The long-term impact of tumor burden in pT3N0M0 esophageal squamous cell carcinoma: A propensity score-matched analysis

The purpose of this study was to assess the impact of tumor burden on the survival of patients with pathologic T3N0M0 (pT3N0M0) esophageal squamous cell carcinoma (ESCC). A total of 84 patients with pathologic T3N0M0 ESCC treated with radical esophagectomy and 3-field lymphadenectomy (3-FL) from January 2008 to December 2009 in our center were analyzed. Receiver-operating characteristic (ROC) curve analysis was performed to calculate the optimal cutoff value. The Kaplan–Meier method and log-rank test were used to assess the overall survival (OS) differences between groups. A regression model was applied to identify prognostic factors for OS. Propensity score matching (PSM) was performed to adjust for the imbalance and indication biases in the 2 groups. The median follow-up time was 62 months (range, 1–84 months), and the 5-year OS rate was 62% (95% confidence interval, 52.2–71.8%). According to the ROC curve analysis, the optimal cutoff values for the maximal esophageal wall thickness, tumor length, and tumor volume were 1.3 cm, 5.9 cm, and 18.6 cc, respectively. Univariate analysis revealed that maximal esophageal wall thickness >1.3 cm (P = .014), tumor volume >18.6 cc (P < .001), and vascular invasion (P < .001) were significantly associated with OS. The multivariate Cox regression model identified tumor volume and vascular invasion as factors affecting OS. After propensity matching, patients with a tumor volume ≤18.6 cc had a better OS than those with a tumor volume >18.6 cc (5-year OS, 85% vs 50%, P = .008). Tumor volume may serve as a good prognostic factor for patients with pT3N0M0 ESCC treated with radical esophagectomy and 3-FL. Larger-scale studies are warranted to validate these findings.