Prognostic analysis of different comprehensive treatment models for locally advanced esophageal squamous cell carcinoma based on propensity score matching

Abstract

Objective: To compare the effects of preoperative neoadjuvant chemotherapy and postoperative adjuvant chemotherapy on the long-term survival of patients with radical resection for esophageal squamous cell carcinoma. Methods: Totally 1 082 patients with stage T3-4aN0-3M0 thoracic esophageal squamous cell carcinoma were recruited in this study who underwent radical resection at Department of Thoracic Surgery, Fourth Hospital, Hebei Medical University from January 2005 to January 2015. There were 798 males and 284 females, with a median age of 61 years (range: 37 to 86 years). There were 138 patients undergoing preoperative neoadjuvant chemotherapy, 392 patients postoperative adjuvant chemotherapy, and 552 patients surgery alone. The neoadjuvant chemotherapy group was used as the benchmark group to match the propensity score with the adjuvant chemotherapy group and the surgery-only group respectively at a ratio of 1∶3. A total of 7 covariates including tumor location, number of positive lymph nodes, tumor invasion depth, tumor differentiation degree, surgical procedure, vascular tumor thrombus and nerve invasion were included, and the caliper value was taken as 0.1. After matching, a total of 699 patients were included for the analysis, including 128 patients in the neoadjuvant chemotherapy group, 267 patients in the adjuvant chemotherapy group, and 304 patients in the surgery alone group. The Kaplan-Meier method was used to generate the survival curves which was tested by the Log-rank method for survival analysis. Results: After matching analysis, the 5-year overall survival rate was 41.5% in the neoadjuvant chemotherapy group with a median overall survival time of 43 months (95%CI: 27 to 59 months), 57.6% in the adjuvant chemotherapy group with a median overall survival time unreached, and 24.9% in the surgery alone group with a median overall survival time of 28 months (95%CI: 25 to 31 months) (χ²=60.475, P<0.01). For overall survival after matching, the adjuvant chemotherapy group was better than the neoadjuvant chemotherapy group (χ²=11.384, P=0.001), the neoadjuvant chemotherapy group was better than the surgery alone group (χ²=8.654, P=0.003), and the adjuvant chemotherapy group was better than surgery alone group (χ²=60.234, P<0.01). Conclusion: Both preoperative neoadjuvant chemotherapy and postoperative adjuvant chemotherapy can improve the long-term survival of patients with locally advanced esophageal squamous cell carcinoma undergoing radical resection, and the improvement effect of postoperative adjuvant chemotherapy is more obvious.