Two-Dimensional CT Tumor Measurement Predicts Pathological Response and Prognosis After Neoadjuvant DCF Therapy in Esophageal Squamous Cell Carcinoma

Background/Objective: Evaluating the response to neoadjuvant chemotherapy in esophageal squamous cell carcinoma (ESCC) is challenging because primary tumors are often classified as non-measurable under the RECIST criteria. This study investigated whether two-dimensional computed tomography (CT) measurements predict pathological response and prognosis after neoadjuvant docetaxel, cisplatin, and 5-fluorouracil (DCF) therapy in ESCC. Methods: We retrospectively analyzed 123 patients who underwent radical esophagectomy following DCF therapy at two institutions (April 2011–March 2024). Changes in the short-axis, long-axis, and short-axis × long-axis diameters of the primary tumor after preoperative chemotherapy were measured on contrast-enhanced CT, and the reduction rate for each parameter was assessed. Based on the optimal cutoff values, univariate and multivariate analyses were conducted to identify significant predictors of pathological response. Results: The short-axis × long-axis diameter reduction rate (SLRR) demonstrated the highest area under the curve (0.901), with a cutoff value of 0.55 for predicting pathological response, and it was the only independent predictor in the multivariate analysis (odds ratio, 6.27; p = 0.048). In group comparisons using the SLRR cutoff value, patients with a high SLRR had significantly better 3-year recurrence-free survival (67.8% vs. 29.4%, p < 0.001) and overall survival (79.5% vs. 46.6%, p < 0.001) than those with a low SLRR. Conclusions: The CT-based SLRR independently predicts both pathological response and prognosis after neoadjuvant DCF therapy in ESCC.