Clinical significance of preoperative chemoradiotherapy for advanced esophageal cancer, evaluated by propensity score matching and weighting of inverse probability of treatment.

ABSTRACT

The present study used inverse probability of treatment weighting (IPTW) and propensity score matching (PSM) to compare survival benefits among 112 patients with resectable, stage II-IV esophageal squamous cell carcinoma (SCC) treated between 1996 and 2016 with neoadjuvant chemoradiotherapy (NAC) plus surgery (Group A, n=55) or with surgery alone (Group B, n=57). Their propensity scores (PS) were calculated using a multivariable logistic regression model in which age, sex, cancer site, primary tumor length, cTNM stage, lymph node metastasis and depth of tumor invasion were the independent variables, and used to match Groups A and B according to the IPTW and matching method. After IPTW and PSM, univariate analysis was used to assess overall survival (OS) and disease-free survival (DFS), followed by Cox proportional hazard models for OS using IPTW between the two groups and the subgroups. After PSM, 5-year OS and DFS were significantly higher in Group A (OS 65.2%, DFS 65.2%) compared with Group B (OS 31.2%, DFS 20.87%). Similarly, after IPTW, OS and DFS were significantly higher in Group A compared with Group B patients. Five-year OS was 73.18% for Group A and 37.69% for Group B (hazard ratio 0.2899, 95% confidence interval 0.1167-0.7205). To conclude, treatment was more effective in Group A patients with clinical stage II, N0 and T3 disease involving the mid-esophagus. It was concluded that for patients with esophageal SCC, NAC plus esophagectomy exhibited improved survival compared with surgery alone, as demonstrated by use of IPTW and PSM methods.