Incidence and risk factors for skin cancer in liver transplant recipients: A systematic review.

Skin cancer is a frequent complication of liver transplantation; however, contemporary incidence rates and associated risk factors remain poorly defined. We conducted a systematic review to summarize the literature on the incidence and risk factors of skin cancer after liver transplant. In July 2024, we searched MEDLINE, CINAHL, EMBASE, ClinicalTrials.gov, ProQuest Dissertations and Theses, and conference proceedings for studies on skin cancer following adult liver transplantations. Primary outcomes included incidence rates, number of de novo tumors, standardized incidence ratios, and significant risk factors for basal cell carcinoma, squamous cell carcinoma, melanoma, and skin cancer. Of the 522 unique studies generated by the search, 90 studies with 323,317 total liver transplant recipients were included. The mean incidence of skin cancer across studies was 1220.3 (SD=1400.0) cases per 100,000 person-years. Incidence rates and standardized incidence ratios varied substantially across studies but were consistently higher in liver transplant recipients than in the general population for non-melanoma skin cancers, most notably squamous cell carcinomas, but not for melanoma. The prominent risk factors included male sex, advanced age, fair complexion, alcohol consumption, sun exposure, and the use of cyclosporine rather than tacrolimus in immunosuppressive regimens. This study was limited by the heterogeneity of the study population, methods, and definitions of skin cancer. Overall, liver transplant recipients face heightened long-term risks of non-melanoma skin cancers, and while key risk factors are well established, there remains a gap in skin cancer surveillance and patient education within this population.