Six cases of primary colorectal cancer after living-donor liver transplantation: a single-institution experience in Japan.

OBJECTIVE Liver-transplant patients have an increased risk of developing primary malignancies, possibly due to prolonged immunosuppression. However, no information on the incidence and biological characteristics of colorectal cancer after living-donor liver transplantation is available. METHODS The medical records of 392 consecutive adult patients who had undergone living-donor liver transplantation were retrospectively analyzed. RESULTS Colorectal cancer developed in 6 (1.5%) patients; 3 of 204 (1.5%) presented with hepatic cirrhosis, 2 of 77 (2.5%) with primary biliary cirrhosis and 1 (2.6%) of 39 with subacute fulminant hepatitis, but none of 13 patients with primary sclerosing cholangitis. Four patients were successfully treated with curative surgery and one with endoscopic resection, while another patient died 3 months after palliative surgery because of the progression of peritoneal metastasis. A pathological study revealed vessel invasion in all the five cases of surgically removed colorectal cancer and nodal metastasis in four (80%) cases. CONCLUSIONS Colorectal cancer develops at a relatively high frequency after living-donor liver transplantation, even in non-primary sclerosing cholangitis cases, and might have high malignant potential. The screening program for colorectal cancer should be more intensified after living-donor liver transplantation compared with that in the general population.