Background
In esophageal cancer, lymph node metastasis most likely occurs on neck, mediastinum and abdomen. Recurrent laryngeal nerve (RLN) lymph node is located at the cervical base continuous to the upper mediastinum, which is one of the most common sites of lymph node metastasis in thoracic esophageal squamous cell carcinoma. The clinical significance of RLN node metastasis in surgical treatment of thoracic esophageal squamous cell carcinoma has been discussed previously. Early metastasis, initial metastasis, and even micrometastasis of esophageal squamous cell carcinoma often occur in RLN nodes. In addition, nodal involvement in RLN has been regarded as an indication for three-field lymphadenectomy in the surgical treatment of esophageal cancer. More importantly, RLN node metastasis has been shown to be a strong predictor of poor prognosis in thoracic esophageal squamous cell carcinoma.
However, some studies showed that the site of nodal involvement was not associated with the prognosis of thoracic esophageal squamous cell carcinoma, and the number of metastatic lymph nodes had a greater prognostic significance in thoracic esophageal squamous cell carcinoma. These results are contradictory to the findings mentioned above that RLN node metastasis is an unfavorable prognostic factor in thoracic esophageal squamous cell carcionoma. To evaluate the outcome of curative esophagectomy treatment, as well as the prognostic impacts of RLN node metastasis and the number of metastatic lymph nodes, in this study, we analyzed a cohort of patients with squamous cell carcinoma of the middle esophagus admitted in our institution.