The existing methods of prophylaxis of the anastomosis sutures insufficiency (ASI) in surgical treatment of complicated colonic cancer (CC) were considered. High safety of the invagination anastomosis formation method, elaborated in the clinic, was shown. It was used in surgical intervention with primary restoration of intestinal continuity, which was performed in 379 patients with complicated CC. Postoperative complications had occurred in 89 (23.5%) patients, 35 (9.2%) of them died. Purulent-septic complications dominated in structure of postoperative complications, the ASI was noted in 4 (1.1%) patients.