What Is Stomach Cancer?

Stomach cancer, also known as gastric cancer, occurs when malignant (cancerous) cells form in the lining of the stomach. It often begins in the mucosa—the innermost layer of the stomach wall—and can grow outward into other layers over time.

Stomach cancer is a relatively rare but serious disease. Because early symptoms can be vague or absent, it is often diagnosed at a more advanced stage. However, early detection significantly improves outcomes and survival rates.

Types of Stomach Cancer

The most common type is adenocarcinoma, which arises from the glandular cells of the stomach lining. Other, less common types include:

  • Gastrointestinal stromal tumors (GISTs)
  • Neuroendocrine tumors
  • Lymphomas of the stomach

Early Signs and Symptoms

Symptoms of stomach cancer are often subtle at first. They may include:

  • Persistent indigestion or heartburn
  • Stomach discomfort or pain
  • Feeling full after eating small amounts
  • Unexplained weight loss
  • Nausea or vomiting
  • Fatigue
  • Bloody or black stools (a sign of gastrointestinal bleeding)

If these symptoms persist for more than a few weeks, especially in people over 50 or with risk factors, medical evaluation is essential.

Risk Factors for Stomach Cancer

Several lifestyle, environmental, and genetic factors can increase the risk:

  • H. pylori infection: Chronic infection with Helicobacter pylori bacteria is a major risk factor.
  • Diet: High intake of smoked, salted, or pickled foods can contribute.
  • Smoking: Tobacco use increases risk significantly.
  • Family history: A genetic predisposition can raise risk.
  • Previous stomach surgery: Especially for ulcers.
  • Pernicious anemia: A condition that affects vitamin B12 absorption.

How Stomach Cancer Is Diagnosed

Diagnostic procedures often include:

  • Upper endoscopy (EGD): A thin tube with a camera is inserted into the stomach to view and biopsy suspicious tissue.
  • Barium swallow: X-rays taken after drinking a contrast liquid to detect abnormalities.
  • CT scans: Used to assess cancer spread and staging.
  • Biopsy: Essential to confirm the presence and type of cancer cells.

Stages of Stomach Cancer

Staging describes the extent of the cancer’s spread:

  • Stage 0: Early cancer found only in the inner lining.
  • Stage I-II: Cancer has invaded deeper layers or nearby lymph nodes.
  • Stage III: More extensive lymph node involvement or spread within the stomach.
  • Stage IV: Distant spread to organs like the liver or lungs (metastatic cancer).

Treatment Options

Treatment depends on the stage, location, and type of cancer, as well as the patient’s overall health. Options include:

Surgery

For localized cancers, partial or total gastrectomy (removal of part or all of the stomach) may be performed. Lymph nodes are often removed as well.

Chemotherapy

May be given before surgery (neoadjuvant) to shrink tumors or after surgery (adjuvant) to kill remaining cancer cells. It can also be used as the primary treatment in advanced stages.

Radiation Therapy

Used in combination with chemotherapy to target specific areas of cancer growth, especially in cases where surgery isn’t feasible.

Targeted Therapy and Immunotherapy

Some cancers express specific proteins (like HER2) that can be targeted with newer medications. Immunotherapy is emerging as a treatment option for some advanced gastric cancers.

Living With and Managing Stomach Cancer

Nutrition, mental health, and symptom control are key parts of ongoing care. Patients often benefit from the support of a multidisciplinary team including oncologists, gastroenterologists, dietitians, and counselors.

FAQs About Stomach Cancer

Is stomach cancer curable?

If detected early, stomach cancer can be cured with surgery and/or chemotherapy. Later-stage cancers are harder to cure but may still be managed for years with treatment.

How is it different from stomach ulcers?

While both can cause stomach pain, ulcers are non-cancerous and often caused by H. pylori or NSAIDs. Stomach cancer is a malignant growth that requires biopsy for diagnosis.

Can I prevent stomach cancer?

Reducing risk factors—such as quitting smoking, treating H. pylori, and eating a healthy diet—can lower your chances.

What age does stomach cancer typically occur?

It is more common in people over 60, but it can occur earlier, particularly in those with genetic predisposition or chronic gastric conditions.

Should I be screened for stomach cancer?

Routine screening isn’t common in the U.S. unless you have high-risk factors or symptoms. In some countries, like Japan and Korea, screening is more widely practiced.

Final Thoughts from Your Gastroenterologist

Stomach cancer is a serious condition that often goes unnoticed until it’s advanced. Awareness of symptoms and risk factors is crucial for early detection. If you experience persistent stomach discomfort, unexplained weight loss, or changes in appetite, don’t ignore it. Consult a gastroenterologist promptly. Early diagnosis can save lives.