A Multicentre Observational Cross-Sectional Study of The Gastric Precancerous Epithelial Pathway Using High-Definition Endoscopy And Histopathology In India

Gastric adenocarcinoma is a major global health problem and remains a leading cause of cancer-related mortality. Early detection significantly improves survival, with 5-year survival rates exceeding 80% in countries with established screening programmes, such as Japan and South Korea. In contrast, most patients in India are diagnosed at advanced stages, resulting in poor outcomes.

The Correa cascade describes a stepwise progression from chronic gastritis to atrophic gastritis, intestinal metaplasia (IM), dysplasia, and invasive adenocarcinoma. Helicobacter pylori infection is a major driver of this pathway. Identifying and characterising gastric precancerous lesions provides an opportunity for surveillance and early intervention. India lacks high-quality multicentre data on the prevalence and spectrum of gastric precancerous lesions and early gastric cancer. This study aims to systematically evaluate the gastric precancerous epithelial pathway using high-definition endoscopy and standardised histopathology across multiple centres in India.

The Observational Study Model is recorded as 'Other' because IND-PREP is a single-time-point, cross-sectional diagnostic study and does not conform to the listed epidemiologic models (cohort, case-control, case-only, case-crossover, ecologic, or family-based). A defined group of patients undergoing upper gastrointestinal endoscopy is assessed at one point for the detection and characterisation of early gastric cancer and precancerous conditions. There is no longitudinal follow-up and no exposure-defined comparison group, consistent with the Cross-Sectional time perspective.

• Adults aged ≥40 years undergoing upper gastrointestinal endoscopy for dyspepsia or other clinical indications (nonalarming and alarming symptoms both).
• Ability to provide written informed consent.

Exclusion criteria

• Known gastric malignancy.
• Prior gastric surgery (excluding H. pylori eradication).
• Contraindications to endoscopy or biopsy.
• Known hereditary gastric cancer syndromes.