What does a gastroscopy biopsy showing intestinal metaplasia indicate?

Gastric Intestinal Metaplasia: Clinical Significance and Management

Gastric intestinal metaplasia (GIM) is a significant precancerous condition that increases the risk of gastric cancer development by approximately 6-fold and requires risk stratification for appropriate surveillance. 1 This finding on gastroscopy biopsy warrants a structured approach to management based on current guidelines.

Clinical Significance of Intestinal Metaplasia

Intestinal metaplasia represents the replacement of normal gastric mucosa with intestinal-type epithelium, characterized by the presence of:

• Goblet cells
• Absorptive cells
• Paneth cells (in complete metaplasia)
• Specialized mucin production

GIM is a key step in the Correa cascade of gastric carcinogenesis, where normal gastric mucosa progresses through inflammation, atrophy, intestinal metaplasia, dysplasia, and eventually to invasive cancer. 2

Risk Stratification

The risk of progression to gastric cancer varies based on several factors:

High-Risk Features:

• Extent of metaplasia: Involvement of both antrum and corpus or extension >20% of gastric mucosa 1
• Histologic subtype: Incomplete intestinal metaplasia carries higher risk than complete metaplasia 3
• Presence of H. pylori infection: Major risk factor for progression 3
• Family history: First-degree relatives of gastric cancer patients 1
• Geographic/ethnic factors: Higher risk in East Asian populations 4

Management Algorithm

1. Test and treat for H. pylori

   • All patients with GIM should be tested and treated for H. pylori to reduce gastric cancer risk 3
   • H. pylori eradication may slow progression even though GIM itself may not regress after treatment 1

2. Risk assessment

   • Determine extent of metaplasia through systematic biopsies
   • Request histologic subtyping (complete vs. incomplete) 3
   • Assess for other risk factors (family history, smoking, etc.)

3. Surveillance decisions

   • According to the 2024 Gut guidelines, only patients with high-risk GIM phenotypes should undergo regular endoscopic surveillance 3
   • High-risk features include:
     • Corpus-extended GIM
     • OLGIM stages III/IV
     • Incomplete GIM subtype
     • Persistent refractory H. pylori infection
     • First-degree family history of gastric cancer 3

4. Surveillance intervals

   • Most guidelines recommend a 3-year interval for high-risk patients 3
   • Low-risk phenotypes (which comprise most patients with GIM) do not require surveillance 3

Endoscopic Technique for Surveillance

For patients requiring surveillance, high-quality endoscopy is essential:

• Follow the updated Sydney System biopsy protocol: 2 biopsies from the antrum (lesser and greater curvature), 1 from the incisura angularis, and 2 from the body (lesser and greater curvature) 3
• Consider special staining techniques like Alcian blue/PAS, which can increase detection of intestinal metaplasia by approximately 14% compared to standard H&E staining 5
• Document findings using standardized reporting systems (OLGA/OLGIM) where available 3

Common Pitfalls to Avoid

1. Failing to distinguish between gastric and esophageal intestinal metaplasia

   • Intestinal metaplasia at the gastroesophageal junction (cardia) has different implications than Barrett's esophagus 3
   • The normal appearing squamocolumnar junction should not be biopsied routinely 3

2. Inadequate biopsy sampling

   • Sampling error can lead to missed diagnoses
   • Always follow systematic biopsy protocols 3

3. Overlooking H. pylori testing

   • H. pylori eradication is the only proven non-endoscopic intervention for gastric cancer prevention 3

4. Overuse of surveillance in low-risk patients

   • Most patients with limited GIM do not require intensive surveillance 3

5. Failure to recognize high-risk features

   • Incomplete-type GIM and extensive GIM require closer monitoring 1

Current guidelines acknowledge evidence gaps in GIM management, particularly regarding optimal surveillance protocols and cost-effectiveness in different populations. The American Gastroenterological Association suggests shared decision-making regarding surveillance given these evidence gaps. 3