5 Gene Variants May Help Show Prostate Cancer Risk, Study Says; Company to Offer Test This Spring

Jan 17, 02:42 PM

Men with a combination of five specific gene variants and a family history of prostate cancer are nine times as likely to develop the disease, a new study shows.

Although the findings suggest that a simple blood test and questionnaire could help doctors determine prostate cancer risk, experts caution that the results give no indication of how aggressive the cancer could be.

"It's not going to change the way we manage cancer right now, but in the future, it may present a new way to assess a person's risk for development of the disease," said David Jarrard, an associate professor of urology at the University of Wisconsin Carbone Comprehensive Cancer Center in Madison.

"This could potentially drive decisions, but I think we'll need to give more thought to the real clinical meaning," said William See, chairman of urology at the Medical College of Wisconsin and chief of urology at Froedtert Hospital in Wauwatosa and the Zablocki Veterans Affairs Medical Center. See was not involved in the study.

Historically, single genetic markers haven't been effective at predicting prostate cancer risk. Therefore, the new study looked at multiple markers to see whether combining them would provide a stronger link.

Using DNA from the blood samples of more than 4,600 Swedish men, researchers identified five genetic locations -- three on chromosome 8 and two on chromosome 17 -- with genetic variations that were more common in men with prostate cancer compared with men without the disease.

Men who had four of the variants were nearly 4.5 times as likely to have prostate cancer, according to the study published today in the New England Journal of Medicine.

The combination of five variants and family history accounted for 46% of prostate cancer cases in the study.

However, researchers say the risk determined by the presence of genetic variants didn't correlate prostate-specific antigen, or PSA, blood-testing results.

"This suggests that a subset of men deemed to have a low risk of prostate cancer based on their PSA levels may in fact be at significantly elevated risk due to inheriting one of more of the genetic variants," S. Lilly Zheng, an associate professor of internal medicine at Wake Forest University Baptist Medical Center and an author of the study, said in a statement.

The findings are based on results from a homogenous population and may not be translatable to men in the United States, Jarrard said.

Still, the study is exciting because "if you can identify individuals of risk, you could continuously develop ways to prevent the development of the disease," he said.

The researchers in the study say they plan to conduct a similar study in the U.S. to see if the same genetic variants persist.

Currently, there is no test for the genetic variants, though Wake Forest researchers founded a company called Proactive Genomics that will begin offering the Focus5 Prostate Cancer Risk Test this spring, said Jianfeng Xu, a professor of epidemiology and cancer biology at Wake Forest and author of the study.

Xu said they have not estimated the cost of the test but don't expect it to be more than $500. It likely won't be covered by insurance, he said.

Copyright 2008, Journal Sentinel Inc. All rights reserved. (Note: This notice does not apply to those news items already copyrighted and received through wire services or other media.)

(c) 2008 Milwaukee Journal Sentinel. Provided by ProQuest Information and Learning. All rights Reserved. 5 Gene Variants May Help Show Prostate Cancer Risk, Study Says; Company to Offer Test This Spring
Back to Current Headlines