr. Charlie Gourley, who led the research at the University of Edinburgh, said:

“We are beginning to understand the importance of tailoring cancer treatments according to the specifics of each patient’s tumor. These findings demonstrate that tumors which arise because of defects in the BRCA1 or BRCA2 genes behave differently to other ovarian cancers. This information should also help us to identify the patients carrying these genetic mutations, give them the most effective treatment for their cancer and offer their relatives genetic counselling.”

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Researchers Identify A New Breast & Ovarian Cancer Susceptibility Gene

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German researchers identify a new breast and ovarian cancer susceptibility gene known as “RAD51C.”  The risk for breast cancer in women with the RAD51C mutation is 60 to 80 percent, while the risk for ovarian cancer is 20 to 40 percent.

The discovery 15 years ago that the genes BRCA1 and BRCA2 confer high risks for breast and ovarian cancer was a breakthrough for cancer prediction and therapy, especially for familial cases.  Now the research group of Prof. Alfons Meindl (Klinikum rechts der Isar of the Technische Universitaet Muenchen), in collaboration with other groups from Germany, the U.K., and the U.S., can identify another gene that increases susceptibility to breast and ovarian cancer. Their results have been published online in Nature Genetics. The identification of such high risk-conferring genes is a prerequisite for offering women tailored early recognition programs and more individualized therapies.

The gene newly identified as causing breast and ovarian cancer in familial cases is designated RAD51C. It is, like BRCA1 and BRCA2, essential for DNA repair within cells. Mutations in the gene can therefore cause either breast or ovarian cancer. In index cases from 1,100 German families with gynecological malignancies, six mutations within the RAD51C gene were found exclusively in 480 pedigrees [i.e., family trees] with occurrence of breast and ovarian cancer. The six RAD51C mutations were not found in 620 pedigrees with breast cancer only, or in 2,912 healthy German controls.  The risk for breast cancer in women with mutation of RAD51C is 60 to 80 percent, while the risk for ovarian cancer is 20 to 40 percent. As the cancers in such families were diagnosed significantly earlier than in women who developed sporadic breast or ovarian cancer, experts might also call the newly identified gene BRCA3.

“These results reinforce our assumption that various rare gene mutations contribute to hereditary breast and ovarian cancer. The now known genes that predispose women to breast and/or ovarian cancer only explain 60 percent of the high-risk families,” says TUM Professor Alfons Meindl, Klinikum rechts der Isar, but novel technologies allow the rapid identification of other such rarely mutated disease-causing genes.

“We are also optimistic that in the future the individual breast cancer risks for the majority of women can be determined. These risk predictions will allow the offering of tailored prevention and small meshed early recognition programs. Risk-aligned prevention will become a new clinical area,” explains Prof. Dr. Rita Schmutzler of the University Hospital of Cologne, one of the other main authors of the article.

About Technische Universitaet Muenchen

Technische Universitaet Muenchen (TUM) is one of Germany’s leading universities. It has roughly 420 professors, 7,500 academic and non-academic staff (including those at the university hospital “Rechts der Isar”), and 24,000 students. It focuses on the engineering sciences, natural sciences, life sciences, medicine, and economic sciences. After winning numerous awards, it was selected as an “Elite University” in 2006 by the Science Council (Wissenschaftsrat) and the German Research Foundation (DFG). The university’s global network includes an outpost in Singapore. TUM is dedicated to the ideal of a top-level research based entrepreneurial university. http://www.tum.de

About Klinikum rechts der Isar, Munich, Germany

The Klinikum rechts der Isar (on the right hand side of the river Isar) serves its patients with a highly skilled team of dedicated doctors, nurses, research scientists, and technical assistants. The Klinikum rechts der Isar is a university hospital of the Technische Universitaet Muenchen.  With a workforce of over 4,000 personnel, the university hospital is a renowned center for the care of the sick, for medical research, and for the teaching of medicine. The Klinikum rechts der Isar is composed of more than 30 separate clinics and departments treating some 45,000 in-house patients and 170,000 out-patients yearly. With more than 1,000 beds, the hospital covers the entire spectrum of modern medicine with state-of-the-art efficiency. Through the close cooperation between health care and research, the latest advances in medical techniques can be quickly integrated into patient treatment procedures.

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Expression of Proteins Linked to Poor Outcome in Women with Ovarian Cancer

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Scientists have established the presence of certain proteins in ovarian cancer tissues and have linked these proteins to poor survival rates in women with advanced stages of the disease.

Christina M. Annunziata, M.D., Ph.D., Assistant Clinical Investigator, Medical Oncology Branch & Affiliates, Molecular Signaling Section, National Cancer Institute

NF-kB Signaling Pathway

Scientists have established the presence of certain proteins in ovarian cancer tissues and have linked these proteins to poor survival rates in women with advanced stages of the disease. The study, led by scientists at the National Cancer Institute (NCI), part of the National Institutes of Health, appears in Cancer online, April 19, 2010.

The proteins in question belong to the nuclear factor kappa Beta (NF-kB) family. NF-kB controls many processes within the cell including cell survival and proliferation, inflammation, immune responses, and cellular responses to stress.

“This study sheds light on the distinctive genetic features of the NF-kB pathway and may provide targets for the development of novel therapies for ovarian cancer,” said lead investigator, Christina M. Annunziata, M.D., Ph.D., associate clinical investigator, Medical Oncology Branch.

Abnormalities in NF-kB signaling have been found in several types of cancer, including ovarian cancer, but the mechanism and importance of such alterations in ovarian cancer was not defined. To address these knowledge gaps, the research team investigated the expression of NF-kB-related proteins in the cells of tumor tissue obtained at surgery from 33 previously untreated women who were newly diagnosed with advanced epithelial ovarian cancer. The patients had similar stage (all late stage), grade, and type of disease. All patients were treated with a three-drug regimen of standard chemotherapy agents in an NCI clinical trial that was conducted at the NIH Clinical Research Center.

To assess NF-kB family members and associated proteins in ovarian tumor cells, the scientists used immunohistochemistry, a method that uses antibodies — a type of protein that the body’s immune system produces when it detects harmful substances — to identify specific molecules in tissue specimens. Subsequently, they looked for associations between the percentage of tumor cells in individual proteins and patient outcomes.

“This study sheds light on the distinctive genetic features of the NF-kB pathway and may provide targets for the development of novel therapies for ovarian cancer,” said lead investigator, Christina M. Annunziata, M.D., Ph.D.

The data revealed that the presence of one NF-kB family member—p50—in more than one-quarter of the cells was associated with poor survival. Low-frequency or nonexpression of a target gene, matrix metallopeptidase 9 (MMP9), was also associated with poor prognosis. Further, the team identified two NF-kB family members—p65 and RelB—and a protein called IKKa that plays a role in promoting inflammation, that were frequently expressed in the same cells, providing more evidence that NF-kB is active in some ovarian cancers. It is possible that the NF-kB activity in these cancers could increase their growth and/or resistance to treatment.

“This work continues to define and characterize the biological relevance of NF-kB activity in ovarian cancer by translating research findings with ovarian cancer cells in the laboratory to ovarian cancer in women at the time of initial diagnosis,” said Annunziata.

About the National Cancer Institute

NCI leads the National Cancer Program and the NIH effort to dramatically reduce the burden of cancer and improve the lives of cancer patients and their families, through research into prevention and cancer biology, the development of new interventions, and the training and mentoring of new researchers. For more information about cancer, please visit the NCI Web site at http://www.cancer.gov or call NCI’s Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).

About the National Institutes of Health

The National Institutes of Health (NIH) — The Nation’s Medical Research Agency — includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

Comment

If NF-kB activity is ultimately determined by Dr. Annunciata et. al. to be biologically significant to ovarian cancer cell growth and/or treatment resistance, there are NF-kB inhibitor drugs (e.g., bortezomib (Velcade) or denosumab (Prolia)) in existence that theoretically could be tested in ovarian cancer clinical trials. In addition genistein, a soy isoflavone, and BAY11-7082, a preclinical compound, could be tested through preclinical/clinical testing as potential NF-kB inhibitors.  See Miller SC et. al. study below for a complete list of known NF-kB pathway inhibiting drugs and compounds.

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Abbott Labs Seeks FDA 510(k) Clearance For New Automated Ovarian Cancer Detection Test

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A new diagnostic tool physicians can use to monitor patients for the most common form of ovarian cancer may soon be available in the United States.

Abbott Laboratories’ ARCHITECT HE4 assay uses a simple blood test to help in monitoring for the recurrence or progression of epithelial ovarian cancer. If approved by the FDA, this important immunoassay would be the first automated HE4 test available in the United States.

A new diagnostic tool physicians can use to monitor patients for the most common form of ovarian cancer may soon be available in the United States.  Abbott Laboratories’ (Abbott’s) ARCHITECT [Human Epididymal Protein 4] HE4 assay uses a simple blood test to help in monitoring for the recurrence or progression of epithelial ovarian cancer. If approved by the U.S. Food & Drug Administration (FDA), this important immunoassay would be the first automated HE4 test available in the United States.

The 2003 Hellstrom et al. study of known ovarian cancer biomarkers found that HE4, which has been detected in high levels in the blood of some ovarian cancer patients, shows the highest sensitivity and specificity of any other marker and is considered the best single marker for stage 1 of the disease.

According to the American Cancer Society, the five-year survival rate of ovarian cancer patients is 46 percent. However, when the disease is diagnosed and treated earlier, the survival rate increases to 93 percent. Less than 20 percent of all ovarian cancer is found in the early stage.

“The ability to monitor the recurrence or progression of ovarian cancer is a critical part of patient care. The ARCHITECT HE4 assay has the potential to be a powerful tool for both physicians and patients in the management of the disease,” said Michael Warmuth, Senior Vice President, Diagnostics, Abbott.

Abbott partnered with Fujirebio Diagnostics, Inc. in the development of the assay. The ARCHITECT HE4 assay is approved for use in Europe, as well as in other countries in Asia Pacific and Latin America. It is currently an investigational device in the United States.

