Screening for prostate cancer: an update of the evidence for the U.S. Preventive Services Task Force.

BACKGROUND: In U.S. men, prostate cancer is the most common noncutaneous cancer and the second leading cause of cancer death. Screening for prostate cancer is controversial.
PURPOSE: To examine for the U.S. Preventive Services Task Force the evidence of benefits and harms of screening and earlier treatment. DATA SOURCES: MEDLINE and the Cochrane Library, experts, and bibliographies of reviews. STUDY SELECTION: Researchers developed eight questions representing a logical chain between screening and reduced mortality, along with eligibility criteria for admissible evidence for each question. Admissible evidence was obtained by searching the data sources. DATA EXTRACTION: Two reviewers abstracted relevant information using standardized abstraction forms and graded article quality according to Task Force criteria. DATA SYNTHESIS: No conclusive direct evidence shows that screening reduces prostate cancer mortality. Some screening tests can detect prostate cancer at an earlier stage than clinical detection. One study provides good evidence that radical prostatectomy reduces disease-specific mortality for men with localized prostate cancer detected clinically. No study has examined the additional benefit of earlier treatment after detection by screening. Men with a life expectancy of fewer than 10 years are unlikely to benefit from screening even under favorable assumptions. Each treatment is associated with several well-documented potential harms.
CONCLUSIONS: Although potential harms of screening for prostate cancer can be established, the presence or magnitude of potential benefits cannot. Therefore, the net benefit of screening cannot be determined.