Prognostic significance of the number of lymph nodes examined in node-negative Siewert type II esophagogastric junction adenocarcinoma

Abstract Background Involvement status of lymph node (LN) is one of the most important prognostic factors for esophagogastric junction (EGJ) adenocarcinoma. However, the prognostic value of the number of examined LNs remains unclear in node-negative (pN0) Siewert type II EGJ adenocarcinoma. Methods A cohort of 262 patients who underwent curative surgery for pN0 Siewert type II EGJ adenocarcinoma from January 2000 to August 2013 were retrospectively analyzed from high-volume center database. All enrolled patients were categorized into 3 groups according to the number of examined LNs (≤14, 15 to 21, ≥22). Kaplan-Meier curves were used for comparing the differences of cancer-specific survival among groups; Correlation between survival and the number of examined LNs were analyzed by using stratified, uni- and multivariate analyses. Results The hazard ratio for cancer-specific mortality decreased sequentially with increasing number of LNs examined. The 5-year cancer-specific survival rates were 45.1%, 58.4% and 65.7% for patients with ≤14 LNs, 15 to 21 and ≥ 22 LNs removed, respectively. The number of removed LNs was significantly correlated with survival in stratified analyses according to T stage. In multivariate model controlling for gender, age, surgical approach, tumor grade, and postoperative chemotherapy, the number of removed LNs and T stage were confirmed to be independent prognostic factors and significantly correlated with disease-specific survival. Conclusion The number of examined LNs is an independent prognostic factor of survival for patients with pN0 Siewert type II EGJ adenocarcinoma. Adequate dissection of LNs (more than 15 LNs) is recommended for patients undergoing curative resection.