About ARCHITECT HE4 Assay

The ARCHITECT HE4 assay is designed to be used as an aid in monitoring recurrence or progressive disease in patients with epithelial ovarian cancer, and must be used in conjunction with other clinical data. The ARCHITECT HE4 assay should not be used as a cancer screening test. In addition, certain types of cancer (e.g., mucinous or germ cell tumors) rarely express HE4, and the use of the ARCHITECT HE4 assay is not recommended for monitoring patients with those types of cancer.

About Ovarian Cancer

Ovarian cancer is the leading cause of death from gynecological cancers and the fifth-leading cause of cancer death in women. An estimated one in 71 women will develop ovarian cancer in their lifetimes. Women who are postmenopausal are at the greatest risk for ovarian cancer.

About Abbott Diagnostics

Abbott Diagnostics is a global leader in in vitro diagnostics (IVD) and offers a broad range of innovative instrument systems and tests for hospitals, reference labs, blood banks, physician offices and clinics. With more than 69,000 institutional customers in more than 100 countries, Abbott’s diagnostic products offer customers automation, convenience, cost effectiveness and flexibility. The history of Abbott Diagnostics is filled with examples of first-of-a-kind products and significant technological advancements, including the development of the very first diagnostic test to detect HIV.

About Abbott’s Diagnostics Businesses

Abbott is a global leader in in vitro diagnostics and offers a broad range of innovative instrument systems and tests for hospitals, reference labs, molecular labs, blood banks, physician offices and clinics. With more than 69,000 customers in more than 100 countries, Abbott’s diagnostic products offer customers automation, convenience, bedside testing, cost effectiveness and flexibility. Abbott has helped transform the practice of medical diagnosis from an art to a science through the company’s commitment to improving patient care and lowering costs.

About Abbott

Abbott (NYSE: ABT) is a global, broad-based health care company devoted to the discovery, development, manufacture and marketing of pharmaceuticals and medical products, including nutritionals, devices and diagnostics. The company employs more than 72,000 people and markets its products in more than 130 countries.

References:

  • FDA 510(k) Clearances – Overview, Device Approvals & Clearances, Products & Medical Procedures, Medical Devices, U.S. Food & Drug Administration, U.S. Department of Health & Human Services.

Additional Information:

Anderson GL, McIntosh M, Wu L, et. al. Assessing lead time of selected ovarian cancer biomarkers: a nested case-control study. J Natl Cancer Inst. 2010 Jan 6;102(1):26-38. Epub 2009 Dec 30. PubMed PMID: 20042715;PubMed Central PMCID: PMC2802285.

Andersen MR, Goff BA, Lowe KA, et. al. Use of a Symptom Index, CA125, and HE4 to predict ovarian cancer. Gynecol Oncol. 2009 Nov 27. [Epub ahead of print] PubMed PMID: 19945742.

Moore RG, McMeekin DS, Brown AK, et. al.  A novel multiple marker bioassay utilizing HE4 and CA125 for the prediction of ovarian cancer in patients with a pelvic mass. Gynecol Oncol. 2009 Jan;112(1):40-6. Epub 2008 Oct 12. PubMed PMID: 18851871.

Hellstrom I, Hellstrom KE. SMRP and HE4 as biomarkers for ovarian carcinoma when used alone and in combination with CA125 and/or each other. Adv Exp Med Biol. 2008;622:15-21. Review. PubMed PMID: 18546615.

Havrilesky LJ, Whitehead CM, Rubatt JM, et. al. Evaluation of biomarker panels for early stage ovarian cancer detection and monitoring for disease recurrence. Gynecol Oncol. 2008 Sep;110(3):374-82. Epub 2008 Jun 27. PubMed PMID: 18584856.

Moore RG, Brown AK, Miller MC, et. al. The use of multiple novel tumor biomarkers for the detection of ovarian carcinoma in patients with a pelvic mass. Gynecol Oncol. 2008 Feb;108(2):402-8. Epub 2007 Dec 3. PubMed PMID:  18061248.

Rosen DG, Wang L, Atkinson JN, et. al. Potential markers that complement expression of CA125 in epithelial ovarian cancer. Gynecol Oncol. 2005 Nov;99(2):267-77. Epub 2005 Aug 2.  PubMed PMID: 16061277.

Drapkin R, von Horsten HH, Lin Y, et. al. Human epididymis protein 4 (HE4) is a secreted glycoprotein that is overexpressed by serous and endometrioid ovarian carcinomas. Cancer Res. 2005 Mar 15;65(6):2162-9. PubMed PMID: 15781627.

Identifying & Overcoming Taxane Drug Resistance

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Proteomics study reveals a protein that, when suppressed, makes cancers more susceptible to chemotherapy involving taxane drugs.

Taxanes, a group of cancer drugs that includes paclitaxel (Taxol®) and docetaxel (Taxotere®), have become front-line therapy for a variety of metastatic cancers. But as with many chemotherapy agents, resistance can develop, a frequent problem in breast, ovarian, prostate and other cancers. Now, cancer researchers at Children’s Hospital Boston report a protein previously unknown to be involved in taxane resistance and could potentially be targeted with drugs, making a cancer more susceptible to chemotherapy.

The researchers believe that this protein, prohibitin1, could also serve as a biomarker, allowing doctors to predict a patient’s response to chemotherapy with a simple blood test. The study was published online by the Proceedings of the National Academy of Sciences in its online early edition during the week of January 25.

Bruce Zetter, Ph.D., Charles Nowiszewski Professor of Cancer Biology, Vascular Biology Program, Department of General Surgery, Children's Hospital Boston

The study, led by Bruce Zetter, PhD, of Children’s Vascular Biology Program, used proteomics techniques to compare the proteins present in Taxol-susceptible versus Taxol-resistant human tumor cell lines. The researchers found that the resistant cell lines, but not the susceptible cell lines, had prohibitin1 on their surface. When they suppressed prohibitin1 with RNA interference techniques, the tumor cells became more susceptible to Taxol, both in cell culture and in live mice with implanted Taxol-resistant tumors.

Zetter’s lab is still investigating why having prohibitin1 on the cell surface makes a tumor cell resistant to taxanes. But in the meantime, he believes that not only could prohibitin1 be suppressed to overcome taxane resistance, but that it could also be exploited as a means of targeting chemotherapy selectively to resistant cancer cells.

“We are working to target various cancer drugs to taxane-resistant cells by attaching them to compounds that bind to prohibitin,” Zetter explains. One such compound is already known, and works well in animals to target other prohibitin-rich cells, but has yet to be tested in humans.

Suppressing prohibitin1 alone probably isn’t enough to make a cancer fully Taxol-susceptible, but could be combined with other strategies aimed at increasing taxane susceptibility, such as targeting another protein called GST Pi, the researchers say. Other mechanisms of resistance are known, but they so far haven’t been shown to present effective targets for therapy.

Zetter’s lab is also trying to develop prohibitin1 as a biomarker for taxane resistance that physicians could use in the clinic. Since it’s on the surface of the cell, Zetter believes prohibitin1 may circulate in the blood where it could easily be detected. His lab is in talks with several cancer centers to obtain serum samples from patients who did and didn’t respond to Taxol, so that prohibitin1 levels could be measured and compared.

Zetter notes that prohibitin1 could easily have been overlooked, and was found only because the team happened to look specifically at proteins in the cell membrane, rather than simply doing a whole-cell proteomic analysis.

“The interesting finding was that prohibitin was not just another over-expressed protein,” Zetter says. “It was up-regulated primarily on the cell surface. When we looked at the whole cell, the absolute amount of prohibitin wasn’t changed. Instead, prohibitin was moving from the inside of the cell to the cell surface. It had shifted from one location to another, and when it did, the tumor cells became resistant to taxanes. The fact that it moves to the cell surface also makes it easier to direct drugs to it.”

Children’s Hospital Boston has pending and issued international patents on this technology.  Nish Patel, PhD, was the study’s first author. The study was funded by a grant from the National Institutes of Health.

About Children’s Hospital Boston

Founded in 1869 as a 20-bed hospital for children, Children’s Hospital Boston today is one of the nation’s leading pediatric medical centers, the primary pediatric teaching hospital of Harvard Medical School, and the largest provider of health care to Massachusetts children. In addition to 396 pediatric and adolescent inpatient beds and more than 100 outpatient programs, Children’s houses the world’s largest research enterprise based at a pediatric medical center, where its discoveries benefit both children and adults. More than 500 scientists, including eight members of the National Academy of Sciences, 11 members of the Institute of Medicine and 13 members of the Howard Hughes Medical Institute comprise Children’s research community. For more information about the hospital visit: www.childrenshospital.org/newsroom.

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Disarming Specialized Stem Cells Might Combat Ovarian Cancer

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Eliminating cancer stem cells (CSCs) within a tumor could hold the key to successful treatments for ovarian cancer, which has been notoriously difficult to detect and treat, according to new findings published this week in the journal Oncogene by Yale School of Medicine researchers.

Eliminating cancer stem cells (CSCs) within a tumor could hold the key to successful treatments for ovarian cancer, which has been notoriously difficult to detect and treat, according to new findings published this week in the journal Oncogene by Yale School of Medicine researchers.

“We found that stopping the expression of two genes—Lin28 and Oct4—reduces ovarian cancer cell growth and survival,” said Yingqun Huang, M.D., Ph.D., assistant professor in the Department of Obstetrics, Gynecology & Reproductive Sciences at Yale School of Medicine.

Ovarian cancer is challenging to treat because it tends to recur frequently and develop resistance to treatment. The poor outcome for women with ovarian cancer is associated with subtle and nonspecific symptoms—earning it the moniker the “disease that whispers.”

“This recurrence and drug resistance may be due to the presence of CSCs within the tumors that have the capacity to reproduce and to differentiate into non-CSC tumor cells that repopulate the tumor mass,” said Huang, who is a member of Yale Stem Cell Center and Yale Cancer Center. “Eliminating these CSCs may be key to successful treatments.”

