The lesser curvature of the stomach has a 1-5% chance of becoming cancerous if an ulcerous and untreated lesion is present. Cancer on the side of the lesser curvature of the gastric antrum basically occurs in the presence of underlying lesions in the lesser curvature of the stomach, such as gastric ulcers. In the absence of underlying lesions, cancer generally does not occur; if the patient develops ulcers in the lesser curvature of the stomach and the ulcers are under control after timely treatment, the chance of cancer will be greatly reduced. However, if the condition is not controlled and the scope of ulcer gradually increases, the chance of cancer will also increase. Therefore, if ulcer in the lesser curvature of the stomach occurs, one should go to a regular hospital for timely consultation and regular review to prevent cancer.