Risk of melanoma and nonmelanoma skin cancer with immunosuppressants, part II: Methotrexate, alkylating agents, biologics, and small molecule inhibitors

In solid organ transplant recipients, skin cancer risk associated with posttransplant immunosuppression has been well-described, and screening practices generally reflect these risks. In addition to agents used posttransplant, other classes of immunosuppressants also have the potential to raise the risk of nonmelanoma skin cancer (NMSC) or melanoma. In the present manuscript, the evidence for melanoma and NMSC risk associated with methotrexate, cyclophosphamide, biologic cytokine inhibitors including TNF (tumor necrosis factor)-alpha and interleukin inhibitors, costimulation blockers such as abatacept, integrin inhibitors such as natalizumab, targeted B-cell, and T-cell inhibitors including CD20 (cluster of differentiate 20), CD52, and BTK (Bruton's tyrosine kinase) inhibitors, and JAK (Janus kinase) inhibitors is reviewed. Based on the available data, we recommend regular skin cancer screening for select nontransplant patients receiving immunosuppressive regimens that are shown to raise the risk of NMSC or melanoma. We also offer suggestions for conscientious use of these therapies in high-risk patients. Finally, a comprehensive summary of the relative risk associated with each immunosuppressant class and associated recommendations is presented.