Gastric Cancer

Related Subjects: |Upper Gastrointestinal Bleed |Oesophageal Variceal Bleeding |Dieulafoy Lesion |Mallory-Weiss Tear |Gastric Cancer |Peptic Ulcer Disease |Oesophagogastroduodenoscopy (OGD/EGD) |Hereditary Haemorrhagic Telangiectasia |Hypovolaemic or Haemorrhagic Shock

📈 Proximal gastric tumours (around the oesophagogastric junction, OGJ) are rising in incidence, while distal stomach cancers are declining. 🍽️ Gastric cancer remains a major global cause of mortality despite falling prevalence in Western countries.

📖 About

• Most gastric cancers are adenocarcinomas arising from the mucosa.
• 6th most common cancer in the UK 🇬🇧, with poor 5-year survival (~10–20%).
• Peak incidence in older adults; ♂:♀ ≈ 2:1.

🔬 Histological Types

• Adenocarcinoma (90–95%) – intestinal vs diffuse types (Lauren classification).
• Lymphoma – MALT type, often linked to chronic H. pylori infection.
• GIST – mesenchymal tumours; KIT/CD117 positive.
• Neuroendocrine tumours – rare, from enteroendocrine cells.

🧪 Pathology

• Gross appearance: ulcerating, polypoid, or infiltrative.
• Linitis plastica: diffuse infiltration → rigid “leather bottle” stomach (poor prognosis).
• Spread routes:
  • Direct → pancreas, colon, liver.
  • Lymphatic → perigastric, celiac, Virchow’s node (L supraclavicular).
  • Haematogenous → liver, lung.
  • Transcoelomic → ovaries (Krukenberg tumour).

🌍 Epidemiology

• Highest in Japan 🇯🇵, Korea, Chile, Eastern Europe.
• Western countries: ↓ distal cancers (due to refrigeration, less salt-preserved food, ↓ H. pylori).
• ↑ proximal/OGJ cancers linked to obesity + reflux disease.

⚠️ Risk Factors

• 🦠 H. pylori → chronic gastritis → metaplasia → carcinoma.
• 🥓 Diet: high salt, smoked/pickled foods; low fruit/veg intake.
• 🚬 Smoking → doubles risk.
• 👨‍👩‍👧 Family/genetic: CDH1 mutation (hereditary diffuse gastric cancer).
• 🔥 Chronic gastritis & atrophy: autoimmune gastritis, pernicious anaemia.
• 👵 Age & sex: elderly, more common in men.

🩺 Clinical Features

• Dyspepsia, early satiety, epigastric pain/discomfort.
• Anorexia, weight loss, fatigue.
• Vomiting → esp. with gastric outlet obstruction.
• GI bleeding: haematemesis or melaena.
• Advanced signs:
  • Virchow’s node (L supraclavicular).
  • Sister Mary Joseph nodule (umbilical deposit).
  • Hepatic mets → jaundice, ascites.
  • Palpable epigastric mass.

🔎 Investigations

• OGD + biopsy: diagnostic gold standard.
• Histology: confirms subtype (adenocarcinoma vs lymphoma, etc).
• Staging: CT chest/abdomen/pelvis, PET, endoscopic US.
• Bloods: FBC (anaemia), LFTs, U&E, tumour markers (CEA, CA19-9 – not diagnostic).

🚑 Complications

• Iron-deficiency anaemia (chronic bleeding).
• Gastric outlet obstruction → persistent vomiting + alkalosis.
• Metastatic disease (liver, peritoneum, ovary).
• Post-gastrectomy: B12 deficiency, dumping syndrome.

🛠️ Management

• Curative intent:
  • Total gastrectomy (proximal/OGJ tumours).
  • Subtotal distal gastrectomy (antral tumours).
  • Usually with D2 lymphadenectomy.
• Chemo: peri-operative regimens (MAGIC – ECF; modern = FLOT).
• Palliative: stenting, gastrojejunostomy, systemic chemo.
• Lymphoma: often responds to H. pylori eradication.

📊 Prognosis

• Japan (screening) → early detection, 5-yr survival up to 90%.
• UK/West → late diagnosis, 5-yr survival ~20%.
• Worse in diffuse type, linitis plastica, and metastatic disease.

📚 Teaching Commentary

🩺 Exam pearls:
– Virchow’s node + weight loss → think gastric cancer.
– Linitis plastica = classic buzzword (“leather bottle”).
– Krukenberg tumour = ovarian mets with signet ring cells.

💡 UK vs Japan: No population screening in UK → late diagnosis explains poor outcomes. In OSCEs, always mention OGD with biopsy as the diagnostic test and multidisciplinary team approach for management.