The incidence of tumours in renal transplant recipients with long-term immunosuppressive therapy

Introduction: The incidence of cancers after renal transplantation is significantly higher than in population that have not undergone transplantation. It is increased by a long-term survival of functional graft requiring long-term immunosuppressive therapy. Material and methods: Since 1972, 620 renal transplantations have been performed for different causes of end stage renal disease. The authors report a group of 18 renal transplant patients (2.9%) who had cancer. Patients with malignancies are reviewed according to their age, sex, type of immunosuppression, interval between transplantation and the diagnosis of cancer, method of treatment and survival. Results: All patients received cadaver kidneys, and secondary transplantation was performed in two patients. Five patients received conventional immunosuppression - azathioprine with prednisone, another 13 patients received cyclosporine with prednisone and/or azathioprine. In 13 males and 5 females (mean age 46.1 years) the malignant disease developed about 62.4 months after renal transplantation. Six patients had epithelial skin cancers (four of them had squamous cell carcinomas and two basal cell carcinomas). Two patients had breast cancer, colorectal carcinoma, renal cell carcinoma and bladder cancer, respectively, one patient had gastric cancer, thyroid carcinoma, carcinoma of tonsilla, and monocytic leukaemia with blastic transformation, respectively. The average survival of patients with malignancies was 20.3 months. Of 17 patients with cancer, 13 underwent surgical treatment, four patients with advanced disease received radiotherapy, hormonal treatment or only symptomatic therapy. In one patient the malignant disease was only discovered at autopsy. Five patients died of progressive malignant disease, four of intercurrent disease. Nine (50%) patients are alive, with no evidence of disease (NED), 31.9 months in average following the diagnosis of malignancy. Three patients returned to dialysis treatment, other 6 patients live with well functioning graft. Conclusions: In patients surviving long time after kidney transplantation the possibility of development of malignant disease should be considered. Preventive evaluation should guarantee early detection of cancer. Appropriate treatment, without cessation of immunosuppressive therapy, is indicated with the intention to prolong the patients' life with a functional graft and without dialysis treatment.