Researchers say prostate cancer preventive overlooked
Researchers are urging doctors to discuss with patients the benefits of Merck Co.'s Proscar for preventing prostate cancer, after a study found that prescribing of the product didn't increase when a 2003 trial showed the medicine wards off tumors.
The drug, also sold generically as finasteride, was shown to reduce some men's risk of developing prostate cancer by a quarter, to 18 percent from 24 percent, in a trial described in the New England Journal of Medicine in July 2003. Over the next two years, there was no increase in finasteride prescriptions aimed at preventing that disease, according to a report in the journal Cancer Epidemiology, Biomarkers Prevention.
Doctors' failure to prescribe more of the medicine may have resulted in more cases of prostate cancer, said Ian M. Thompson, lead author of the 2003 study and chairman of the department of urology at the University of Texas Health Science Center, in San Antonio. If men over the age of 55 with certain risk factors were given finasteride, diagnoses of prostate cancer in the U.S. would shrink by 40,000 to 60,000 a year, he said.
"There are no other proven ways of reducing your risk of prostate cancer - this is the only one," said Thompson. If people at risk took the medicine, "tens of thousands wouldn't be diagnosed" or get sick, he said. Risk factors include being black, having a family history, being over the age of 65, or showing elevated levels of prostate-specific antigen, or PSA, according to the study.
The National Cancer Institute estimates that 217,730 men in the United States will be diagnosed with prostate cancer this year and that almost 32,050 will die of it.
The new study, by doctors at the Veterans Health Association in Durham, N.C.; Duke University School of Medicine in Durham; and the University of Toronto offers several explanations why physicians seven years ago didn't act on the data on finasteride.
While the results, which were based on a study called the Prostate Cancer Prevention Trial, showed reduced risk for the disease overall, there was also evidence that finasteride might raise the some men's likelihood of developing aggressive tumors.
Subsequent research showed these worries were overstated, according to new study. Three articles published since 2003 "suggest finasteride does not increase the risk of high-grade disease," the authors wrote. "The rate of true high-grade disease may have been lower" among men taking finasteride.