Family History of Skin Cancer Is Associated With Increased Risk of Cutaneous Squamous Cell Carcinoma

BACKGROUND The contribution of family history to cutaneous squamous cell carcinoma (SCC) risk has not been systematically quantified. OBJECTIVE To examine the association between self-reported family history of skin cancer and SCC risk. METHODS AND MATERIALS Cases (n = 415) with a pathology-verified SCC and 415 age-, gender-, and race-matched controls were identified within a large integrated health care delivery system. Family history and skin cancer risk factors were ascertained by survey. Odds ratios (ORs) for associations of SCC with family history of skin cancer were estimated using conditional logistic regression adjusted for environmental and innate SCC risk factors. RESULTS Any known family history of skin cancer was associated with a four-fold higher risk of SCC, adjusting for known environmental and innate SCC risk factors (OR, 4.0; confidence interval [CI]: 2.5-6.5). An unknown family history of skin cancer showed similar risk for SCC (OR, 3.9; CI: 2.4-6.5). In models including skin cancer type, the strongest association was for family history of basal cell carcinoma (OR, 9.8; CI: 2.6-36.8) and for multiple skin cancer types (OR, 10.5; CI: 3.7-29.6). CONCLUSION Family history of skin cancer is an important independent risk factor for cutaneous SCCs.