The result is over-treatment for many men, researchers say
MONDAY, Aug. 31 (HealthDay News) -- Mass screening for prostate cancer with a test for prostate-specific antigen (PSA) has led to mass over-diagnosis and over-treatment, a new study contends.
Since the PSA screening test came into use in 1986, federal government data show that the number of prostate cancer cases in the United States has risen substantially, said the report in the Aug. 31 online issue of the Journal of the National Cancer Institute.
Treatments for prostate cancer include surgery and radiation therapy, and possible side effects are incontinence and impotency.
"The ideal screening test would have no effect on the number of cases," said study co-author Dr. H. Gilbert Welch, a professor of medicine at the Dartmouth Medical School's Institute for Health Policy and Clinical Practice. "It would change the time in life that the cancers were diagnosed, but not the number. Instead, there has been a sustained change in the number of cases -- 1.3 million more that would not have been diagnosed previously."
The death rate from prostate cancer has fallen in the United States, but not necessarily because of mass screening, Welch contended. "There are a number of reasons why mortality might fall, but the most obvious is that we have better treatment," he said. "Even without early detection, I expect mortality would fall."
Results of a European study reported earlier this year indicated that "to save the life of one man, 50 must be over-diagnosed," he said.
Guidelines for screening for blood levels of PSA -- a protein produced by the prostate gland -- differ widely. The American Cancer Society says that a PSA test should be offered at age 50, accompanied by an explanation of the potential benefits and hazards. The American Urological Association recommends a first PSA test at age 40, with follow-ups depending not only on
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