Many women with ovarian cancer that is in remission have tests and scans to check whether their cancer has recurred. But guidelines do not recommend regular scans to look for recurrence because they have not been shown to offer any benefit. A blood test to monitor for recurrence may be recommended, but its benefits have been questioned, and it may result in unnecessary anxiety and reduced quality of life.

Ovarian cancer recurs after initial treatment in the majority of those diagnosed. The blood test routinely used to watch for recurrence examines the level of an ovarian cancer-linked protein called CA-125.

The National Comprehensive Cancer Network (NCCN) recommends CA-125 testing for patients in remission only if they had elevated levels at the time of their diagnosis. (Most women have elevated CA-125 at diagnosis.) Recommendations developed by the Society of Gynecologic Oncology (SGO) in 2011 say the test is optional. The only randomized trial to investigate using CA-125 levels to guide treatment, published in 2010 in the Lancet, found that starting treatment because the CA-125 level increased, in the absence of other symptoms, does not confer any survival benefit or improve quality of life.

Ovarian Cancer Screening in Healthy Women

Studies have not shown the CA-125 blood test is effective for screening.

Although the majority of women diagnosed with ovarian cancer have an elevated CA-125 level, studies have not shown that the CA-125 blood test is an effective screening test for ovarian cancer in healthy women. Even so, there have been many attempts over the past several decades to find ways to use the CA-125 blood test as a screening test.

In response to the marketing of a new screening test directly to healthy women, the U.S. Food and Drug Administration (FDA) issued a public warning on Sept. 7, 2016, stating: “There are currently no screening tests for ovarian cancer that are sensitive enough to reliably screen for ovarian cancer without a high number of inaccurate results.”

The agency specifically mentioned the ROCA (Risk of Ovarian Cancer Algorithm) test, which uses scores from annual blood tests for the CA-125 protein along with a computerized calculation (algorithm) that takes into account age, menopausal status and overall risk to determine the likelihood a woman has ovarian cancer. The test, made by Abcodia, a company based in Cambridge, England, became available to women in parts of the U.S. in late 2015. Six days after the FDA issued its warning, Abcodia released a statement saying it was “voluntarily choosing to temporarily suspend” sales in the U.S., even though it remained confident in its test.

Computed tomography (CT) of the chest, abdomen and pelvis is also commonly used to look for recurrence. As part of the Choosing Wisely initiative, which aims to cut down on unnecessary medical care, the SGO discourages routine scans. CT scans and other types of imaging are recommended by the NCCN only when “clinically indicated,” which is generally interpreted to mean only in response to symptoms of disease or rising CA-125 levels.

To learn how doctors at leading U.S. cancer centers monitor for ovarian cancer recurrence, Kate Esselen, a gynecologic oncologist at Beth Israel Deaconess Medical Center in Boston, and her colleagues analyzed the records of 1,241 ovarian cancer patients who were treated at six cancer centers between 2004 and 2012. The findings, published July 21, 2016, in JAMA Oncology, showed that about 90 percent of patients received three or more CA-125 tests within a year after remission. About 30 percent had three or more CT scans and about 80 percent had more than one CT scan during this period.

Ritu Salani, a gynecological oncologist at the Ohio State University Wexner Medical Center and a co-author of the SGO recommendations, notes that the study found the blood test was being used in women who did not have a high CA-125 level when they were diagnosed. “That, to me, is a complete waste of resources,” she says.

The 2010 Lancet study enrolled women whose ovarian cancer was in remission after initial treatment with chemotherapy. It found that starting treatment earlier based on rising CA-125 alone did not lengthen survival. It also led to earlier worsening of quality of life, probably because of treatment side effects and psychological distress.

In her own practice, Salani monitors CA-125 levels only in women who had an elevated CA-125 level at initial diagnosis. She says her recommendations to start treating after recurrence are based on a patient’s symptoms, not on their CA-125 level alone.

Esselen discusses the test with patients who had an elevated CA-125 level at the time of their diagnosis, explaining that the test has not been shown to improve survival. Many patients opt for the test. “They’re coming in for these visits usually asymptomatic and wanting confirmation they don’t have recurrent disease,” she says. “They just want to know for their own peace of mind.”