01OverviewDefinition, clinical context and the essential points that orientate the chapter.
Most gastric cancers are adenocarcinomas, conventionally divided into intestinal and diffuse patterns, while lymphoma, gastrointestinal stromal tumour and neuroendocrine neoplasms require distinct pathways. Important risks include H. pylori, extensive atrophy or intestinal metaplasia, autoimmune gastritis, smoking, family history and inherited cancer syndromes. A risk factor raises vigilance but screening is not offered indiscriminately to the general UK population.
Presentation ranges from vague dyspepsia and appetite change to iron-deficiency anaemia, progressive vomiting from antral obstruction, dysphagia from junctional disease, bleeding, a Virchow node or metastatic ascites. The symptom threshold in NG12 is designed to obtain timely endoscopy before obvious advanced disease. If gastroscopy finds an ulcer or infiltrative area, adequate targeted biopsies and clear site documentation are essential; a smooth or benign-looking ulcer cannot be accepted without histology and healing follow-up.
After diagnosis, the oesophago-gastric MDT determines resectability and treatment intent. Protocolled CT evaluates nodes and distant organs, and laparoscopy can detect small peritoneal deposits or positive washings that make radical gastrectomy inappropriate. EUS helps stage selected early lesions considered for endoscopic therapy. Treatment choices range from endoscopic submucosal dissection to subtotal or total gastrectomy with nodal dissection, peri-operative chemotherapy, and biomarker-directed systemic or symptom-focused care.
Key points
- Gastric adenocarcinoma often causes non-specific early symptoms, so progressive weight loss, early satiety, anaemia, persistent vomiting and age-based NICE combinations must trigger timely endoscopy.
- NICE includes people aged 55 or over with weight loss plus upper abdominal pain, reflux or dyspepsia in the suspected oesophageal or stomach cancer pathway.
- High-quality gastroscopy should define tumour site, size, morphology and junctional relationship and obtain multiple adequate biopsies while inspecting the whole stomach for synchronous disease.
- Diffuse infiltrative cancer can produce linitis plastica with deceptively subtle mucosa and negative superficial biopsies; CT, EUS and deeper or alternative tissue acquisition may be needed.
- CT establishes gross local and metastatic anatomy, while potentially curative gastric cancer commonly requires staging laparoscopy to find radiologically occult peritoneal disease.
- Very early low-risk mucosal neoplasia may be treated endoscopically, whereas resectable invasive cancer usually requires gastrectomy with lymphadenectomy and peri-operative oncological treatment.
- Advanced disease treatment depends on performance status, histology and current predictive biomarkers; the oncology MDT must use up-to-date national approval and local genomic pathways.
- Nutrition, iron deficiency, sarcopenia, postoperative micronutrient loss and symptom control are treatment components from diagnosis through survivorship or palliative care.
02AetiologyUnderlying causes, associations and risk factors, with why each one matters.
Helicobacter-associated atrophy
Longstanding H. pylori gastritis can progress through gland loss, intestinal metaplasia and dysplasia to intestinal-type gastric adenocarcinoma.
Autoimmune and inherited risk
Autoimmune gastritis, pathogenic hereditary cancer variants and strong family history increase risk and may alter the distribution or age of presentation.
Environmental and host factors
Smoking, high-salt preserved foods, increasing age and previous gastric surgery modify risk, while many patients have no single identifiable exposure.
03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.
- 1Premalignant mucosal change
Chronic inflammation and atrophy create a field in which metaplastic epithelial clones acquire progressive dysplastic alterations.
- 2Invasive growth
Malignant glands or poorly cohesive cells cross the mucosa, infiltrate the stomach wall and sometimes produce diffuse linitis plastica.
- 3Lymphatic and peritoneal spread
Tumour disseminates early through rich gastric lymphatics and later to liver, peritoneum and distant sites, shaping stage and treatment options.
04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.
Persistent new dyspepsia, reduced appetite or epigastric discomfort has low specificity, but age, treatment resistance, family history, anaemia and objective weight change determine whether direct-access endoscopy or cancer referral is needed.
Early satiety, smaller meals and progressive unintentional weight loss may reflect reduced gastric compliance, outlet narrowing or systemic cancer. Quantify weight and intake at the first assessment.
