Trends of ulcerative colitis-associated colorectal cancer in Korea: A KASID study

The number of patients with ulcerative colitis (UC) in Korea has increased. In addition, the number of patients with colorectal cancer (CRC) associated with UC has also increased. Therefore, this population-based nationwide study was conducted to investigate the incidence of CRC in patients with UC in Korea and compare these results to those of studies conducted in other countries.

The Korean Association for the Study of Intestinal Diseases (KASID) reviewed 7061 cases of UC that occurred between 1970 and 2005 and found a total of 26 cases of CRC.

The overall prevalence of CRC in patients with UC was 0.37%. In addition, the estimated cumulative risk of UC-associated CRCs was 0.7% for patients that had UC for 10 years, 7.9% for patients that had UC for 20 years, and 33.2% for patients that had UC for 30 years. The mean age at the time of diagnosis with CRC was 49.6 years, and the mean duration of UC prior to the development of CRC was 11.5 years. Most UC-associated CRCs were diagnosed after they were already in advanced stages; however, the stage at diagnosis was lower in patients that had good compliance with medical treatment.

The cumulative incidence of UC-associated CRCs in Korea was found to be comparable to that of western countries. The overall occurrence of UC-associated CRC in Korea may be growing, therefore, intensive surveillance colonoscopy and constructive chemoprevention should be encouraged to enable early detection and treatment of UC-associated CRCs in Korea.