Skip to main content

Saturn Medic

Gastric Cancer

Clinical Subject Page

Gastric Cancer

Gastric carcinoma is a malignant tumor of the stomach. Adenocarcinoma accounts for
approximately 95% of gastric cancers and is classified into intestinal and diffuse types

Also called

Gastric Carcinoma

ICD-10

C15

Specialty

Gastroenterology

Onset

Chronic

Reviewed

July 2026

On This Page

Overview

Gastric cancer is the fifth most common cancer worldwide. Although its incidence has declined in
the United States, it remains common in several Asian countries. The major risk factor is
Helicobacter pylori infection. Early disease is often asymptomatic or presents with nonspecific
symptoms, resulting in delayed diagnosis and a poor overall prognosis.

Etiology & Risk Factors

Etiology

Gastric cancer is a malignant tumor arising from the gastric mucosa, with adenocarcinoma accounting for more than 90% of cases. It develops through a multistep process involving chronic inflammation, mucosal atrophy, intestinal metaplasia, dysplasia, and invasive carcinoma.

Risk Factors

  • Helicobacter pylori infection (most important risk factor)

  • Chronic atrophic gastritis

  • Intestinal metaplasia

  • Smoking

  • Family history of gastric cancer

  • Advanced age

  • Male sex

  • Diet high in smoked, salted, or preserved foods

  • Low fruit and vegetable intake

  • Previous partial gastrectomy

  • Pernicious anemia

  • Epstein–Barr virus infection

  • Hereditary diffuse gastric cancer (CDH1 mutation)

  • Familial adenomatous polyposis (FAP)

  • Lynch syndrome

Pathophysiology

1. Chronic exposure to carcinogenic or inflammatory factors leads to malignant transformation of
the gastric mucosa.
2. Adenocarcinoma (95%) develops and is classified as:
– Intestinal type
– Diffuse type
3. Tumor progressively invades the gastric wall.
4. Local invasion, lymphatic spread, and distant metastasis may occur.

Clinical Presentation

  • Early disease:
    • Often asymptomatic
    • Dyspepsia
    • Epigastric pain
    Advanced disease:
    • Gastric outlet obstruction
    • Gastrointestinal bleeding
    • Ascites
    • Features of metastatic disease

History Taking

  • Ask about:
    • Dyspepsia
    • Epigastric pain
    • Duration and progression of symptoms
    • Weight loss (if present)
    • Symptoms of gastric outlet obstruction
    • Gastrointestinal bleeding
    • History of H. pylori infection
    • Smoking history
    • Dietary habits (high salt or nitrate intake)
    • History of GERD

Physical Examination

Assess for:
• Epigastric tenderness
• Signs of gastrointestinal bleeding
• Ascites
• Clinical evidence of metastatic disease
• Nutritional status

Investigations

      • Initial Laboratory Tests

        • Complete blood count (CBC)

        • Liver function tests (LFTs)

        • Renal function tests

        • Electrolytes

        • Iron studies (if anemia is suspected)

        Diagnostic Investigations

        Upper Gastrointestinal Endoscopy (EGD) with Biopsy – Gold Standard

        • Gold standard investigation

        • Direct visualization of the lesion

        • Multiple biopsies for histopathological confirmation

        Staging Investigations

        • Contrast-enhanced CT chest, abdomen, and pelvis

        • Endoscopic ultrasound (EUS) for T and N staging

        • PET-CT (selected patients)

        • Diagnostic laparoscopy for locally advanced disease to detect occult peritoneal metastases

        Additional Investigations

        • HER2 testing

        • MSI/MMR testing

        • PD-L1 testing (advanced disease)

Diagnosis

-Diagnosis is confirmed by:
• Upper endoscopy demonstrating the lesion
• Histopathological examination of biopsy tissue
Tumor staging is based on:
• Imaging
• Diagnostic laparoscopy

Home / Home / Clinical Cases / Gastrointestinal System Clinical Cases / Gastric Cancer

Related Topics

Management

1. Early Gastric Cancer

  • Endoscopic mucosal resection (EMR)

  • Endoscopic submucosal dissection (ESD) (selected patients)

2. Localized Resectable Disease

  • Gastrectomy with lymph node dissection

  • Perioperative chemotherapy

  • Adjuvant chemotherapy when indicated

3. Advanced or Metastatic Disease

  • Systemic chemotherapy

  • Immunotherapy (selected patients)

  • HER2-targeted therapy (HER2-positive tumors)

  • Palliative radiotherapy or surgery when indicated

4. Supportive Care

  • Nutritional support

  • Pain management

  • Palliative care for advanced disease

5. Follow-Up

    • Regular clinical review

    • Surveillance imaging/endoscopy when indicated

    • Monitor for recurrence and nutritional deficiencies

Complications

• Gastric outlet obstruction
• Gastrointestinal bleeding
• Ascites
• Metastatic disease

Prognosis

  • Prognosis depends largely on tumor stage at diagnosis.
  • Overall survival is poor because many
    patients are diagnosed only after symptoms develop and the disease has advanced

Key Points / Clinical Pearls

• Gastric carcinoma is the fifth most common cancer worldwide.
• Adenocarcinoma accounts for 95% of cases.
• The main risk factor is Helicobacter pylori infection.
• Other risk factors include GERD, smoking, and diets high in salts and nitrates.
• Early disease is often asymptomatic or causes nonspecific dyspepsia.
• Upper endoscopy with biopsy is the diagnostic test of choice.
• Imaging and diagnostic laparoscopy are used for staging.
• Early disease is treated with surgery and perioperative chemotherapy.
• Advanced disease is managed with systemic therapy, chemoradiation, targeted therapy, or
palliative care.
• Prognosis is generally poor due to late presentation