Immunosuppressant Drug Specific Risk of Malignancy After Organ Transplantation: A Population-Based Analysis of Texas Medicare Beneficiaries

Background/Objectives: Prolonged use of immunosuppressive drugs (IMDs) is correlated with increased risk of cancer in transplant patients. However, detailed side-by-side analysis of cancer risk associated with individual IMDs in the same population is not available. The aim of this study was to identify drug-specific risks of cancer for commonly used transplant IMDs. Methods: We analyzed the risk of cancer for the IMDs commonly used in transplant patients (tacrolimus (TAC), cyclosporin (CY), sirolimus (SIR), mycophenolate (MMF), and their combinations) in Texas Medicare beneficiaries between 2007 and 2018. Results: Of 7721 transplant recipients receiving an IMD of interest, 2261 developed cancer. There was an increased risk of any cancer diagnosis with the use of TAC (HR: 1.49; 95% CI: 1.25–1.78) and CY (HR: 1.51; 95% CI: 1.19–1.92), and decreased risk with use of MMF (HR: 0.77; 95% CI: 0.67–0.89). Cancer-specific models revealed increased risk of liver cancer (HR: 5.25, 95% CI: 2.03–13.61) and decreased risk of ovarian/uterine cancer (HR: 0.25, 95% CI: 0.07–0.84) with TAC; increased risk of lung cancer with CY (HR: 5.06, 95% CI: 1.47–17.41); and increased risk of lymphoma associated with SIR (HR: 2.80, 95% CI: 1.00–7.81). Conclusions: TAC increases cancer risk, and MMF decreases cancer risk. Individual cancer types also vary in risk associated with individual IMDs. This study provides new information on IMD-specific cancer risk that can guide individualized screening/treatment decisions to reduce the risk associated with specific cancers after transplantation.