Inflammatory Bowel Disease-Associated With Colorectal Cancers in Korea: A Single-Center Experience

Abstract

Although a colorectal cancer (CRC) is a well-known complication of inflammatory bowel disease (IBD), the epidemiology and characteristics of CRC associated with IBD in Asians are still unclear. We retrospectively reviewed the medical records of IBD patients who were registered at the Asan Medical Center from July 1989 to August 2012. Patients who were diagnosed with CRC at the time of or after diagnosis of IBD were identified. A total of 3575 patients with definite IBD (1877 with ulcerative colitis [UC] and 1698 with Crohn's disease [CD]), were enrolled and 25 patients diagnosed with IBD-associated colorectal adenocarcinoma (15 with UC and 10 with CD) were identified. There were 14 females (56%) and the median age at diagnosis of CRC was 43.1 years (interquartile range [IQR], 32.0-52.1 years). Two UC patients had combined primary sclerosing cholangitis. The median interval from IBD diagnosis to cancer diagnosis was 11 years (IQR, 5.1-16.8 years). Five patients (20%) were diagnosed with cancer at the time of IBD diagnosis. Three patients (12%) had synchronous lesions. The histologies of CRCs were as follows; moderately differentiated adenocarcinoma in 11 (44%), mucinous adenocarcinoma in 6 (24%), poorly differentiated adenocarcinoma in 4 (16%), well differentiated adenocarcinoma in 3 (12%), and signet ring cell carcinoma in 1 (4%). The stage distribution of cancer was as follows; I in 3 (12%), II in 8 (32%), III in 5 (20%) and IV in 9 (36%). The cumulative risk of CRC in IBD, UC and CD patients were 0.6%, 0.7% and 0.5%, respectively after 10 years and 5.8%, 5.1% and 7.2% respectively after 20 years. The IBD-associated CRC tends to show an advanced stage at diagnosis. The risk of CRC in Korean IBD patients appears to be comparable to that of Western IBD patients.