To Test or Not to Test
Prostate Tests Draw New Questions
Associated Press
January 10, 2006; Page D4
Two widely used tests for prostate cancer failed to save lives in a new study, adding to the debate over whether men should be screened for the disease.
The study was small -- only 1,002 men -- and won't be the final word on the issue. But it may hint at what lies ahead when the results of two large studies of prostate-cancer screening appear in a few years.
The researchers looked at two screening tests that are performed millions of times a year in the U.S.: a blood test that measures prostate specific antigen, or PSA, and a digital rectal exam, the rubber-glove test in which a doctor feels for abnormalities in the prostate through the rectal wall.
Study co-author John Concato, a clinical epidemiologist at the VA Connecticut Healthcare System, said that for now, doctors should tell men that screening tests for prostate cancer aren't perfect, and men should decide for themselves whether to get screened.
In the study, published in yesterday's Archives of Internal Medicine, researchers compared two groups of men treated at 10 Veterans Affairs medical centers.
Doctors have long known that some cases of prostate cancer can be so slow-growing that they never cause symptoms, much less death. In addition, surgery and radiation treatment for prostate cancer can cause incontinence and impotence. So for some men, detecting prostate cancer early through screening can do more harm than good.
In addition, the PSA tests can yield ambiguous results. Most men who undergo a biopsy because they have elevated PSA levels don't have prostate cancer. And some men with low PSA levels do have cancer.
Medical organizations differ on their screening recommendations. But generally, most say men should be told the risks and benefits of screening first.
"We should tell patients about the uncertainty," said Howard Parnes of the National Cancer Institute. "All too often we behave as if we know screening is a good thing."
The findings support an earlier review by the U.S. Preventive Services Task Force. That agency said in 2002 that it found "insufficient evidence" for a recommendation that men be screened.
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