Ophira M. GinsburgCharmaine Kim-SingWilliam D. Foulkes • Parviz GhadirianHenry T. LynchPing SunSteven A. Narod • Hereditary Breast Cancer Clinical Study Group

BRCA1 and BRCA2 mutation carriers have elevated risks of breast and ovarian cancers. The risks for cancers at other sites remain unclear. Melanoma has been associated with BRCA2 mutations in some studies, how- ever, few surveys have included non-melanoma skin can- cer. We followed 2729 women with a BRCA1 or BRCA2 mutation for an average of 5.0 years. These women were asked to report new cases of cancer diagnosed in them- selves or in their family. The risks of skin cancer were compared for probands with BRCA1 and BRCA2 muta- tions. Of 1779 women with a BRCA1 mutation, 29 developed skin cancer in the follow-up period (1.6%). Of the 950 women with a BRCA2 mutation, 28 developed skin cancer (3.0%) (OR = 1.83 for BRCA2 versus BRCA1; 95% CI 1.08-3.10; P = 0.02). The odds ratio for basal cell carcinoma was higher (OR = 3.8; 95% CI 1.5-9.4; P = 0.002). BRCA2 mutation carriers are at increased risk for skin cancer, compared with BRCA1 carriers, in par- ticular for basal cell carcinoma.