While in the process of studying the functions of stem cell proteins in human embryonic stem cells, Huang and her colleagues unexpectedly discovered that a sub-population of ovarian cancer cells express stem cell proteins Lin28 and Oct4. They also found that the two proteins appear to act together in ovarian cancer tissue cells to produce more advanced tumors. Inhibiting their combined expression led to a significant decrease in the growth and survival of cancer cells. A larger-scale ovarian cancer study is currently underway to confirm the significance of the findings.

Genetic researchers prevent genes from functioning — a process commonly referred to as “knocking down” the gene — by inserting small interfering RNA (siRNA) molecules into the cells. Next, the research team will examine the effect of siRNA in ovarian cancer cells in the lab, and test the technique on mice. If successful, human clinical trials would follow. Treatment on cancer patients could occur within 10 years, Huang said.

“We hope we will soon be able to apply this new information to improve outcomes, perhaps by developing better diagnostic markers and treatment strategies that may be useful in customizing treatment for ovarian cancer patients,” said Huang.

The study was supported by Connecticut Innovations, the Fannie E. Rippel Foundation and the National Cancer Institute.

Other Yale authors on the study included Nita Maihle, Ph.D., and Shuping Peng.

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Removal of Ovarian Cancer Cells From Human Ascites Fluid Using Magnetic Nanoparticles

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Scientists at Georgia Tech and the Ovarian Cancer Institute have further developed a potential new treatment against cancer that uses magnetic nanoparticles to attach to ovarian cancer cells, removing them from the body. The treatment, tested in mice in 2008, has now been tested using samples from human ovarian cancer patients. The results appear online in the journal Nanomedicine.

Nanoparticles, in brown, attach themselves to ovarian cancer cells, in violet, from the human abdominal cavity. (Credit: Ken Scarberry/Georgia Tech)

Scientists at Georgia Institute of Technology (Georgia Tech) and the Ovarian Cancer Institute have further developed a potential new treatment against cancer that uses magnetic nanoparticles to attach to ovarian cancer cells, removing them from the body. The treatment, tested in mice in 2008, has now been tested using samples from human ovarian cancer patients. The results appear online in the journal Nanomedicine.

John McDonald Ph.D., Professor & Associate Dean for Biology Program Development, Georgia Institute of Technology; Chief Research Scientist, Ovarian Cancer Institute (Credit: Georgia Tech)

“We are primarily interested in developing an effective method to reduce the spread of ovarian cancer cells to other organs ,” said John McDonald, professor at the the School of Biology at the Georgia Institute of Technology and chief research scientist at the Ovarian Cancer Institute.

The idea came to the research team from the work of Ken Scarberry, then a Ph.D. student at Georgia Tech. Scarberry originally conceived of the idea as a means of extracting viruses and virally infected cells. At his advisor’s suggestion Scarberry began looking at how the system could work with cancer cells.

He published his first paper on the subject in the Journal of the American Chemical Society in July 2008. In that paper he and McDonald showed that by giving the cancer cells of the mice a fluorescent green tag and staining the magnetic nanoparticles red, they were able to apply a magnet and move the green cancer cells to the abdominal region.

Recently, McDonald and Scarberry (currently a postdoctoral fellow in McDonald’s lab) have shown that the magnetic technique works with human ovarian cancer cells.

Ken Scarberry Ph.D., Postdoctoral Fellow, McDonald Laboratory, Georgia Institute of Technology (Credit: Robert Felt, Georgia Tech.)

“Often, the lethality of cancers is not attributed to the original tumor but to the establishment of distant tumors by cancer cells that exfoliate from the primary tumor,” said Scarberry. “Circulating tumor cells can implant at distant sites and give rise to secondary tumors. Our technique is designed to filter the peritoneal fluid or blood and remove these free floating cancer cells, which should increase longevity by preventing the continued metastatic spread of the cancer.”

In tests, they showed that their technique worked as well with capturing ovarian cancer cells from human patient samples as it did previously in mice. The next step is to test how well the technique can increase survivorship in live animal models. If that goes well, they will then test it with humans.

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Elevated Proteins May Warn of Ovarian Cancer, But Sufficient Lead Time & Predictive Value Still Lacking

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Fred Hutchinson Cancer Center researchers discovered that concentrations of the serum biomarkers CA125, human epididymis protein 4 (HE4), and mesothelin began to rise 3 years before clinical diagnosis of ovarian cancer, according to a new study published online December 30 in the Journal of the National Cancer Institute. However, the biomarkers became substantially elevated only in the last year prior to diagnosis. … In an accompanying editorial to the study results reported by Anderson et. al., Patricia Hartge, ScD, of the Division of Cancer Epidemiology and Genetics at the National Cancer Institute, applauds the researchers for taking the field one step closer to successful screening study designs by showing that the levels of certain biomarkers do not increase early enough to be used for screening.

Fred Hutchinson Cancer Center researchers discovered that concentrations of the serum biomarkers CA125, human epididymis protein 4 (HE4), and mesothelin began to rise 3 years before clinical diagnosis of ovarian cancer, according to a new study published online December 30 in the Journal of the National Cancer Institute (JNCI). [1] However, the biomarkers became substantially elevated only in the last year prior to diagnosis.

Garnet L. Anderson, Ph.D., Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA.

CA125, HE4, mesothelin, B7-H4, decoy receptor 3, and spondin-2 have been identified as potential ovarian cancer serum biomarkers, but their behavior in the prediagnostic period, with the exception of CA125, has not been evaluated.  In the JNCI study, Garnet L. Anderson, Ph.D., of the Division of Public Health Sciences at the Fred Hutchinson Cancer Research Center in Seattle, and colleagues analyzed prediagnostic serum samples and patient data from the Carotene and Retinol Efficacy Trial (CARET), a randomized, double-blind, placebo-controlled chemoprevention trial testing the effects of beta-carotene and retinol on lung cancer incidence among individuals at high risk for lung cancer. Prediagnostic serum samples (taken up to 18 years prior to diagnosis) were obtained for 34 CARET patients with ovarian cancer and 70 matched control CARET subjects. Changes in the levels of these biomarkers prior to ovarian cancer diagnosis were analyzed.

Anderson et. al. discovered that concentrations of CA125, HE4, and mesothelin (but not B7-H4, decoy receptor 3, and spondin-2) began to increase slightly in cancer patients relative to control subjects approximately 3 years before diagnosis, but became substantially elevated within one year prior to diagnosis. Thus, the diagnostic value of these biomarkers is limited because accuracy only increased shortly before diagnosis. “Although these markers are not accurate enough to prompt early intervention in existing screening protocols, the multivariable regression analyses identified modest but statistically significant increases in risk associated with CA125, HE4, and mesothelin, which are consistent with many of the established epidemiological risk factors for ovarian cancer,” say the authors of the study.

“I still think biomarkers may play a role in a cost-effective screening program, although none of these seem accurate enough either alone or together to justify their use in average-risk women,” Anderson told Medscape Oncology. “I do not know of any other currently identified biomarkers that hold more promise than these, but there has been a massive effort over the last few years to identify candidates and not all have been thoroughly vetted,” said Dr. Anderson.

One problem, cites Dr. Anderson, may lie in the approach used in identifying potential ovarian cancer biomarkers. “Most of the discovery work done so far has been conducted in women with advanced-stage disease and compared them to healthy women,” she explained. “If discovery work were done in samples like the ones we used here, representing specimens collected months to years prior to the advanced stage diagnosis, we might have a better chance of finding earlier signals of aggressive disease.”

Another opportunity for improving screening and early diagnosis lies in imaging, she adds. “Currently the most common and only affordable imaging option that could be considered for routine screening is transvaginal ultrasound, but it performs poorly in terms of accurately determining those women [who] have ovarian cancer from those who do not,” said Dr. Anderson. “A substantial improvement in this area would be very exciting.”

Study Limitations Cited By JNCI Editors

The JNCI editors state three limitations that they believe are associated with the study by Anderson et. al. First, the study sample size was small.  Second, all women who participated in CARET had a history of heavy smoking, and therefore, the JNCI editors believe that the blood serum testing results obtained by Anderson et. al. may not apply to other non-smoking groups. Third, the blood collected from women participating in CARET was collected at different times, but only a few samples were collected during the last 2–3 years before ovarian cancer diagnosis.

Designing Ovarian Cancer Early Detection Programs — Accompanying JNCI Editorial

Patricia Hartge, Sc.D. Deputy Director, Epidemiology and Biostatistics Program, Division of Cancer Epidemiology & Genetic, National Cancer Institute

In an accompanying editorial to the study results reported by Anderson et. al., Patricia Hartge, ScD, of the Division of Cancer Epidemiology and Genetics at the National Cancer Institute, applauds the researchers for taking the field one step closer to successful screening study designs by showing that the levels of certain biomarkers do not increase early enough to be used for screening. [2]

Dr. Hartge notes that despite the discovery that CA125 and other serum markers increase before the clinical onset of ovarian cancer, it has been exceedingly difficult to devise a successful ovarian cancer early screening program for asymptomatic women. Nevertheless, Hartge believes that Anderson et al. take a valuable step toward the design of such a successful screening program by demonstrating why screening regimens that are based on markers, or panels of markers, can fail. Specifically, the researchers discovered that blood levels of CA125, HE4, mesothelin, and three other promising markers did not increase early enough in the course of the disease to allow detection in early stages. Dr. Hartge emphasizes that the markers typically rose within one year of the disease symptoms that led to an accurate diagnosis, and therefore, many of the ovarian cancer patients were diagnosed with advanced stage disease.

Hartge further states “[t]hat the results of Anderson et al. are not the last word in serum markers or in combinations of markers.” “Serum markers likely will form a key element in any screening regimen, with the lead time and other parameters of each marker or combination of markers being taken into account. The careful evaluation technique applied in the current study fits into a staged approach necessary for testing performance of early markers of disease.” Hartge adds that “[o]nly the time-consuming, expensive, and demanding randomized clinical trial can reveal whether an early detection program that includes the biomarkers can save lives.”

