Prognostic significance and optimal staging of supraclavicular lymph node metastasis in upper esophageal squamous cell carcinoma undergoing chemoradiotherapy

BACKGROUND: The optimal staging of supraclavicular lymph node metastasis (SCLNM) in upper esophageal squamous cell carcinoma (UESCC) remains debated. This study aimed to evaluate its prognostic significance and clinical implications in patients treated with definitive chemoradiotherapy. METHODS: This study included 435 newly diagnosed UESCC patients who received definitive chemoradiotherapy between January 2013 and October 2022. Survival and prognostic factors were analyzed by Kaplan-Meier and Cox regression methods. RESULTS: SCLNM was diagnosed in 49 patients (11.3%) and was strongly associated with metastasis at stations 101, 106rec, 106pre, and 106tb. Multivariate analysis confirmed SCLNM as an independent prognostic factor. Patients with SCLNM had poorer survival than those with M0 disease but better than those with other distant metastases (median overall survival: 24.0 vs. 67.0 vs. 8.0 months). Survival was significantly lower in SCLNM patients compared to N0M0 (P < 0.001) and N1M0 (P = 0.004) patients, but no significant difference was observed compared to N2M0 (P = 0.477) or N3M0 (P = 0.204) patients. After reclassifying SCLNM as a regional lymph node metastasis, N1 patients with SCLNM exhibited worse overall survival than those without SCLNM, although the statistical significance was marginal (P = 0.048); however, this difference was not seen in N2 or N3 categories. In the revised staging system where SCLNM was assigned to N2 or higher, survival differentiation across stages became more distinct, yielding a higher prognostic accuracy compared to the current AJCC staging system. CONCLUSIONS: SCLNM in UESCC patients undergoing definitive CRT shows prognostic similarity to N2-3 disease, but this finding is preliminary and requires further validation.