A small study of 21 ovarian cancer patients reported that killing tumors by freezing them through cryoablation can extend the lives of select women with metastatic disease which has spread to the abdomen, liver, lung or bone, and can not be removed surgically. From the time of diagnosis of metastatic disease, the average patient survival time was more than four years and seven months.
Killing tumors by freezing them through cryoablation can extend the lives of women with ovarian cancer that has spread to other parts of the body and is cost-effective, according to research being presented at the 4th annual Symposium on Clinical Interventional Oncology (CIO), in collaboration with the International Symposium on Endovascular Therapy (ISET).
Cryoablation Study Results
The study included 21 patients whose tumors in the abdomen, liver, lung and bone could not be removed surgically. Cryoablation was used to treat 48 tumors, killing 47 of them (98 percent). From the time of diagnosis of metastatic disease, average patient survival time was more than four years and seven months. That’s significant because when tumors are not successfully removed surgically – which occurs in about 60 percent of cases, according to studies – women typically survive from about seven months to 2 ½ years. On average, more than three years had transpired from the time of diagnosis to the first cryoablation treatment, meaning these women had already passed their expected survival time, and yet cryoablation was able to extend their survival even further. Some patients had multiple cryoablation treatments and of 41 procedures, there were three major complications (7 percent). The complications included two deaths that were attributed to the cancer, not to the procedure.
The study also determined the treatment was extremely cost-effective, costing an average of $26,806 per life year saved, well below the current standard of $100,000.
“This study adds to the evidence that cryoablation is an effective option for patients who can’t have surgery,” said study author Hyun J. Bang, M.D., a radiologist resident at Wayne State University/Detroit Medical Center. “This procedure is often overlooked, but based on the high survival rate, cost effectiveness, consistent local control and safety of the procedure, we should be taking a closer look at cryoablation.”
In cryoablation, a small needle is inserted into the tumor using imaging guidance. High pressure argon flows to the tip of the cryoprobe where it expands in an internal chamber, causing a powerful cooling effect on the outside of the probe. This allows for rapid ice formation which freezes and kills tumor cells.
For more about CIO and ISET, visit www.ISET.org/oncology.
Cryoablation Study Shortcomings — Potential Selection Bias
“While an interesting abstract, it must be stressed that the total number of patients included is extremely limited, and it is not appropriate to make any statement regarding the impact of this strategy on survival,” cautioned Maurie Markman, M.D., the senior vice president of clinical affairs and national director of medical oncology at the Cancer Treatment Centers of America Eastern Regional Medical Center in Philadelphia, Pennsylvania, in an interview with Medscape Medical News.
“Any observed outcome could very easily reflect bias in the selection of patients who have been included in this series. Considerable additional clinical evaluation must be undertaken to include far larger patient populations before any statement can be made regarding the potential of this approach to be a reasonable alternative to the current standard of care in the management of ovarian cancer,” Dr. Markman added.
- Tumor-Freezing Treatment Gives Ovarian Cancer Patients Extra Time, ISET Daily News (page 4 digital edition), The International Symposium on Endovascular Therapy, Sunday, January 15, 2012.
- Targeted Cryoablation Boosts Survival in Ovarian Cancer, by Martha Kerr, Medscape Medical News, January 19, 2012. [Free Medscape registration required to view article]