MONDAY, April 9, 2012 (HealthDay News) -- The discovery of two inherited genetic variations may help doctors identify men at greater risk for aggressive prostate cancer, a new study suggests.
A man's risk for the disease could triple or even quadruple depending on the genetic variant they have, according to the researchers from Weill Cornell Medical College in New York City and elsewhere.
"We used to think that only genes that made proteins were responsible for disease, but this study shows us that there is inherited information in the non-coding areas of the genome that appear to play a strong role in development of cancer," study co-author Dr. Mark Rubin, professor of oncology in pathology, said in a Weill Cornell news release.
Having a family history of prostate cancer is the strongest risk factor for the disease. As a result, the researchers set out to find DNA that is deleted or duplicated in the genetic information of men with prostate cancer compared to those who do not have the disease.
In order to do that they analyzed 1,900 blood samples from men involved in the Tyrol Early Prostate Cancer Detection Program in Austria, a program that has been screening men ranging in age from 45 to 75 since 1993. Of the men participating in the study, 867 had cancer and 1,036 did not.
The study, published online April 9 in the Proceedings of the National Academy of Sciences, showed these so-called copy number variations (CNVs) play a significant role in the development of prostate cancer. The researchers discovered two CNVs that were significantly different between men with aggressive prostate cancer and those without cancer. They were also able to duplicate that finding in a group of 800 patients in the United States.
"The study shows that copy number variations matter in cancer," added the study's co-lead investigator, Dr. Francesca Demichelis, who is now an assistant professor at the Center of Integrative Biology at the University of Trento in Italy and an adjunct assistant professor in the Institute for Computational Biomedicine at Weill Cornell Medical College, in the news release.
In testing the effect of the two inherited variants in a lab, the investigators showed that the variants helped cancer cells grow and invade, putting some men at four times greater risk for prostate cancer.
In the general population, up to 3 percent of men inherit these variants. This percentage is much higher among men with aggressive prostate cancer, the authors pointed out.
The researchers noted, however, these variants are not the only cause of aggressive prostate cancer, and likely contribute to other risk factors that can lead to development of prostate cancer. They noted that they are looking for other variants, which could help them develop a comprehensive DNA test to identify men at risk for aggressive prostate cancer.
"In this new area of research, we are starting to appreciate that the differences in inherited genomic variants account not only for why we look different or respond in various ways to medication, but also for why we develop disease," said Rubin. "This is the first study to suggest these variants may account for susceptibility to cancer. This new line of research will also allow us to study the biology around prostate cancer initiation."
The U.S. National Cancer Institute has more about prostate cancer.