Endoscopic Surveillance on a High-risk Population for Gastric Cancer in Latin America: The ECHOS Cohort Study.

Study Overview
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Brief Summary
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The goal of this observational study is to evaluate the risk factors associated with incident HGD/GA in patients with CAG with or without IM who are enrolled in endoscopic surveillance, as well as to compare GA incidence according to the OLGA and OLGIM scales in patients 18 years or older. . The main questions it aims to answer are: What risk factors are associated with incident HGD/GA in patients with CAG with or without IM? What is the comparative HGD/GA incidence according to the OLGA and OLGIM scales?

Detailed Description
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The Endoscopic Cohort and Histological OLGA staging (ECHOS) study is a retrospective longitudinal cohort developed in the Pontificia Universidad Católica de Chile health care system, an open health care system with 3 endoscopic units in Santiago, Chile. Patients 18 years or older were eligible for the study if they had at least one non-urgent outpatient EGD with gastric biopsies collected following the USSBP between June 2015 and June 2021. The baseline EGD was defined as the earliest examination conducted between this time frame that met inclusion criteria. Participants were included in the cohort if they underwent a subsequent surveillance EGD. In order for the subsequent EGD to qualify as surveillance, it needed to occur at least 6 months after the baseline EGD and include gastric biopsies collected according to the USSBP; one exception to the USSBP requirement was if HGD or GA was detected on the surveillance (i.e. non-baseline) EGD. Patients with prior history of HGD or any type of gastric malignancy, gastrectomy or non-gastric active malignancy were excluded. Also, patients with HGD or GA on the baseline EGD were excluded. Patients with indefinite (IND) or low-grade dysplasia (LGD) on the baseline EGD were considered for the cohort.

Official Title
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The Impact of Endoscopic Surveillance of Atrophic Gastritis With and Without Intestinal Metaplasia on a High-risk Population for Gastric Cancer in Latin America: The ECHOS Cohort Study.

Conditions
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Gastric Cancer, Dysplasia Stomach, Atrophic Gastritis, Helicobacter Pylori Infection

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: At least one non-urgent outpatient esophagogastroduodenoscopy (EGD) with gastric biopsies collected following the Updated Sydney System Biopsy Protocol (USSBP) between June 2015 and June 2021. Underwent a subsequent surveillance EGD. For the subsequent EGD to qualify as surveillance, it needed to occur at least six months after the baseline EGD and include gastric biopsies collected according to the USSBP; one exception to the USSBP requirement was if HGD or GA was detected on the surveillance. Exclusion Criteria: Prior history of HGD or any type of gastric malignancy, gastrectomy, or non-gastric active malignancy. HGD or GA on the baseline EGD was excluded.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| High grade dysplasia/Gastric adenocarcinoma | Progression from chronic atrophic gastritis or intestinal metaplasia according to baseline Operative Link on Gastritis Assessment (OLGA) staging in baseline measurement to high-grade dysplasia and adenocarcinoma. The OLGA uses grades from in tiered scale from 0 to IV, resulting from the combination of atrophic changes (0 = absent; 1 = mild; 2 = moderate; 3 = severe) in the two mucosal compartments (antrum and corpus). | At least 6 months between first and second EGD, assessed up to 96 months |