Prognostic significance of solitary lymph node metastasis in patients with squamous cell carcinoma of middle thoracic esophagus

BACKGROUND The aim of this study is to compare clinical outcomes between patients with solitary lymph node metastasis and node-negative (N0) patients in squamous cell carcinoma of the middle thoracic esophagus. METHODS A series of 135 patients with squamous cell carcinoma of the middle thoracic esophagus were retrospectively investigated. There were 33 patients with solitary lymph node metastasis and 102 N0 patients. Skip metastasis in 33 patients with solitary lymph node metastasis was defined according to three criteria: Japanese Society for Esophageal Disease (JSED), American Joint Commission on Cancer (AJCC), and the anatomical compartment. RESULTS In 33 patients with solitary lymph node metastasis, skip metastasis was shown in 13, 23, and 8 patients according JSED, AJCC and anatomical compartment respectively. The 5-year survival rates for N0 patients and patients with solitary lymph node metastasis were 58% and 32% respectively (P =0.008). Multivariate analysis revealed that skip metastasis was not an independent prognostic factor. CONCLUSIONS For patients with middle thoracic esophageal squamous cell carcinoma, solitary lymph node metastasis has a negative impact on survival compared with N0 disease; skip metastasis, however, is comparable to N0 diseases in predicting prognosis.