Although unprecedented advances have been made in the field of esophageal cancer in recent decades, the prognosis for patients with locally advanced esophageal squamous cell carcinoma (ESCC) remains extremely poor, accounting for 30-40% of overall survival at 5 year. In recent years, multimodal treatments have proven to be an appropriate therapeutic approach for locally advanced ESCC. Recently, immunotherapy developed rapidly. The purpose of this study was to observe the efficacy and safety of cardonilizumab combined with chemoradiotherapy in the treatment of locally advanced ESCC.

Inclusion Criteria:

• 18-80 years old；
• Eligible patients were histologically confirmed esophageal squamous cell carcinoma;
• Eligible patients were proven locally advanced ESCC (cT1-2N1-3M0-1, cT3/T4N0-3M0-1, M1 was limited to supraclavicular lymph node metastasis）diagnosed by computed tomography [CT] and/or endoscopic ultrasonography [EUS] according to the American Joint Committee on Cancer (AJCC) 8th edition staging system；
• ECOG PS score: 0~1；
• Main organs and bone marrow function are normal: routine blood tests: hemoglobin (Hb) ≥100g/L ; absolute neutrophil count (NEUT)≥1.5×109/L; platelets (PLT) ≥100×109/L; white blood cell (WBC)≥3.5×109/L,biochemical examination: alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤1.5×UNL; serum total bilirubin (TBIL) ≤1.5×UNL; serum creatinine ( Cr) 1.0×1.5UNL, and BUN≤1.0×UNL;

Exclusion Criteria:

• Those combined with other primary malignant tumors other than esophageal cancer (except cured basal cell carcinoma of the skin and carcinoma in situ of the cervix);
• patients who had previously received other treatments
• At the time of diagnosis, there were distant and hematogenous metastases beyond the supraclavicular lymph node region, including retroperitoneal multiple lymph node metastasis, bone metastasis, brain metastasis, lung metastasis, liver metastasis, malignant pleural effusion and ascites
• Those who already have esophageal perforation or are at high risk of esophageal perforation
• Patients whose tumors invade close to large blood vessels and are at risk of bleeding in the
• there are active infections, such as active tuberculosis and hepatitis
• There are contraindications to immunotherapy.
• Pregnant or lactating women and women of childbearing age do not take reliable contraceptive measures
• Combined with serious cardiovascular diseases, such as uncontrolled heart failure, coronary heart disease, cardiomyopathy, uncontrolled arrhythmia, uncontrolled hypertension, or a history of myocardial infarction within the past 6 months; and those combined with other uncontrolled acute and chronic diseases such as hypertension and diabetes.
• Violation of inclusion and exclusion criteria, or other reasons that the researcher believes cannot continue the study of drug treatment.