Iron-deficiency anaemia, fatigue, breathlessness or positive occult blood may be the only clue. In an at-risk adult, iron replacement should accompany rather than replace gastrointestinal investigation.
Recurrent non-bilious food vomiting, dehydration and a succussion splash suggest antral or pyloric tumour and require admission when liquids, renal function or electrolytes are compromised.
Haematemesis, melaena, sudden severe pain, free gas or peritonism is an oncological emergency complication managed through acute bleeding or surgery pathways before elective staging.
Ascites, hepatomegaly, a left supraclavicular node, an umbilical nodule, pelvic mass, jaundice or bone pain may represent disseminated disease and should be recorded before staging.
05InvestigationsWhat to request, why it matters and how to interpret it.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
High-quality gastroscopy and biopsyFirst step - Why
- Locate the lesion, establish histology and assess synchronous gastric disease.
- Interpretation and limitations
- Take multiple targeted samples from viable tumour and report exact location, especially relation to the gastro-oesophageal junction. Repeat or deepen tissue acquisition when linitis, subepithelial or extrinsic disease makes superficial samples negative.
- 02
Histopathology and predictive testing - Why
- Define tumour type and information that changes current systemic options.
- Interpretation and limitations
- Confirm adenocarcinoma versus lymphoma, GIST or neuroendocrine disease before applying a pathway. Advanced adenocarcinoma tissue enters the current regional panel for treatment-relevant biomarkers; requirements change as NICE approvals evolve.
- 03
Contrast CT staging - Why
- Assess primary anatomy, nodes, liver, lung, peritoneum and other metastatic sites.
- Interpretation and limitations
- CT determines whether radical staging should continue but misses small-volume peritoneal spread. Apparent unresectability or an unexpected solitary metastasis should be reviewed by the specialist MDT.
- 04
Staging laparoscopy - Why
- Detect occult peritoneal or surface liver disease before radical gastric surgery.
- Interpretation and limitations
- Use for potentially curable gastric cancer according to the oesophago-gastric pathway, often with peritoneal washings. Positive disease can prevent a non-beneficial laparotomy and redirect systemic care.
- 05
Endoscopic ultrasound - Why
- Refine depth and local-node assessment in selected early lesions.
- Interpretation and limitations
- EUS is most useful when endoscopic resection versus surgery depends on depth. Ulceration, fibrosis and stenosis can reduce accuracy; definitive resection histology may upstage a lesion.
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Fitness and nutrition work-up - Why
- Prepare a safe radical or palliative plan and identify reversible depletion.
- Interpretation and limitations
- Measure weight loss, frailty, performance status, FBC, iron, renal and liver function and cardiopulmonary reserve. Malnutrition requires active support but should be integrated without avoidable staging delay.
06Differential diagnosisRealistic alternatives and the features that help distinguish them.
Peptic ulcer disease
Benign ulcer symptoms and appearance overlap; multiple adequate biopsies and documented healing are needed because gastric cancer can ulcerate deceptively.
Functional dyspepsia
A stable symptom pattern without weight loss, anaemia, vomiting, mass or structural lesion supports functional disease after proportionate assessment.
Gastric lymphoma or subepithelial tumour
Different endoscopic layer, biopsy morphology and staging pattern identify lymphoma, gastrointestinal stromal tumour or another non-adenocarcinoma lesion.
07ManagementImmediate care, first-line treatment, alternatives and escalation.
01DetectRoute symptoms to endoscopyFirst stepWeight loss, early satiety, persistent vomiting, iron deficiency or a current NG12 age-and-symptom combination raises gastric cancer concern.+
- 1Check dysphagia, bleeding, vomiting, measured weight, anaemia, abdominal findings and family history, then use the suspected-cancer or direct-access endoscopy route specified by current NICE and local services.
- 2Send relevant FBC, renal and liver profiles without allowing normal results to delay endoscopy when the symptom combination already qualifies.
- 3Safety-net inability to tolerate liquids, haematemesis and sudden pain as acute complications rather than asking the patient to wait for the outpatient cancer pathway.
