Screening for ovarian cancer is reminiscent of screening for prostate cancer: Although we have tests that seem like they should work to reduce mortality (e.g., cancer antigen [CA] 125 measurement plus ultrasonography, prostate-specific antigen testing), unfortunately we are not there yet. Publication of the United Kingdom Collaborative Trial of Ovarian Cancer Screening (UKCTOCS)1 generated a lot of publicity because on the surface it appeared to deliver on the promise of effective screening for ovarian cancer. The protocol consisted of the rigorous application of a risk of ovarian cancer algorithm (ROCA) rather than simply relying on the results of CA 125 testing with a single cutoff value for an abnormal result. From the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial, we already know that using a single cutoff value does not reduce mortality.2 Although some findings seemed promising in the current study, they ultimately did not show convincing effectiveness. Shortcomings included the following:
(1) The reduction in ovarian cancer mortality was not statistically significant.
(2) The reduction was not constant over time.
(3) Only one-fourth of the patients were followed long enough to begin to see a possible benefit.
(4) The effect of screening on all-cause mortality was not reported.
(5) The ROCA is a proprietary algorithm patented by the investigators.
The final point is potentially problematic because physicians and patients, inspired by this trial's publicity, might embark on a screening program but not employ the precise protocol used in the study. However, this protocol has been commercialized (at $295 per use) and promoted to the public in an unqualified way.
In keeping with the principles of the Choosing Wisely campaign, physicians and patients would do well to avoid the pitfalls of overscreening and wait for results that promise more hope than hype.
editor's note: Dr. Siwek is editor of American Family Physician.