Influential task force revises its position on PSA screening tests

Charlie Schmidt

In 2012, the US Preventive Services Task Force (USPSTF) took the unprecedented step of recommending against prostate cancer screening for all men, regardless of age, race, or family history. Now this influential group of independent experts is reassessing its position based on more recent data. Instead of discouraging screening altogether, the UPSTF is urging doctors to discuss its potential benefits and harms with men 55 to 69 years of age. The same recommendation applies to all men in this age group, including those at higher risk of prostate cancer, such as African Americans and men with a family history of the disease. The USPSTF continues to recommend against screening men older than 70, since they’re unlikely to experience a survival benefit from treatment during their expected lifespans. The USPSTF was silent on men younger than 55, because Task Force members don’t believe there is sufficient information for them to make a recommendation.

Screening is usually done with a blood test that measures levels of a protein released by the prostate gland called prostate-specific antigen, or PSA. Elevations in PSA may be due to prostate cancer, but other conditions can also cause levels to rise, such as inflammation or an enlarged prostate. PSA levels also vary from man to man and can be unusually high in men who are otherwise healthy. To confirm or rule out a cancer diagnosis, doctors will typically order a biopsy of the prostate. However, prostate biopsies can lead to complications like infection, bleeding, and pain, and they often detect slow-growing, low-risk cancers that may never cause a man any harm during his lifetime. Treating low-risk cancers can leave men impotent and incontinent for years without extending their survival.

The USPSTF recommended against screening five years ago because its members felt the harms of treatment outweighed the benefits. However, newer data make the tradeoffs between potential harms and benefits too close to call. A European study published in 2014 found that PSA tests can prevent three cancers from spreading, and prevent one to two prostate cancer deaths, for every 1,000 men screened over 13 years. Then a study published last year found no difference in 10-year survival among men who were monitored or treated for low-risk prostate cancer. Monitoring, which is also called active surveillance, entails periodic PSA tests and biopsies to check for cancer growth, and thus allows men with low-risk prostate cancer to avoid the harms of treatment, at least temporarily.

It’s important to emphasize that the Task Force is not recommending that men in the 55-69 age group be screened, only that they talk about it with their doctors and then decide personally if it’s something they want to do, in accordance with their own values and preferences.

“Even the most serious student of prostate cancer and prostate cancer screening can appreciate the enormous endeavor that the Task Force undertook,” said Dr. Marc Garnick, the Gorman Brothers Professor of Medicine at Harvard Medical School and Beth Israel Deaconess Medical Center, and editor in chief of HarvardProstateKnowledge.org. “Patients should consider shared decision making with their health provider when it comes to screening. But as in 2012, the ability to show an overall survival benefit from any screening recommendation still eludes us, and the cancer-specific survival benefit, if one exists at all, is at best very modest.”