USPSTF recommends against prostate-specific antigen screening

The U.S. Preventive Services Task Force (USPSTF) released its final recommendations on prostate-specific antigen (PSA) screening today, recommending against using the test for prostate cancer screening in men of all ages in the general population.

The USPSTF's 2008 statement on this topic recommended against PSA screening in men age 75 years or older and concluded that the evidence was insufficient to weigh benefits and harms in younger men. For the new recommendations, an expert panel reviewed two major trials of PSA testing in asymptomatic men published since 2008 to examine whether the screening saved lives and prevented symptomatic disease. Draft recommendations were posted for comment in October 2011; the final recommendations were published May 22 by Annals of Internal Medicine.

Of the two new trials examined by the panel, the first, conducted in the U.S., demonstrated no reduction in prostate cancer mortality as a result of screening. The second trial was conducted in seven European countries and found that PSA screening reduced prostate cancer deaths by about one death prevented per 1,000 men screened in a subgroup of men aged 55 to 69 years. However, these results relied heavily on trials in two countries; five countries found no statistically significant reduction in deaths, and all-cause mortality was nearly identical in the screened and nonscreened groups. Strong evidence indicates that PSA screening is associated with significant harms, including overdiagnosis and adverse effects of treatment, the Task Force noted.

“The primary goal of PSA-based screening is to find men for whom treatment would reduce morbidity and mortality. Studies demonstrate that the number of men who experience this benefit is, at most, very small, and PSA-based screening as currently implemented in the United States produces more harms than benefits in the screened population,” the Task Force wrote.

A related commentary argued that the USPSTF recommendation underestimates the benefits and overestimates the harms of prostate cancer screening. The authors noted that the USPSTF panel does not include urologists or oncologists and said that the studies on which it based its recommendations are flawed and did not include sufficient follow-up time. The USPSTF recommendations also focus only on mortality and do not address the potential benefits of screening in high-risk patients or younger men, the commentary authors wrote.

In another commentary, however, the medical director of the American Cancer Society argued that overdiagnosis can make it seem as if screening saves lives when it actually does not. Many men are diagnosed with and treated for prostate cancer that may never have progressed within their lifetime.

“We must heed science when making clinical and policy decisions about PSA-based prostate cancer screening,” the commentary author wrote. “The harms are well-proven, whereas the evidence of benefit is weak. Even if one accepts that true benefits exist, the documented harms are likely greater than those small benefits.”

Despite its clear recommendation against PSA screening, the Task Force noted that clinicians should make the final decision.

“The USPSTF recognizes that clinical decisions involve more considerations than evidence alone,” the recommendation statement said. “Clinicians should understand the evidence but individualize decision making to the specific patient or situation.”