Pre-tracheal lymph node metastasis in squamous cell carcinoma of the thoracic esophagus

Aims To clarify the incidence of pre-tracheal lymph node metastasis in squamous cell carcinoma of the esophagus, and their impact on survival. Methods A cohort of 101 patients with squamous cell carcinoma of the thoracic esophagus who underwent esophagectomy together with 2-field lymphadenectomy including the pre-tracheal region was analysed, retrospectively. The p-TNM staging included stage I in 9, stage IIa in 33, stage IIb in 4, stage III in 43, and stage IV in 12 cases. Results Nodal metastases were identified in 56 patients (55.4%). Subcarinal lymph node and pre-tracheal lymph-node metastases were found in 24 patients (23.8%) and 15 patients (14.9%), respectively. The 5-year cumulative survival rates were 26.5 and 2.5% in nodal negative and nodal positive patients, respectively. Patients with pre-tracheal nodal metastasis all died within 2 years. Cox proportional hazards model in patients with nodal involvement revealed T-factor (p=0.0017), pre-tracheal nodal involvement (p=0.0055) and distant metastasis (p=0.0024) as independent prognostic factors. Conclusions Our findings suggest that pre-tracheal lymph node metastasis indicates a dismal prognosis. Its occurrence is not unusual, especially in tumour of upper or middle thoracic esophagus. The subcarinal node cannot be regarded as a sentinel node of the pre-tracheal nodal station. Complete lymphadenectomy excluding the pre-tracheal lymph nodes in treating esophageal cancers is only a myth.