Melanoma incidence, stage, and survival after solid organ transplant: A population-based cohort study in Ontario, Canada

Background: Risk of melanoma is increased with potentially worse outcomes after solid organ transplant. Objective: To estimate the incidence, stage, and survival in transplant recipients with melanoma. Methods: Population-based, retrospective, observational study using linked administrative databases. Adults receiving their first solid organ transplant from 1991 through 2012 were followed to December 2013. Results: We identified 51 transplant recipients with melanoma, 11 369 recipients without melanoma, and 255 matched patients with melanoma from the nontransplant population. Transplant recipients were at increased risk of melanoma (standardized incidence ratio, 2.29; 95% confidence interval [CI], 2.07-2.49) and more likely to be diagnosed at stages II through IV (adjusted odds ratio, 4.29; 95% CI, 2.04-9.00) compared with the nontransplant population. Melanoma-specific mortality was increased in transplant recipients compared with the nontransplant population (adjusted hazard ratio, 1.93; 95% CI, 1.03-3.63). Among transplant recipients, all-cause mortality was increased after melanoma compared with those without melanoma (stage T1/T2: adjusted hazard ratio, 2.18; 95% CI, 1.13-4.21; T3/T4: adjusted hazard ratio, 4.07; 95% CI, 2.36-7.04; III/IV: adjusted hazard ratio, 7.92; 95% CI, 3.76-16.70). Limitations: The databases did not contain data on immunosuppressive drugs; ascertainment of melanoma metastasis relied on pathology reports. Conclusion: Melanoma after solid organ transplant is more often diagnosed at a later stage and leads to increased mortality, even for early-stage tumors.