Comparison of mediastinal lymph node metastases from adenocarcinoma of the esophagogastric junction versus lower esophageal squamous cell carcinoma with involvement of the esophagogastric junction

The distribution of mediastinal lymph node metastasis in patients with adenocarcinoma of the esophagogastric junction (AEG) remains unclear. Additionally, the distribution of nodal mediastinal metastasis from squamous cell carcinoma (SCC) of the lower esophagus with involvement of the esophagogastric junction remains unclear, given the very limited number of these patients. In this retrospective review, we compared the outcomes of radical lymphadenectomy of the mediastinum, including upper mediastinal lymphadenectomy, between patients with AEG and those with SCC. From 2005 to 2017, 69 consecutive patients underwent esophagectomy via right thoracotomy or minimally invasive esophagectomy for a Siewert type I or II tumor with esophageal invasion >= 3 cm. We analyzed the incidences of mediastinal lymph node metastasis in this group relative to those of 73 patients with SCC with involvement of the esophagogastric junction who consecutively underwent esophagectomy during the same period. Mediastinal lymph node metastasis was seen in 26 of 69 patients with AEG (38%), with upper, middle, lower mediastinal nodal metastasis instances of 20%, 17%, and 23%, respectively. Mediastinal lymph node metastasis was seen in 23 of 73 patients with SCC (32%), with upper, middle, lower mediastinal nodal metastasis instances of 12%, 16%, and 19%, respectively. This mediastinal lymph nodal metastasis distribution did not statistically differ between patients with AEG and those with SCC. The relapse-free survival outcomes were poor for patients with clinical (P < 0.01) or pathological (P < 0.01) nodal metastasis of the mediastinum with AEG. In contrast, patients with clinical or pathological mediastinal nodal metastases of SCC did not have extremely poor survival outcomes, compared to patients with AEG. Despite the limited dataset available for analysis, patients with AEG and those with SCC might exhibit similar incidences and distribution of mediastinal lymph node metastasis. However, the clinical or pathological metastasis of AEG to the mediastinum was associated with poor survival outcomes, even if radical mediastinal lymphadenectomy including the upper mediastinal lymphadenectomy was performed.