Risk factors for non-melanoma skin cancer development in renal transplant recipients: a 40-year retrospective study in Croatia

AIM: To determine the prevalence of non-melanoma skin cancer (NMSC) and disease-specific risk factors in renal transplant recipients (RTRs). METHODS: This retrospective cohort study enrolled 1232 RTRs (736 men) treated in University Hospital Center Zagreb over 40 years. The effect of sex, age at transplantation, geographic residence, dialysis vintage, and the type of immunosuppressive therapy on NMSC occurrence was investigated. RESULTS: The prevalence of NMSC was 6.81%. Overall, 60.7% of patients developed basal cell carcinoma (BCC) and 30.9% of patients developed cutaneous squamous cell carcinoma (cSCC). Only 8.3% developed both tumors. The BCC:cSCC ratio was 1.76:1. The risk for NMSC was 50% higher in men. Patients older than 50 years at transplantation were at greater risk for NMSC development. Residence in an area with higher ultraviolet exposure and dialysis vintage before transplantation did not influence NMSC development. Cyclosporine and azathioprine treatment conferred a greater risk for NMSC than tacrolimus or mycophenolate mofetil treatment. CONCLUSION: RTRs are at high risk for NMSC development. Sex, age at transplantation, and type of immunosuppressive therapy play a role in tumor development.