What happens if stomach cancer is not treated?

As a stomach tumour enlarges, it can reduce the space available for food and make swallowing or eating uncomfortable. Feeling full quickly, loss of appetite, persistent abdominal pain, nausea, or vomiting may lead to poor nutrition and reduced strength. A tumour can bleed, causing dark stools or anaemia. Growth through the stomach wall may involve nearby organs, while cancer cells can travel to lymph nodes, the liver, lungs, or the lining of the abdomen. The pattern depends on the tumour’s type and stage.

Arrange prompt review with a gastroenterology or oncology team. They may discuss endoscopy and scans, nutritional support, surgery, medicines, HER2-targeted therapy, or immunotherapy according to tumour features and fitness. Treatment can aim to remove or control cancer, relieve blockage or bleeding, and support eating and comfort. Mention previous Helicobacter pylori infection, swallowing changes, appetite, pain, vomiting, black stools, and unplanned weight change.

Get urgent help for vomiting blood, black or bloody stools, severe abdominal pain, persistent vomiting, inability to swallow fluids, fainting, confusion, or signs of dehydration such as very little urine and extreme dizziness.

Ask whether the tumour is blocking or bleeding, which tests define its stage and molecular features, how nutrition will be supported, and which treatment goals matter most to you.