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.