Gene may pinpoint most aggressive prostate cancer

WASHINGTON (Reuters) - Researchers have found a genetic mutation that helps predict which men will have aggressive prostate cancer and said it might help doctors choose who needs treatment and who does not.

Men with the genetic change had a 26 percent higher risk of having aggressive prostate cancer, the researchers reported in the Proceedings of the National Academy of Sciences.

“A single variant with a moderate effect such as this is unlikely to be sufficient on its own at predicting risk,” said Jianfeng Xu of Wake Forest University School of Medicine in North Carolina, who led the study.

“But its identification is significant because it indicates that variants predisposing men to aggressive disease exist in the genome.”

Prostate cancer is the second-leading cancer killer of U.S. men, after lung cancer, with more than 192,000 cases diagnosed in 2009 and 27,000 deaths, according to the American Cancer Society.

Most cases are very slow-growing and would never kill the patient or even cause symptoms, but it is very difficult to predict whose tumors are likely to spread.

A report in the Journal of the American Medical Association in September said that 85 percent of cases will never spread, and another study published in August found that 1 million U.S. men had been diagnosed with and treated for prostate tumors that would never have harmed them.

“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,” Xu said.

The international team of researchers studied 4,849 men with aggressive prostate cancer that had spread and 12,205 men with slow-growing disease, looking at 27,000 different genetic mutations called single nucleotide polymorphisms or SNPs.

They found one that was 26 percent more common in the men with aggressive disease. It was found in 32 percent of 4,829 men with aggressive disease and 28 percent of 12,205 men who had slow-growing cancers.

This could be more useful than some of the other SNPs that have been linked with prostate cancer, they said, but will not, on its own, be good for predicting who needs surgery or radiation to treat early stage prostate cancer.

Editing by Vicki Allen