In subgroup analyses, except the limited benefit observed in the programmed death-ligand 1 (PD-L1) combined positive score < 1 subgroup, none of the following factors significantly influenced the efficacy of PD-1 inhibitor therapy: advanced age, metastatic status, number of metastatic organs, or presence of liver metastases.<h4>Conclusion</h4>The combination of PD-1 inhibitors with chemotherapy demonstrates superior efficacy as first-line therapy for advanced esophageal squamous cell carcinoma. Here, CD274 is linked to esophageal squamous cell carcinoma.