Neoadjuvant programmed death-1 blockade plus chemotherapy in locally advanced esophageal squamous cell carcinoma.

e16076 Background: Immunotherapy is effective in treating advanced esophageal squamous cell carcinoma (ESCC), but little known about its role the setting of neoadjuvant therapy. Methods: Data from a retrospective cohort and prospective locally ESCC patients were analyzed. All included had received camrelizumab plus nab-paclitaxel S1 capsule followed by radical esophagectomy. The main purpose this study was to evaluate safety feasibility treatment. In addition, pathological response relationship between tumor immune microenvironment features (TIME)/tumor mutational burden (TMB) treatment also explored. Results: A total 25 both cohorts included, which 12 13 cohort. Only two experienced grade 3 or 4 adverse events, including onehad anemia other (4%) limb numbness. No surgical delay perioperative death reported. Sixteen (64%) responded treatment, eight (32%) with complete major response. Neither programmed death-ligand 1 expression nor TMB correlated terms TIME analysis, better primary significantly higher abundance CD56 dim natural killer cells (109 vs 32, P= 0.01), while lower density M2-tumor-associated macrophages associated numerically lymph nodes (47 163.1, 0.55). Conclusions: Neoadjuvant safe, feasible effective, efficacy could be predicted TIME, worthy further investigation. Clinical trial information: ChiCTR2000029807.