Evaluating Neoadjuvant Chemotherapy for Lower Esophageal Squamous Cell Carcinoma by Measuring Esophageal Wall Thickness.

BACKGROUND/AIM:The aim of this study was to evaluate the efficacy of preoperative chemotherapy for stage II-III esophageal squamous cell carcinoma based on an objective computed tomography method. PATIENTS AND METHODS:A total of 82 patients who underwent preoperative chemotherapy followed by surgery for advanced esophageal squamous cell carcinoma from January 2006 to June 2019 were included. Treatment effect was evaluated by measuring the esophageal wall thickness before and after neoadjuvant chemotherapy using contrast-enhanced thoracoabdominal computed tomography. The percentage decrease in esophageal wall thickness was calculated using the following formula: reduction (%)=(wall thickness before preoperative chemotherapy - wall thickness after preoperative chemotherapy)/(wall thickness before preoperative chemotherapy)×100. We demonstrated the efficacy of this measurement method and then analyzed which patient factors might affect the treatment effect. RESULTS:Receiver operating characteristic analysis showed the percentage tumor reduction to be a good predictor of histological therapeutic effect (grade ≥2) (area under the curve=0.727). In the multivariate analysis, tumor location (lower versus upper esophagus) was identified as an independent factor associated with tumor reduction (odds ratio=0.15; 95% confidence interval=0.03-0.79; p=0.025). CONCLUSION:We demonstrated an association between the reduction of esophageal wall thickness in the tumoral area and the histological therapeutic effect of chemotherapy. Secondary analysis showed poorer tumor reduction in patients with lower esophageal cancer than in those with upper esophageal cancer.