Screening for Prostate Cancer: Recommendation and Rationale

Summary of the Recommendation

The U.S. Preventive Services Task Force (USPSTF) concludes that the evidence is insufficient to recommend for or against routine screening for prostate cancer using prostate-specific antigen (PSA) testing or digital rectal examination (DRE). This is a grade I recommendation. (See Appendix Table 1 for a description of the USPSTF classification of recommendations.)

The USPSTF found good evidence that PSA screening can detect early-stage prostate cancer but mixed and inconclusive evidence that early detection improves health outcomes. (See Appendix Table 2 for a description of the USPSTF classification of levels of evidence.) Screening is associated with important harms, including frequent false-positive results and unnecessary anxiety, biopsies, and potential complications of treatment of some cases of cancer that may never have affected a patient's health. The USPSTF concludes that evidence is insufficient to determine whether the benefits outweigh the harms for a screened population.

Clinical Considerations

Prostate-specific antigen testing and DRE can effectively detect prostate cancer in its early pathologic stages. Recent evidence suggests that radical prostatectomy can reduce prostate cancer mortality in men whose cancer is detected clinically. The balance of potential benefits (the reduction of morbidity and mortality from prostate cancer) and harms (false-positive results, unnecessary biopsies, and possible complications) of early treatment of the types of cancer found by screening, however, remains uncertain. Therefore, the benefits of screening for early prostate cancer remain unknown. Ongoing screening trials, and trials of treatment versus “watchful waiting” for cancer detected by screening, may help clarify the benefits of early detection of prostate cancer.

Despite the absence of firm evidence of effectiveness, some clinicians may opt to perform prostate cancer screening for other reasons. Given the uncertainties and controversy surrounding prostate cancer screening, clinicians should not order the PSA test without first discussing with the patient the potential but uncertain benefits and the possible harms of prostate cancer screening. Men should be informed of the gaps in the evidence, and they should be assisted in considering their personal preferences and risk profile before deciding whether to be tested.

If early detection improves health outcomes, the population most likely to benefit from screening will be men 50 to 70 years of age who are at average risk and men older than 45 years of age who are at increased risk (African-American men and those with a first-degree relative with prostate cancer) (1). Benefits may be smaller in Asian-American persons, Hispanic persons, and persons in other racial and ethnic groups that have a lower risk for prostate cancer. Older men and men with other significant medical problems who have a life expectancy of fewer than 10 years are unlikely to benefit from screening (1).

Prostate-specific antigen testing is more sensitive than DRE for the detection of prostate cancer. Prostate-specific antigen screening with the conventional cut-point of 4.0 ng/dL detects a large majority of prostate cancer; however, a significant percentage of early prostate cancer (10% to 20%) will be missed by PSA testing alone (2). Using a lower threshold to define an abnormal PSA level detects more cases of cancer at the cost of more false-positive results and more biopsies.

The yield of screening in terms of cancer detected declines rapidly with repeated annual testing (1). If screening were to reduce mortality, biennial PSA screening could yield as much benefit as annual screening.

The brief review of the evidence that is normally included in USPSTF recommendations is available in the complete recommendation and rationale statement on the USPSTF Web site (http://www.preventiveservices.ahrq.gov).

Recommendations of Others

Most major U.S. medical organizations recommend that clinicians discuss with patients the potential benefits and possible harms of PSA screening, consider patient preferences, and individualize the decision to screen. They generally agree that the most appropriate candidates for screening include men older than 50 years of age and younger men at increased risk for prostate cancer but that screening is unlikely to benefit men who have a life expectancy of fewer than 10 years. These organizations include the American Academy of Family Physicians, the American Cancer Society, the American College of Physicians–American Society of Internal Medicine, the American Medical Association, and the American Urological Association (3-7). None of these organizations endorses universal or mass screening for any group of men. In 1994, the Canadian Task Force on Preventive Health Care recommended against the routine use of PSA or transrectal ultrasonography as part of the periodic health examination (8); while recognizing the limitations of DRE, it concluded that the evidence was insufficient to recommend that physicians discontinue use of DRE in men 50 to 70 years of age. The Canadian Task Force is in the process of updating its recommendations.