A primary or metastatic malignant neoplasm involving the stomach. The disease is Monarch Disease Ontology id MONDO_0001056 (gastric cancer). Also known as: Ca lesser curvature - stomach, GC, cancer of stomach, gastric cancer risk after h. pylori infection, gastric cancer, somatic, malignant gastric neoplasm, malignant gastric tumor, malignant gastric tumour.