Sometimes none. Unfortunately, early on there may be no symptoms; most symptoms of gastric cancer are signs of advanced disease. These symptoms can include indigestion, nausea or vomiting, difficulty swallowing, feeling full after eating only a little, loss of appetite, black tarry stools, bloody vomit, and weight loss.
Can be subtle. These can be subtle, especially when stomach cancer is early. Many patients don't have any symptoms until it is late stage. The symptoms may include dark blood in the stool, nausea, vomiting, sensation of filling up too quickly with meals, abdominal pain, unusual weight loss, or vomiting blood.