Stomach Cancer



Cancer happens when cells divide without control or order. These cells grow together to form a tumor. They can invade and damage nearby tissues. They can also spread to other parts of the body.

It is not clear what causes changes in the cells. It is likely a combination of genes and environment.

Risk Factors

Stomach cancer is more common in men. It is also more common in people from eastern Asia, eastern Europe, and South America. Other things that may raise the risk are:

  • Certain infections, such as Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV)
  • Genes, or family history of stomach cancer—or certain cancer syndromes
  • A diet high in:
    • Salt, salt-preserved, and pickled foods
    • Red or processed meat
  • Being overweight or obese
  • Smoking or alcohol use disorder
  • Pernicious anemia
  • Previous stomach surgery
  • Ménétrier disease, or certain types of long-term gastritis



In some people, stomach cancer may have no symptoms. Others may have:

  • Belly pain, discomfort, bloating, or fullness
  • Weight loss without trying
  • Loss of hunger
  • Painful swallowing
  • Blood in vomit or stool
  • Weakness or tiredness
  • Lasting nausea and vomiting
  • A swelling or mass in the belly area


The doctor will ask about symptoms and past health. A physical exam will be done.

Tests may include:

  • Blood tests
  • Fecal occult blood test—to test for blood in the stool

Imaging tests will be used to look for stomach cancer or spreading of the cancer. They may include:

  • Upper GI endoscopy
  • CT scan
  • Ultrasound
  • positron emission tomography (PET) scan
  • Laparoscopy

Stomach cancer is diagnosed with a biopsy. This means taking and testing a small sample of stomach tissue.

The exam and test results are used to diagnose the cancer. They are also used for staging. Stomach cancer is staged from 0 to 4. The lower the number, the less the cancer has spread.



Cancer treatment depends on the stage and type of cancer. A combination of therapies may be used.

Surgery may be done to remove the cancer to try to cure it. Or, surgery may be done to ease symptoms in advanced stomach cancer.

Surgery may include:

  • Endoscopic mucosal resection—removal of the tumor through an endoscope
  • Subtotal gastrectomy—removal of the lower part of the stomach
  • Total gastrectomy—removal of the whole stomach and often nearby lymph nodes

Chemotherapy (chemo) includes drugs that may be given by mouth or IV—to kill cancer cells. It may be used:

  • Before surgery, sometimes with radiation—to shrink the tumor
  • After surgery, often with radiation—to remove any remaining cancer cells
  • As the main treatment—if the cancer:
  • Has spread to distant parts of the body
  • Cannot be removed with surgery

Radiation therapy shrinks or kills cancer cells with high energy rays or particles. It may be used with chemo before, after, or instead of surgery.

Other treatments that may be used include:

  • Targeted therapy—drugs that target cancer cells
  • Immunotherapy—drugs that help the body fight cancer


The risk of stomach cancer may be lowered by:

  • Achieving and maintaining a healthy weight
  • Treating H. pylori infection
  • Eating a healthy diet, and:
    • Limiting salted, pickled, and smoked foods
    • Limiting red meat
    • Limiting alcohol
  • Not smoking

Some people have a very high risk of stomach cancer due to genes. For them, stomach removal (gastrectomy) may be an option.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.