Prognostic impact of lymph node involvement and the extent of lymphadenectomy (LAD) in adenocarcinoma of the esophagogastric junction (AEG)

Background: The prognostic importance of lymph node (LN) involvement for patients with adenocarcinoma of the esophagogastric junction (AEG) is well-known. In the latest edition of the UICC staging system, the number of metastatic LNs was taken into account, while the extent of lymphadenectomy (LAD) remains unaddressed. Removal of at least six LNs is recommended, but there is no defined minimum number as to classify as (y)pN0. We examined the prognostic value of the number of positive LNs, number of LNs removed, and LN ratio (LNR) in order to determine the influence of an adequate LAD on overall survival (OS). Methods: We analyzed data of 316 patients with AEG treated in our institution (2001-2011) regarding clinicopathological data, treatment, morbidity, mortality, and long-term prognosis. Univariate and multivariate analysis was performed using Cox regression to evaluate the prognostic impact of(y)pN category, number of LNs removed and LNR. Results: OS decreased with higher count of positive LNs (p < 0.001) and higher LNR (p < 0.001). Whether >6, >15, or >30 LNs were removed did not influence OS, neither in the entire study population nor within individual (y)pT or (y)pN categories. Multivariate analysis revealed LNR (p < 0.001) besides M category (p = 0.015) and tracheotomy during the postoperative course (p = 0.005) as independent predictors of OS. Conclusion: The classification according to the number of involved LNs in the latest edition of the UICC staging system improves prognostication in patients with AEG. The importance of an adequate LAD is shown by the high prognostic relevance of the LNR rather than the absolute number of LNs removed.