Dissecting the Role of MIcrobioMe in gastroEsophageal Tumor: a multIdisCiplinary Longitudinal Study

Gastric cancer (GC) is the second leading cause of cancer mortality and remains the fourth common cancer worldwide. Gastric and esophageal cancers treated with curative intent both have a poor prognosis with five-year survival rate varying between 30% and 40% \[Hagen\]. Therefore, even in the localized or locally advanced (LA) disease, relapse-related death remains a major challenge for curative treatment. Currently, there are several strategies for the curative treatment of GC including perioperative chemotherapy (peri-Op cht), adjuvant chemotherapy and adjuvant chemoradiotherapy. Despite the therapeutic management of localized or LA GC is well established, there is uncertainty about the power of prognostic and predictive factors to tailor anticancer treatments. In addition to that, further investigation is needed to investigate if pre-existing environment factors may act on carcinogenesis and to explore the molecular mechanisms that underlying cancer growth and invasiveness.