Report on post-transplantation cancer in southeast Asia from the Thai kidney transplantation cohort.

Post-transplantation cancer is a significant cause of mortality among kidney transplant recipients (KTR). The incidence of post-transplantation cancer varies based on geographic region and ethnicity. However, data on KTR from South East Asia, where characteristics differ from other parts of Asia, is lacking. We conducted a retrospective cohort study at a transplant center in Thailand to investigate the incidence of post-transplantation cancer and mortality rates. Factors associated with post-transplantation cancer and patient outcomes were analyzed using competing-risks regression. The study included 1156 KTR with a post-transplant follow-up duration of 5.1 (2.7-9.4) years. The age- and sex-adjusted incidence rate of post-transplant cancer was highest for urothelial cancer (6.9 per 1000 person-years), which also resulted in the highest standardized incidence ratio (SIR) of 42.5 when compared to the general population. Kidney cancer had the second-highest SIR of 24.4. Increasing age was the factor associated with an increased risk of post-transplant cancer (SHR 1.03; 95% CI 1.01-1.05). Human leukocyte antigen (HLA) DR mismatch was associated with a decreased risk of post-transplant cancer (SHR 0.72; 95% CI 0.52-0.98). Post-transplantation cancer was significantly associated with patient mortality (HR 3.16; 95% CI 2.21-4.52). Cancer significantly contributes to KTR mortality, and the risk profile for cancer development in Thai KTRs differs from that of Western and most Asian counterparts. Further research is essential to explore appropriate screening protocols for countries with high rates of urothelial and kidney cancer, including Thailand.