報告例からみた潰瘍性大腸炎以外のcolitic cancerの実態―chronic radiation colitis

Review of Case Reports of Radiation-Induced Colitic Cancer

要旨　腹部放射治療後の放射線誘発大腸癌として本邦にて症例報告された58症例63病変を対象とした．放射線治療が施行された原疾患としては，婦人科腫瘍が95％を占めた．大腸癌罹患時の年齢の中央値は67歳（38～80歳）であった．放射線治療から大腸癌発生までの期間の中央値は17年（2～35年）であった．出血症状と便通異常を主訴とする症例がそれぞれ52％を占め，また発生部位は直腸前壁が54％と多かった．病理組織学的には粘液癌が24％を占め，また72％の症例において病理組織学的にchronic radiation colitisの合併を認めた．大腸癌罹患後の生存期間の中央値は3年（1か月～25年）であった．

　The subjects of our study were sixty-three lesions in 58 patients reported to have radiation-induced colitic cancer after abdominal radiation therapy in Japan. As the primary diseases treated with radiation therapy, gynecological malignancies accounted for 95%. The median age of patients of colitic cancer was 67 years (38 to 80 years). The median value of the period from radiation therapy to onset of colitic cancer was 17 years (2 to 35 years). The patients complaining mainly of bleeding symptoms and abnormal bowel habits accounted for 52%, and the colitic cancer occurred on the anterior wall of the rectum in 54% of patients. Histopathologically, mucinous carcinoma accounted for 24%, and complication from radiation colitis was histopathologically observed in 72% of patients. The median survival time after suffering colitic cancer was 3 years (1 month to 25 years).