02StageDefine treatment intentBiopsy confirms gastric malignancy and immediate emergency treatment is not the sole priority.+
- 1Review pathology and tumour location in the oesophago-gastric MDT, distinguishing adenocarcinoma from lymphoma, GIST and neuroendocrine neoplasia because their treatments diverge.
- 2Complete protocolled CT and, when disease appears potentially curable, staging laparoscopy; use EUS selectively for early local staging and obtain adequate predictive-marker tissue for advanced disease.
- 3Assess frailty, cardiopulmonary reserve, nutrition and the patient's goals in parallel, then explain curative probability and consequences of endoscopic therapy, gastrectomy, systemic treatment or supportive care.
03TreatIntegrate tumour and whole-person carePreferredThe MDT has established stage, resectability, physiological fitness and preferred treatment goals.+
- 1Refer eligible superficial low-risk disease for expert en-bloc endoscopic resection, using final depth, margins and lymphovascular findings to decide whether additional surgery is needed.
- 2For resectable invasive adenocarcinoma, coordinate subtotal or total gastrectomy and nodal dissection with peri-operative oncological therapy and prehabilitation according to the current regional protocol.
- 3For advanced disease, choose biomarker-informed systemic treatment and proportionate relief of bleeding, pain or obstruction, maintaining dietetic, palliative and psychological support throughout.
08ComplicationsImportant consequences, why they occur and why they matter clinically.
Bleeding and anaemia
Friable tumour causes chronic occult loss or haematemesis, producing iron deficiency, fatigue and reduced treatment resilience.
Outlet obstruction or perforation
Antral narrowing causes retained food and vomiting, while deep ulceration can perforate and present as an acute surgical emergency.
Metastasis and cachexia
Hepatic, nodal and peritoneal spread produces ascites, pain, early satiety and catabolic weight loss that may require early nutritional and palliative support.
09Monitoring and follow-upTreatment response, safety checks and longer-term review.
- Track completion of histology, CT, laparoscopy where indicated, biomarker testing and MDT decision so no single staging gap silently delays treatment.
- Measure weight, intake, muscle function, FBC, iron and relevant micronutrients through prehabilitation, treatment and recovery, escalating enteral support when oral intake is inadequate.
- After gastrectomy, monitor dumping symptoms, pancreatic or bile-related maldigestion where relevant, iron, B12, folate, vitamin D, calcium, bone health and weight under the surgical nutrition plan.
- During systemic therapy, follow regimen-specific haematological, renal, hepatic, neurological and immune toxicities through current oncology protocols.
- Investigate new dysphagia, vomiting, bleeding, early satiety, pain or weight loss during surveillance rather than waiting for the next routine appointment.
- In non-curative care, reassess obstruction, stent or bypass function, analgesia, nausea, bleeding, nutrition and goals whenever performance status or treatment benefit changes.
10Special situationsVariants, exceptions and circumstances that change the usual approach.
Mucosa can look modest
Diffuse infiltrative cancer spreads within the wall and can spare the surface, so repeated ordinary forceps biopsies may remain negative despite a rigid non-distensible stomach.
Laparoscopy changes intent
Tiny peritoneal deposits often evade CT but can be found before gastrectomy, preventing a major operation unlikely to achieve cure.
Location changes pathway
A tumour near the gastro-oesophageal junction must be assigned carefully because staging, reconstruction and oncological evidence differ from a distal gastric lesion.
Early can be endoscopic
Selected mucosal cancers with very low nodal risk can be removed en bloc, preserving the stomach while providing a specimen for definitive pathological staging.
Survival needs nutrition
Gastrectomy permanently changes reservoir function and micronutrient absorption, so nutritional follow-up remains necessary long after the wound has healed.
11Common pitfallsFrequent interpretation and management errors.
- 01
Treating persistent dyspepsia repeatedly without applying current age, weight-loss and anaemia investigation thresholds.
- 02
Calling a gastric ulcer benign from appearance or a single non-diagnostic superficial biopsy.
- 03
Proceeding to curative gastrectomy without completing peritoneal staging when indicated.
- 04
Applying an adenocarcinoma treatment plan to lymphoma, GIST or neuroendocrine histology.
- 05
Delaying nutrition support until all staging and oncology decisions are complete.
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Using an obsolete biomarker or chemotherapy list instead of the current regional NICE-approved oncology pathway.