Fig. 1

Results of gastroscopy. A The gastric cancer in stage I, manifesting as gastric antrum mucosal congestion and edema, irregular ulcers, surrounding mucosa protrusion, poor elasticity in biopsy, and easy bleeding. B The gastric cancer in stage II, manifesting as irregular ulcer on the anterior wall of gastric antrum, surrounding mucosa protrusion, poor elasticity in biopsy, and easy bleeding. C The gastric cancer in stage III, manifesting as huge ulcerative lesion in gastric antrum, slight protrusion of surrounding mucosa, surface hyperemia and edema, and tough quality in biopsy. D The gastric cancer in stage IV, manifesting as huge ulcerative lesions in the gastric body, surface congestion, edema, erosion, covered with dirty of purulent surface, and fresh bleeding, fragile quality in biopsy, and poor elasticity