In support of her position, Dr. Hartge observes that current randomized trials are testing the value of different screening programs that are built on combinations of CA125, ultrasound, and risk factor data (e.g., family history and age). After four rounds of screening 34,261 postmenopausal women for ovarian cancer with both CA125 and ultrasound, University of Alabama at Birmingham School of Medicine investigators of the large U.S. screening trial observed that the predictive value of a positive screen was quite low — approximately 1%. Of the 60 screen-detected cancers, 72% had already advanced to at least stage III. [3] In addition, of every 20 women who underwent surgery after a positive screen, only one women was diagnosed with cancer. Furthermore, in a recent UK trial with a slightly different design, positive predictive values from the first round of screening were higher; 35% in the 50,078 women whose risk was assessed with CA125 and risk factor data, followed by ultrasound only if indicated, and 3% in the 50,639 women screened first with ultrasound. [4] The effects on mortality in both trials remain to be determined.

Confronting The “Daunting Arithmetic” Required To Detect Early Stage Ovarian Cancer

Based upon the foregoing, Dr. Hartge highlights the “daunting arithmetic” required to detect early stage ovarian cancer. In the U.S., Surveillance, Epidemiology and End Results (SEER) data indicates that incidence amounts to 13 cases of ovarian cancer per 100,000 woman per year, referred to by Dr. Hartge as the “proverbial needles in the haystack.” [5] So as not to present a problem without a potential solution, Hartge provides a roadmap to additional factors that may help future researchers develop early screening methods to identify those rare cases of ovarian cancer in the general population.  Notably, SEER data also indicates that incidence of ovarian cancer steadily increases with age from 21 cases per 100,000 women per year within the 50-54 age range to 57 cases per 100,000 women per year within the 80-84 age range. [6] Furthermore, family history, low parity, and more ovulations over a woman’s lifetime predict additional risk, with the strongest but least common predictor being a mutation in the BRCA1 or BRCA2 gene. Thus, the general approach suggested by Hartge focuses on women with higher baseline risks, for whom the predictive value of a positive serum test tends to increase. Dr. Hartge believes that the performance of an overall screening program will improve by targeting higher-risk subgroups of women for screening by combining personal history, genetic abnormality status, and levels of serum markers in one prediction model. With ongoing advances in understanding the origin and causes of ovarian cancer, Hartge states that the risk models that are useful for screening programs should also improve.

Further technology advancements may also improve future ovarian cancer early detection screening models, says Hartege. For example, a screening program that is based on a panel of biomarkers can be improved by developing new medical imaging technology that is more specific than current ultrasound technology.  If better imaging existed, fewer women would undergo surgery following a suspicious biomarker finding.  Similarly, development of less invasive surgery could further reduce harmful side effects.  Although Hartge observes that a highly accurate biomarker(s) or an overall screening program does not yet exist, she also explains that the current study by Anderson et. al., with its sobering implications, brings future researchers closer to understanding the crucial elements in designing an effective early detection program for ovarian cancer.

References:

1/Anderson GL , McIntosh M, Wu L, et. al. Assessing Lead Time of Selected Ovarian Cancer Biomarkers: A Nested Case–Control Study. Journal of the National Cancer Institute Advance Access published on January 6, 2010, DOI 10.1093/jnci/djp438. J. Natl. Cancer Inst. 102: 26-38.

2/Hartge P. Designing Early Detection Programs for Ovarian Cancer. Journal of the National Cancer Institute Advance Access published on January 6, 2010, DOI 10.1093/jnci/djp450. J. Natl. Cancer Inst. 102: 3-4.

3/Partridge E, Kreimer AR, Greenlee RT, et al. Results from four rounds of ovarian cancer screening in a randomized trial. Obstet Gynecol (2009) 113(4):775–782. [PMCID: PMC2728067; PMID: 19305319].

4/Menon U, Gentry-Maharaj A, Hallett R, et al. Sensitivity and specificity of multimodal and ultrasound screening for ovarian cancer, and stage distribution of detected cancers: results of the prevalence screen of the UK Collaborative Trial of Ovarian Cancer Screening (UKCTOCS). Lancet Oncol (2009) 10(4):327–340. [PMID: 19282241]

5/ Horner MJ, Ries LAG, Krapcho M, et al, eds. SEER Cancer Stat Fact Sheets (2009) Bethesda, MD: National Cancer Institute. http://seer.cancer.gov/statfacts/html/ovary.html. Accessed December 2, 2009.

6/Horner MJ, Ries LAG, Krapcho M, et. al., eds. SEER Cancer Statistics Review, 1975-2006, National Cancer Institute. Bethesda, MD, http://seer.cancer.gov/csr/1975_2006, based on November 2008 SEER data submission, posted to the SEER web site, 2009 [See Table 21.6: Incidence & Mortality Rates By Age].

Sources:

MAGP2 Gene Expression Signature: A Potential Ovarian Cancer Personalized Treatment Target

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A multi-institutional study has identified a potential personalized treatment target for the most common form of ovarian cancer. In the December 8 issue of Cancer Cell, the research team describes finding that a gene called MAGP2 – not previously associated with any type of cancer – was overexpressed in papillary serous ovarian tumors of patients who died more quickly. They also found evidence suggesting possible mechanisms by which MAGP2 may promote tumor growth.

A multi-institutional study has identified a potential personalized treatment target for the most common form of ovarian cancer. In the December 8 issue of Cancer Cell, the research team describes finding that a gene called MAGP2 (microfibril-associated glycoprotein 2) – not previously associated with any type of cancer – was overexpressed in papillary serous ovarian tumors of patients who died more quickly. They also found evidence suggesting possible mechanisms by which MAGP2 may promote tumor growth.

Michael Birrer, MD, Ph.D., Professor, Department of Medicine, Harvard Medical School; Director GYN/Medical Oncology, Medicine, Massachusetts General Hospital

“Ovarian cancer is typically diagnosed at an advanced stage when it is incurable, and the same treatments have been used for virtually all patients,” says Michael Birrer, MD, PhD, director of medical gynecologic oncology in the Massachusetts General Hospital (MGH) Cancer Center, and the study’s corresponding author. “Previous research from my lab indicated that different types and grades of ovarian tumors should be treated differently, and this paper now shows that even papillary serous tumors have differences that impact patient prognosis.” Birrer was with the National Institutes of Health when this study began but later joined the MGH Cancer Center.

The fifth most common malignancy among U.S. women, ovarian cancer is expected to cause approximately 15,000 deaths during 2009. Accounting for 60 percent of ovarian cancers, papillary serous tumors are typically diagnosed after spreading beyond the ovaries. The tumors typically return after initial treatment with surgery and chemotherapy, but while some patients die a few months after diagnosis, others may survive five years or longer while receiving treatment.

To search for genes expressed at different levels in ovarian cancer patients with different survival histories, which could be targets for new treatments, the researchers conducted whole-genome profiling of tissue samples that had been microdissected – reducing the presence of non-tumor cells – from 53 advanced papillary serous ovarian cancer tumors. Of 16 genes that appeared to have tumor-associated expression levels, MAGP2 had the strongest correlation with reduced patient survival.

Further analysis confirmed that MAGP2 expression was elevated in another group of malignant ovarian cancer tumors but not in normal tissue. MAGP2 gene expression was also reduced in patients whose tumors responded to chemotherapy. Recombinant expression of MAGP2 in samples of the endothelial cells that line blood vessels caused the cells to migrate and invade normal tissue.  In addition, MAGP2 gene overexpression increased microvessel density — a measurement used to determine the extent of tumor angiogenesis. The latter two observations suggest a potential role for MAGP2 gene overexpression in the growth of an ovarian cancer tumor’s blood supply.

“By confirming that different ovarian tumors have distinctive gene signatures that can predict patient prognosis, this study marks the beginning of individualized care for ovarian cancer,” says Birrer, a professor of Medicine at Harvard Medical School. “MAGP2 and the biochemical pathways it contributes to are definitely targets for new types of therapies, and we plan to pursue several strategies to interfere with tumor-associated pathways. But first we need to validate these findings in samples from patients treated in clinical trials.”

About The Study

Co-lead authors of the Cancer Cell paper are Samuel Mok, M.D., M.D. Anderson Cancer Center, and Tomas Bonome, National Cancer Institute (NCI). Additional co-authors are Kwong-Kowk Wong, M.D. Anderson; Vinod Vathipadiekal, Aaron Bell, Howard Donninger, Laurent Ozbun, Goli Samimi, John Brady, Mike Randonovich, Cindy Pise-Masison, and Carl Barrett, NCI; Michael Johnson, Dong-Choon Park, William Welch and Ross Berkowitz, Brigham and Women’s Hospital; Ke Hao and Wing Wong, Harvard School of Public Health; and Daniel Yip, University of South Florida. The study was supported by grants from the National Institutes of Health, the Ovarian Cancer Research Fund and the National Cancer Institute.

About Massachusetts General Hospital

Massachusetts General Hospital, established in 1811, is the original and largest teaching hospital of Harvard Medical School. The MGH conducts the largest hospital-based research program in the United States, with an annual research budget of more than $600 million and major research centers in AIDS, cardiovascular research, cancer, computational and integrative biology, cutaneous biology, human genetics, medical imaging, neurodegenerative disorders, regenerative medicine, systems biology, transplantation biology and photomedicine.

