Gastric (stomach) cancer is the fourth most common cancer worldwide. It begins in the stomach lining and can spread to lymph nodes or other organs. Most cases are adenocarcinomas, though rarer forms include gastrointestinal stromal tumours, carcinoid tumours, and lymphomas.
A key risk factor is infection with Helicobacter pylori, which can cause inflammation and ulcers. Other risks include a family history of stomach cancer, certain inherited genetic syndromes, smoking, heavy alcohol use, obesity, a high-salt diet, and exposure to industrial chemicals. Men and people of African American, Hispanic, or Asian descent face higher risk.
Early stages often produce few or no symptoms. When present, warning signs may include difficulty swallowing, stomach pain or discomfort, bloating after small meals, nausea or vomiting (sometimes with blood), blood in the stool, and unexplained weight loss. Because these symptoms can mimic common digestive issues, medical evaluation is important for accurate diagnosis.
