Azathioprine and risk of non-melanoma skin cancers in organ transplant recipients: a systematic review and update meta-analysis

Background: Immunosuppression might increase the risk of skin cancer in organ transplant recipients (OTRs), with azathioprine (AZA), exerting a fundamental role in the carcinogenesis of those tumors. This systematic review and meta-analysis aims to address the risk of developing malignant skin neoplasms in OTRs undergoing immunosuppression with AZA.

Methods: PubMed, Cochrane and Embase were searched for studies with OTRs who have a treatment regimen involving Azathioprine therapy after transplantation and that analyzed the emergence of skin neoplasia. We performed the meta-analysis using RStudio v4.4.2 software.

Results: A total of 17 studies comprising a total of 12,708 patients were included, of whom 3567 (28,06%) had a treatment regimen involving AZA therapy after transplantation. The majority of individuals were male 7298 (56,52%) and the median age of patients ranged from 41.5 to 63.2 years. The overall summary estimate showed a significantly increased risk of all types of skin cancer in relation to AZA exposure (OR 1.55; 95% CI 1.07-2.25; p = 0.018; I² = 82%). These results show that the overall result is statistically significant, which means that the observed effect is unlikely to be caused by chance.

Conclusion: This study highlights the increased risk of developing skin cancer, particularly squamous cell carcinoma (SCC), in OTRs receiving immunosuppressive therapy with AZA, which allows for rigorous screening and appropriate preventive and therapeutic interventions.