Impact of Metastatic Lymph Nodes on Survival of Patients with pN1-Category Esophageal Squamous Cell Carcinoma: A Long-Term Survival Analysis

Abstract Background The morbidity and mortality rates of esophageal squamous cell carcinoma (ESCC) are high in China. The overall survival (OS) of patients with ESCC is related to lymph node (LN) metastasis (LNM). This study aimed to discuss the impact of metastasis in LN stations on the OS of patients with pathologic N1 (pN1) ESCC. Methods Data were obtained from the Esophageal Cancer Case Management database of Sichuan Cancer Hospital and Institute (SCCH-ECCM). Additionally, data of patients with pN1-category ESCC collected between January 2010 and December 2017 were retrospectively analyzed. Results Data from 807 patients were analyzed. The median OS of the patients with one metastatic LN (group 1) was 49.8 months (95 % confidence interval [CI], 30.8–68.9 months), whereas the OS of those with two metastatic LNs (group 2) was only 33.3 months ( P = 0.0001). Moreover, group 1 did not show a significantly longer OS than group 2.1 (patients with 2 metastatic LNs in 1 LNM station; P = 0.5736), but did show a significantly longer OS than group 2.2 (patients with 2 metastatic LNs in 2 LNM stations; P < 0.0001). After propensity score-matching, the 5-year survival rate for group 1 was 28 %, whereas that for group 2 was 14 % ( P = 0.0027). Conclusions The OS for the patients with one metastatic LN in one LNM was not significantly longer than for the patients with two metastatic LNs in one LNM station. Patients with one LNM station had a significantly longer OS than those with two LNM stations. Thus, the number of LNM stations is a significant determinant of OS in pN1 ESCC.