Prostate cancer screening still unproven: report

NEW YORK (Reuters Health) - PSA blood tests are often used to screen men for prostate cancer, but there is still no good evidence that they cut death rates from the disease, a new review finds.

Based on two recent major clinical trials, the practice of routinely screening men with the PSA test has "at best" a small effect on deaths from prostate cancer, according to the review, published in CA: A Cancer Journal for Clinicians.

The studies, which came out earlier this year in The New England Journal of Medicine, appear to bolster the positions of the American Cancer Society (ACS) and other major medical groups, which do not recommend routine PSA screening for symptom-free men at average risk of developing prostate cancer.

PSA, or prostate-specific antigen, is a protein produced by the prostate gland, blood levels of which generally rise when a prostate tumor is present. PSA blood tests can catch the cancer in its early stages.

But while use of the test has led to more prostate cancer diagnoses, it has done little to nothing to actually cut death rates from the disease, according to the researchers on the new review, led by Dr. Otis W. Brawley of the ACS.

In one of the recent trials, U.S. researchers found that among more than 38,000 men between the ages of 55 and 70, annual PSA screening was no more effective than less-frequent screening at cutting prostate cancer death rates.

The second study, of 182,000 European men, found that PSA screening every few years was associated with only a modest reduction in death risk.

The central problem with prostate cancer screening is that most prostate tumors are slow-growing and would not be deadly even without treatment. So screening can lead to unnecessary treatment of cancers that would never had been life-threatening.

Because prostate cancer treatments, such as surgery and radiation, can have side effects -- incontinence and erectile dysfunction, for instance -- it is possible to do many men more harm than good by treating small tumors.