Early Treatment of Recurrent Ovarian Cancer Based Upon Rising CA-125 Levels Does Not Increase Survival

“European researchers report [at the 2009 American Society of Clinical Oncology Annual Meeting being held in Orlando, Florida from May 29 through June 2nd] that starting treatment early for an ovarian cancer relapse based on CA125 blood levels alone does not improve overall survival, compared with delaying treatment until symptoms arise.”


PLENARY PRESENTATION
SUNDAY, MAY 31, 1:45 PM EDT
LEVEL 2, WEST HALL D2
PLENARY SESSION
[2009 American Society of Clinical Oncology Annual Meeting, Orlando FL, May 29 – June 2, 2009.]

Lead Author: Gordon Rustin, MD
Mount Vernon Cancer Center
Hertfordshire, United Kingdom

Treatment Based on Rising CA125 Blood Levels Does Not Improve Survival for Recurrent Ovarian Cancer, Compared to Waiting for Symptoms to Arise

European researchers report that starting treatment early for an ovarian cancer relapse based on CA125 blood levels alone does not improve overall survival, compared with delaying treatment until symptoms arise.

“Women who’ve completed ovarian cancer treatment often worry about a relapse, and they undergo frequent blood tests for CA125 in the hope of catching it early,” said lead author Gordon Rustin, MD, professor of oncology at Mount Vernon Cancer Center in Hertfordshire, United Kingdom. The study was conducted by the MRC/NCRI and EORTC Gynae Cancer Intergroups. “We thought that delaying chemotherapy might make overall quality of life worse, due to the symptoms of ovarian cancer, but this was not seen in women on this trial. Since there is no benefit from early chemotherapy, patients may choose to avoid the inconvenience and anxiety associated with frequent retesting for CA125 levels as well as unnecessary early initiation of treatment for relapse.”

CA125 is a marker of growth for several cancers, including ovarian cancer, and is measured by a blood test. Women who have undergone treatment for ovarian cancer may have their CA125 levels tested as often as every three months for several years after initial treatment.  In this study, investigators compared overall survival between 265 women with ovarian cancer in remission after initial chemotherapy who began second-line chemotherapy after experiencing a rise in CA125, and 264 women with rising CA125 whose treatment was delayed until symptoms of relapse appeared (such as pelvic pain or bloating).

Even though the early treatment group started second-line chemotherapy an average five months before the delayed treatment group, overall survival was the same between both groups: 41 months since completion of first-line chemotherapy.  The researchers added that this trial provides important information that will help women make informed choices about their follow-up and treatment. They can be reassured that treatment can safely be delayed until symptoms develop.

Abstract P1

[Title:A randomized trial in ovarian cancer (OC) of early treatment of relapse based on CA125 level alone versus delayed treatment based on conventional clinical indicators (MRC OV05/EORTC 55955 trials). G. J. Rustin, M. E. van der Burg, on behalf of MRC and EORTC collaborators, [The 2009 American Society of Clinical Oncology Annual Meeting, May 29 – June 2, 2009, Abstract #P1].

Background: Serum CA125 often rises several months before women with OC [ovarian cancer] have symptoms or clinical signs of relapse. OV05/55955 was designed to determine whether there were benefits from early treatment based on a confirmed elevation of CA125 levels versus delaying treatment until clinically indicated.

Methods: Women with OC in clinical complete remission after first line platinum-based chemotherapy and a normal CA125 were registered. CA125 was measured every 3 months but patients and investigators were blinded to the results, which were only monitored by the trials units. If CA125 levels exceeded twice the upper limit of normal, patients were randomized to either immediate treatment or to remain having blinded CA125 measurements with treatment commencing when clinical or symptomatic recurrence appeared. Patients in both arms were treated according to standard local practice. The primary outcome measure was overall survival. The study was designed to detect a 10% improvement in 2-year overall survival in the immediate treatment arm with at least 85% power and 5% significance level (2-sided).

Results:  1442 patients were registered from 59 sites in 10 countries between 1996 and 2005. Randomization closed on 31 March 2008 with 527 patients (264 immediate and 263 delayed) randomized and when the targeted number of events (deaths) were reached. 915 patients have not been randomized due to: no CA125 rise and no relapse (48%); relapse with or without CA125 rise (30%); death (6%); patient withdrawal (14%); or other reasons (2%). For randomized patients baseline characteristics were well balanced between the groups. Median age at registration was 61 years; 81% were FIGO stage III/IV. Second-line chemotherapy started a median of 5 months earlier in the immediate arm.  With a median follow up of 49 months from randomization and a total of 351 deaths, there was no evidence of a difference in overall survival between the immediate and delayed arms, hazard ratio 1.01, 95% CI 0.82-1.25, p =0.91.

Conclusions: There is no survival benefit from early treatment based on a raised serum marker level alone, and therefore no value in the routine measurement of CA125 in the follow-up of ovarian cancer patients.

The American Society of Clinical Oncology

The American Society of Clinical Oncology is a non-profit organization founded in 1964 with the overarching goals of improving cancer care and prevention. More than 27,000 oncology practitioners belong to ASCO, representing all oncology disciplines and subspecialties. Members include physicians and health-care professionals in all levels of the practice of oncology.

2 thoughts on “Early Treatment of Recurrent Ovarian Cancer Based Upon Rising CA-125 Levels Does Not Increase Survival

  1. IF CA125 tracking doesn’t provide any benefit, then how is a patient supposed to track if their disease is progressing? Would one just depend on pelvic bloating/pain symptoms which is not dependable as the cancer could have spread to other areas of the body that migh tnot ellicit symptoms.
    Is the patient left with only performing a CT scan/MRI on a yearly basis?

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    • Dear Sara,

      Thank you so much for commenting on the website. This issue caused quite a stir back in 2009-2010. The gist of the medical study finding is that early treatment of biological recurrence determined solely through CA-125 does not increase survival compared to waiting for clinical symptoms to develop. In this instance, we are generally talking about a situation in which a CT scan would not be able to detect the recurrence.

      We recommend that you listen to our June 2011 WORD of HOPE podcast that addresses this important issue. In that podcast, we point out at least one additional study that indicates that waiting for clinical symptoms could become problematic when a secondary cytoreductive surgery is possible. By waiting in this example, a patient’s chances of obtaining an “optimal” cytoreductive surgery (with post-surgical residual disease of less than 1 cm) may be decreased with the passage of time.

      In our experience, most doctors will follow up a trend of rising CA-125 with a medical imaging scan (e.g., PET/CT, CT, and/or MRI). Once the scan confirms a recurrence, most doctors will begin treatment upon disease recurrence confirmation. Most ovarian cancer survivors simply do not feel comfortable waiting for clinical symptoms to develop after experiencing a rising CA-125 trend. It seems that the use of a PET/CT or CT scan to confirm a recurrence that is possibly evidenced by rising CA-125 results strikes a sort of middle ground.

      We hope the information above is responsive to your question. As always, if you have additional questions, please feel free to contact us.

      Best regards,

      Paul

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