Study on the Biomarker of First-line Immunotherapy Combined With Chemotherapy in Advanced Esophageal Cancer

Inclusion Criteria: * Unresectable locally advanced/ recurrent or distant metastatic esophageal squamous cell carcinoma confirmed by histology or cytology; * Not received any previous systematic antitumor therapy. * Eastern Cooperative Oncology Group (ECOG) fitness status score was 0 or 1 within 3 days before the first administration of the intervention. * 8-10 tumor tissue samples can be provided. * Demonstrate good organ and bone marrow function. * Consent to participate in the contraceptive methods related to clinical research. Exclusion Criteria: * Have a history of allergy to monoclonal antibodies, any component of SHR-1210, albumin-paclitaxel, carboplatin, and other platinum drugs; * Weight loss \> 20% in the past 3 months. * Major surgery within 28 days prior to enrollment. * Have received systemic chemotherapy or radiation therapy for esophageal cancer. * Had a myocardial infarction within the past 6 months. * Have any medical history or current evidence, treatment, or laboratory abnormalities that prevent the subject from participating fully in the study with the investigator's opinion. * Prior treatment with immunotherapy drugs. * Received live vaccine within 30 days prior to initial administration of the investigational drug. * Have been diagnosed with immunodeficiency or are receiving immunosuppressive treatment. * Another malignancy is known to exist. * Have active infections that require systemic treatment. * Pregnant or lactating, or planning to become pregnant or become a father during the study period (180 days for lactating subjects receiving carboplatin) from the beginning of the screening visit until 120 days after the last dose of the study intervention.