Beneficial subgroups for PD-1 inhibitor plus chemotherapy in first-line treatment of advanced esophageal squamous cell carcinoma: A systematic review and meta-analysis

The combination of PD-1 inhibitors with chemotherapy demonstrates superior efficacy as first-line therapy for advanced esophageal squamous cell carcinoma. Both elderly patients and those with metastatic involvement derive universal benefit without increased adverse risks. However, patients with PD-L1 combined positive score < 1 may experience restricted clinical benefits. Thus, more precise predictive markers are required to stratify potential responders, enabling broader patient populations to derive benefits from PD-1 inhibitor-chemotherapy regimens.