Pembrolizumab Plus Chemo in Neoadjuvant Treatment of Esophageal Squamous Cell Carcinoma (Eastern Cooperative Thoracic Oncology Projects 2004, ECTOP-2004)

This study tests whether adding pembrolizumab (an immunotherapy drug) to standard chemotherapy before surgery improves outcomes for people with locally advanced esophageal squamous cell carcinoma — a cancer in the tube connecting the throat to the stomach. This is called neoadjuvant (pre-surgery) treatment. **You may be eligible if...** - You are 18 or older with locally advanced esophageal squamous cell carcinoma that can be surgically removed - You have not previously received any treatment for this cancer - Your overall health is good (ECOG performance status 0 or 1) **You may NOT be eligible if...** - You have previously received immunotherapy (anti-PD-1 or PD-L1 agents) - You have active autoimmune disease requiring systemic treatment - You have a history of severe lung inflammation (pneumonitis) - You have an active infection requiring treatment - You are pregnant or breastfeeding - You have had an organ transplant Talk to your doctor to see if this trial is right for you.