Malignancy after Pediatric Kidney Transplantation: The 30-Year Experience of a Single Center

Objectives: We aimed to investigate the incidence, manifestations, and outcomes of malignancy after pediatric kidney transplantation (KT) at our center over 30 years. Methods: We retrospectively reviewed the medical records of 155 patients under 18 years of age who underwent KT between January 1990 and February 2020 at Asan Medical Center. Results: Twelve patients (7.7%) were diagnosed with a malignancy after KT. Malignancy was diagnosed after a mean period of 6.4±5.9 years (median 4.6, range 0.5-20.6 years) after KT. Nine (75.0%) of the 12 cancer patients were diagnosed with post-transplant lymphoproliferative disease (PTLD), and the other three had papillary thyroid cancer, mucoepidermoid cancer of the hard palate, and T-cell acute lymphoblastic leukemia, respectively. PTLD was diagnosed within a mean of 3.7±3.4 years (median 3.7, range 0.5-9.8 years) after KT. Five patients diagnosed with PTLD were cured without recurrence. Three patients with PTLD died from the disease, and one patient with mucoepidermoid cancer from a non-PTLD malignancy died after progression, despite surgical resection and chemotherapy. Three (33.3%) of the nine survivors progressed to end-stage renal disease (ESRD) after completing cancer treatment. No patient with post-transplant malignancy (PTM) experienced critical renal deterioration during cancer treatment. Conclusion: PTLD was the most common PTM, occurring at 5.8% of the pediatric KT patients after KT in our center. Careful follow up is needed particularly considering the risk of PTLD after KT in children.