Catching aggressive prostate cancer

(Ivanhoe Newswire) -- Researchers are on the way to solving a critical question in the treatment of prostate cancer -- that is, how to tell at an early stage whether the cancer is aggressive or slow-growing.

Researchers at Wake Forest University Baptist Medical Center and colleagues have identified a genetic variant associated with aggressive prostate cancer, paving the way for genetic information to one day play a pivotal role in guiding treatment decisions.

"This finding addresses one of the most important clinical questions of prostate cancer -- the ability at an early stage to distinguish between aggressive and slow-growing disease," Jianfeng Xu, M.D., Dr. P.H., professor of epidemiology and cancer biology, was quoted as saying. "Although the genetic marker currently has limited clinical utility, we believe it has the potential to one day be used in combination with other clinical variables and genetic markers to predict which men have aggressive prostate cancer at a stage when the disease is still curable."

Prostate cancer accounts for one-fourth of all cancer diagnoses in the United States. Autopsy studies suggest that most aging men will develop prostate lesions which, if detected, would be diagnosed as cancer.
Although most men have a slow-growing form of the disease, aggressive prostate cancers are currently the second-leading cause of cancer death in the U.S., accounting for 27,000 deaths annually.

"The current inability to accurately distinguish risk for life-threatening, aggressive prostate cancer from the overwhelming majority of slow-growing cases creates a treatment dilemma," Dr. Xu said.

"Identifying factors that are associated with a risk of having or developing aggressive disease is urgently needed to reduce over-diagnosis and over-treatment of this common cancer," co-author Karim Kader, M.D., Ph.D., a Wake Forest Baptist urologist specializing in prostate cancer, was quoted as saying.
The study involved analysis of genetic information from 4,849 men with aggressive disease and 12,205 with slow-growing disease. The researchers identified a genetic variant (rs4054823) that was associated with a 25 percent higher risk of developing aggressive disease.

"A single variant with a moderate effect such as this is unlikely to be sufficient on its own at predicting risk," Dr. Xu said. "But its identification is significant because it indicates that variants predisposing men to aggressive disease exist in the genome."

"We speculate that a panel of variants could be an important part of developing a screening strategy that could reduce the number of men requiring screening, thereby reducing over-diagnosis, while also identifying men at risk for developing aggressive disease at a stage when the disease is potentially curable."
SOURCE: Proceedings of the National Academy of Sciences, January 11-15, 2010

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