Number of Resected Lymph Nodes and Survival of Patients with Locally Advanced Esophageal Squamous Cell Carcinoma Receiving Preoperative Chemoradiotherapy

Background: The association of extended lymph node (LN) dissection with improved outcomes in patients with locally advanced esophageal squamous cell carcinoma (ESCC) who received preoperative chemoradiotherapy (CRT) followed by surgery is debatable. Patients and Methods: We reviewed data from patients with esophageal cancer enrolled in three phase II clinical trials of preoperative paclitaxel and cisplatin-based CRT during 2000-2012. Patients with ESCC who underwent planned esophagectomy were enrolled. The number of resected LNs and other clinicopathological factors were analyzed regarding their impact on progression-free (PFS) and overall (OS) survival using Cox proportional hazards model. Results: In total, 139 patients were included. The median PFS and OS were 24.4 and 31.8 months, respectively. The median number of resected and positive LNs were 19 (range=2-96) and 0 (range=0-9), respectively. The mean number of positive LNs did not differ significantly among quartile groups of total resected LNs (quartile 1: 2-12, 2: 13-19, 3: 20-29, and 4: 30-96). The resected LN number analyzed as dichotomies divided by the median or as continuous variables was not associated with PFS or OS. However, in an exploratory analysis, patients of quartiles 2 and 3 had longer PFS and OS than those with quartiles of 1 and 4 in multivariate analysis (p=0.019 and 0.005, respectively). Conclusion: Although extensive LN dissection was not associated with improved survival, resection of 13-29 LNs was associated with improved survival in patients with locally advanced ESCC receiving preoperative paclitaxel and cisplatin-based CRT.