Am Fam Physician. 2009;80(4):381-382
Summary of Recommendations and Evidence
The U.S. Preventive Services Task Force (USPSTF) concludes that the current evidence is insufficient to assess the balance of benefits and harms of prostate cancer screening in men younger than 75 years. I statement.
The USPSTF recommends against screening for prostate cancer in men 75 years and older. D recommendation.
Rationale
Importance. Prostate cancer is the most common nonskin cancer and the second leading cause of cancer death in men in the United States.
Detection. The USPSTF found convincing evidence that prostate-specific antigen (PSA) screening can detect some cases of prostate cancer.
Benefits of detection and early treatment. In men younger than 75 years, the USPSTF found inadequate evidence to determine whether treatment for prostate cancer detected by screening improves health outcomes, compared with treatment after clinical detection.
In men 75 years and older, the USPSTF found adequate evidence that the incremental benefits from treatment for prostate cancer detected by screening are small to none.
Harms of detection and early treatment. The USPSTF found convincing evidence that treatment for prostate cancer detected by screening causes moderate-to-substantial harms, such as erectile dysfunction, urinary incontinence, bowel dysfunction, and death. These harms are especially important because some men with prostate cancer who are treated would not have developed symptoms related to cancer during their lifetime. There is also adequate evidence that the screening process produces at least small harms, including pain and discomfort associated with prostate biopsy and psychological effects of false-positive test results.
USPSTF assessment. The USPSTF concludes that in men younger than 75 years, the benefits of screening for prostate cancer are uncertain, and the balance of benefits and harms cannot be determined ( Online Table A).
In men 75 years and older, there is moderate certainty that the harms of screening for prostate cancer outweigh the benefits.
Clinical Considerations
Patient population. This recommendation applies to men in the general U.S. population.
Risk assessment. Older men, black men, and men with a family history of prostate cancer are at increased risk of diagnosis and death from prostate cancer.1 The previously described gaps in the evidence regarding potential benefits of screening also apply to these men.
Screening tests. The PSA test is more sensitive than the digital rectal examination for detecting prostate cancer. The conventional PSA screening cutpoint of 4.0 ng per mL (4.0 mcg per L) detects many prostate cancer cases; however, some early cases of prostate cancer will be missed by this cutpoint.2,3 Using a lower cutpoint to define an abnormal PSA level detects more cases of cancer.
The proportion of cancer cases detected by lower cutpoints that would become clinically apparent is unknown; lower cutpoints would label many more men as potentially having cancer. For example, lowering the PSA cutpoint to 2.5 ng per mL (2.5 mcg per L) would more than double the number of U.S. men between 40 and 69 years of age with abnormal results.4
Variations of PSA screening, including the use of age-adjusted PSA cutpoints, free PSA, PSA density, PSA velocity, PSA slope, and PSA doubling time, have been proposed to improve detection of “clinically important” prostate cancer cases. However, no evidence suggests that any of these testing strategies improves health outcomes.2,5
Suggestions for practice. Given the uncertainties and controversy surrounding prostate cancer screening in men younger than 75 years, physicians should not order PSA testing without first discussing with the patient the potential but uncertain benefits and the known harms of prostate cancer screening and treatment. Men should be informed of the gaps in the evidence and should be assisted in considering their personal preferences before deciding whether to be tested.
Treatment. Because of the uncertainty about the benefits of treating prostate cancer detected by screening in men younger than 75 years, there is no consensus regarding optimal treatment. Current management strategies for localized prostate cancer include watchful waiting (observation with palliative treatment for symptoms only), active surveillance (periodic biochemical monitoring with conversion to curative treatment for signs of disease progression), radical prostatectomy, external-beam radiation therapy, and brachytherapy (or radioactive seed implantation therapy).6
If treatment for prostate cancer detected by screening improves health outcomes, the population most likely to benefit from screening will be men 50 to 74 years of age. Even if prostate cancer screening is determined to be effective, the length of time required to experience a mortality benefit is greater than 10 years. Because a 75-year-old man has an average life expectancy of about 10 years, few men 75 years and older would experience a mortality benefit. Similarly, men younger than 75 years who have chronic medical problems and a life expectancy of less than 10 years are also unlikely to benefit from screening and treatment.2
Screening intervals. The yield of screening in terms of cancer cases detected declines rapidly with repeated annual testing. If screening were to reduce deaths, PSA screening as infrequent as every four years could yield as much of a benefit as annual screening.7
Useful resources. Shared decision-making resources specific to prostate cancer screening for physicians and patients are available from the Centers for Disease Control and Prevention (http://www.cdc.gov/cancer/dcpc/publications/prostate.htm).