Public Health - October 2008
Tex Med . 2008;104(10):45-46.
By Crystal Conde
The U.S. Preventive Services Task Force recommends not screening men 75 and older for prostate cancer and adds that younger men should discuss the benefits and harms of the prostate-specific antigen (PSA) test with clinicians before being tested. The recommendation and accompanying evidence summary appear in the Aug. 5 issue of the Annals of Internal Medicine .
The task force found evidence that screening for prostate cancer provided few health benefits but led to substantial physical harm and some psychological harm in men 75 and older. In men younger than 75, the task force concluded that current evidence is insufficient to assess the balance of benefits and harms of prostate cancer screening. An estimated 218,890 U.S. men were diagnosed with prostate cancer in 2007, and one in six men will be diagnosed in his lifetime.
Screening for prostate cancer is usually performed using PSA tests and digital rectal exams. The PSA test is more likely to detect prostate cancer than the digital rectal exam.
However, prostate cancers found with a PSA test take years to affect health; most prostate cancers that grow serious enough to cause death take more than 10 years to do so. Because a 75-year-old man has an average life expectancy of about 10 years and is more likely to die from other causes such as heart disease or stroke, prostate cancer screening is unlikely to help men older than 75 live longer.
For the same reasons, men younger than 75 with chronic medical problems and a life expectancy of fewer than 10 years are also unlikely to benefit from screening. Harmful effects of the screening include biopsies, unnecessary treatment, and false-positive results that may lead to anxiety.
In addition, complications often result from treating prostate cancer and may include urinary incontinence and impotence. These slow-growing cancers may never have affected a patient's health or well-being if screening had not detected them.
"Because many prostate cancers grow slowly, early detection may not benefit a patient's health and in some cases may even cause harm," said Task Force Chair Ned Calonge, MD, MPH, also chief medical officer for the Colorado Department of Public Health and Environment. "We encourage men younger than 75 to discuss with their clinicians the potential - but uncertain - benefits and the possible harms of getting the PSA test before they decide to be screened."
Current data show that one-third of all men in the United States older than 75 receive PSA testing. Although most major medical organizations suggest that prostate cancer screening may be discontinued in men with a life expectancy of fewer than 10 years, the task force is the first group to define an age cutoff above which screening is likely to be ineffective or harmful.
The results of two ongoing clinical trials - the National Cancer Institute's Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial and the European Study of Screening for Prostate Cancer - should help clarify the potential benefits of screening in men younger than 75.
The task force, supported by the Agency for Healthcare Research and Quality (AHRQ), assesses scientific evidence for the effectiveness of a broad range of clinical preventive services, including screening, counseling, and preventive medications.
The recommendations and materials for clinicians are available on the AHRQ Web site at www.ahrq.gov/clinic/uspstf/uspsprca.htm . For men diagnosed with prostate cancer, AHRQ has two new guides that compare the effectiveness and risks of prostate cancer treatments. More information about the guides is available at www.effectivehealthcare.ahrq.gov .
Crystal Conde can be reached at (800) 880-1300, ext. 1385, or (512) 370-1385; by fax at (512) 370-1629; or by email at Crystal Conde .