Introduction. Numerous studies indicate an increased incidence of skin malignancies among organ transplant recipients. Melanoma pose a significant threat to post-transplant recipients, leading to considerable mortality. This study explores the incidence of melanoma after 17,252 organ transplantations in Poland over the past 13 years.

Materials and methods. The data on the occurrence of melanoma in patients after renal, heart, or liver transplantation were obtained from the National Health Fund, encompassing individuals who underwent kidney, heart, or liver transplantation between 2010 and 2022. The analysis focused on skin melanoma (C43).

Results. The study examined skin melanoma in renal (12,250 cases), liver (3,584 cases), and heart (1,418 cases) transplant recipients over thirteen years. Melanoma incidence slightly increased in renal recipients (1-year cumulative incidence 0.016% vs 0.007%, p = 0.024; 5-year cumulative incidence 0.131% vs. 0.040% p < 0.001; the 10-year cumulative incidence 0.213% vs. 0,09, p < 0.001). In liver transplant recipients there is non-significant difference 1-year after transplantation (cumulative incidence 0.03% vs. 0.01%, p = 0.337) but after 5 and 10 year the difference between the two groups remaining statistically significant (5-year cumulative incidence 0.14% vs. 0.04%, p < 0.014; the 10-year cumulative incidence 0.14% vs. 0.09%, p < 0.001). In heart transplant recipients, a paradoxical reduction in incidence was observed compared to the general population (1-year cumulative incidence 0% vs. 0.01%, p = 0.317; 5-year cumulative incidence 0.07% vs. 0.04%, p = 0.049; the 10-year cumulative incidence 0.07% vs. 0.09, p < 0.001).

Conclusions. The incidence of melanoma increases in kidney transplant recipients over the first 10 years post-transplant, with a peak between 4 to 7 years. For heart and liver transplant recipients, melanoma cases occur within the initial 5 years post-transplant, and no new cases were recorded afterward. The long-term surviving kidney, heart, and liver transplant recipients show a steady rise in new cases over time. Our study, based on a thorough analysis of data from the National Health Fund, confirms the link between an elevated risk of melanoma in organ transplant recipients.