Clinical manifestations Once gastric cancer occurs, cancer cells will continue to proliferate and infiltrate and expand to surrounding tissues or spread metastasis to distant places, resulting in various symptoms and signs, and finally leading to death. According to statistics, the natural history of progressive gastric cancer is 3-6 years, and the speed of its development is mainly determined by the biological behavior of cancer tumors and the immune status of patients. Symptoms The early stage of gastric cancer often has no specific symptoms. However, such symptoms are not unique to gastric cancer and are often similar to chronic gastric diseases such as gastritis and ulcer disease. The main symptom is upper abdominal pain or discomfort (84.8%), followed by weight loss (73.8%) and loss of appetite (58.5%). Stomach pain is the most common symptom of gastric cancer, and it is also the most non-specific and easily ignored symptom. Once gastric cancer is perforated, gastric perforation symptoms of severe abdominal pain may appear. Loss of appetite, emaciation and weakness. Nausea and vomiting. Bleeding and black stool. Other symptoms: Patients may sometimes have diarrhea due to lack of gastric acid and accelerated gastric emptying, some may have constipation and lower abdominal discomfort, and fever may also occur. Signs In early stage gastric cancer, there are often no obvious signs. In advanced gastric cancer, a mass in the upper abdomen may be found in the pyloric sinus or gastric body; in female patients, a pushable mass in the middle and lower abdomen may be a Krukenberg tumor. In pyloric obstruction, there may be gastric pattern and tremors; in case of peritoneal metastasis, ascites may appear; in small intestine or mesenteric metastasis, narrowing of intestinal lumen may lead to partial or complete intestinal obstruction; in case of perforation of cancer, peritoneal irritation may appear. Pre-rectal palpable mass, umbilical mass and enlarged supraclavicular lymph nodes are all signs of advanced gastric cancer or metastasis.