Increased Risk of Second Primary Cancers After a Diagnosis of Melanoma

OBJECTIVE To quantify the risk of subsequent primary cancers among patients with primary cutaneous malignant melanoma. DESIGN Population-based registry study. SETTING We evaluated data from 9 cancer registries of the Surveillance, Epidemiology, and End Results program from 1973-2006. PARTICIPANTS We included 89 515 patients who survived at least 2 months after their initial melanoma diagnosis. RESULTS Of the patients with melanoma, 10 857 (12.1%) developed 1 or more subsequent primary cancers. The overall risk of a subsequent primary cancer increased by 28% (observed to expected [O:E] ratio = 1.28). One quarter of the cancers were subsequent primary melanomas (O:E = 8.61). Women with head and neck melanoma and patients younger than 30 had markedly increased risks (O:E = 13.22 and 13.40, respectively) of developing a subsequent melanoma. Second melanomas were more likely to be thin than were the first of multiple primary melanomas (thickness at diagnosis