Stages III and IV are considered high-risk phenotypes for gastric adenocarcinoma and require endoscopic surveillance according to MAPS II guidelines.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Prognostic staging of gastric atrophy for gastric cancer (GC) risk assessment
To guide the frequency of endoscopic surveillance in patients with chronic gastritis
To monitor the progression or stabilization of mucosal damage following H. pylori eradication
Philosophy of OLGA
The OLGA (Operative Link on Gastritis Assessment) system recognizes that the risk of gastric cancer is proportional to the biological degree and anatomical extent of atrophy (loss of specialized glands).
Section 2
Formula & Logic
The Sydney Biopsy Protocol
01
Standardized biopsies are required: 2 from the antrum, 1 from the incisura, and 2 from the corpus.
02
The pathologist grades the atrophy percentage (0–3) in each specimen.
OLGA Matrix (Stages 0–IV)
Stage 0
No atrophy in any biopsy.
Stage I–II
Low Risk: Atrophy limited to the antrum or sparse in the corpus.
Stage III–IV
High Risk: Extensive atrophy involving both the antrum and corpus.
Interpretation
Stage III/IV patients carry a significantly higher relative risk for developing intestinal-type gastric adenocarcinoma.
Section 3
Pearls/Pitfalls
OLGA vs. OLGIM
OLGIM replaces "Atrophy" with "Intestinal Metaplasia" (IM). While IM is easier for pathologists to identify reliably (better inter-observer agreement), OLGA is often considered more "biologically sensitive" because atrophy precedes metaplasia in the Correa cascade.
The H. pylori Factor
Atrophy (OLGA Stage) may stabilize or even slowly regress after successful H. pylori eradication, but the "point of no return" is generally thought to be the development of Intestinal Metaplasia.
Clinical Pearls
OLGA Stage III/IV patients require endoscopic surveillance every 3 years (MAPS II European Guidelines)
The "Incisura Angularis" is a bridge between the antrum and corpus and is the most common site for early neoplasia
OLGA staging should always be interpreted alongside H. pylori status and family history of gastric cancer
Section 4
Next Steps
Surveillance Interval
01
OLGA Stage III/IV: High-definition endoscopy every 3 years.
02
OLGA Stage 0-II: No routine surveillance needed unless other high-risk factors (Family hx) exist.
Complementary Tools
Correa Cascade (Gastritis Staging)
H. pylori Eradication Algorithm
Gastric TNM Staging
Section 5
Evidence Appraisal
The Definitive System
Gastritits staging in clinical practice: the OLGA staging system.
Rugge M et al. • Gut. 2007;56(5):631-6. The primary proposal and validation study.
Developed by Massimo Rugge and a group of expert GI pathologists. They recognized that the "Sydney System" provided a language of description but failed to provide a "Stage" that clinicians could use to manage cancer risk, leading to the creation of the OLGA Matrix.
