Gastric Cancer

• Epidemiology
  • Gender: More common in men
  • Age: 40 to 70 years

• Pathophysiology
  • Adenocarcinoma accounts for 95% of cases
  • Atrophic Gastritis precedes metaplasia and malignancy

• Risk Factors
  • Familial Adenomatous Polyposis
  • Non-polyposis hereditary Colon Cancer
  • Gastric adenoma
  • Barrett’s Esophagus (cardiac and esophageal border)
  • Tobacco Abuse
  • Chronic atrophic Gastritis
  • positive family history in 4% of cases
  • diseases that produce hypochlorhydric or achlorhydric states
    • 🡪 encourage bacterial colonization and conversion of dietary nitrates and nitrites into nitrosamines:
    • pernicious anaemia
    • chronic gastritis
      • Helicobacter pylori
    • Pernicious Anemia 
    • Prior subtotal gastrectomy (after 15-20 years) – risk of malignancy in residual stump is increased 2-6 fold
  • increased incidence in certain ethnic and racial groups
    • blacks, American Indians, Maori’s, Japanese
  • Environmental
    • Tobacco smoking, obesity, occupations involving rubber production and exposure to X-radiation or gamma radiation

• Symptoms
  • Asymptomatic in early stages in 80% of cases
  • Late stage symptoms
    • Weight loss
    • Nausea and Vomiting
    • Abdominal Pain
    • Early satiety

• Signs
  • Palpable epigastric mass
  • Hepatomegaly
  • Lymphadenopathy (e.g. periumbilical or supraclavicular)

• Differential Diagnosis
  • Peptic Ulcer Disease
  • Gastroesophageal Reflux disease

• Diagnostic Testing
  • Upper endoscopy (Esophogastroduodenoscopy or EGD)
  • Endoscopic Ultrasonography (EUS)

• Prognosis: Five year survival
  • Stages (Summary of AJCC Staging – not an exact list)
  • Stage 0: Tis, N0, M0 (Carcinoma in-situ) 90%
  • Stage I: T1, N0, M0 (Submucosa involved) <78%
  • Stage II: T1-T3, N0-N2, M0 (visceral peritoneum) 34%
  • Stage III: T2a-T4, N0-N2, M0 (local tumor invasion) <20%
  • Stage IV: T1-T4, N1-N3, M0-1 (increased metastases) 7%

• Prevention
  • Tobacco Cessation
  • Dietary changes (possible benefit)
    • Decrease Alcohol intake
    • Decrease smoked, pickled or salted food intake
    • Increase fruit and vegetable intake
  • Aggressively treat and monitor associated conditions
    • Barrett’s Esophagus
    • Atrophic Gastritis
    • Helicobacter Pylori infection
  • Screening EGD for high risk patients every 1-3 years