Malignancies in a renal transplant population: The St. Michael's Hospital experience

INTRODUCTION: Previous publications have shown an increased incidence of various malignancies amongst renal transplant populations. The objective of this study was to analyze the rate and types of malignancies occurring in the St. Michael's Hospital renal transplant population and to determine whether our results were comparable to those previously published. METHODS: After approval by the hospital's research ethic board, review of the records and pathology of the 1584 patients in the renal transplant clinic database patients was performed. The reports dated back to the year 1970. RESULTS: Amongst the 1584 renal transplant patients, 106 patients with 132 dysplastic and malignant posttransplant lesions were identified. The highest incidence amid the malignancies was in nonmelanoma skin malignancies squamous cell carcinoma (SCC), basal cell carcinoma, and Kaposi sarcoma, with a total of 32 patients having 54 separate tumors (2.02% of all patients, 43.2% of tumors). Following skin tumors in incidence were genitourinary (28 tumors), gastrointestinal tract (GIT) lesions (8 adenocarcinomas, 14 dysplastic lesions, 1 low grade neuroendocrine tumor/carcinoid), posttransplant lymphoproliferative disorders (PTLDs) (10 cases), gynecologic (6 carcinomas), cervical/anal/vulvar dysplasia and invasive (SCCs) (4), and thyroid (3 papillary tumors). Nine patients had tumors of multiple sites/types. With respect to outcome, 14 patients died of malignancy, with the highest mortality being in the GIT malignancies (six patients). Second in mortality were the PTLD and skin tumor groups. DISCUSSION: Information on the incidence and outcome of various malignancies in renal transplant patients is important in designing guidelines for the follow-up of these patients regarding tumor screening and prevention. The rate of malignancies in our group is comparable to that reported in other centers.