Definition
Gastric cancer is a malignant tumor that develops in the stomach. It is among the most common cancers globally, with incidence varying geographically, and is often diagnosed at an advanced stage.

Pathogenesis
Gastric cancer development is associated with:

  • H. pylori infection: Causes chronic inflammation and increases risk.
  • Dietary habits: Diets high in salty, smoked, and processed foods raise risk.
  • Genetic predisposition: Family history and genetic syndromes like Lynch syndrome.
  • Risk factors: Chronic gastritis, gastric ulcers, alcohol consumption, smoking, and obesity.

Diagnosis
Diagnosis is via endoscopy with biopsy, confirming malignancy. CT, PET-CT, and endoscopic ultrasound are used for staging and assessing spread.

Treatment
Treatment depends on the disease stage:

  • Endoscopic resection: Removal of early-stage tumors locally.
  • Surgery: Partial or total gastrectomy for localized or locally advanced stages.
  • Chemotherapy: Administered pre-surgery (neoadjuvant) to shrink tumors or post-surgery to reduce recurrence risk.
  • Radiotherapy: In select cases for adjunctive treatment.
  • Immunotherapy and targeted therapies: For metastatic or resistant gastric cancer.

Prevention
Prevention includes maintaining a healthy lifestyle, managing H. pylori infection, reducing salty and processed food consumption, and quitting smoking and alcohol. Regular screening is recommended for high-risk individuals.

Early diagnosis and effective treatment are critical for improving survival and quality of life.

An example of treating an early lesion is the resection of a 4 cm lesion of the prepyloric antrum, where gastric motility makes the working field unstable.

The most important modifiable risk factor is chronic gastritis due to Helicobacter pylori. Early lesions can be removed with endoscopic submucosal dissection, preserving the stomach.

Frequently asked questions

What role does Helicobacter pylori play?

It is the single most important modifiable risk factor. Chronic infection causes atrophic gastritis and intestinal metaplasia, which can progress to dysplasia and cancer. Eradication reduces that risk, and is most effective when carried out before atrophy is advanced.

Why is gastric cancer often diagnosed late?

Because early symptoms are vague and easily attributed to indigestion: mild epigastric discomfort, early satiety, bloating, nausea. Alarm features such as weight loss, vomiting, difficulty swallowing, anaemia or black stools appear later. Persistent upper abdominal symptoms, especially after 45, should prompt gastroscopy.

Can early gastric cancer be removed endoscopically?

Yes, in selected cases. When the lesion is confined to the mucosa and meets defined criteria, endoscopic submucosal dissection removes it in a single piece with the stomach preserved. Deeper invasion or risk of lymph node spread requires surgery. Staging determines the choice.

Sources


Content last updated: September 2026 (15/09/2026).