Background: Nonmelanoma skin cancer occurs frequently in organ transplant recipients, but the relative importance of different immunosuppressive therapy regimens is unclear.
Objective: We studied the risk of skin cancer in the complete, single-center Norwegian cohort of kidney and heart transplant recipients (n = 2561).
Methods: We determined cancer risk estimation by means of standardized incidence ratios and multivariate Cox regression.
Results: Transplant recipients had an increased risk of cutaneous squamous cell carcinoma (SCC) (65-fold), malignant melanoma (3-fold), and Kaposi's sarcoma (84-fold), and of lip SCC (20-fold), compared with the general population. After adjustment for age, kidney transplant recipients receiving cyclosporine, azathioprine, and prednisolone had a significantly (2.8 times) higher risk of cutaneous SCC relative to those receiving azathioprine and prednisolone. After adjustment for age and type of immunosuppressive regimen, heart transplant recipients had a significantly (2.9 times) higher risk than kidney transplant recipients.
Conclusion: The risk of cutaneous SCC, malignant melanoma, Kaposi's sarcoma, and lip SCC is increased in kidney and heart transplant recipients. The risk of posttransplant cutaneous SCC is related to the degree of immunosuppression caused by long-term immunosuppressive therapy.