Clinical significance of lymphatic invasion in the esophageal region in patients with adenocarcinoma of the esophagogastric junction

Background and Objectives The lymphatic flow around the esophagogastric junction is complicated. Therefore, it is unclear whether lymphatic invasion in the esophageal region (eLI) and in the gastric region (gLI) in patients with adenocarcinoma of the esophagogastric junction (AEG) equally affect the incidence of lymph node metastases (LNM), and consequently, survival. Methods We retrospectively reviewed clinicopathological data of 175 patients with AEG between January 2008 and July 2017. Risk factors for LNM and impacts of eLI or gLI on survival outcomes were investigated. Results eLI was identified in 34% of the patients (59/175). By multivariate analysis, eLI was associated with an increased risk of both mediastinal LNM (odds ratio [OR] = 2.98, 95% confidence interval [CI]: 1.26‐7.05) and abdominal LNM (OR = 5.44, 95% CI: 1.95‐15.20). The 5‐year overall survival for patients with eLI (53%) was significantly worse than for patients without eLI (76%) (hazard ratio = 2.45, 95% CI: 1.37‐10.01). gLI was not selected in either of these analyses. Conclusions Positive eLI was strongly associated with mediastinal and abdominal LNM and worse survival in patients with AEG compared with gLI. In the histopathological examination, it seems to make sense to assess eLI and gLI separately.