Stomach cancer (gastric cancer) develops in the lining of the stomach. It's a serious disease but understanding your risk factors, screening options, and treatment choices empowers you to take action early. Most cases are diagnosed in advanced stages in the US, but early detection is possible through screening in high-risk individuals.

What This Is

The stomach is a muscular organ that breaks down food. Stomach cancer usually starts in the mucus-producing cells lining the stomach (adenocarcinoma). About 28,560 new cases and 11,080 deaths occur annually in the US. Survival rates are higher in countries with routine screening programs.

Key Risk Factors

  • Helicobacter pylori (H. pylori) infection: Most important risk factor; bacteria increases risk significantly.
  • Tobacco smoking: Increases risk 1.5–2x.
  • Heavy alcohol use: Chronic irritation of stomach lining.
  • Obesity: Associated with increased risk.
  • Family history: Some familial clustering observed.
  • Chronic stomach inflammation or ulcers: Can increase cancer risk.
  • Pernicious anemia: Lack of vitamin B12 increases risk.

Symptoms (often late)

  • Persistent indigestion or heartburn
  • Difficulty swallowing
  • Feeling full quickly when eating
  • Unintentional weight loss
  • Stomach pain or discomfort
  • Vomiting (sometimes with blood)
  • Dark or tarry stools

Early stomach cancer often has no symptoms, which is why screening high-risk people is important.

Diagnosis and Treatment

Diagnosis involves:

  • Upper endoscopy (camera down throat into stomach)
  • Biopsy of suspicious tissue
  • Imaging (CT, ultrasound) to check for spread

Treatment options:

  • Surgery (gastrectomy): Partial or total stomach removal. Most important curative treatment.
  • Chemotherapy: Often given before (neoadjuvant) or after (adjuvant) surgery.
  • Radiation: May be used with chemotherapy.
  • Targeted therapy: For specific mutations (e.g., HER2).
  • Immunotherapy: For specific tumor characteristics (MSI-H, PD-L1+).

Sources and References

  • National Cancer Institute. "Stomach Cancer—Patient Version." cancer.gov
  • American Cancer Society. "Stomach (Gastric) Cancer." cancer.org
  • NCCN Clinical Practice Guidelines: "Gastric Cancer." Version 3.2024.

Last reviewed: February 2026. This page is not medical advice.