Gastric cancer
Gastric cancer is mostly adenocarcinoma, split into an H. pylori-driven intestinal type arising through chronic atrophic gastritis and intestinal metaplasia and a diffuse signet-ring type causing linitis plastica, and it typically presents late with alarm dyspepsia and weight loss. Upper endoscopy with biopsy confirms the diagnosis, TNM stage with endoscopic ultrasound, CT, and diagnostic laparoscopy sets treatment, and management ranges from endoscopic resection for early T1a disease to gastrectomy with D2 lymphadenectomy and perioperative FLOT chemotherapy for resectable disease to palliative chemotherapy for advanced disease.
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What this article covers
- Overview
Definition: gastric cancer is a malignant tumor of the gastric mucosa, overwhelmingly adenocarcinoma, developing through a multistep progression from chronic inflammation to invasive carcinoma.
- Epidemiology
Falling but still major: United States incidence about 6.6 per 100,000 and mortality about 3.1 per 100,000, steadily declining since the 1990s alongside falling H.
- Risk factors
Helicobacter pylori infection: the primary nongenetic risk factor, associated with both intestinal and diffuse types through chronic inflammation and mucosal atrophy.
- Pathophysiology
Intestinal type follows a defined cascade: chronic H.
- Clinical features
Early disease is asymptomatic or vaguely dyspeptic, which is why most gastric cancer is diagnosed only after alarm features develop.
- Differential diagnosis
Peptic ulcer disease: meal-related epigastric pain without systemic weight loss; any gastric ulcer must be biopsied and followed to healing to exclude malignant transformation (peptic ulcer disease).
- Diagnosis
Upper endoscopy with biopsy establishes the diagnosis: multiple biopsies of any suspicious lesion, ulcer, or mucosal irregularity give the histologic diagnosis and distinguish adenocarcinoma from…
- Management
First, confirm resectability and stage, because management is entirely stage-dependent rather than a single algorithm.
- Complications
Gastric outlet obstruction: from a distal antral or pyloric tumor, causing early satiety, postprandial vomiting, and inability to maintain oral intake.
- Prognosis
Stage at diagnosis dominates survival: early-stage disease resected endoscopically or surgically has a favorable prognosis, whereas unresectable or metastatic disease has five-year survival below 10%.
- Prevention
Test-and-treat for Helicobacter pylori, particularly with a family history of gastric cancer, chronic atrophic gastritis, or intestinal metaplasia, because earlier eradication may decrease…
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Peptic ulcer disease is a mucosal break in the stomach or duodenum caused chiefly by Helicobacter pylori infection or NSAID use, diagnosed by upper endoscopy with biopsy of gastric ulcers to exclude malignancy. Treatment eradicates H. pylori when present, stops the ulcerogenic drug, and heals the ulcer with a proton pump inhibitor, while its complications of bleeding, perforation, and obstruction drive most of its morbidity.
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- Barrett esophagus
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- Pernicious anemia
Pernicious anemia is autoimmune atrophic gastritis that destroys gastric parietal cells and abolishes intrinsic factor production, causing vitamin B12 malabsorption, megaloblastic macrocytic anemia, and a potentially irreversible myelopathy and neuropathy. Diagnosis rests on a low or borderline B12 with an elevated methylmalonic acid, confirmed by anti-intrinsic factor antibody, and treatment is lifelong vitamin B12 replacement.
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