Screening for prostate cancer (updated)

A US federal task force recently concluded that doctors should stop testing elderly men for signs of prostate cancer, and put in question 'whether the screening is worthwhile for younger men'.

Screening for prostate cancer standardly begins with a simple blood test to measure the level of prostate-specific antigen (PSA) in the blood. The procedure is both quick and painless. But, in view of the anxieties the results of a PSA test can produce, and the possible risks and side effects of the biopsy tests and treatments that might follow, the federal task force judged that the risks of harm for men of 75 and over outweighed the possible benefits. As this report from the Washington Post (free registration) says, it is 'perhaps the most important and contentious issue in men's health'. The report also mentions a 'highly critical' response to the task force's conclusions from other specialists.

One such specialist is William J. Catalona. In a piece earlier this week, also from the Washington Post, he argues that screening has paid off:

Rates of death from prostate cancer and rates of diagnosis at advanced stages have decreased markedly since testing became widespread.
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Consider that in the United States alone, the rate of advanced cancer at the time of diagnosis has fallen 75 percent since the PSA screening era began, and age-adjusted prostate cancer death rates have declined 35 percent. Statistical studies suggest that 45 to 70 percent of this decrease is due to PSA screening.
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On a global scale, prostate cancer death rates have decreased in countries where PSA screening and active treatment are typically practiced and have remained stable or increased in countries where screening and active treatment are not practiced.

Catalona also notes that prostate cancer can reach an incurable stage before any symptoms appear; and he refers to a recommendation for screening 'beginning at age 50 in men with a life expectancy of 10 years'.

I'm in no position to comment on the medical evidence either way. But men who discover they have prostate cancer too late to benefit from curative treatments are unlikely to be convinced by the arguments against screening. Most of them will prefer to have had a PSA test in good time and, after getting the result, to have been able to weigh the options before them in the light of the known risks.

Update on August 30, 2008: For another view, see Anthony at Black Triangle.