NEW YORK (Reuters Health) - A variation of the gene for the vitamin D receptor appears to increase the risk of melanoma, a serious and sometimes fatal skin cancer, Italian researchers report.
The authors believe that the altered form of the receptor is less able to bind to vitamin D, a vitamin that can be produced in sun-exposed skin. Prior research has suggested that this binding helps protect against melanoma.
Variants in the vitamin D receptor gene have been hypothesized to affect the risk of melanoma, but findings from prior studies have been conflicting. The current investigation represents the first combined analysis performed using published data, according to the report in the journal Cancer.
Data from six studies, which included a total of 2,152 patients with melanoma and 2,410 subjects without the cancer, were included in the analysis. Together, the studies examined the impact of five vitamin D receptor gene variations, or "variants," designated TaqI, FokI, BsmI, EcoRV, and Cdx2, on the risk of melanoma.
Patients with the BsmI variant had a 30-percent increased risk of melanoma, report Dr. Simone Mocellin and Dr. Donato Nitti, from the University of Padua. This would account for close to 10 percent of melanoma cases.
The FokI variant did not affect the risk of melanoma and the impact of the other three variants was less clear.
The authors conclude that although the effects of the BsmI variant are not fully known, "these findings indirectly support the hypothesis that sun exposure may have an anti-melanoma effect through activation of the vitamin D system."
SOURCE: Cancer, online September 22, 2008.
