Multicentric, exploratory, non-pharmacologic, retrospective/prospective, translational study aiming to identify the molecular, cellular and psychological-sociological variables predictive of response to chemotherapy in gastric cancer patients.

Gastric cancer (GC) is a complex disease that represents the fifth most common malignancy in the world and the third leading cause of cancer death in both sexes. Chemotherapy (CT) combined with surgery represents the standard of care for stages II-III GC, but the efficacy of such treatments is still limited for many patients. It is mandatory to develop novel strategies aimed at identifying predictive markers, as well as deciphering the impact of the psychological-social and cultural environment of each patient on the outcome. GRAMMY study proposes a novel interdisciplinary approach integrating high impact basic, translational and psychological/sociological research towards developing an optimized patient stratification tool for the early prediction of therapy-resistant GC patient groups.

Inclusion Criteria:

• Patients with diagnosis of histologically confirmed, potentially resectable adenocarcinoma of the stomach (GC) or the gastric-esophageal junction (GEJ) treated with the standard regimens (5-Fluoro-Uracil or Capecitabine + Oxaliplatin +/- Docetaxel)
• Participant is willing and able to give informed consent for participation in the study (prospective and retrospective cohort) or Substitutive Informed Consent Declaration Form will be subscribed by the PI for patients that are not reachable
• Male or Female, aged >18 years
• Availability of tissue samples and clinico-pathological data for retrospective cohort

Exclusion Criteria:

• Age < 18 years
• Early Gastric Cancer and T2 (if N0)
• Linitis plastica
• Positive peritoneal cytology or peritoneal involvement
• Distant metastases
• Patient refusal to participate
• Patient refusal to the use of their own samples for research
• Patient withdrawing from treatment plan whilst under therapy due to patient co-morbidities or failure to comply with clinical counselling
• Patients with underlying pathologies rendering sampling of biological material either as endangering patient's clinical status or as unusable
• Patients with mental illness hindering the capacity to provide precise information in questionnaires or successfully comply with caregiver's recommendations

Patients diagnosed with potentially resectable adenocarcinoma of the stomach (GC) or the gastric-esophageal junction (GEJ) who received pre- or peri-operative chemotherapy or up-front surgery followed by chemotherapy