Use of a blood test in the monitoring of ovarian cancer patients who are in remission is an example of the “fatal attraction of more information” in medicine, according to an editorial published July 21 in JAMA Oncology.

The commonly used cancer antigen 125 (CA-125) test is irresistibly and destructively attractive to both oncologists and patients, suggests editorialist James Goodwin, MD, from the University of Texas Medical Branch, Galveston.

He explains that the routine use of the CA-125 test was proven to be “harmful” in this setting in a major clinical trial in 2009  ( ASCO Ann Meet Proc. 2009;27[18s]:1).

In that trial, patients randomized to routine CA-125 testing had no better survival and worse quality of life compared with patients who were randomized to clinical observation (and did not receive test results) because, overall, the test results triggered earlier second-line chemotherapy, which was not efficacious.

Now, 7 years later, a new study has been published as follow-up on this subject ”” to learn if the evidence from 2009 changed practice.

This new study, also published online in JAMA Oncology, prompted Dr Goodwin’s “fatal attraction” comment in the accompanying editorial.

The researchers, led by Katharine Esselen, MD, MBA, from Harvard Medical School in Boston, reviewed the use and frequency of CA-125 testing in 1241 women in remission after initial treatment of ovarian cancer at six National Cancer Institute-designated cancer centers from 2004 to 2011. They found that almost all of the study’s patients received CA-125 testing every 3 to 4 months, both before and after the 2009 study.

In short, the 2009 study results did not change CA-125 testing.

This becomes the leaping off point for Dr Goodwin’s editorial as he asks: “Why did practice not change?”

Physicians are capable of “rapid change in practice in the face of new information,” he says.

He cites an example: When a study showed an absolute survival improvement of 2% at 18 months after treatment with a taxane plus doxorubicin compared with doxorubicin alone in node-positive breast cancer, there was a doubling of use of the combination therapy within 3 months of an oral report of the findings (J Natl Cancer Inst. 2006;98[6]:382-388).

Dr Goodwin then proposes that two sets of factors contribute to the lack of change after the 2009 ovarian cancer study; the first is “the fundamental attractiveness of testing.”

“Physicians practice in a sea of uncertainty. Making life-altering decisions based on incomplete information is one of the major stresses of becoming a physician,” he writes. Thus physicians seek “more information through testing to reduce uncertainty.

This seems benign, suggests Dr Goodwin, who asks, “How could more information possibly hurt?” He also says that avoiding information “sounds antiscientific” and doctors are confident that they can interpret results “wisely.”