By Marc B. Garnick, M.D., Editor in Chief, Annual Report on Prostate Diseases
For decades, men have been encouraged to undergo routine prostate cancer screening with a prostate-specific antigen (PSA) blood test. The thinking was that early detection of a prostate tumor would save lives. But two large studies released in 2009 did not definitively support that theory. (These findings—and the issue of PSA screening in general—are discussed in detail in the 2011 Annual Report on Prostate Diseases.) Now another trial, the longest-running one to date, offers more evidence that PSA screening does little to cut a man’s chances of dying of the disease.
The latest study, launched in 1987, followed 9,026 Swedish men for 20 years. From that population, 1,494 men were randomly chosen to be screened with digital rectal exams and, beginning in 1993, PSA testing; the rest of the men made up the control group.
Not surprisingly, more men were diagnosed with prostate cancer in the group that was screened for the disease than in the control group—5.7% vs. 3.9%. However, the researchers found no statistically significant difference between the two groups in terms of survival, even though the tumors found as a result of screening were generally smaller and had not spread. The results of the study were published online in the journal BMJ on March 31.
Such findings are undoubtedly confusing to men, who have been told for years that cancer screening is a “good thing.” While it’s true that PSA testing can help detect hidden prostate tumors, many such tumors are unlikely to cause problems during a man’s lifetime. Once diagnosed, however, many men feel compelled to treat the disease, risking erectile dysfunction, urinary incontinence, and bowel symptoms.
I don’t think this study, or the ones that preceded it, tell men to rule out PSA testing. Rather, as this new study reminds us, men should talk with their doctor to assess their personal risk of prostate cancer as well as the hazards and potential benefits of screening before having a PSA test.
Posted April 7, 2011