Supraclavicular lymph node metastasis should not be defined as regional lymph node metastasis in cervical and upper thoracic esophageal squamous cell carcinoma

The importance of supraclavicular lymph node (SCLN) metastasis in cervical and upper thoracic esophageal squamous cell carcinoma (ESCC) has not been determined. The aim of the present study was to provide a detailed definition of the range of SCLN regions and to explore whether SCLNs should be considered as a regional lymph nodes for patients with cervical and upper thoracic ESCC. A retrospective analysis was performed on 230 patients with locally advanced cervical or upper thoracic ESCC who underwent radical radiotherapy and chemotherapy. The range of SCLN regions was defined in detail on contrast enhanced computed tomography images of the neck. According to whether the patient had lymph node metastasis in the supraclavicular region, the included patients were divided into two groups, and the survival differences and reasons for treatment failure between the two groups were analyzed. Of the 230 patients with ESCC, 71 (30.87%) exhibited lymph node metastases in the supraclavicular region. The median overall survival time of ESCC patients with and without SCLN metastasis was 17 and 30 months, respectively (P<0.001). After propensity score matching (PSM), the median overall survival time of ESCC patients with and without SCLN metastasis was 17 and 28 months, respectively (P<0.001). During the follow-up period, there were a total of 101 cases of failure of treatment in the irradiation field, 6 cases had esophageal metastasis in the non-irradiated field and 27 cases had regional lymph node metastasis in the non-irradiated field. In addition, there were 33 cases of metastasis to the distant lymph nodes or organs. There was no significant difference in the local treatment failure rate between the groups with or without SCLN metastasis in both the irradiation field and the non-irradiation field, but the probability of distant metastasis in the SCLN metastasis group was significantly higher than that in the group without SCLN metastasis (P=0.025). In conclusion, patients with cervical and upper thoracic ESCC with SCLN metastasis have a poor prognosis and the median overall survival time is closer to that of metastatic ESCC than ESCC with regional lymph node metastasis; therefore, SCLNs should not be defined as regional lymph nodes in patients with cervical and upper thoracic ESCC.