"We are finding the places in the genome that are associated with the risk for prostate cancer," Chanock said. "The reason this is so important is that prostate cancer is a complex disease and is not due to one genetic defect or one environmental exposure," he said.
Similar findings are being reported with breast cancer, colon cancer and lung cancer, Chanock said. "The same thing is happening in other diseases, such as diabetes, heart disease and stroke," he said. "Most diseases are complex and associated with multiple genes."
Exactly how each of these genes contributes to the risk for prostate cancer isn't clear, Chanock said. "Some of them may be responsive to environmental triggers, such as what you eat or what you inhale," he said. "Somewhere down the line, these findings may be clinically relevant, but it's too early to do that, because we are still discovering more."
In the third report, Julius Gudmundsson's team from deCODE Genetics Corp. in Iceland, found genes associated risk of prostate cancer on chromosomes 2 and X.
Although most of the gene variants are associated with a moderate risk, they are common in the population. Some of these variants are linked to more than less aggressive disease, Gudmundsson's team noted.
A substantial number of men have many risk variants that together confer clinically significant risk. In fact, 10 percent of men are at twice the risk and 1 percent of men are at three times the risk of developing the disease in the general population, Gudmundsson's group said.
One expert thinks these papers add to the general knowledge about prostate cancer's genetic underpinnings. However, how this will be translated into clinical practice is still unknown.
"These papers are adding a little bit to our knowledge of prostate cancer in the genome," said Dr. Durado Brooks, director of prostate and colorectal cancers at the American Cancer Society.
Brooks thinks the Gudmundsson paper is important, because it shows a link between genes and aggressive prostate cancer. "This is the sort of information that has the potential to be most useful in a clinical setting," he said.