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OU’s Non-Toxic Drug Makes Ovarian Cancer Cells Respond To New Treatment & Undergo Cell Suicide

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“Cancer researchers at the University of Oklahoma Health Sciences Center have found a way to turn ineffective new cancer drugs into cancer-fighters. By using their patented chemical compound, SHetA2, researchers tricked cancer cells into responding to new treatments and undergoing cell suicide. … [T]he compound will work with several cancers, including lung, kidney, ovarian, colon and pancreatic cancer. … [The] research team … patented the SHetA2 Flex-Het and hope[s] to start clinical trials for the compound within a year. …“

Cancer researchers at the University of Oklahoma Health Sciences Center have found a way to turn ineffective new cancer drugs into cancer-fighters. By using their patented chemical compound, SHetA2, researchers tricked cancer cells into responding to new treatments and undergoing cell suicide. The research appears in the journal Gynecologic Oncology.

Doris Mangiaracina Benbrook, Ph.D., is in her lab at the University of Oklahoma Health Sciences Center in Oklahoma City. (Photo: Univ. of Oklahoma Health Sciences Center)

“This discovery means that we can use our non-toxic cancer prevention pill to improve treatment for people who already have cancer,” said Doris Mangiaracina Benbrook, Ph.D., principal investigator on the project. “All studies to date have not found any side effects of taking our drug, giving hope that we can prevent cancer in healthy people, and improve treatment for cancer patients, without increasing toxicity.”

The latest study looked at an upcoming class of cancer treatment drugs that worked well in experimental models, but proved ineffective against many human tumors. Dr. Benbrook and her team decided to test their compound’s ability to “fix” the problem. It worked.

“The new chemotherapy drugs are antibodies that bind to cell surface receptors called ‘Death Receptors.’ The binding of the antibodies activates the death receptors in cancer cells and causes cell suicide with little harm to normal cells. Many cancers, however, are resistant to the antibodies,” Benbrook said. “We’ve shown that SHetA2 treatment can make ovarian and kidney cancer cells sensitive to the death receptor antibodies and kill the cancer.”

Benbrook said the compound will work with several cancers, including lung, kidney, ovarian, colon and pancreatic cancer.

“It would be a significant advancement in health care if we could avoid the severe toxicity and suffering that late stage cancer patients have to experience,” Benbrook said.

The synthetic compound, SHetA2, a Flex-Het drug, was created by Benbrook with the help of chemist Darrell Berlin at Oklahoma State University. The compound directly targets abnormalities in cancer cell components without damaging normal cells. The disruption causes cancer cells to die and keeps tumors from forming.

Flex-Hets or flexible heteroarotinoids are synthetic compounds that can change certain parts of a cell and affect its growth. Benbrook and her research team have patented the SHetA2 Flex-Het and hope to start clinical trials for the compound within a year. If the compound continues to be found safe, it would be developed into a pill to be taken daily like a multi-vitamin to prevent cancer. This new discovery means that the pill also could be used to make patients, who already have cancer, better respond to treatment.

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MIT Develops New Platinum Compound As Powerful As Cisplatin But Better Able To Destroy Tumor Cells

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MIT chemists have developed a new platinum compound that is as powerful as the commonly used anticancer drug cisplatin but better able to destroy tumor cells.

A diagram of cisplatin which is a platinum chemotherapy drug.

Massachusetts Institute of Technology chemists have developed a new platinum compound that is as powerful as the commonly

Stephen J. Lippard Ph.D., Arthur Amos Noyes Professor of Chemistry, Massachusetts Institute of Technology

used anticancer drug cisplatin but better able to destroy tumor cells.

The new compound, mitaplatin, combines cisplatin with another compound, dichloroacetate (DCA), which can alter the properties of mitochondria selectively in cancer cells. Cancer cells switch their mitochondrial properties to change the way they metabolize glucose compared to normal cells, and DCA specifically targets the altered mitochondria, leaving normal cells intact.

“This differential effect conveys on mitaplatin the ability to kill cancer cells selectively in a co-culture with normal fibroblast cells, the latter being unaffected at the doses that we apply,” says Stephen Lippard, the Arthur Amos Noyes Professor of Chemistry.

How they did it: The chemists designed mitaplatin so that when it enters a cell, it releases cisplatin and two units of DCA by intracellular reduction. Therefore, mitaplatin can attack nuclear DNA with cisplatin and mitochondria with DCA. DCA promotes the release of cell-death-promoting factors from the mitochondria, enhancing the cancer cell-killing abilities of cisplatin.

Next steps: Lippard’s laboratory has shown that in rodents, mitaplatin can be tolerated at much higher doses than cisplatin, and they have begun studies in mice transplanted with human tissues. If those results are promising, the researchers plan more studies for further demonstration of mitaplatin’s ability in cancer therapy.

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PI3K Pathway: A Potential Ovarian Cancer Therapeutic Target?

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…[T]here are several PI3K signaling pathway targeting drugs in clinical development for use against ovarian cancer and solid tumors, including GDC-0941, BEZ235, SF1126, XL-147, XL-765, BGT226, and PX-866.  The results of two recent medical studies suggest that the use of PI3K-targeted therapies may offer an effective therapeutic approach for patients with advanced-stage and recurrent ovarian cancer, including a generally chemotherapy-resistant histological subtype of epithelial ovarian cancer known as “ovarian clear cell cancer” (OCCC).  The targeting of the PI3K pathway in endometrial, ovarian, and breast cancer is also being investigated by a Stand Up To Cancer “Dream Team.” …

PI3K Cellular Signaling Pathway — An Overview

PI3K/AKT cellular signaling pathway (Photo: Cell Signaling Technology(R))

In 2004 and 2005, multiple researchers identified mutations in the PIK3CA  gene with respect to multiple cancers.[1]  The PIK3CA gene encodes the PI3K catalytic subunit p110α. PI3K (phosphoinositide 3- kinase) proteins have been identified in crucial signaling pathways of ovarian cancer cells. PI3Ks are also part of the PI3K-AKT-mTOR signaling pathway which promotes cellular glucose metabolism, proliferation, growth, survival, and invasion and metastasis in many cancers. PIK3CA gene mutations can increase PI3K signaling, thereby activating the PI3K-AKT-mTOR pathway within cancer cells.

As of this writing, there are several PI3K signaling pathway targeting drugs in clinical development for use against ovarian cancer and solid tumors, including GDC-0941, BEZ235, SF1126, XL-147, XL-765, BGT226, and PX-866. [2]  The results of two recent medical studies suggest that the use of PI3K-targeted therapies may offer an effective therapeutic approach for patients with advanced-stage and recurrent ovarian cancer, including a generally chemotherapy-resistant histological subtype of epithelial ovarian cancer known as “ovarian clear cell cancer” (OCCC).  The targeting of the PI3K pathway in endometrial, ovarian, and breast cancer is also being investigated by a Stand Up To Cancer “Dream Team.”

Frequent Mutation of PIK3CA Gene In Recurrent & Advanced Clear Cell Ovarian Cancer

OCCC is one of the five major subtypes of epithelial ovarian cancer. OCCC accounts for only 4% to 12% of epithelial ovarian cancer in Western countries and, for unknown reasons, it comprises more than 20% of such cancers in Japan [3,4,5]. OCCC possesses unique clinical features such as a high incidence of stage I disease, a large pelvic mass, an increased incidence of venous thromboembolic complications, and hypercalcemia. It is frequently associated with endometriosis.  Compared to serous ovarian cancer, OCCC is relatively resistant to conventional platinum and taxane-based chemotherapy. For these reasons, new effective therapies are desperately needed for OCCC.

Researchers from Johns Hopkins and the University of California, Los Angeles (UCLA) analyzed 97 OCCC tumors for genetic sequence mutations in KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog), BRAF (v-raf murine sarcoma viral oncogene homolog B1), PIK3CA (phosphoinositide-3-kinase, catalytic, alpha polypeptide), TP53 (tumor protein p53), PTEN (phosphatase and tensin homolog), and CTNNB1 (Catenin, Beta-1) as these mutations frequently occur in other major types of ovarian cancers.[6] The samples tested included the following:

  • 18 OCCCs for which affinity-purified tumor cells from fresh specimens were available;
  • 10 OCCC tumor cell lines.

Upon test completion, the researchers discovered that sequence mutations of PIK3CA, TP53, KRAS, PTEN, CTNNB1, and BRAF occurred in 33%, 15%, 7%, 5%, 3%, and 1% of OCCC cases, respectively.

Clear cell carcinoma of the ovary (Photo: Geneva Foundation For Medical Education & Research)

The sequence analysis of the 18 affinity purified OCCC tumors and the 10 OCCC cell lines showed a PIK3CA mutation frequency of 46%. Based upon these findings the researchers concluded that the use of PIK3CA-targeting drugs may offer a more effective therapeutic approach compared with current chemotherapeutic agents for patients with advanced-stage and recurrent OCCC. As noted above, there are several PI3K-targeting drugs in clinical development for use against ovarian cancer and solid tumors.[2]

Notably, one of the researchers involved with this OCCC study is Dennis J. Slamon, M.D., Ph.D. Dr. Slamon serves as the Director of Clinical/Translational Research, and as Director of the Revlon/UCLA Women’s Cancer Research Program at the Jonsson Comprehensive Cancer Center. Dr. Slamon is also a professor of medicine, chief of the Division of Hematology/Oncology and Executive Vice Chair of Research for UCLA’s Department of Medicine. Dr. Slamon is a co-discoverer of the breast cancer drug Herceptin®. Herceptin is a monoclonal antibody targeted therapy used against HER-2 breast cancer, an aggressive breast cancer subtype that affects 20% to 30% of women with the disease. Herceptin’s development was based, in part, upon the unique genetic profile of HER-2 breast cancer as compared to other forms of breast cancer. Herceptin® revolutionized the treatment of HER-2 postive breast cancer and is recognized worldwide as the standard of care for that subtype of breast cancer.  The approach taken by Johns Hopkins and UCLA researchers in this study — the identification of  a subtype within a specific form of cancer that may be susceptible to a targeted therapy —  bears a striking similarity to the overarching approach taken in the development of Herceptin®.

Ovarian Cancer & Other Solid Tumors With PIK3CA Gene Mutations Respond To PI3K-AKT-mTOR Pathway Inhibitors In Phase I Clinical Testing.

