炎症性腸疾患と大腸癌―第55回大腸癌研究会アンケート結果

Colorectal Cancer in Patients with Inflammatory Bowel Disease in Japan

要旨　第55回大腸癌研究会主題「炎症性腸疾患と大腸癌のすべて」に関連して会員に行った炎症性腸疾患（潰瘍性大腸炎，Crohn病）に合併した大腸癌のアンケート結果を報告する．潰瘍性大腸炎では観察された4,796例中123例（2.6％）に大腸癌を認めた．経過年数別発症率は10年まで2％未満，10年を経過すると5％前後に漸増し，21年以降10％以上であった．早期癌が52例（42.3％）を占め，根治度A症例では5生率87.2％であった．Crohn病では観察された2,500例中12例（0.5％）に大腸癌を認めた．経過年数別発症率は経過年数に必ずしも比例しなかった．直腸肛門領域に好発し局所進行した症例が多く転帰不良であった．

　A questionnaire related to the 55th meeting of the Japanese Society for Cancer of the Colon and Rectum was sent to members of the Society. It concerned colorectal cancer complicated with inflammatory bowel disease. One hundred and twenty-three patients with colorectal cancer were diagnosed during follow-up of 4,796 patients with ulcerative colitis. The incidence rate of colorectal cancer was less than 2% in the just 10 years of follow-up, about 5% after 10 years, and more than 10% after 21 years of follow-up. Early cancer made up 42% of all patients, and a 5 year survival was enjoyed by 87% of patients with curability A.

　On the other hand, twelve patients with colorectal cancer were diagnosed during follow-up of 2,500 patients with Crohn's disease. The incidence of colorectal cancer didn't increase relative to the follow-up time. Most of the cancers affected the rectum and anus, and advanced locally, so the oncological outcome was poor.