The Neoadjuvant Administration of PD-1 Inhibitor plus Concurrent Chemoradiotherapy in Patients with Locally Advanced Esophageal Squamous-Cell Carcinoma

Objective. Programmed cell death-1 (PD-1) inhibitors have shown potency for neoadjuvant therapy in several cancers, while their administration combined with concurrent chemoradiotherapy (CCRT) as a neoadjuvant therapy for locally advanced esophageal squamous-cell carcinoma (ESCC) is seldom reported. The current study aimed to investigate the pathological response, survival, and safety of neoadjuvant PD-1 inhibitor plus CCRT in locally advanced ESCC patients. Methods. Twenty-five locally advanced ESCC patients who underwent PD-1 inhibitor plus CCRT neoadjuvant therapy were retrospectively reviewed. Data regarding radiological response, pathological response, disease-free survival (DFS), overall survival (OS), and adverse events were retrieved. Results. Two (8.0%), 14 (56.0%), 9 (36.0%), and 0 (0.0%) patients had a clinical response of complete response, partial response, stable disease, and progressive disease after neoadjuvant therapy by radiological evaluations, respectively. Notably, 25 (100.0%) patients had successful tumor resections, 24 (96.0%) patients realized R0 resection, and 13 (52.0%) patients achieved pathological complete response (pCR) by pathological evaluations. Regarding survival profiles, the 1-year and 2-year accumulating DFS rates were 90.0% and 74.6%, respectively; then, the 1-year and 2-year accumulating OS rates were 95.5% and 90.4%, respectively. The top prevalent adverse events were fatigue (48.0%), nausea and vomiting (40.0%), leukopenia (36.0%), neutropenia (36.0%), and peripheral neuropathy (36.0%). In addition, grades 3-4 adverse events included peripheral neuropathy (12.0%), nausea and vomiting (4.0%), leukopenia (4.0%), neutropenia (4.0%), anemia (4.0%), and pruritus (4.0%). Conclusion. Neoadjuvant PD-1 inhibitor plus CCRT shows a good efficacy and acceptable tolerance for locally advanced ESCC treatment, but further large-scale study validation is needed.