Risk of Graft Failure in Kidney Recipients with Cured Post-Transplant Cancer

Background: Post-transplant cancer (PTC) is a critical complication after kidney transplantation. However, whether successfully cured PTC affects the long-term graft outcome remains unclear. Methods: We retrospectively reviewed 1,629 kidney transplant recipients from 1995 to 2017 after excluding patients with post-transplant hematologic or advanced non-curable cancers and who underwent allograft nephrectomy because of cancer. Cured PTCs were defined as cancers treated with curative methods and/or adjuvant therapy without recurrence during >= 2 years. Propensity score matching was performed to match cured PTC patients with cancernaive patients (i.e., non-PTC group). Results: During the median period of 7 years (maximum, 23 years), 70 patients (4.3%) had cured PTCs. The PTC group showed significantly higher risks of death-censored graft failure (adjusted hazard ratio [HR], 2.56 [1.05-6.23]), class II donor-specific antibodies (adjusted HRs, 3.37 [1.30-8.71]), estimated glomerular filtration rate < 30 mL/min/1.73 m(2) (adjusted HR, 2.68 [1.43-5.02]) and random urine protein/creatinine ratio > 1 g (adjusted HR, 3.61 [1.92-6.79]) compared to non-PTC group. However, the risk of mortality was not different between the PTC and non-PTC groups. According to the cancer type, only urogenital cancer had a significant association with graft failure (adjusted HR, 4.26 [1.19-15.22]) and the gastrointestinal cancer showed elevated risk of T cell mediated rejection compared to non-PTC (adjusted HR, 20.44 [6.02-69.39]). Conclusion: Appropriate monitoring of graft function is necessary in patients with cured PTCs.