Gastric Neoplasms

Gastric Neoplasms

Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management

Definition

Gastric neoplasms refer to abnormal growths in the stomach, which can be benign (polyps, gastrointestinal stromal tumours) or malignant (gastric adenocarcinoma, lymphoma, carcinoid tumours).

Aetiology

  • Gastric adenocarcinoma (90-95% of cases): develops from chronic inflammation or intestinal metaplasia.
  • Gastrointestinal stromal tumours (GISTs): mesenchymal tumours arising from interstitial cells of Cajal.
  • Gastric lymphoma: associated with Helicobacter pylori infection.
  • Carcinoid tumours: neuroendocrine tumours arising from enterochromaffin cells.

Pathophysiology

  • Chronic gastritis (due to H. pylori or autoimmune disease) leads to intestinal metaplasia and dysplasia.
  • Progression to invasive gastric adenocarcinoma occurs with further genetic mutations.
  • GISTs arise from mutations in the KIT or PDGFRA genes.

Risk factors

  • H. pylori infection (strongest risk factor for gastric adenocarcinoma).
  • Smoking and excessive alcohol consumption.
  • Diet high in salted, smoked, or pickled foods.
  • Pernicious anaemia and atrophic gastritis.
  • Family history of gastric cancer.
  • Previous gastric surgery (e.g., Billroth II procedure).

Signs and symptoms

  • Early-stage disease: often asymptomatic or vague dyspepsia.
  • Weight loss: unintentional and progressive.
  • Persistent epigastric pain.
  • Dysphagia: if tumour is near the gastroesophageal junction.
  • Early satiety: due to gastric outlet obstruction.
  • Iron-deficiency anaemia: from occult gastrointestinal bleeding.
  • Palpable epigastric mass: suggests advanced disease.
  • Virchow’s node: left supraclavicular lymphadenopathy (metastatic disease).
  • Sister Mary Joseph nodule: periumbilical metastasis.

Investigations

  • Blood tests:
    • Full blood count (may show anaemia).
    • Liver function tests (assess for metastases).
    • Tumour markers: CA 19-9 and CEA (not diagnostic but useful for monitoring).
  • Endoscopy with biopsy (gold standard): confirms diagnosis and histological type.
  • CT chest/abdomen/pelvis: assesses tumour staging.
  • Endoscopic ultrasound: evaluates tumour invasion depth.
  • PET-CT: identifies distant metastases.

Management

1. Early-Stage Disease:

  • Endoscopic resection: if confined to mucosa (T1a disease).
  • Surgical resection (gastrectomy): partial or total gastrectomy with lymph node dissection.

2. Locally Advanced Disease:

  • Neoadjuvant chemotherapy: often FLOT regimen (5-FU, leucovorin, oxaliplatin, docetaxel).
  • Radical gastrectomy: with D2 lymphadenectomy.
  • Adjuvant chemotherapy: if high-risk features present.

3. Metastatic Disease:

  • Palliative chemotherapy: e.g., fluoropyrimidines, platinum agents.
  • Targeted therapy: HER2 inhibitors (trastuzumab) if HER2-positive.
  • Symptomatic relief: nutritional support, analgesia.
GastroenterologymypanotesGastric Neoplasms