Comparative Review of Standardized Incidence Ratio of Nonlymphoid, De Novo Malignancies After Liver Transplant Versus After Kidney Transplant

Objectives: De novo malignancies are the most common cause of death after solid-organ transplant. Here, we aimed to summarize standard incidence ratios of de novo malignancies after liver and kidney transplant within the same geographical locations, compare these ratios among different types of de novo malignancies after liver and kidney transplant, and elucidate differences in de novo malignancies between liver and kidney transplant recipients. Materials and Methods: We performed a systematic review to identify studies on standard incidence ratios of de novo malignancies after liver and kidney transplant in the United Kingdom, Sweden, South Korea, and Taiwan. Results: Four articles reported standard incidence ratios of de novo malignancies in 14 016 liver transplant recipients (mean follow-up 4.3 ± 0.7 y) and 48 179 kidney transplant recipients (mean follow-up 6.1 ± 2.1 y). Mean ratios of oropharyngeal, pulmonary, colorectal, renal, and breast malignancies were 5.3, 1.6, 1.9, 1.8, and 1.1, respectively, after liver transplant and 3.2, 1.7, 1.5, 17.0, and 1.3, respectively, after kidney transplant. Mean ratios of bladder, cervix-uterus, and stomach de novo malignancies were 1.8, 2.0, and 2.9, respectively, after liver transplant and 13.0, 1.9, and 1.9, respectively, after kidney transplant. Mean ratios of prostatic and esophageal malignancies were 1.6 and 1.8 after liver transplant and 1.2 and 1.1 after kidney transplant. Mean ratio of ovarian cancer was 1.2 and 2.9, respectively, after liver and kidney transplant. Conclusions: Low-frequency and lower standard incidence ratios were observed for testicular, ovarian and central nervous system malignancies after kidney and liver transplant. Standard incidence ratios of oropharyngeal and hepatic malignancies were higher after liver transplant compared with kidney transplant. After kidney transplant, standardized ration for renal malignancy were 9.4 times and bladder malignancies were 7.2 times higher compared with liver transplant recipients.