Advanced GC Multi-omic Characterization in EU and CELAC Populations

Cases:

* Inclusion criteria:

  * Subjects ≥18 years old.
  * GC diagnosis stages III and IV (including gastroesophageal junction cancer) and/or a gastroscopy indication due to the high diagnostic suspicion of GC as part of the study of his disease.
  * Has given and signed the IC to participate in this study.
* Exclusion criteria:

  • Patients diagnosed with GC early disease (stage I and II) suitable for resectable strategy.
* Withdrawal criteria:

  * Patients initially recruited with high suspicion of GC diagnosis but not confirmed by the pathological report.

Controls:

* Inclusion criteria (only for microbiome analysis):

  * Subjects ≥18 years old.
  * Subjects to whom a gastroscopy is indicated within clinical care and is confirmed absent of GC in the same centres will be matched in age (+/- 10 years), gender and pertaining from the same region of the GC case.
  * Has given and signed the IC to participate in this study.
* Exclusion criteria:

  * Subjects from a different geographic area from the cases.
  * Patients with high suspicion of GC.
  * Patients with previous histopathologic diagnosis of peptic (gastric or duodenal) ulcer disease and/or atrophy or intestinal metaplasia.
  * Patients that have received antimicrobials during the 4 weeks period prior to the endoscopy.
  * Patients that have received proton pump inhibitors or H2-receptor antagonists, at least 2 weeks prior to the endoscopy