Testing patients with cancer for PIK3CA gene mutations is feasible and may allow targeted treatment of the PI3K-AKT-mTOR cellular signaling pathway, according to the results of a University of  Texas, M.D. Anderson Cancer Center study presented on November 17, 2009 at the 2009 AACR (American Association for Cancer Research)-NCI (National Cancer Institute)-EORTC (European Organization For Research & Treatment of Cancer) International Conference on Molecular Targets and Cancer Therapeutics.[7]

mTOR cellular signaling pathway (Photo: Cell Signaling Technology(R))

Filip Janku, M.D., Ph.D, a clinical research fellow with the M.D. Anderson Cancer Center’s department of investigational cancer therapeutics, and colleagues conducted a mutational analysis of exon 9 and exon 20 of the PI3KCA gene using DNA from the tumors of patients referred to targeted therapy clinical trials. Patients with PIK3CA mutations were preferably treated whenever possible with regimens utilizing PI3K-AKT-mTOR signaling pathway inhibitors.

As part of this study 117 tumor samples were analyzed. PIK3CA mutations were detected in 14 (12%) patients.  In tumor types with more than 5 patients tested, PIK3CA mutations were identified in endometrial cancer (43%, 3 out of 7 patients), ovarian cancer (22%, 5 out of 23 patients), squamous head and neck cancer (14%, 1 out of 7 patients), breast cancer (18%, 2 out of 11 patients), and colon cancer (15%, 2 out of 13 patients). No mutations were identified in patients with melanoma or cervical cancer.

Of the 14 patients found to possess PIK3CA mutations, 10 were treated based upon a clinical trial protocol that included a drug targeting the PI3K-AKT-mTOR pathway.  A partial response to treatment was experienced by 4 (40%) patients. Although the total number of patients is small, there were 2 (67%) patient responses in 3 endometrial cancer cases, 1 (25%) patient response in 4 ovarian cancer cases, 1 (100%) patient response in 1 breast cancer, and no patient response in 1 colorectal cancer case.  Although the total number of study patients is small, the researchers conclude that the response rate appears high (40%) in tumors with PIK3CA mutations treated with PI3K-AKT-mTOR pathway inhibitors.

“The implications of this study are twofold,” said Dr. Janku.  “We demonstrated that PIK3CA testing is feasible and may contribute to the decision-making process when offering a patient a clinical trial. Although this study suffers from low numbers, the response rate observed in patients treated with inhibitors of PI3K/AKT/mTOR pathway based on their mutational status was well above what we usually see in phase-1 clinical trials.”  “These results are intriguing but at this point should be interpreted with caution,” said Janku. “The promising response rate needs to be confirmed in larger groups of patients. We expect to learn more as this project continues to offer PIK3CA screening to patients considering a phase-1 clinical trial.”

Stand Up 2 Cancer Dream Team: Targeting the PI3K Pathway in Women’s Cancers

The potential importance of the PI3K pathway in the treatment of ovarian cancer is emphasized by the two medical studies above.  This issue is also receiving considerable attention from one of the Stand Up 2 Cancer (SU2C) “Dream Teams,” which is going to evalute  the potential for targeting the PI3K pathway in women’s cancer.  SU2C assigned $15 million of cancer research funding to this critical issue.  The scientists involved in this SU2C Dream Team are the pioneers who discovered the PI3K pathway and validated its role in human cancers, and they will focus on breast, ovarian and endometrial cancers, all of which possess the PI3K mutation.

The leader and co-leaders of the PI3K pathway SU2C team are set forth below.

Leader:

Lewis C. Cantley, Ph.D., Director, Cancer Center at Beth Israel Deaconess Medical Center.

Co-Leaders:

Charles L. Sawyers, M.D., Director, Human Oncology and Pathogenesis Program, Memorial Sloan-Kettering Cancer Center.

Gordon B. Mills, M.D., Ph.D., Chair, Department of Systems Biology, University of Texas, M.D. Anderson Cancer Center.

The specific SU2C Dream Team research goal with respect to targeting the PI3K pathway in women’s cancers is stated as follows:

The PI3K pathway is mutated in more cancer patients than any other, and these mutations are the most frequent events in women’s cancers, making it an attractive molecular target for agents that inhibit these genetic aberrations. If successful, this project will allow clinicians to use biomarkers and imaging techniques to predict which patients will benefit from PI3K pathway inhibitors and lead to the development of therapeutic combinations that will hit multiple targets in the complex pathways that contribute to cancer cell growth.  This work will help assure that these therapies are given to patients who will benefit from them, and it will also increase the overall pace of clinical trials targeting PI3K inhibitors.

Based upon the two studies discussed, and the creation and funding of the SU2C Dream Team for the purpose of targeting the PI3K pathway in women’s cancer, the future holds great promise in the battle against ovarian cancer (including OCCC).  It is our hope that more clinical study investigators will offer PI3K pathway mutation screening to all ovarian cancer patient volunteers.  Libby’s H*O*P*E*™ will continue to monitor the clinical development of PI3K pathway inhibitors, and make our readers aware of all future developments.

________________________________

References:

1/Yuan TL, Cantley LC. PI3K pathway alterations in cancer: variations on a theme. Oncogene. 2008 Sep 18;27(41):5497-510. PubMed PMID: 18794884
Samuels Y, Ericson K. Oncogenic PI3K and its role in cancer. Curr Opin Oncol. 2006 Jan;18(1):77-82. PubMed PMID: 16357568.
Levine DA, Bogomolniy F, Yee CJ, et. al. Frequent mutation of the PIK3CA gene in ovarian and breast cancers. Clin Cancer Res. 2005 Apr 15;11(8):2875-8. PubMed PMID: 15837735.
Samuels Y, Wang Z, Bardelli A, et. al. High frequency of mutations of the PIK3CA gene in human cancers. Science. 2004 Apr 23;304(5670):554. Epub 2004 Mar 11. PubMed PMID: 15016963.

2/For open ovarian cancer clinical trials using a PI3K-targeted therapy; CLICK HERE; For open solid tumor clinical trials using a PI3K-targeted therapy, CLICK HERE.

3/ Itamochi H, Kigawa J & Terakawa N.  Mechanisms of chemoresistance and poor prognosis in ovarian clear cell carcinoma. Can Sci 2008 Apr;99(4):653-658. [PDF Document]

4/Schwartz DR, Kardia SL, Shedden KA, et. al.  Gene Expression in Ovarian Cancer Reflects Both Morphology and Biological Behavior, Distinguishing Clear Cell from Other Poor-Prognosis Ovarian Carcinomas.  Can Res 2002 Aug; 62, 4722-4729.

5/Sugiyama T & Fujiwara K.  Clear Cell Tumors of the Ovary – Rare Subtype of Ovarian Cancer, Gynecologic Cancer, American Society of Clinical Oncology (ASCO) Educational Book, 2007 ASCO Annual Meeting, June 2, 2007 (Microsoft Powerpoint presentation).

6/Kuo KT, Mao TL, Jones S, et. al. Frequent Activating Mutations of PIK3CA in Ovarian Clear Cell Carcinoma. Am J Pathol. 2009 Apr 6. [Epub ahead of print]

7/Janku F, Garrido-Laguna I, Hong D.S.  PIK3CA mutations in patients with advanced cancers treated in phase I clinical trials, Abstract #B134, Molecular Classification of Tumors, Poster Session B, 2009 AACR-NCI-EORTC Molecular Targets and Cancer Therapeutics Conference. [PDF Document].

UCLA Researchers Significantly Inhibit Growth of Ovarian Cancer Cell Lines With FDA-Approved Leukemia Drug Dasatinib (Sprycel®)

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The drug dasatinib (Sprycel®), approved for use by the U.S. Food and Drug Administration in patients with specific types of leukemia, significantly inhibited the growth and invasiveness of ovarian cancer cells and also promoted their death, say UCLA researchers in the November 10th issue of the British Journal of Cancer. The drug, when paired with a chemotherapy regimen, was even more effective in fighting ovarian cancer cell lines in which signaling of the Src family kinases — associated with approximately one-third of ovarian cancers– is activated. Clinical trials that involve the testing of dasatinib against ovarian cancer and solid tumors are currently ongoing.

Researchers affiliated with the University of California, Los Angeles (UCLA), Mayo Clinic and Harvard Medical School announced that they have established a biological rationale to support the clinical study of the U.S. Food & Drug Administration (FDA)-approved leukemia drug dasatinib (U.S. brand name: Sprycel®), either alone or in combination with chemotherapy, in patients with ovarian cancer. The study appears in the November 10th edition of the British Journal of Cancer.

Background

Dasatinib is an FDA-approved drug for the treatment of chronic myeloid leukemia (CML) and Philadelphia chromosome positive acute lymphoblastic leukemia (ALL). Dasatinib is a small-molecule inhibitor that targets several tyrosine kinases, including the Src kinase family, Ephrin type-A receptor 2 ( EphA2) , and the focal adhesion kinase (FAK).

Src is the prototypic member of a family of nine non-receptor tyrosine kinases (Src, Lyn, Fyn, Lck, Hck, Fgr, Blk, Yrk, and Yes). The Src family kinase (SFK) proteins regulate four main cellular fuctions that ultimately control the behavior of transformed cancer cells:  cell proliferation, adhesion, invasion, and motility.

Eph receptors and ephrins are integral players in cancer formation and progression, and are associated with advanced ovarian cancer and poor clinical outcome.

FAK is a non-receptor tyrosine kinase involved in the regulation of cell adhesion, survival, and migration.  Preclinical studies indicate that FAK plays a signficant role in ovarian cancer cell migration and invasion.

Dasatinib Study Methodology & Findings

slamon1

One of the dasatinib study authors is Dennis J. Slamon, M.D. Ph.D. Dr. Slamon is the Director of Clinical/Translational Research & Director of the Revlon/UCLA Women's Cancer Research Program, at the UCLA Jonsson Comprehensive Cancer Center. He is also the co-discoverer of Herceptin®, a targeted therapy that revolutionized the treatment of HER-2 positive breast cancer.

