Incidence of cancer after kidney transplant: Results from the North Italy transplant program

Background. Patients undergoing kidney transplantation demonstrate a higher risk of developing cancer as the result of immunosuppressive treatment and concurrent infections. Methods. The incidence of cancer in a cohort of patients who underwent kidney transplantation between 1990 and 2000, and who survived the acute phase (10 days), was analyzed as part of the North Italy Transplant program. Results. A total of 3,521 patients underwent transplantation during a 10-year period in 10 of 13 participating centers; the length of follow-up after kidney transplant was 67.7±36.0 months. During the follow-up, 172 patients developed cancer (39 with Kaposi sarcoma, 38 with lymphoproliferative diseases, and 95 with carcinomas [17 kidney, 11 non-basal cell carcinoma of the skin, 10 colorectal, 8 breast, 7 gastric, 7 lung, 6 bladder, and 3 mesotheliomal). The average time to cancer development after transplant was 40.1±33.4 months (range 0-134 months). Twenty-four patients developed cancer within 6 months from the transplant (10 with carcinomas, 7 with Kaposi sarcoma, and 7 with lymphoproliferative diseases). Three patients demonstrated a second primary cancer. The average cancer incidence was 4.9%. The incidence of cancer was 0.01 per year. Independent determinants of cancer development were age, gender, and immunosuppressive protocol including induction. Ten-year mortality was significantly higher in patients with cancer (33.1%) than among patients without cancer (5.3%). The relative risk of death in subjects with cancer was 5.5 (confidence interval 4.1-7.4). Conclusions. These preliminary data underline the importance of long-term surveillance of transplant recipients, choice of immunosuppressive treatment, and careful donor selection.