Crohn病に合併した消化管悪性腫瘍

Gastrointestinal Malignancies with Crohn's Disease

要旨　Crohn病に合併する悪性腫瘍として，消化管では食道癌，胃癌，小腸癌，大腸癌が挙げられ，これらのうちで小腸癌，大腸癌は一般人口に比べて多い．小腸癌の合併はまれであるが，相対危険度は非常に高く，早期診断は困難である．大腸癌は欧米では結腸癌が多いが，本邦では痔瘻癌を含む直腸肛門管癌が多く，長期経過例が増加した近年では，癌合併例は徐々に増加し，進行癌で発見されることが多いため予後は不良である．現状では狭窄症状の進行，下血などの臨床症状の変化に留意し，癌合併を念頭に置いて積極的な細胞診，組織診が必要と考えられる．癌サーベイランス法の確立について，現在，厚労省難治性炎症性腸管障害に関する調査研究班では，本症に合併した直腸，肛門管癌に対する本邦独自のsurveillance programの確立の可否を多施設でのpilot studyで検討している．

　Cancer with Crohn's disease has occurred in the esophagus, stomach, small intestine, large intestine and cancer of the small intestine and large intestine are known to occur with high incidence, especially colorectal cancer including cancer with anal fistulae in Japan. Survival ratio after treatment including surgery has been low because the majority of patients had advanced cancer. It is important to take biopsies for the patients with a long history of Crohn's disease who have shown the change of clinical symptoms such as progressive stricture and anal bleeding. A pilot study involving a surveillance program for anorectal cancer with Crohn's disease is going on supported by the IBD research group, the Japanese Ministry of Health, Labor and Welfare.