術後残存腸管は癌のリスクファクターか―異時性多発病変を中心として

Surveillance of Colorectal Remnant after Surgery for Carcinoma

要旨　過去11年間（1981～1991年）に癌研究会附属病院で切除した大腸癌術後患者の残存腸管のサーベイランス結果に基づいて，腫瘍性病変の発見率とリスクファクターを検討した．489例（36.0％）が内視鏡によるサーベイランスを受け，110例（22.5％）に腺腫，32例（6.5％）に癌が発見された．癌を発見した32例中10例は局所再発ないし播種性病変と判断され，7例は同時性多発癌と判断され，15例が異時性多発癌と考えられた．手術時腺腫合併例での腺腫，癌の発見率はそれぞれ37.5％，8.2％で，非合併例では，それぞれ15.4％，2.7％だった．大腸癌の家族歴や，他臓器癌の既往も異時性多発病変のハイリスクと考えられた．また，腺腫を合併しない症例のサーベイランスで，早期に進行癌で発見される症例があり，rapid growing typeの大腸癌の存在が示唆された．

　It is well known that patients having colorectal neoplasms are at high risk of developing the second neoplasms. Of 1,358 patients who underwent surgical operation in a period of 11 years from 1981 to 1991 at the Cancer Institute Hospital, 489 cases (36.0%) were submitted to surveillance colonoscopy. Among them, adenoma was found in 22.5% (110/489) and carcinoma was found in 6.6% (32/489). In 32 carcinomas 10 were regarded as local recurrence or dissemination, 7 were considered to be synchronous carcinoma, and 15 were judged to be metachronous carcinoma. The presence of a rapid growing type carcinoma was also suggested.

　The detection rate of new adenoma and carcinoma was 37.5% and 8.2% respectively in the cases in which adenoma was present in the initial surgery. It was 15.4% and 2.7% respectively in those without adenoma in the initial surgery. The patients having a history of colorectal carcinoma in the first degree relatives and/or extracolonic carcinoma were considered to be much higher risk of developing second neoplasms in the colorectal remnant.

　In conclusion, surveillance colonoscopy with an interval of 2 years is necessary in patients with a history of surgery for colorectal carcinoma especially in those with a history extracolonic carcinoma, and/or with a family history of colorectal carcinoma in the first degree relatives.