[Prevention of peritoneal dissemination after colorectal surgery--significance of MMC administration in abdominal cavity].

Peritoneal lavage cytology during surgery was done in 287 patients with colorectal cancer. Positive cytologic specimens were obtained from 21 patients. Of 13 patients who had free cancer cells in peritoneal cavity but no peritoneal dissemination macroscopically, 5 patients received intraperitoneal administration of 20 mg of MMC dissolved in 500 ml of saline. Peritoneal dissemination occurred in 0/5 (0%) of the MMC treated group and in 5/8 (63%) of the untreated group (p less than 0.05). Our results indicate that intraperitoneal administration of MMC (20 mg) is an effective method of preventing peritoneal dissemination after resection of colorectal cancer.