Several newly identified genetic variants on chromosome 8 are associated with increased risk of developing prostate cancer, according to three studies to be published online this week in Nature Genetics.
Last year scientists in Iceland reported that a variant on chromosome 8 is associated with elevated risk of prostate cancer.
Three groups have now revisited this region on chromosome 8, and have found additional variants that independently contribute to prostate cancer susceptibility. One group, led by Kari Stefansson, reports that a second variant is associated with the disease in several populations. This variant is relatively uncommon in individuals of European descent, but quite common in African Americans, suggesting that it accounts for some of the higher risk for prostate cancer observed in individuals of African descent.
The second group, led by David Reich, identified this same variant, as well as five previously undescribed risk variants in populations representing five different ethnic backgrounds. Finally, the third group, led by Stephen Chanock, found one of the variants reported by the Broad study to be associated with elevated risk in five different populations.
According to Reich and colleagues, combinations of these risk variants could account for up to two-thirds of prostate cancer cases in African Americans, and up to one-third of cases in European Americans. The variants do not map to a particular gene, but each group speculates that collectively they could promote amplification of this entire region of chromosome 8, an event that is commonly observed in prostate tumors.