[The current status of ulcerative colitis-associated colorectal cancer in Korea: a KASID study]

The number of patients with ulcerative colitis has steadily increased since the mid-1980s. As the risk of colon cancer increases with duration and extents, colitic cancers are expected to increase in number in Korea. We surveyed the current status of colitic cancers and provided the perspectives in Korea.

Korean Association for the Study of Intestinal Diseases (KASID) collected and descriptively analyzed a total of eleven cases of colitic cancers occurred between 1993 and 2003.

The mean age at the diagnosis of colitic cancer was 49.3 years, and the mean duration of ulcerative colitis was 12.5 years. Of the diagnosed cases, 91% was associated with pancolitis, 28% had right colon cancers and 18.2% had multiple tumors. Colitic cancers diagnosed at Dukes' stage D were 36.3%. Stages at diagnosis were lower in patients with good compliance. Up to 2003, cumulative incidence ratio of colitic cancer to ulcerative colitis was estimated to be 0.5%, which was much less than the overall prevalence of 3.7% in the Western countries. This incidence was also less than the expected cumulative incidence ratio of 0.9%, which was estimated by adopting the average results of meta-analysis in the Western world.

As the incidence of ulcerative colitis has not reached a plateau, and as the diagnosis of colitic caners are delayed in Korea, the cumulative incidence of colitic cancers might have appeared to be low. Geographic and racial factors, and the effect of preventive measures might have contributed to the lower incidence which remains to be proven. Since colitic cancers are expected to increase steeply in the near future in Korea, the importance of surveillance and prevention cannot be over-emphasized.