Incidence and mortality of post‐transplant lymphoproliferative disorders after kidney transplantation: A real‐world retrospective analysis in Japan

Objectives Post‐transplant lymphoproliferative disorder is a potentially life‐threatening complication that has a greater risk of occurrence in the setting of immunosuppression and oncogenic viral infections after transplant surgery. Few studies have reported the cumulative incidence, histological subtypes and clinical outcomes of this disorder in kidney transplant recipients. Methods We retrospectively investigated 34 post‐transplant lymphoproliferative disorder patients diagnosed out of the 1210 kidney transplant recipients who had undergone the surgery at the two largest centers in Japan between January 1983 and December 2017. Results A total of 32 patients (94.1%) developed late‐onset post‐transplant lymphoproliferative disorder (diagnosed 1 year after transplantation). The cumulative incidence rates were 0.76% and 1.59% at 5 and 10 years post‐transplantation, respectively. The central nervous system was the most common site (35.3%, 12/34). Overall survival was similar between patients with and without central nervous system lesions (P = 0.676). Of all of the cases, 23.5% (8/34) were detected through cancer screening. Importantly, patients with screening‐detected post‐transplant lymphoproliferative disorder had better overall survival than those with the disorder who had been symptom detected (P = 0.0215). Overall survival was significantly reduced in patients who developed the disorder compared with those who did not (P = 0.0001). Conclusions Post‐transplant lymphoproliferative disorder was more likely to occur in the late post‐transplantation period, which showed that long‐term medical examination for transplant recipients is required. Based on our findings, we propose vigilant, long‐term, cancer screening in kidney transplant recipients.