NEW YORK - A combination of common and minor variations in five regions of DNA can help predict a man's risk of getting prostate cancer, researchers are reporting.
And, they say, a company formed by researchers at Wake Forest University School of Medicine expects to offer the test, which will analyze DNA in blood or saliva samples. The test should be available in a few months, said Karen Richardson, a Wake Forest spokeswoman, and should cost less than $300.
This is, some medical specialists say, a first taste of what is expected to be a revolution in medical prognostication. The results, they agree, are clear. But the question is what happens next. And will patients be helped or harmed? Because the new test cannot predict which men will get aggressive cancers, it could lead to more screening and unnecessary surgery and complications. But, proponents say, it could also help men decide whether they want aggressive screening in the first place.
The researchers found that about 90 percent of the men in the study had one or more of the gene variants and more than half had two or more. The cancer risk increased as the number of variants rose and increased substantially when men had four or five of the variants.
Men with four or five variants made up only 2 percent of the study population but had a 4.5-fold increased risk of having prostate cancer compared with men who had none of the variants. If the men also had a family history of prostate cancer, their risk was nearly tenfold higher than that of men with none of those risk factors. Less than 1 percent of the population had all the variants and a family history.
Prostate cancer becomes more common as men age. Autopsies of elderly men find that most had prostate cancer, whether they knew it or not. But the men in this study had an average age of about 65, when the disease is less common and when it has more time to spread and kill.
William B. Isaacs, a professor of urology and oncology at Johns Hopkins University and an author of the new report, said that if research validates what has been found, men may want to get the new genetic test when they are as young as 35. Those at high risk because of their genetics might then choose to start prostate-cancer screening earlier than the usual age of about 50, using a blood test that looks for proteins secreted by prostate tumors.
