Early signs of stomach cancer are often difficult to catch as it generally presents as indigestion, nausea, and stomach pain. Most stomach cancer sufferers realize there is a true problem when they notice weight loss and the passing of blood in bowel movements.
The most common symptoms will be dyspepsia (difficulty digesting food), also more commonly thought of as heartburn. The patient will have ulcer like symptoms that will grow worse with time. Pain is common and its usually not until something drastic happens that the cancer is diagnosed (like vomiting blood), its a hard cancer to catch.