Experimental model for the study of perianastomotic recurrence in colorectal cancer.

OBJECTIVE: To determine if an experimental model is valid for the study of perianastomotic recurrence in colorectal cancer, comparing it with previous experimental models.

METHODS: Experimental study with 40 male Sprague-Dawley rats, assigned to one of the study groups: control group (n = 20), with manipulation of large descending bowel, and colonic anastomosis group (n = 20), with colonic section and colocolic anastomosis. After pharmacological carcinogenesis with 1-2 dimethylhydrazine at a weekly dose of 25 mg/kg for 18 weeks, colonic tumours were studied at the 20th postoperative week.

RESULTS: Number of tumours, colic tumoral area and percentage of colic tumoral area were greater in the colonic anastomosis group. In this group with colonic anastomosis all determinations were higher at the perianastomotic large bowel.

CONCLUSIONS: We think this experimental model may be the best model to study perianastomotic recurrence in large bowel cancer. The high incidence of induced colic tumours and their location at the perianastomotic area offer a good field to determine response to experimental manipulations on colorrectal cancer.