Perioperative Cadonilimab Combined With Neoadjuvant Chemotherapy in Resectable Esophageal Squamous Cell Carcinoma (ESCC)

Inclusion Criteria: * Be able and willing to provide written informed consent and to comply with all requirements of study participation (including all study procedures). * ≥18 years old and ≤ 75 years (regardless of sex). * Pathologically confirmed esophageal squamous cell carcinoma, assessed as resectable. * Adequate pulmonary function. * Adequate tumor tissue samples. * ECOG performance status of 0-1. * Adequate organ function. * Within 7 days prior to the first dose, women of childbearing potential must have a negative urine or serum pregnancy test and agree to use effective contraception during the study treatment period and for 120 days after the last dose. Exclusion Criteria: * Presence of suspected distant metastatic lesions, or locally advanced unresectable disease. * Histologically confirmed as other pathological types. * Previous surgery precludes the use of gastric substitution for esophageal reconstruction in the current procedure. * History of other malignant tumors within the past 5 years. * Within 4 weeks prior to randomization, presence of conditions such as severe esophagogastric varices, active ulcers, unhealed wounds, gastrointestinal perforation, or intestinal obstruction. * Active or documented history of inflammatory bowel disease. * Clinically symptomatic or recurrent pleural, pericardial, or ascitic fluid requiring drainage. * Uncontrolled concurrent illnesses. * Acute exacerbation of chronic obstructive pulmonary disease within 4 weeks prior to ra…