CEACAM5 and intestinal obstruction: Patients are considered high-risk if they have T4 depth of invasion, peritumoral lymphatic/venous invasion, a histological grade of 3 or greater, R1-R2 margin status, bowel obstruction or perforation, elevated carcinoembryonic antigen (CEA) exceeding 5 ng/mL or fewer than 12 nodes retrieved.