Cancer Test Gets Bad Reviews

US Preventive Services Task Force recommends against a commonly used prostate cancer screening.

May 22, 2012
Sabrina Richards

ISTOCKPHOTO.COM

Prostate cancer screening based on the prostate-specific antigen (PSA) blood test was given a D grade by the independent group that assesses clinical practice and advices the US government, reported Nature.

The US Preventive Services Task Force (USPSTF) now recommends that most men do not get screened via the PSA test, which measures the amount of PSA, an enzyme produced by the prostate gland, in the blood. Risk of prostate cancer increases with increasing PSA levels, but benign prostate enlargement or prostate infection can also prompt an increase in PSA serum levels. As a result, the USPSTF found, PSA screening leads to false positive diagnoses and avoidable complications from biopsies and cancer treatment that may never have been warranted. According to the USPSTF’s calculations, for every 1,000 men screened, 1 life will be saved, between 30 and 40 men will experience erectile dysfunction or incontinence from unnecessary medical treatments, 2 will suffer serious cardiac events, and 1 man will have a blood clot. For every 3,000 men screened, 1 will die from surgical interventions. Given that most tumors detected by the blood test are slow-growing, these risks do not outweigh the benefits, the USPSTF concluded.

Many urologists disagreed with this assessment, however. In a commentary accompanying the USPSTF’s recommendation, published this week (May 21) in the Annals of Internal Medicine, urological specialists argued that screening should be recommended because prostate cancer is the second leading cause of cancer deaths among men. The authors argue especially that the USPSTF did not give enough consideration to high risk populations.

“It is inappropriate and irresponsible to issue a blanket statement against PSA testing, particularly for at-risk populations, such as African American men,” the American Urological Association said in a statement. “Men who are in good health and have more than a 10–15 year life expectancy should have the choice to be tested and not discouraged from doing so.” The USPSTF, in turn, argued for more research that could help refine the test, such that it produces fewer false positives and distinguishes more lethal fast-growing tumors from slow-growing tumors with little impact on health.