Stomach cancer can cause pain in the upper abdomen, pain in the lower back, and pain behind the sternum. The location of pain usually varies according to the location of tumor growth and severity of disease. 1. Epigastric pain: Early stage of gastric cancer will have mild epigastric pain, accompanied by symptoms such as fullness, indigestion, etc. The pain of some patients is similar to that of peptic ulcer, and due to atypical symptom, it is often regarded as common gastritis or ulcer disease and neglected. 2. Lumbar back pain: as the cancer involves organs or tissues such as retroperitoneal nerve plexus and pancreas in the progressive stage of gastric cancer, the pain will continue to aggravate and radiate to the lumbar back. 3. Poststernal pain: if stomach cancer occurs in cardia, it will cause poststernal pain, and patients will also have progressive difficulty in swallowing and other symptoms. If there is pain in the above areas, it is recommended to have a gastroscopy to avoid delay in treatment.