This prospective study aims to clarify the clinical efficacy and survival prognosis of neoadjuvant immune checkpoint inhibitor (ICI) combined with chemotherapy for esophageal cancer. It also explores predictive biomarkers and potential therapeutic targets for locally advanced esophageal cancer based on plasma metabolomics and peripheral blood immune cell clustering analysis. Each patient received 2-3 cycles of neoadjuvant immunotherapy with programmed cell death 1 (PD-1) blockade in combination with albumin paclitaxel and platinum. Exploratory analysis of plasma metabolomics combined with peripheral blood subsets of immune cells can reveal biomarkers that predict the efficacy and prognosis of patients undergoing neoadjuvant immunotherapy for locally advanced esophageal cancer, which also provide new ideas for the selection of immune adjuvants and therapeutic targets in ICIs combination therapy strategies.

Inclusion Criteria:

1. age ≥ 18 years and ≤89 years;
2. pathological histological examination confirmed the diagnosis of esophageal squamous cell carcinoma and esophageal adenocarcinoma;
3. clinical stage II-IVA;
4. adequate organ function;
5. no previous chemotherapy or radiotherapy;
6. voluntarily signed informed consent.

Exclusion Criteria:

1. the presence of concurrent malignancies that interfere with the prognosis of esophageal cancer;
2. patients with immunodeficiency or autoimmune diseases that seriously affect the body's immune system, such as those who test positive for HIV;
3. patients undergoing systemic corticosteroid or other immunosuppressive treatments;
4. patients with a history of allergy to the components of this test drug.

There is not a plan to make IPD available.