Reuters
Thursday, July 24, 2003; Page A03

The widely used PSA blood test for prostate cancer misses 82 percent of tumors in men younger than 60 as it is currently used, according to a study released yesterday. The prostate-specific antigen test missed 65 percent of cancers in older males, the study, published in the New England Journal of Medicine, found.

Rinaa Punglia of Harvard Medical School and her team said the accuracy of the test has been overrated because doctors do not routinely double-check what seems to be a healthy reading on the test. Currently, a PSA level of 4 or under is considered healthy.

The American Cancer Society says a level above 4 but less than 10 means a 25 percent chance of having prostate cancer. At 10 or above, the cancer risk is more than 67 percent. Punglia's team recommended lowering the "healthy" reading to 2.6 -- even though many more men who do not have cancer will have to undergo painful biopsies to verify whether they actually have cancer.

The PSA test, approved in 1986, measures levels of prostate-specific antigen, a protein produced by prostate cells and over-produced by prostate tumors. The test has been credited with detecting prostate cancer in its early stages 80 percent of the time.

The Punglia team evaluated 6,691 volunteers at the Washington University School of Medicine in St. Louis

In an editorial in the journal, Fritz Schroder and Ries Kranse of the Erasmus Medical Center in Rotterdam cautioned there is no conclusive evidence that the PSA screening test reduces the risk of death from prostate cancer without reducing a man's quality of life.

Prostate cancer is usually a slow-growing cancer and often does not require any treatment. However, prostate cancer kills about 29,000 Americans each year and is the second most common cancer killer of U.S. men, after lung cancer.