The researchers carried out the study by testing the effects of dasatinib on human ovarian cancer cells in vitro, using a panel of 34 established human ovarian cancer cell lines.  The 34 cell lines selected were representative of the major epithelial ovarian cancer subtypes:

On this basis, the researchers examined the effects of dasatinib on ovarian tumor cell proliferation, invasion, apoptosis, and cell-cycle arrest.  To more fully understand the activity of dasatinib, the researchers also studied the efficacy of chemotherapeutic drugs (i.e., carboplatin and paclitaxel) in combination with dasatinib against ovarian cancer cells that were previously determined to be dasatinib-sensitive.

The overarching goals of the study were (i) to provide a rationale to test dasatinib as a single agent or in combination with chemotherapy in patients with ovarian cancer, and (ii) to identify molecular markers that may help define subsets of ovarian cancer patients most likely to benefit from treatment with dasatinib.

Significant findings reported in the dasatinib study are summarized below.

  • Concentration-dependent, anti-proliferative effects of dasatinib were seen in all ovarian cancer cell lines tested.
  • Dasatinib significantly inhibited tumor cell invasion, and induced tumor cell death, but was less effective in causing tumor cell-cycle arrest.
  • At a wide range of clinically achievable drug concentrations, additive and synergistic interactions were observed for dasatinib plus carboplatin or paclitaxel.
  • 24 out of 34 (71%) representative ovarian cancer cell lines were highly sensitive (i.e.,  ≥ 60% growth inhibition) to dasatinib.
  • 6 cells lines were moderately sensitive (i.e., 40% – 59% growth inhibition) to dasatinib.
  • 4 cell lines were resistant (i.e., < 40% growth inhibition) to dasatinib.
  • When comparing dasatinib sensitivity between cell lines based solely upon histological subtype (i.e., serous papillary, clear cell, endometrioid, mucinous, and undifferentiated ovarian cancer cell lines), no single histological subtype was more sensitive than another.
  • Ovarian cancer cell lines with high expression of Yes, Lyn, Eph2A, caveolin-1 and 2, moesin, annexin-1 and 2 and uPA (urokinase-type Plasminogen Activator), as well as those with low expression of IGFBP2 (insulin-like growth factor binding protein 2), were particularly sensitive to dasatinib.
  • Ovarian cancer cell lines with high expression of HER-2 (Human Epidermal growth factor Receptor 2), VEGF (Vascular endothelial growth factor) and STAT3 (Signal Transducer and Activator of Transcription 3) were correlated with in vitro resistance to dasatinib.

Based upon the findings above, the researchers concluded that there is a clear biological rationale to support the clinical study of dasatinib, as a single agent or in combination with chemotherapy, in patients with ovarian cancer.

Konecny

Gottfried E. Konecny, M.D., UCLA Assistant Professor of Hematology/Oncology, UCLA Jonsson Comprehensive Cancer Center Researcher & First Author of the Dasatinib Study

Ovarian cancer, which will strike 21,600 women this year and kill 15,500, causes more deaths than any other cancer of the female reproductive system. Few effective therapies for ovarian cancer exist, so it would be advantageous for patients if a new drug could be found that fights the cancer, said Gottfried E. Konecny, M.D., a UCLA assistant professor of hematology/oncology, a Jonsson Comprehensive Cancer Center researcher, and first author of the study.

“I think Sprycel® could be a potential additional drug for treating patients with Src dependent ovarian cancer,” Konecny said. “It is important to remember that this work is only on cancer cell lines, but it is significant enough that it should be used to justify clinical trials to confirm that women with this type of ovarian cancer could benefit.”

Recent gene expression studies have shown that approximately one-third of women have ovarian cancers with activated Src pathways, so the drug could potentially help 7,000 ovarian cancer patients every year. Notably, a gene expression study published in 2007 reported Src activation in approximately 50% of the ovarian cancer tumors examined.

In the dasatinib study, the UCLA team tested the drug against 34 ovarian cancer cell lines and conducted genetic analysis of those lines. Through these actions, the researchers were able to identify genes that predict response to dasatinib. If the work is confirmed in human studies, it may be possible to test patients for Src activation and select those who would respond prior to treatment, thereby personalizing their care.

“We were able to identify markers in the pre-clinical setting that would allow us to predict response to Sprycel®,” Konecny said. “These may help us in future clinical trials in selecting patients for studies of the drug.”

Dasatinib is referred to as a “dirty” kinase inhibitor, meaning it inhibits more than one cellular pathway. Konecny said it also inhibits the focal adhesion kinase (FAK) and ephrin receptor, also associated with ovarian cancer, in addition to the Src cellular pathway.

The next step, Konecny said, would be to test the drug on women with ovarian cancer in a clinical trial. The tissue of responders would then be analyzed to determine if the Src and other pathways were activated. If that is confirmed, it would further prove that dasatinib could be used to fight ovarian cancer. In studies, women would be screened before entering a trial and only those with Src dependent cancers could be enrolled to provide further evidence, Konecny said, much like the studies of the molecularly targeted breast cancer drug Herceptin® enrolled only women who had HER-2 positive disease.

“Herceptin® is different because we knew in advance that it only worked in women with HER-2 [gene] amplification,” he said. “In this case, we don’t clearly know that yet. The data reassures us that the drug works where the targets are over-expressed but we need more testing to confirm this.”

The tests combining the drug with chemotherapy are significant because chemotherapy, namely carboplatin and paclitaxel, is considered the standard first line treatment for ovarian cancer patients following surgery. Because dasatinib proved to have a synergistic effect when combined with chemotherapy, it may be possible to add this targeted therapy as a first line treatment if its efficacy is confirmed in future studies.

Dasatinib Study Significance

The dasatinib study is potentially significant to the area of ovarian cancer treatment for several reasons.

First, although this study only tested dasatinib in vitro against ovarian cancer cell lines, the drug is already FDA-approved.  Accordingly, the general safety of the drug has already been established by the FDA.

Second, 71% of the ovarian cancer lines were highly sensitive to dasatinib.

Third, dasatinib was additive to, or synergistic with, the standard of care chemotherapy drugs used in first line ovarian cancer treatment, i.e., carboplatin and paclitaxel.

Fourth, the study established molecular markers that may be predictive of dasatinib effectiveness in particular patients.  In theory, a patient’s tumor biopsy could be tested for the presence of those molecular markers to determine whether a patient will benefit from dasatinib.

Fifth, one of the dasatinib study authors is Dennis J. Slamon, M.D. Ph.D. Dr. Slamon is the director of Clinical/Translational Research, and director of the Revlon/UCLA Women’s Cancer Research Program, at the UCLA Jonsson Comprehensive Cancer Center. Dr. Slamon is also the co-discoverer of Herceptin®, a targeted therapy that revolutionized the treatment of HER-2 positive breast cancer.  Herceptin® is a targeted therapy that kills HER-2 positive breast cancer cells while leaving normal cells unaffected.  The potential use of dasatinib to treat select ovarian cancer patients who test “positive” for specific molecular markers (e.g., Src cellular pathway activation) is similar to the extremely successful drug development approach used for Herceptin®.

Open Clinical Trials Testing Dasatinib (Sprycel®) Against Ovarian Cancer & Solid Tumors

As of this writing, there are several open (i.e., recruiting) clinical trials that involve testing dasatinib against ovarian cancer and solid tumors.

For a list of open clinical trials that involve testing dasatinib against ovarian cancer, CLICK HERE.

For a list of open clinical trials that involve testing dasatinib against solid tumors, CLICK HERE.

All potential volunteers must satisfy the clinical trial entrance criteria prior to enrollment.  Depending on the drug combination being tested, one or more of the solid tumor clinical trials may not be appropriate for an ovarian cancer patient.

About the UCLA Jonsson Comprehensive Cancer Center

UCLA’s Jonsson Comprehensive Cancer Center (JCCC) has more than 240 researchers and clinicians engaged in disease research, prevention, detection, control, treatment and education. One of the nation’s largest comprehensive cancer centers, JCCC is dedicated to promoting research and translating basic science into leading-edge clinical studies. In July 2009, JCCC was named among the top 12 cancer centers nationwide by U.S. News & World Report, a ranking it has held for 10 consecutive years. For more information on JCCC, visit the website at http://www.cancer.ucla.edu.

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UA Research Team Designing Holographic Imaging System For Ovarian Cancer

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University of Arizona researchers Jennifer Barton and Ray Kostuk have received a five-year, $2.4 million grant from the National Institutes of Health to build the instrument that they hope will one day be used to monitor women at high risk for ovarian cancer.

Hologram of Human Ovary

Human ovary image captured with the use of the prototype holographic imaging system the team developed. (Photo: Univ. of Arizona News)

Hologram of An Orange

For comparison, an onion is imaged with the use of the prototype system the team developed. (Photo: Univ. of Arizona News)

Two University of Arizona [UA] researchers have formed a research team to design, build and evaluate two versions of an ovarian cancer medical imaging and screening instrument that will use holographic components in a new type of optical microscope.

Raymond Kostuk and Jennifer Barton have secured a five-year, $2.4 million grant from the National Institutes of Health to build the instrument that they hope will one day be used to monitor women at high risk for ovarian cancer. Kostuk is the Kenneth Von Behren Professor of Electrical and Computer Engineering and professor of optical sciences. Barton heads the UA department of biomedical engineering and is assistant director of the BIO5 Institute.

The system is unique in that it will for the first time project multiple spatial images from different depths within a tissue sample and simultaneously provide spectral information from optical markers in order to better identify cancerous cells.

This combined spectral spatial imaging technique shows potential to be much more effective in identifying cancerous tissue sites than by separately using spatial or spectral information.

The grant was issued following the successful two-year development of a prototype system the team built. It tests the validity of using holographic technology for subsurface imaging without having to perform surgery and take tissue samples.

