Genes involved in skin pigmentation have an effect on a person’s skin cancer risk beyond their influence on a person’s hair or skin color, a new study shows.
Women who carried one so-called “red hair color” gene but had medium or olive skin, as opposed to fair skin, actually had the highest skin cancer risk among a group of Caucasian women, Dr. Jiali Han of Harvard Medical School in Boston and colleagues found.
Han and colleagues studied variants of the melanocortin 1 receptor (MC1R) gene, which influences how the pigment melanin is processed in the skin and helps determine skin color. The MC1R gene is highly variable among light-skinned populations.
The researchers looked at three variations of the gene strongly linked to red hair, fair skin, and resistance to tanning, which are known as red hair color (RHC) variants, as well as four variants less strongly linked to red hair, termed non-red hair color (NRHC) variants, in a subgroup of women participating in the Nurse’s Health Study.
Their analysis included 219 melanoma patients, 286 women with squamous cell carcinoma (SCC), 300 with basal cell carcinoma (BCC), and 873 skin-cancer-free controls.
After the researchers controlled for the effects of skin color and other skin cancer risk factors, they found that the RHC variants still increased risk, especially a variant dubbed 151Cys.
Women with the 151Cys variant had a 65 percent increased risk of melanoma, the most deadly type of skin cancer, while their risk of SCC and BCC were 67 percent and 56 percent greater, respectively.
Melanoma risk was greatest, the researchers found, among women with one RHC gene, one NRHC gene, and medium to olive skin.
Women with red hair who carried the 151Cys variant were at an increased risk of melanoma, but the gene variant did not confer greater risk for women without red hair.
The findings support past proposals that identifying a person’s MC1R variant could help predict melanoma risk, but need to be confirmed in a larger study, the researchers conclude.