Scientists at deCODE genetics along with academic colleagues in Iceland, the US and Sweden have reported the discovery of a common genetic variant that predisposes to prostate cancer.
The variant was discovered in Iceland and confirmed in several American and Swedish cohorts.
About 19% of men of European ancestry with prostate cancer carry at least one copy of the variant, which confers an approximately 60% increase in risk of the disease and accounts for approximately 8% of cases.
The variant confers roughly the same increase in risk among African Americans but is twice as common.
The variant thus accounts for approximately 16% of prostate cancer among African American men and thereby contributes to the higher incidence of the disease among African Americans.
The paper is entitled: "A common variant associated with prostate cancer in European and African populations." It is published in an online edition of Nature Genetics, and will appear in the journal’s June print edition.
"This is one of the first genetic variants ever found to confer significant risk of a major cancer among the population in general," said Kari Stefansson, CEO of deCODE and senior author on the study.
"Most previously identified cancer genes have their effect on cancer risk only in families with a clear family history of cancer, or are only found mutated in tumors."
"This discovery is important from a medical standpoint because the only firmly established risk factors for the disease until now have been age, family history and ethnicity."
"As this variant also appears to be associated with the development of more aggressive prostate tumors, a diagnostic test for the variant may enable doctors to make more informed decisions as to how closely they should monitor those who are at high risk, and how aggressively they should treat the disease once it presents."
"We plan to use this discovery as the basis for the development of such a diagnostic test."
The variant is located within a putative gene of unknown function in a region on chromosome 8 known to be one of the most frequently amplified chromosomal regions in prostate tumors.