Colorectal cancer after renal transplantation

Background. The risk of developing malignancy is increased after transplantation, which is believed to be related to the use of immunosuppressive agents. Although the risk of hematological malignancies and skin cancer are clearly increased in this setting, the association with colorectal cancer is controversial. Method. Retrospective analysis of patients with renal transplantation who developed colorectal cancer (1985-2001). Results. Over 17 years (1985-2002), 31 (5.5%) patients out of 556 renal transplant recipients developed cancer; 23 skin cancer and 8 non skin cancer. Three patients (0.5%) developed colorectal cancer. All were men of mean age 65 years. The mean elapsed time from transplantation to symptoms was 11 years. They were all treated with azathioprine, antilymphocyte globulin, prednisone, and additional immunosuppressive agents, such as mycophenolate mofetil, or cyclosporine. The patients with colorectal cancer underwent resection with primary anastomosis. They all experienced uneventful postoperative courses; no anastomotic leak occurred. Two patients were found to have liver metastases at the time of operation. Conclusion. Our cases and a literature review suggest that there is no increase risk of colorectal cancer among transplant recipients compares to the general population. Whether colorectal cancer has a more aggressive course in transplant patients needs further evaluation.