Screening for prostate cancer: explaining new trial results and their implications to patients.

The best available evidence for making decisions about prostate-specific antigen (PSA) screening comes from two recent randomised trials, the larger and more robust of which showed that PSA screening reduced the risk of death from prostate cancer, but that the absolute benefit was small, and the chance of prostate cancer being diagnosed and treated (even if biologically unimportant) was increased by a much larger amount. The important question is whether the small reduction in numbers of deaths outweighs the harms inherent in the diagnosis and treatment of many additional cancers. Men considering screening should understand both its possible benefit and its possible harms, and that the harms are more immediate than any benefit. The challenge for future research is to find a test that reliably detects prostate cancers that are curable if they are treated early and life-threatening if they are not.