We have been writing about the ABIM Foundation Choosing Wisely Campaign which has focused on identifying ways forpracticing clinicians to contribute to the delivery of high-value, cost-conscious health care by limiting the use of common treatments or screening and diagnostic tests in ways that do not reflect high-value care. This discussion focuses on screening for ovarian cancer by the serum marker CA-125 or ultrasound.
Like discussing the pros and cons of a lollipop with a tantruming 2-year-old, applying logic to some circumstances is not beneficial. Although using the serum marker CA-125 to screen women for ovarian cancer makes sense on first glance, the harms of doing so far outweigh the benefits. Good evidence finds using a CA 125 test results in a false positive rate of up to 12% (Health Technol Assess 1998;2(2):i-iv, 1-84. Review), even for those with a first degree relative with ovarian cancer. A positive screen requires surgical biopsy and tissue to rule out cancer, and this intervention results in a significant complication rate of 0.5-1%.
What can cause a false positive CA-125? Common conditions like menses, pregnancy, fibroids, endometriosis, PID and hepatitis. And while the result is elevated in advanced ovarian cancer, the CA-125 is frustratingly NORMAL in the majority of those with Stage I disease!
Like CA 125, transvaginal ultrasound (TVU) has been studied and found to be an ineffective method to screen the general population of women, and again, even for those who have a first degree relative with ovarian cancer. When used in the general population, up to 12% of women will have an abnormal result, and of those less than 0.1% have cancer. (Lancet Oncol. 2009 Apr;10(4):327-40). And again, the only way to rule out disease is by surgical biopsy with its accompanying risks and complications
So, what are we to do? Counsel women who might request testing with this data; help them understand that until we find a better method of screening, testing presents significant risks, and to focus on health interventions that do work to improve health: exercise, appropriate diet, etc.
- Frank J. Domino, MD