Chilean consensus by expert panel using the Delphi technique for primary and secondary prevention of gastric cancer

Introduction: Gastric cancer (GC) is the first cause of cancer-related death in Chile and 6^th in Latin America and the Caribbean (LAC). Helicobacter pylori (H. pylori) is the main gastric carcinogen, and its treatment reduces GC incidence and mortality. Esophageal-gastro-duodenoscopy (EGD) allows for the detection of premalignant conditions and early-stage GC. Mass screening programs for H. pylori infection and screening for premalignant conditions and early-stage GC are not currently implemented in LAC. The aim of this study is to establish recommendations for primary and secondary prevention of GC in asymptomatic standard-risk populations in Chile.

Methods: Two on-line synchronous workshops and a seminar were conducted with Chilean experts. A Delphi panel consensus was conducted over 2 rounds to achieve>80% agreement on proposed primary and secondary prevention strategies for the population stratified by age groups.

Results: 10, 12, and 12 experts participated in two workshops and a seminar, respectively. In the Delphi panel, 25 out of 37 experts (77.14%) and 28 out of 52 experts (53.85%) responded. For the population aged 16-34, there was no consensus on non-invasive testing and treatment for H. pylori, and the use of EGD was excluded. For the 35-44 age group, non-invasive testing and treatment for H. pylori is recommended, followed by subsequent test-of-cure using non-invasive tests (stool antigen test or urea breath test). In the ≥45 age group, a combined strategy is recommended, involving H. pylori testing and treatment plus non-invasive biomarkers (H. pylori IgG serology and serum pepsinogens I and II); subsequently, a selected group of subjects will undergo EGD with gastric biopsies (Sydney Protocol), which will be used to stratify surveillance according to the classification Operative Link for Gastritis Assessment (OLGA); every 3 years for OLGA III-IV and every 5 years for OLGA I-II.

Conclusion: A "test-and-treat" strategy for H. pylori infection based on non-invasive studies (primary prevention) is proposed in the 35-44 age group, and a combined strategy (serology and EGD) is recommended for the ≥45 age group (primary and secondary prevention). These strategies are potentially applicable to other countries in LAC.