INTRODUCTION
esophageal cancer, PD‐L1, cancers, adenocarcinoma of distal esophagus, aggressive malignancies, Cancers of the upper gastrointestinal tract, deaths, gastric cancer
CPS, CANCERS, OESOPHAGEAL CANCER, GASTRIC CANCER
Cancers of the upper gastrointestinal tract including esophageal, gastric, and gastroesophageal junction (GEJ) cancers are a group of highly aggressive malignancies and a major public health problem globally. Approximately 604,000 new cases with 544,000 deaths of esophageal cancer and over 1 million new cases with 769,000 deaths of gastric cancer are diagnosed in 2020.This single arm phase II trial is aimed to evaluate efficacy and safety of pembrolizumab, in combination with mFOLFOX at the perioperative (both pre‐ and post‐operative) setting in patients with potentially resectable adenocarcinoma of distal esophagus, GEJ, and stomach. The study is also designed to analyze the expression of ICI treatment related markers PD‐L1 (CPS), CD8, and CD20 in the real time before and after preoperative therapy.