PSA Worthless for Prostate Cancer Screening?
'PSA Era Over,' Test's Pioneer Now Says
Sept. 10, 2004 -- PSA screening for prostate cancer is dead, one of the test's earliest advocates now says.
PSA stands for prostate-specific antigen. It's a protein thrown off by a growing prostate gland. Growing prostate cancers give off a lot of PSA. So blood tests for PSA are widely used as an early warning system for prostate cancer.
Men with a PSA level of 4.0 or more are almost always sent to a urologist for a prostate biopsy. And men with a positive biopsy usually opt for surgery or radiation therapy.
Experts disagree on how often, or even if, men should have their PSA regularly checked. Some experts recommend annual PSAs starting at age 50 -- or age 40 for men at high risk of prostate cancer, such as black men or men with a family history of it.
But there's no proof that PSA screening saves lives. Thomas A. Stamey, MD, founding chairman of the Stanford University urology department, led many of the studies that led to the wide acceptance of PSA screening. Now, Stamey says, the PSA era is over.
"You can biopsy according to whether a man has blue eyes or green eyes and get pretty much the same results as biopsying according to PSA," Stamey tells WebMD. "We can't understand this disease except by first knowing we men all get it, and, second, by knowing that we are very unlikely to die from it."
Stamey says that to put PSA screening into context, two things must be understood:
- Nearly all men eventually get prostate cancer. It's found in some 8% of men in their 20s and in 80% of men in their late 70s, Stamey says.
- Relatively few men die of prostate cancer. In the U.S., Stamey says, there are 226 prostate-cancer deaths for every 100,000 men. So a man has only a 0.2% chance of dying from the disease.
20 Years and 1,317 Prostates
Stamey's latest findings -- reported in the October issue of the Journal of Urology -- come from a study of 1,317 prostate glands removed by the same surgeon between 1983 and 2003. All of the patients had PSA tests. All had biopsies that showed signs of cancer.