Preoperative use of 5-fluorouracil suppository for carcinoma of the rectum.

A total of 50 patients with carcinoma of the rectum were treated with 5-fluorouracil suppository before operation. The suppository, which was made of Witepsol suppository base containing 5-fluorouracil, yielded high drug concentrations in carcinoma, draining blood and regional lymph nodes. As a clinical response to the suppository, a significant decrease in the size of tumor mass was noted in 8 of 50 carcinomas, but in other cases the gross change was unmeasurable. Thirty-three percent of the surgically resected carcinomas were histologically judged to have responded to the suppository. In such cases, histologic changes correlated well with the total dose of 5-fluorouracil. The adverse effects of the suppository were confined to anal pain, tenesmus and anal bleeding, probably due to the topical effect of 5-fluorouracil on the rectal mucosa.