Ovarian cancer surveillance with CA-125 tests, CT scans common despite lack of proven benefit

Cancer antigen 125 tests and CT scans are routinely used for surveillance of patients with ovarian cancer despite a lack of proven benefit, according to results of a prospective cohort study.

Cancer antigen 125 (CA-125) testing for routine surveillance in ovarian cancer failed to extend survival, increased chemotherapy use and decreased patients’ quality of life compared with clinical observation, according to results of a randomized clinical trial presented by Rustin and colleagues at the ASCO Annual Meeting in 2009.

The Society of Gynecologic Oncology classified CA-125 testing as optional, but it recommended against routine imaging for ovarian cancer surveillance as part of the Choosing Wisely campaign, designed to identify procedures and tests that are commonly performed but are not supported by evidence.

“Surveillance testing remains controversial, and it is unclear how frequently such testing is performed in patients with ovarian cancer,” Katherine M. Esselen, MD, MBA, instructor of obstetrics and gynecology at Harvard Medical School and gynecologic oncologist at Beth Israel Deaconess Medical Center, and colleagues wrote.

Esselen and colleagues examined the use of CA-125 testing and CT scans in clinical practice before and after 2009 to gauge the clinical impact of the study results presented at ASCO that year.

Secondary outcomes included the time from CA-125 markers doubling to retreatment, as well as the costs associated with surveillance testing.

The analysis included 1,241 women (mean age, 59 years; 89.6% white) with ovarian cancer who were in clinical remission after completion of primary cytoreductive surgery and chemotherapy at six NCI–designated cancer centers between 2004 and 2011. Researchers followed the women until Dec. 31, 2012.

When researchers compared testing rates before and after 2009, they calculated no significant difference in the percentage of women who underwent three or more CA-125 tests (86% vs. 91%), or in the percentage of women who underwent more than one CT scan (81% vs. 78%).

Among women whose CA-125 markers doubled (n = 511), the median time to retreatment with chemotherapy before 2009 compared with after 2009 did not differ significantly (2.8 months vs. 3.5 months).

Study participants underwent a mean 4.6 CA-125 tests and 1.7 CT scans during a 12-month period. A cost analysis, performed using 2015 Medicare reimbursement rates, calculated cost estimates of $1.9 million per year for CA-125 tests, and $16.1 million per year for CA-125 tests and CT scans combined.

Researchers acknowledged their inability to distinguish between imaging performed in response to symptoms and routine testing for asymptomatic patients as a potential study limitation.

“Our results demonstrate that the recommendation to avoid routine surveillance testing has not been adopted into clinical practice in the United States,” Esselen and colleagues wrote. “Although the routine use of CT scans has been strongly discouraged by guideline committees, CT scans appear to be routinely used, at significant cost. ... Future studies should examine which patient populations benefit most from surveillance testing to improve the value of cancer care.”

In an era of increased shared decision-making, patients’ desires for more information likely contributed to the continued use of surveillance testing, James S. Goodwin, MD, chair of geriatric medicine in the department of internal medicine at University of Texas Medical Branch, wrote in an accompanying editorial.

“But why would clinicians present the option of CA-125 testing?” Goodwin wrote. “Shared decision-making does not require that physicians present the patient with harmful options. We do not discuss heart transplants with patients who have mild congestive heart failure. Why would we discuss CA-125 testing with women who have ovarian cancer in remission?”

The practice of routine CA-125 testing likely will not change, Goodwin wrote.

“The moving target argument is too strong,” he wrote. “There will be better tests and more effective treatments. And studies like that of Rustin with uncomfortable results are usually not replicated. The issue is allowed to fade away. The fatal attraction of more information is too compelling.” – by Nick Andrews

Disclosure: The researchers and Goodwin report no relevant financial disclosures.