# Melanoma Risk in 12,205 Kidney Transplant Recipients Receiving Calcineurin Inhibitor-Based Immunosuppression: A Nationwide Analysis of Polish National Health Fund Data (2010–2022)

## TL;DR

This study analyzed melanoma risk in kidney transplant recipients in Poland and found it to be rare, with no significant difference between two immunosuppressive drugs.

## Contribution

The study provides a nationwide analysis of melanoma risk in kidney transplant recipients using Polish health data from 2010–2022.

## Key findings

- Melanoma occurred in 0.23% of 12,205 kidney transplant recipients over 13 years.
- All melanoma cases occurred in patients on tacrolimus, but differences were not statistically significant.
- The study highlights the need for regular dermatologic monitoring in all transplant recipients.

## Abstract

Kidney transplant recipients have an increased risk of skin cancer due to long-term immunosuppressive therapy, but data on melanoma risk associated with specific immunosuppressive drugs remain limited. In this nationwide study, we analyzed the occurrence of cutaneous melanoma among kidney transplant recipients in Poland between 2010 and 2022 using national administrative databases. Melanoma was a rare event, affecting fewer than 1 in 400 transplant recipients over more than 10 years of follow-up. All observed melanoma cases occurred in patients treated with tacrolimus-based immunosuppression, while no cases were observed among patients receiving cyclosporine; however, the differences between treatment groups were not statistically significant due to the small number of events. These findings suggest that melanoma risk after kidney transplantation is low but underscore the importance of regular dermatologic surveillance in all transplant recipients, regardless of the specific calcineurin inhibitor used.

Background: Numerous studies have demonstrated the impact of post-transplant immunosuppressive therapy on cancer development, particularly in the skin. Despite the growing number of observations, there is still a lack of comprehensive analyses assessing the influence of specific immunosuppressive regimens on the development of melanoma in kidney transplant recipients. The aim of this study was to describe the incidence and temporal patterns of cutaneous melanoma (CM) among kidney transplant recipients in Poland between 2010 and 2022, with particular focus on recipients treated with calcineurin inhibitor (CNI)-based immunosuppression, including cyclosporine (CsA) and tacrolimus (TAC). Methods: This nationwide, descriptive analysis was conducted using comprehensive national administrative data obtained from the Polish National Health Fund (PNHF) and the Polish National Cancer Registry (PNCR). The study assessed the incidence of cutaneous melanoma and temporal trends over the study period. Results: Melanoma skin cancer occurred in 27 cases observed in a population of 12,205 kidney transplant recipients over 13 years of follow-up, corresponding to a final cumulative incidence of 0.23% (95% CI: 0.15–0.34). Calcineurin inhibitor (CNI)-based regimens in kidney transplant recipients were associated with significantly lower risk profiles over 10 years, with only nine cases observed in a cohort of 7107 patients, culminating in a cumulative incidence of 0.13% (95% CI: 0.06–0.24). The stratified analysis of CM incidence under CNI-based immunosuppressive regimens by calcineurin inhibitor type revealed a modest cumulative risk in the TAC subgroup, reaching 0.14% (95% CI: 0.06–0.26) by year 10, with all nine observed cases occurring exclusively in this group, while the CsA subgroup reported zero events throughout the follow-up period. Risk differences progressively increased to 0.14% (95% CI: −0.20 to 0.26) by year 10, but they were not statistically significant in any year (p ≥ 0.230). Conclusions: Although all melanoma cases occurred in the TAC subgroup, the data do not allow us to conclude that TAC confers a higher risk than CsA. This lack of significance likely reflects both the rarity of events and the limited statistical power to detect small differences between TAC and CsA. These results highlight the need for careful dermatologic monitoring in all kidney transplant recipients, while the choice of calcineurin inhibitor should be individualized based on patient-specific factors.