Prognostic impact of supraclavicular lymph node metastasis in thoracic oesophageal squamous cell carcinoma in a large retrospective study

The definitions of regional nodes differ between the 12th edition of the JES and the UICC staging systems, and the most prominent difference is in the status of the supraclavicular lymph nodes (SCLN). This study was designed to investigate the prognostic impact of metastasis to SCLN in patients with thoracic oesophageal squamous cell carcinoma (ESCC). The study group consisted of 1639 patients with thoracic ESCC who underwent oesophagectomy with 3-field lymphadenectomy at the Department of Thoracic Surgery, Fujian Cancer Hospital and whose clinical and survival information were collected.Of the 1639 patients, 668 (40.8%) had no lymph node metastases, 805 (49.1%) had at least 1 positive node but were SCLN-negative, and 166 (10.1%) had SCLN metastases. The 5-year survival rate was 74.1% for node-negative patients, 44.3% for node-positive patients without SCLN metastases, and 33.7% for patients with SCLN metastases. A comparison of the 5-year survival rates among patients with SCLN metastases revealed that the SCLN-positive group was more similar to the N2 group ( P = 0.342) than to the N3 group ( P = 0.027). In the multivariate analysis, the male sex ( P < 0.001), a higher pT stage ( P = 0.005), a poorer degree of pathological differentiation ( P = 0.045), and a higher N stage ( P < 0.001) retained statistical significance as adverse prognostic factors for overall survival, while SCLN metastasis did not ( P = 0.956). The survival benefit of 3-field lymphadenectomy including metastases to SCLNs was indicated in patients with thoracic ESCC. SCLNs appear to be regional nodes similar to other regional lymph nodes.