Use of CA125 for Monitoring Ovarian Cancer

Results of a multi-institutional European trial on the utility of CA125 in monitoring ovarian cancer after completion of primary therapy have recently been reported at the annual meeting of the American Society of Clinical Oncology. The main conclusion was that women with relapsed ovarian cancer did not live longer if chemotherapy was started earlier based on a rising CA 125, as opposed to delaying treatment until symptoms developed. It was found that the group undergoing CA125 monitoring received five more months of chemotherapy overall, whereas quality of life measures were higher in women who were treated at the time of clinically evident recurrence. The results of this study have been featured in various professional and consumer media outlets, and physicians and patients will be seeking guidance regarding the implications.

The Society of Gynecologic Oncology commends the investigators of this study for contributing valuable data that further informs evidence-based management of ovarian cancer. The strength of this study is that it was a prospective randomized trial, but the study also had some significant limitations. The trial did not address the role of secondary cytoreduction in recurrent cases, participants were not stratified for residual disease after cytoreduction, remission was not consistently confirmed by imaging and treatment regimens at relapse were not standardized. The most pressing issue in the management of ovarian cancer is the development of new treatments that will further extend survival and cure more women.

Although there may not presently be a major survival advantage to the use of CA125 monitoring for earlier diagnosis of recurrence, patients and their physicians should still have the opportunity to choose this approach as integral to a philosophy of active management that includes participation in trials of novel therapies. Other patients, particularly those with a less robust performance status, might be more suitable for watchful waiting with an emphasis on quality of life. In practice, many have already been opting for such an approach without the support of data from clinical trials. The value of the present study is the confirmation that this is safe and reasonable. Patients and their physicians should be encouraged to actively discuss the pros and cons of CA125 monitoring and the implications for subsequent treatment and quality of life.