According to the National Institutes of Health, there is, to date, no single effective screening test for ovarian cancer, so ovarian cancer is rarely diagnosed in its early stages. The result is that in more than 50 percent of women with ovarian cancer are diagnosed in the late stages of the disease when the cancer has already advanced.

  • About 76 percent percent of women with ovarian cancer survive one year after diagnosis.
  • About 45 percent live longer than 5 years after diagnosis.

Barton said ovarian cancer provides a compelling case to test holographic imaging and its efficacy in detecting cancers. At the present time the preferred treatment is surgery, which is also often needed to diagnose ovarian cancer. The procedure includes taking tissue samples, which may threaten the woman’s ability to have children in the future.

Jennifer Barton, UA

Jennifer Barton, Professor & Chair, Department of Biomedical Engineering; Assistant Director, BIO5 Institute. (Photo: Univ of Arizona News)

“Ovarian cancer has no symptoms until it is highly advanced making the five-year prognosis extremely poor. Those at high risk – with a family history of ovarian cancer or those who carry genetic mutations in the BRCA1 and BRCA2 genes, which normally help protect against both breast and ovarian cancer – may be counseled to have their ovaries removed through laparoscopic surgery,” Barton said. “Now imagine if you are an 18-year-old woman who has this history – ovaries are an important part of your overall health. They produce hormones you need over and above the notion that you would need your ovaries should you want to have children in the future.”

Thus, new technology capable of reliably diagnosing ovarian cancer in earlier stages could reduce the morbidity, high mortality and economic impact of this disease.

The system will work like a high-powered microscope that can be used to study tissue samples already removed. In addition, an endoscopic version is in the design stage to safely scan the ovaries for cancer during laparoscopic screenings in high-risk women, or as an adjunct to other laparoscopic procedures in all women.

The team will work with Dr. Kenneth D. Hatch, president of the Society of Pelvic Surgeons, and a professor of obstetrics and gynecology and director of female pelvic medicine and reconstructive surgery at the UA College of Medicine.

Through Hatch and a partnership with his patients who consent, Barton and Kostuk will be able to identify abnormal spatial and spectral markers of cancerous ovarian tissue.

Ray Kostuk

Ray Kostuk, Kenneth Von Behren Professor of Electrical and Computer Engineering & Professor of Optical Sciences, University of Arizona (Photo: Univ. of Arizona News)

The new imaging system will be tested on high-risk patients who are willing to participate and provide some future benefit to other patients who find themselves in a similar situation, Barton said.

Kostuk and Barton’s aim is to design the imaging system so that it is easy to use, requiring very little training, and also be cost effective.

“The system will image like an MRI or a CT scan but with much higher resolution than an ultrasonic image and will be a lot less expensive than an MRI. As an additional benefit no radiation will be used or exposed to sensitive ovary areas during the cancer screenings,” Kostuk said.

During the past 25 years Kostuk has researched different aspects of holography and holographic materials for use as optical elements.

The holographic imaging system being designed combines an optical technique that creates images capable of detecting subtle tissue microstructure changes. Together with fluorescence spectroscopy methods, the system has demonstrated capability for early cancer detection.

Another member of the team, UA research professor Marek Romanowski, with the UA department of biomedical engineering and the BIO5 Institute, is working on the development of targeted fluorescent dyes that will be used on tissue samples to identify or confirm suspected cancerous areas shown in the spatial image.

The multidisciplinary approach to the design of the hologram-based imaging system is a testament to the complexity of treating cancers.

“One of the advantages of being part of the UA is the ability to interact collaboratively with people in other disciplines,” Kotuk said. “Jennifer is a wonderful colleague who can identify important medical applications for new techniques and is able to bridge the gap between traditional engineering and medicine. Her skill and knowledge is critical to the success of the program,” he said.

“To solve the really interesting problems of today, no one person has all the expertise needed,” Barton added.

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New Study Shows Four-Year Window for Early Detection of Ovarian Cancer

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A new study by Howard Hughes Medical Institute researchers shows that most early stage ovarian tumors exist for years at a size that is a thousand times smaller than existing tests can detect reliably.  But the researchers say their findings also point to new opportunities for detecting ovarian cancer—a roughly four-year window during which most tumors are big enough to be seen with a microscope, but have not yet spread.

Tiny Early-Stage Ovarian Tumors Define Early Detection Challenge

Currently available tests detect ovarian cancer when it is about the size of the onion in the photograph. To reduce ovarian cancer mortality by 50 percent, an early detection test would need to be able to reliably detect tumors the size of the peppercorn. (Photo Source: Patrick O. Brown, Howard Hughes Medical Institute Investigator, Research News Release, July 28, 2009)

Currently available tests detect ovarian cancer when it is about the size of the onion in the photograph. To reduce ovarian cancer mortality by 50 percent, an early detection test would need to be able to reliably detect tumors the size of the peppercorn. (Photo Source: Patrick O. Brown, Howard Hughes Medical Institute Investigator, Research News Release, July 28, 2009)

A new study by Howard Hughes Medical Institute researchers shows that most early stage ovarian tumors exist for years at a size that is a thousand times smaller than existing tests can detect reliably.

But the researchers say their findings also point to new opportunities for detecting ovarian cancer—a roughly four-year window during which most tumors are big enough to be seen with a microscope, but have not yet spread.

“Our work provides a picture of the early events in the life of an ovarian tumor, before the patient knows it’s there,” says Howard Hughes Medical Institute researcher Patrick O. Brown. “It shows that there is a long window of opportunity for potentially life-saving early detection of this disease, but that the tumor spreads while it is still much too small to be detected by any of the tests that have been developed or proposed to date.”

According to the American Cancer Society, some 15,000 women in the United States and 140,000 women worldwide die from ovarian cancer each year. The vast majority of these deaths are from cancers of the serous type, which are usually discovered only after the cancer has spread.

“Instead of typically detecting these cancers at a very advanced stage, detecting them at an early stage would be enormous in terms of saving lives,” says Brown, who is at Stanford University School of Medicine. Early detection would enable surgeons to remove a tumor before it spreads, he adds.

The article—co-authored by Chana Palmer of the Canary Foundation, a nonprofit organization focused on early cancer detection—was published July 28, 2009, in the open access journal PLoS Medicine.

“Like almost everything with cancer … the more closely you look at the problem, the harder it looks,” Brown says. “That’s not to say that I don’t believe it’s a solvable problem. It’s just a difficult one.” — Patrick O. Brown, M.D. Ph.D.

Patrick O. Brown, M.D. Ph.D., Howard Hughes Medical Institute Investigator, Stanford University School of Medicine

Patrick O. Brown, M.D. Ph.D., Howard Hughes Medical Institute Investigator, Stanford Univ. School of Medicine

“Like almost everything with cancer … the more closely you look at the problem, the harder it looks,” Brown says. “That’s not to say that I don’t believe it’s a solvable problem. It’s just a difficult one.”

In the quest to develop early detection methods for ovarian cancer, Brown says, science hasn’t had a firm grasp on its target. So he and Palmer took advantage of published data on ovarian tumors to generate a better understanding of how the cancer progresses in its earliest stages.

The team analyzed data on serous-type ovarian tumors that were discovered when apparently healthy women at high genetic [BRCA1 gene mutation] risk for ovarian cancer had their ovaries and fallopian tubes removed prophylactically. Most of the tumors were microscopic in size; they were not detected when the excised tissue was examined with the naked eye.

The analysis uncovered a wealth of unexplored information. Thirty-seven of the early tumors had been precisely measured when they were excised – providing new details about the size of the tumors when they were developing prior to intervention, Brown says. By extrapolating from this “occult” size distribution to the size distribution of larger, clinically evident tumors, the researchers were able to develop a model of how the tumors grew and progressed. “We are essentially trying to build a story for how these tumors progress that fits the data,” Brown explains.

Among the study’s findings:

  • Serous ovarian tumors exist for at least four years before they spread.
  • The typical serous cancer is less than three millimeters across for 90 percent of this “window of opportunity for early detection.”
  • These early tumors are twice as likely to be in the fallopian tubes as in the ovaries.
  • To cut mortality from this cancer in half, an annual early-detection test would need to detect tumors five millimeters in diameter or less – about the size of a black peppercorn and less than a thousandth the size at which these cancers are typically detected today.

Brown’s lab is now looking for ways to take advantage of that window of opportunity to detect the microscopic tumors and intervene before the cancer spreads.

One strategy the laboratory is pursuing is to examine tissues near the ovaries, in the female reproductive tract, for protein or other molecular markers that could signify the presence of cancer. Brown says answering another question might also prove helpful: whether there is any reliable flow of material from the ovaries and fallopian tubes through the uterus and cervix into the vagina—material that might be tested for a specific cancer marker.

Despite science’s broad understanding of cancer at a molecular level, it has been challenging to identify simple molecular markers that signal the presence of early disease. One current blood marker, CA-125, has proven useful in monitoring later-stage ovarian cancer, but it has not been helpful for early detection. So Brown’s lab is also looking for biomarkers that are present only in ovarian tumors and not in healthy cells, instead of relying on tests that look for unusually high levels of a molecule that is part of normal biology (like CA-125).

The researchers are doing extensive sequencing of all messenger RNA molecules (which carry information for the production of specific proteins) in ovarian cancer cells, searching for evidence of proteins in these cells that would never be found in non-cancer cells. These variant molecules could be produced as a result of chromosome rearrangements—when the genome is cut and spliced in unusual ways—in ovarian cancers. “It’s a long shot,” says Brown, “but it’s important enough to try.”

Source: Tiny Early-Stage Ovarian Tumors Define Early Detection Challenge, Research News, Howard Hughes Medical Institute, July 29, 2009 [summarizing Brown PO, Palmer C, 2009 The Preclinical Natural History of Serous Ovarian Cancer: Defining the Target for Early Detection. PLoS Med 6(7): e1000114. doi:10.1371/journal.pmed.1000114].