USE OF INTRAPERITONEAL 5-FLUOROURACIL AND CHLORHEXIDINE FOR PREVENTION OF RECURRENCE OF PERFORATED COLORECTAL-CARCINOMA IN A RAT MODEL

PURPOSE: Colorectal cancer is a prevalent and mortal disease, resultin g in nearly 55,000 deaths in the United States annually. Preoperative or intraoperative spillage of tumor cells because of perforation occur s in up to 10 percent of cases. When this spillage occurs, the chance of recurrence and death is dramatically increased. METHODS: In an effo rt to reduce the chance of recurrence and death, we used a rat model t o evaluate the efficacies of intraperitoneal 5-fluorouracil and chlorh exidine in reducing the incidence of recurrence. Rats were injected wi th 10 mg/kg azoxymethane subcutaneously weekly for 12 weeks to induce colorectal cancers. At 20 weeks, subtotal colectomies were performed o n rats with colorectal tumors and without peritoneal implants or liver metastases, At the time of surgery, a cut portion of the tumor was pl aced in the abdomen for 30 minutes; the rats then randomly received pe ritoneal irrigation with 5-fluorouracil, chlorhexidine, or sterile wat er (control). Eight weeks postoperatively a necropsy was performed. At that time, obvious and suspected recurrences and the anastomotic area were sampled for histologic evaluation. RESULTS: Significant differen ces were seen with chlorhexidine vs. water for gross tumor (P = 0.05) and microscopic tumor (P < 0.05). 5-Fluorouracil showed a greater rate of abscess formation vs. both control and chlorhexidine (P > 0.05). C ONCLUSIONS: Use of chlorhexidine intraperitoneal therapy at the time o f the operation for perforated colorectal cancer significantly decreas es the frequency of gross tumor recurrence but not total recurrences. Intraperitoneal 5-fluorouracil does not significantly decrease recurre nce and may increase the risk of abscess when used intraoperatively.