Peripheral Blood Biomarkers for Predicting the Efficacy of Neoadjuvant Immunochemotherapy in Locally Advanced Esophageal Squamous Cell Carcinoma.

OBJECTIVE: This study aimed to evaluate pre- and intra-treatment peripheral blood inflammatory and cellular indicators as predictors of pathological response to neoadjuvant immunotherapy plus chemotherapy (nICT) in locally advanced esophageal squamous cell carcinoma (ESCC), and their correlation with prognosis. METHODS: 310 patients with locally advanced ESCC who received nICT plus radical surgery (Jan 2020-Dec 2025) were retrospectively divided into the pathological complete response (pCR) (n=63) and non-pCR (n=247) groups. Blood indicators at baseline, post-cycle 1, and pre-surgery were analyzed. Univariate and multivariate logistic regression identified independent predictors of response. Receiver operating characteristic curves assessed predictive efficacy and recurrence associations. RESULTS: Overall pCR rate was 20.32% (63/310). Univariate analysis showed baseline (L0) and post-cycle 1 (L1) lymphocyte counts, and preoperative D-dimer (D-dimer2) significantly correlated with pCR (all P<0.05). Multivariate analysis identified L1 as an independent protective factor (OR=0.308, 95% CI: 0.146-0.652, P=0.002) and D-dimer2 as a risk factor (OR=3.842, 95% CI: 1.102-13.386, P=0.035) for pCR. The area under the curve of L1 was 0.710 (95% CI: 0.635-0.785, P<0.001). Recurrent patients had lower L0 and L1 levels than non-recurrent (P<0.010), and L1 independently predicted recurrence (OR=3.490, 95% CI: 1.077-11.315, P=0.037). CONCLUSION: nICT induces favorable pathological responses in locally advanced ESCC. Post-cycle lymphocyte count was associated with treatment response and recurrence risk, while elevated D-dimer2 is associated with poor pathological response. These findings suggest that these biomarkers may hold promise for efficacy evaluation and risk stratification, though prospective validation is required.