Observational Study of Patients Treated With Nivolumab and Chemotherapy for Advanced or Metastatic Esophageal, Gastroesophageal or Gastric Cancer in France

This is an observational study in France tracking real-world outcomes for patients with advanced stomach, gastroesophageal junction (where the esophagus meets the stomach), or esophageal cancer who are being treated with nivolumab (an immunotherapy) combined with chemotherapy as their first treatment. No new drugs are assigned — researchers are simply collecting data on how patients do on their current standard treatment. **You may be eligible if...** - You are 18 or older with confirmed advanced or metastatic gastric, gastroesophageal junction, or esophageal cancer - You are starting or have recently started nivolumab plus chemotherapy as first-line treatment - Your tumor meets specific PD-L1 expression criteria - You have provided consent to have your data collected **You may NOT be eligible if...** - You have had another active cancer in the last 5 years - You are enrolled in an interventional (treatment-assigning) clinical trial for your cancer - You do not meet the specific tumor type or PD-L1 criteria Talk to your doctor to see if this trial is right for you.