A clinical study of salvage radiotherapy for supraclavicular lymph node metastasis in patients with esophageal cancer

Objective To evaluate the efficacy of salvage radiotherapy for supraclavicular lymph node metastasis (SLNM) after initial treatment in patients with esophageal cancer. Methods A total of 117 patients with SLNM after radical resection for esophageal cancer were enrolled as subjects from 2006 to 2012. All patients received three-dimensional radiotherapy with 1.8-2.0 Gy per cycle, 5 cycles a week. The survival rates were calculated using the Kaplan-Meier method and analyzed using the log-rank test. The Cox model was used for multivariate analysis. Results The follow-up rate was 100%. In all the patients, the 1-and 3-year overall survival (OS) rates were 38.5% and 14.1%, respectively. The 1-and 3-year OS rates were significantly higher in patients treated with salvage radiotherapy or radiochemotherapy (n=100) than in patients without any salvage treatment (n=17)(42% vs. 18%, P=0.008; 17% vs. 0%, P=0.008). The patients treated with radiochemotherapy (n=32) had significantly higher 1-and 3-year OS rates than those treated with radiotherapy alone (n=68)(59% vs. 34%, 36% vs. 11%, P=0.002) or without any salvage treatment (n=17)(59% vs. 18%, 36% vs. 0%, P=0.002). Patients without visceral metastasis (n=80) had significantly higher 1-and 3-year OS rates than those with visceral metastasis (n=37)(44% vs. 27%, P=0.002; 22% vs. 0%, P=0.002). Patients with supraclavicular doses of ≥60 Gy in salvage radiotherapy (n=75) had significantly higher 1-and 3-year OS rates than those with supraclavicular doses of<60 Gy in salvage radiotherapy (n=25)(75% vs. 25%, P=0.000; 24% vs. 8%, P=0.000). The multivariate analysis using the Cox model showed that supraclavicular doses of ≥60 Gy, mediastinal metastasis, visceral metastasis, and salvage treatment method were independent factors for survival (P=0.001, 0.015, 0.009, 0.025). Conclusions Salvage radiotherapy can improve the survival of patients with SLNM in esophageal cancer. Salvage radiotherapy or radiochemotherapy is highly recommended for patients with SLNM alone. A radiation dose of ≥60 Gy in salvage radiotherapy improves survival in patients. Key words: Esophagus neoplasms; Supracevicular lymph node metastasis; Salvage treatment; Prognosis