Risk factor of mediastinal lymph node metastasis of Siewert type I and II esophagogastric junction carcinomas

Background: Incidence of esophagogastric junction (EGJ) carcinoma has been increasing worldwide. Several studies revealed that the distance from the EGJ to the proximal edge of the primary tumor (esophageal invasion: EI) may be a significant indicator of metastasis in the mediastinal lymph nodes in patients with Siewert type II carcinomas. However, few studies have been conducted in patients with carcinomas located at Siewert type II sequentially to upper carcinomas (Siewert type I) for mediastinal metastasis regardless of histological types. Methods: This was a single-center retrospective cohort study. EGJ carcinomas located at Siewert type I and II regions including both squamous cell carcinoma (SCC) and adenocarcinoma were analyzed in terms of lymph node metastasis patterns. Results: We included 121 patients in this study. Thirty-three (27.3%) patients had SCC. In multivariate analysis, the distance of EI (> 20 mm) was an independent risk factor (OR 11.80, p = 0.005) for lower mediastinal lymph node metastasis. In terms of above the middle mediastinal metastasis, the distance of EI (> 30 m), histological type (SCC), and tumor size (> 40 mm) were risk factors in univariate analysis. Furthermore, EI was significant (OR 13.50, p = 0.026) in multivariate analysis. Conclusions: The distance of EI was the independent risk factor for mediastinal lymph node metastasis, especially > 20 mm related with a higher risk for mediastinal lymph node metastasis. Furthermore, EGJ carcinoma patients who have EI > 30 mm, large SCC carcinoma, and multiple lymph node metastasis might be considered the middle-upper mediastinal lymph node dissection by transthoracic approach.