Prostate cancer test increasingly used, though benefits unproven, study finds

Doctors are ordering tests to screen men for prostate cancer more often, even though there is no clear evidence that the blood tests reduce deaths related to the disease, according to a study by three Boston researchers. Younger men and African-American men had the biggest increases in testing, they found.

Prostate cancer is the most common cancer among men in the United States, with 200,000 new cases expected by the end of 2007. About 12 percent of these men will die of the disease, the authors write in the Archives of Internal Medicine.

There have been no randomized clinical trials showing that the prostate specific antigen, or PSA, test has been effective in reducing that death rate, Dr. Wildon R. Farwell of the Veterans Affairs Boston Healthcare System said in an interview. Yet primary care physicians were 50 percent more likely to order a PSA test during a clinical visit and three times more likely to order one during a preventive exam from 2000 to 2004 than during the previous five years, according to records of men 35 and older from the National Ambulatory Medical Care Survey.

Men who were 35 to 49 years old had 82 percent higher odds of being tested in the later time period. For African-American men, they were 127 percent more likely to be tested.

The best current evidence says that PSA testing might be helpful for men between the ages of 50 and 74, Farwell said, so he and his co-authors from Brigham and Women's Hospital and the Harvard School of Public Health were surprised to find that testing had increased so much in younger men. They were not surprised that more African-American men were being tested because they are at higher risk for prostate cancer. That recognition by physicians, demand by patients or changes in access to healthcare may have caused more of these men to be screened, Farwell said.

Prostate cancer is a spectrum of disease, he said, and the PSA is not a very specific marker of the disease.

"Some men will have prostate cancer that they die from and other men will have prostate cancer that they die with," he said. "The challenge is to determine which type of prostate cancer a man may have. I think the jury is still out on what the utility of the test actually is."

In the meantime, men should talk with their physicians about how effective the screening test is and what to do if they decide to have it.

"It's not a simple blood test. There are consequences of the results of that test," Farwell said. "For most men, they will either not be diagnosed with prostate cancer or the prostate cancer they will be diagnosed with will be a less severe form."