Esophageal cancer is a kind of disease with high incidence and mortality. Definitive concurrent chemoradiotherapy is an important treatment for locally advanced esophageal squamous cell carcinoma. To Investigate the value of immunotherapy consolidation in locally advanced esophageal squamous cell carcinoma after completing radical concurrent chemoradiotherapy.

In East countries, especially China, more than 75 percent of esophageal cancers are primary squamous cell cancers located in the middle and upper thoracic segments, whereas adenocarcinoma accounted for less than 20 percent.Unlike other malignancies, more than half of esophageal cancer were diagnosed as locally advanced at the time of diagnosis. Definitive concurrent chemoradiotherapy is an important treatment for locally advanced esophageal squamous cell carcinoma.

Immune checkpoint inhibitors are a new class of antitumor drugs. They are different from traditional cytotoxic chemotherapy drugs and can target the regulatory molecules that play an inhibitory role in the tumor immune system.

Recent clinical studies had shown that for locally advanced non-small cell lung cancer, maintenance therapy with the immune checkpoint inhibitor could significantly improve the overall survival for locally advanced non-small cell lung cancer after definitive concurrent chemoradiotherapy. Moreover, the immune checkpoint inhibitor PD-1 has also been shown to be a promising anticancer agent in esophageal cancers. Therefore, the present study intended to give a standard dose (50.4Gy/28F) to locally advanced esophageal squamous cell carcinoma for radical chemoradiotherapy, and than to give the Sintilimab as consolidation therapy for 1 year after completion of radiotherapy. At the time point of 6 weeks after radiotherapy, all participates need a full evaluation of the treatment response. In patients with residual disease, we would give them an additional radiotherapy boost to 61.2 Gy/34F under the guidance of PET-CT or ultrasound endoscopy.

Inclusion Criteria:

• ECOG 0-1; Life expectancy >6 months;
• Stage II/III esophageal cancer;
• Pathology confirmed squamous cell carcinoma;
• Hemoglobin ≥10g/dl, WBC ≥3.0 x 109/L, platelet ≥100 x 109/L; CR≤ 1.0x normal upper limit, total bilirubin ≤ 1.5x normal upper limit, AST and ALT≤ 1.5x normal upper limit, AKP≤ 2.5x normal upper limit;
• Have a full understanding of this study, participate voluntarily, have follow-up conditions and sign the informed consent;

Exclusion Criteria:

• Stage IV esophageal cancer;
• Esophageal adenocarcinoma;
• Gastric esophageal junction adenocarcinoma;
• ECOG > 2;
• Progression after first-course radiotherapy;
• Existing active infection, such as active tuberculosis, hepatitis, etc.;