In the latest article in our Clinical Practice review series, “Screening for Prostate Cancer,” current recommendations for prostate-specific antigen testing are reviewed, as well as the initial results of two randomized trials. The potential risks of screening, including morbidity from overdiagnosis and overtreatment, are described.
In the United States, approximately 90% of prostate cancers are detected by means of screening.
• How common is prostate cancer in older men?
Autopsy series suggest that 30% of men older than 50 years of age and 70% of those older than 70 years of age have prostate cancer. The great majority of men with a diagnosis of prostate cancer die from other causes.
• Approximately how many men need to be screened for prostate cancer to prevent one death?
The European Randomized Study of Screening for Prostate Cancer, conducted in nine European centers, randomly assigned 182,160 men who were 50 to 74 years of age to PSA screening every 4 years or usual care (no PSA screening). During a median follow-up of 9 years, prostate cancer was detected in 8.2% of the screened subjects as compared with 4.8% of the control subjects (a 71% increase). The absolute difference in mortality between groups was only 0.7 deaths per 1000 men, suggesting that 1410 men would need to be screened approximately twice over a period of 9 years to prevent 1 death from prostate cancer.
Table 2. Prostate-Cancer Screening Guidelines.
Morning Report Questions
Q: What are the prostate-cancer screening guidelines?
A: The most recent guideline from the U.S. Preventive Services Task Force recommends against screening men 75 years of age or older and considered evidence to be insufficient to recommend for or against screening younger men. The American Cancer Society and the American Urological Association continue to recommend annual prostate-cancer screening with PSA beginning at age 50 and 40, respectively, until life expectancy is less than 10 years.
Q: Does prostatectomy reduce prostate-cancer-specific mortality?
A: The Prostate Cancer Intervention versus Observation Trial randomly assigned 731 men with early-stage prostate cancer to either radical prostatectomy or watchful waiting. Three fourths of tumors were diagnosed primarily on the basis of abnormal PSA values, and about half were palpable. Preliminary results showed no significant differences in overall or disease-specific mortality after 12 years of follow-up, particularly among men with low-risk cancers.