Yearly Prostate Cancer Tests May Save Lives

Oct. 19, 2005 (Denver) -- The American Cancer Society and the American Urological Association have both backed annual PSA ( prostate-specific antigen) screening -- a blood test -- and digital rectal exams starting at age 50 for men with average risk.

For men with a higher risk (African-Americans and those with a family history of prostate cancer) the American Cancer Society recommends starting at age 40.

Screening for prostate cancer is one of the most controversial issues in men's health today. The U.S. Preventive Services Task Force says there is not enough evidence to recommend for or against such routine screening. And many doctors have spoken out -- loudly -- against routine screening.

Now, a new study, presented Wednesday at the annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO), suggests that men who have yearly screening are three times less likely to die from prostate cancer than men who don't have the annual tests.

"This simple yearly blood test would appear to discover prostate cancers when they are more curable and may lower the risk of dying from prostate cancer," says researcher Jason Efstathiou, MD, PhD, of the Harvard Radiation Oncology Program.

The study suggests that over a 10-year period, 11.3% of men who don't have annual PSA screens will die from the disease, compared with only 3.6% of those who do have yearly tests, he tells WebMD.

The test measures blood levels of PSA, a protein produced by the prostate gland. Rising PSA levels can occur with age or noncancerous conditions as well as from cancer.

PSA Debate Continues

But don't look for the findings to end the debate over annual prostate screens anytime soon. For that, "we really need the results of three massive trials going on in the U.S. and Europe," Efstathiou says. Those findings are due out in 2008.

The reason: Those large trials are following men -- half of whom get annual screens and half of whom don't -- to see how many develop prostate cancer and die from the disease over time. In contrast, Efstathiou studied a group of men who had already had surgery for prostate cancer. Then, he looked back to see how many had had annual screens before their operation. Such studies are open to a slew of problems, as doctors don't really know that much about the men and their other risk factors for the disease.

"What our findings do give us are clues into what I expect the large trials will show," Efstathiou says. "If those studies confirm the results of this trial, annual PSA testing will become standard.

Theodore Lawrence, MD, chairman of the board of ASTRO and chairman of radiation oncology at the University of Michigan School of Medicine in Ann Arbor, agrees.

"There's no question that PSA can detect early-stage prostate cancer, but the question is whether it will improve survival and lower deaths from prostate cancer," he tells WebMD.

There are other problems with the strategy as well, he notes. While cancer causes PSA levels to increase, PSA levels can also rise with benign conditions such as prostate enlargement or benign prostatic hyperplasia (BPH). And even when the PSA increase is due to cancer, the cancer could be so slow-growing as to never be life-threatening.