Study on the Regulation of the Response to Concurrent Chemoradioimmunotherapy in Locally Advanced Esophageal Squamous Cell Carcinoma by Oral-Blood Microecology via Peripheral Blood Immune Cells

INTERVENTION: Group A :Radiotherapy (50–50.4 Gy) combined with camrelizumab, albumin‐bound paclitaxel, and carboplatin, administered in 3‐week cycles for 2 to 4 cycles. ;Group B: Radiotherapy (50–50.4 Gy) combined with camrelizumab and capecitabine, administered in 3‐week cycles for 2 to 4 cycles.; CONDITION: Esophagus cancer PRIMARY OUTCOME: One‐year progression‐free survival rate; SECONDARY OUTCOME: progression‐free survival ;overall survival; INCLUSION CRITERIA: 1. Age = 18 years old; 2. Histologically or cytologically confirmed esophageal squamous cell carcinoma (ESCC); 3. Locally advanced resectable stage II/III/IVa (cT1b‐4aN0‐3M0) ESCC patients; 4. No previous chemotherapy, radiotherapy or surgery for esophageal cancer; 5. At least one measurable lesion according to the Response Evaluation Criteria in Solid Tumors (RECIST 1.1); 6. ECOG: 0‐1; 7. Expected survival = 12 weeks; 8. Within 7 days before enrollment, the blood routine and biochemical indicators of the subjects should meet the following standards: (1). Hemoglobin = 90g/L; absolute neutrophil count (ANC) = 1.5×109/L; platelet = 100×109/L (the subjects should not have received blood transfusion or growth factor support within 14 days before blood sample collection); (2). ALT, AST = 2.5 times the upper limit of normal (ULN); ALP = 2.5 times ULN; c. Serum total bilirubin < 1.5 times ULN (patients with Gilbert's syndrome can be enrolled if t