Genitourinary Cancers Following Kidney Transplant: Our 20 Years of Experience With Mechanistic Target of Rapamycin Inhibitors.

Abstract

We investigated patients with genitourinary cancer after kidney transplant and the effects of immunosuppression reduction and switching to mechanistic target of rapamycin inhibitors. We retrospectively evaluated kidney transplant recipients seen at our center between January 2000 and January 2020. Patients with <1 year of follow-up were excluded. Of 827 patients, genitourinary cancer was detected in 11 (1.3%): prostate cancer in 5 patients (45%), renal cell carcinoma in native kidney in 3 (27%), renal cell carcinoma in allograft kidney in 2 (18%), and transitional cell carcinoma of the bladder in 1 (9%). All patients had surgery. Two patients had bone metastasis due to prostate cancer at diagnosis. Two patients had allograft nephrectomy due to de novo renal cell carcinoma. Mean follow-up and age were 97 ± 45 months (range, 26-189) and 50 ± 10.2 years (19% female). After cancer diagnosis, excluding the 2 patients with allograft nephrectomy, immunosuppression was changed in 8 patients (88.8%) (1 patient received the same treatment before and after cancer diagnosis). Six patients received double-drug and 3 received triple-drug protocols. Of 9 patients, 2 were already using mechanistic target of rapamycin inhibitors before cancer diagnosis and 7 were switched: 4 to double-based and 3 to triple-based regimens. Six were switched from tacrolimus. With new treatments, patients showed no progressive kidney failure or rejection (38 ± 40 mo average follow-up). At last follow-up, mean glomerular filtration rate was 62.8 ± 34 mL/min/1.72 m2, which was similar to rate at cancer diagnosis (58.9 ± 24 mL/ min/1.72 m2; P = .78). During follow-up, no patients developed local recurrence of primary tumor or new metastasis, and none showed adverse effects after switch to mechanistic target of rapamycin inhibitors. Three patients died of malignancy-unrelated reasons (ileus, urinary sepsis, heart failure). Mechanistic target of rapamycin inhibitor-based drugs can be an important maintenance immunosuppressive treatment option for kidney transplant recipients with genitourinary cancers.