抗癌剤長期投与により興味ある経過をとった直腸癌の1例

Remarkable Effects of 5-Fluorouracil on Rectal Cancer

　現在癌の治療法としては，手術治療が中心ではあるが，化学療法の分野にもその進歩に著しいものがあり，薬剤の開発だけでなく，多剤併用，間歇あるいは連続投与，動脈内注入などその投与方法の改善により，副作用を少なくしつつ制癌効果をあげるべく努力がなされている．最近は切除不能例ばかりでなく，根治手術が行われたと判断されたものに対しても，再発予防的な化学療法を行う傾向になっている．5-FUはこれらの薬剤の中でも，結腸，直腸，および乳腺の腺癌に対し，かなり特異的に効果を示すといわれている^1)～4)．

　筆者らは今回，直腸進行癌と診断されてから，8カ月にわたる5-FUを主とした化学療法を施行した後に手術を行い，癌の浸潤が粘膜下層にとどまり，リンパ節転移のない，いわゆる大腸早期癌であり，しかも組織学的に，5-FUの効果と思われる所見を示した1例を経験し，5-FUによるものと思われる粘膜変化について，若干の知見を得たので発表する

　A case of rectal cancer is reported for which 5-Flurouracil has been very effective. A 72-year-old woman had a diagnosis of rectal cancer subsequent to several examinations such as digital examination of the rectum, barium enema study, romanoscopy and inferior mesenteric angiography. General condition of the patient was observed over 8 months, and a total of 24 gm of 5-fluorouracil was given in between. Nine months later, as the patient's condition was regarded good enough to tolerate a surgical intervention, Miles' operation was performed. Pathological study of the excised specimen revealed carcinoma focus, 1.2×1.3 cm in diameter, invasive only in the submucosa with no metastasis in the regional lymph nodes. Histological signs of remarkable effects of 5-Fluorouracil on the cancer was recognized such as edematous swelling of tumor cell nucleus and destruction of carcinoma focus. At the same time, diffuse remarkable atrophy of the mucosa and thickned circumferential fibrosis of the submucosa were revealed in all the regions of the excised colon and rectum. These changes were probably induced by long-term and massive administration of 5-Fluorouracil.

　Some discussions have been done about such colonic fibrosis for which there have been few reports so far.