Stomach cancer. Gastroscope (endoscope) view of a gastric tumour (adenocarcinoma, centre left) in a 34 year-old man. This is a retroflexed view (bent backward) of the cardia, the upper part of the stomach, the endoscope is also seen (black). An adenocarcinoma is a cancer that arises from the glandular tissue of an organ's epithelium (lining). Stomach cancers cause similar symptoms to indigestion, and may develop undiagnosed until they have spread beyond the stomach. If they are discovered early, as in this case, a gastrectomy (removal of the stomach) may effect a cure. Stomach cancers are thought to be linked to a Western (high fat, low fibre) diet.