Prognostic significance and risk factors of mediastinal lymph node metastasis in esophagogastric junction cancer: a single-center, retrospective study

Background Although the optimal extent of lymph node dissection in esophagogastric junction cancer (EGJC) has been reported, the efficacy of mediastinal lymph node dissection remains unclear. We aimed to identify risk factors for mediastinal lymph node metastasis and its prognostic impact in patients with EGJC. Methods A total of 100 consecutive patients who underwent curative surgery for EGJC were eligible. We examined the rates of metastasis, prognosis, and therapeutic value index at each mediastinal lymph node station. In addition, multivariate analyses were performed to identify risk factors for mediastinal lymph node metastasis. Results The rates of upper, middle, and lower mediastinal lymph node metastases were 12.0%, 20.7%, and 13.2%, respectively. The 5-year overall survival rate was lower in patients with mediastinal lymph node metastasis than in those without mediastinal lymph node metastasis (11.1% vs. 59.2%, p < 0.01). The therapeutic value index was 0 in patients with upper/middle mediastinal lymph node metastasis, and mediastinal lymph node metastasis was an independent prognostic factor (hazard ratio 6.59, 95% confidence interval [CI] 2.48-17.9, p < 0.01). Additionally, the length of esophageal invasion and the presence of hiatal hernia were independent predictors of mediastinal lymph node metastasis (odds ratio 8.21, 95%CI 1.44-46.8, p = 0.02 and odds ratio 7.13, 95%CI 1.22-41.8, p = 0.03). Conclusion No survival benefit of mediastinal lymph node dissection was observed. Intensive multidisciplinary treatment could be considered in patients with predicted mediastinal lymph node metastasis, such as those with longer esophageal invasion and those with hiatal hernia.