Unique features of stomach in relation to TNM cancer classification 1. Cancer penetrates the muscular propria and invades the ligaments (gastrohepatic and gastrocolic, i.e. lesser and greater omentum respectively) subserosally without breeching the serosa. Gastric cancer invasion of the lesser and greater omentum is T3, not T4. Perforation of the … Continue reading TNM and Staging of Gastric Carcinoma Simplified