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This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- ~95% are adenocarcinomas. Risk factors: H. pylori (strongest), smoking, salt/nitrosamine-rich diet, pernicious anaemia, blood group A
- Presents late: dyspepsia, weight loss, dysphagia, early satiety, iron deficiency anaemia
- Urgent 2WW endoscopy: ≥55 with new-onset dyspepsia + weight loss, or dysphagia at any age (NICE NG12)
- Gastric ulcers MUST be biopsied and re-scoped at 6–8 weeks to exclude malignancy
- Curative treatment: gastrectomy (subtotal or total) with D2 lymphadenectomy ± perioperative chemotherapy (FLOT)
Overview
Gastric cancer is the fifth most common cancer worldwide but less prevalent in the UK. The vast majority (~95%) are adenocarcinomas, classified histologically as intestinal type (well-differentiated, associated with H. pylori and intestinal metaplasia) or diffuse type (poorly differentiated, includes linitis plastica — "leather bottle stomach"). Other rarer gastric tumours include GIST (gastrointestinal stromal tumour), lymphoma (MALT lymphoma — H. pylori-associated), and neuroendocrine tumours. The adenocarcinoma pathway follows chronic H. pylori gastritis → atrophic gastritis → intestinal metaplasia → dysplasia → carcinoma (Correa cascade).
Epidemiology
Approximately 6,500 new cases per year in the UK. More common in males (2:1), with peak incidence in the 70s. Incidence has declined in the UK over decades (partly due to H. pylori eradication and improved food preservation). Five-year survival is poor (~20% overall) due to late presentation. Significantly more common in East Asia (Japan, South Korea) where screening programmes exist.
Clinical Features
Symptoms
Dyspepsia (new-onset or treatment-resistant, especially in over-55s)
Unintentional weight loss (often significant by time of diagnosis)
Dysphagia (tumours of gastric cardia/GOJ)
Nausea, vomiting, early satiety
Epigastric pain (constant, not meal-related like PUD)
Iron deficiency anaemia (chronic occult blood loss)
Haematemesis or melaena (ulcerated tumour)
Signs
Epigastric mass (advanced disease)
Virchow node (Troisier sign): left supraclavicular lymphadenopathy (metastatic spread via thoracic duct)
Sister Mary Joseph nodule: periumbilical metastatic nodule
Ascites (peritoneal carcinomatosis)
Krukenberg tumour: bilateral ovarian metastases (signet-ring cell adenocarcinoma)
Acanthosis nigricans (paraneoplastic — associated with gastric adenocarcinoma)
Cachexia
Investigations
First-line
Upper GI endoscopy (OGD) with biopsyGold standard diagnosis. Biopsy ALL gastric ulcers (minimum 6 biopsies from ulcer edge and base). Urgent 2WW OGD if alarm features
FBCIron deficiency anaemia
Second-line
CT chest/abdomen/pelvis (staging)Assess local extent and distant metastases (liver, lung, peritoneum)
Endoscopic ultrasound (EUS)T-staging: depth of wall invasion and regional lymph node assessment
Staging laparoscopyBefore curative surgery — to exclude peritoneal disease not visible on CT
Specialist
HER2 testingOn tumour biopsy — HER2-positive tumours eligible for trastuzumab (Herceptin) in advanced disease
PET-CTIf considering curative resection with equivocal CT findings
PD-L1 scoringGuides eligibility for checkpoint inhibitor immunotherapy
1
Curative surgery
- Subtotal gastrectomy: distal tumours (antral/body)
- Total gastrectomy: proximal or diffuse tumours
- D2 lymphadenectomy: standard of care (minimum 15 lymph nodes sampled)
- Endoscopic mucosal resection: early gastric cancer (T1a, well-differentiated, <2 cm)
2
Perioperative chemotherapy
- FLOT regimen (5-FU, leucovorin, oxaliplatin, docetaxel): 4 cycles pre-op + 4 cycles post-op
- Improves survival compared with surgery alone for locally advanced disease
- Neoadjuvant chemotherapy aims to downstage tumour and treat micrometastases
3
Advanced/metastatic disease
- Palliative chemotherapy: doublet or triplet regimens (platinum + fluoropyrimidine ± docetaxel)
- Trastuzumab: add to chemotherapy if HER2-positive
- Nivolumab: for PD-L1-positive advanced gastric cancer
- Palliative endoscopic stenting for obstructing tumours
- Best supportive care and palliative input for advanced disease
Complications
- Gastric outlet obstruction: From antral tumours — projectile vomiting, metabolic alkalosis
- GI bleeding: Acute haemorrhage or chronic iron deficiency anaemia
- Perforation: Rare but life-threatening
- Linitis plastica: Diffuse signet-ring cell infiltration — rigid non-distensible "leather bottle" stomach, very poor prognosis
- Peritoneal carcinomatosis: Ascites and Krukenberg tumours (ovarian metastases)
UKMLA Exam Tips
- 1Virchow node (Troisier sign) = left supraclavicular lymph node = intra-abdominal malignancy (classic for gastric cancer)
- 2Krukenberg tumour = bilateral ovarian metastases from signet-ring cell gastric cancer (transcoelomic spread)
- 3Sister Mary Joseph nodule = periumbilical metastasis — think intra-abdominal malignancy
- 4H. pylori → atrophic gastritis → intestinal metaplasia → dysplasia → carcinoma (Correa cascade)
- 5Blood group A is associated with gastric cancer (particularly diffuse type)
- 6MALT lymphoma of the stomach: low-grade, associated with H. pylori — may regress with H. pylori eradication alone
- 7All gastric ulcers must be biopsied and re-scoped at 6–8 weeks — essential to exclude malignancy
practicetest your knowledge on gastric cancerApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — gastroenterology and beyond.
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