Review of Standardized Incidence Ratios (SIR) of non-lymphoid de novo malignancies after liver transplantation: Structured analysis of global differences

Introduction: De Novo malignancy after liver transplantation (LTx) is the second most common cause of death in adult LTx recipients. The current report identifies differences in Standardized Incidence Ratios (SIR) for various non-lymphoid de novo malignancies by comparing and analyzing post LTx SIR for non-lymphoid de novo malignancies. Material and methods: A thorough search of PubMed and Web of Science databases was conducted; 25 publications describing de novo malignancies post-LTx with SIR were identified. Results: Overall SIR varied from 1.4 to 11.6 (median 2.4). Oropharyngeal/larynx (OPL), lung, colo-rectal, and kidney malignancies were more prevalent with higher SIR (median = 4.4, 1.9, 2.67, 2.5, respectively). Breast and prostate malignancies were also more prevalent with lower SIR (median = 0.9, 1.0, respectively). Pancreatic, central nervous system (CNS), melanoma, rare cancers and Kaposi's sarcoma were less prevalent (except in Italy and Sweden) but had much higher SIR (median = 2.6, 2.4, 2.02, 22.5 and 53.6, respectively). The overall higher SIR values are related to the age of the recipient, length of follow-up, the grouping of different organ systems, inclusion or exclusion of epidermal non-malacotic skin cancers, lymphoid malignancy, and occurrence of rare malignancies including Kaposi's sarcoma. Conclusion: OPL, lung, gastrointestinal, kidney, and bladder malignancies were more prevalent with higher SIR. Breast and prostate cancers were more prevalent with lower SIR. Pancreatic, CNS, melanoma, rare cancers and Kaposi's sarcoma were less prevalent with higher SIR. Age of the recipients, length of follow-up, and rare cancer types influence overall SIR values with some global differences.