De novo malignancy in organ transplant recipients in Taiwan: a nationwide cohort population study

Organ transplant recipients appear to have a higher risk of de novo malignancy. The aim of the study was designed to estimate cancer risk in heart, lung, kidney and liver transplant recipients. The cohort study used the Taiwan National Health Insurance Research Database (1996-2011) and followed the outcomes of organ recipients until 2012. De novo cancer and mortality rates after organ transplantation were evaluated using standardized incidence ratios, excess absolute risks of cancer, and standardized mortality ratios in recipients were compared with those in the general population. We identified 40, 231, 2, and 115 patients who developed cancer after heart, kidney, lung, and liver transplantation, which corresponded to a cancer incidence of 878.4, 1101.2, 728.9, and 1361.4 cases per 100,000 person-years, respectively. In heart, kidney, lung, and liver recipients, the overall standardized incidence ratios were 1.65 (1.21-2.24), 3.33 (2.93-3.79), 1.82 (0.45-7.27) and 3.37 (2.81-4.05) and the overall standardized mortality ratios were 5.45 (4.96-5.98), 1.47 (1.34-1.61), 8.92 (7.10-11.20), and 3.83 (3.48-4.20), respectively. These results reveal a three-fold increase in de novo cancer risk in organ transplant patients compared with the general population. This study illustrated the importance of de novo malignancy after organ transplantation.