- Chronic Gastritis → Chronic Atrophic Gastritis → Gastric intestinal metaplasia → Dysplasia → Cancer
- Chronic Gastritis
- Inflammation due to:
- H. pylori, NSAIDS, Bile Reflux, Autoimmune Inflammation, EtoH, Nitrates from meat/food
- Chronic Atrophic Gastritis
- Atrophy/loss of the original gastric glands
- Atrophy leads to decreased acid & increased pH
- Proliferation of anaerobic bacteria
- Increased conversion of nitrates to nitrites → N-nitrosamines
- Gastric intestinal metaplasia
- Replacement of the normal gastric epithelium by a different type of epithelial tissue due to chronic irritation or injury
- Gastric dysplasia – architectural and cellular atypia
- Accumulated genetic mutations and epigenetic changes lead to abnormal epithelial proliferation.
- Dysplastic cells have atypical architecture, loss of differentiation, and increased mitotic activity.
- Low grade – progresses to adenocarcinoma 25% by 4 yrs
- High grade – progresses to adenocarcinoma – up to 60-80% at 4 yrs
- Vienna Classification
- Category 1: Negative for neoplasia/dysplasia
- Category 2: Indefinite for neoplasia/dysplasia
- Category 3: Non-invasive low-grade neoplasia (low-grade adenoma/dysplasia)
- Category 4: Non-invasive high-grade neoplasia
- 4.1: High-grade adenoma/dysplasia
- 4.2: Non-invasive carcinoma (carcinoma in situ)
- 4.3: Suspicion of invasive carcinoma
- Category 5: Invasive neoplasia
- 5.1: Intramucosal carcinoma (invasion into the lamina propria or muscularis mucosae)
- 5.2: Submucosal carcinoma or beyond