Shanghai Chest Hospital, Shanghai Jiao Tong University Shanghai, Shanghai
Y. Lu1, Y. Zeng2, X. Su1, J. Jia1, Y. Wang1, Z. Yang1, L. Zhao3, T. Zhou1, W. Feng1, and X. Cai1; 1Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China, 2Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai, China, 3Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
Purpose/Objective(s):Although prospective studies have failed to confirm the survival advantages of postoperative radiotherapy (PORT) in stage III (N2) non-small cell lung cancer (NSCLC) patients, subgroup analysis and most retrospective studies have shown that N2 patients with with high risks were potential beneficiaries of PORT. However, the current PORT clinical target volume (CTV) for stage III (N2) NSCLC does not include supraclavicular lymph nodes (SLN). The aim of this study was to investigate the supraclavicular lymph node recurrence in postoperative NSCLC patients with positive lymph node and to explore its impact on PORT CTV. Materials/Methods: A total of 1309 patients with stage III (N2) NSCLC who underwent surgical resection and were pathologically confirmed by Shanghai Chest Hospital from 2012 to 2016 were enrolled. The chi-square test was used to compare the supraclavicular lymph node recurrence rate in different positive uppermost mediastinal lymph nodes groups, especially the second mediastinal lymph node (LNS 2) positive and LNS 2 negative patients. The log-rank test was used to compare the locoregional recurrence rate. Results: A total of 1309 patients were enrolled, with a median follow-up time of 47.8 (95% CI 46.2-49.4) months. Among these patients, 401 received PORT. The locoregional mediastinal recurrence rate of in the PORT group was significantly lower than that in the non-PORT group (17.6% vs 27.0%,log-rank p=0.004), while there was no significant difference in the supraclavicular lymph node recurrence rate between the two groups (13.1% vs 6.9%,log-rank p=0.217). In PORT group, the supraclavicular lymph node recurrence rate in LNS 2 positive patients was significantly higher than that in LNS 2 negative patients (13.1% vs. 2.4%, p=0.009), but there was no significant difference in the locoregional mediastinal recurrence rate between the two groups (16.8% vs 20.7%, p=0.493). Among LNS 2 positive patients who had supraclavicular lymph node recurrence, the proportions of patients with ipsilateral, contralateral and bilateral recurrence were 50%, 35.7% and 14.3% respectively. Conclusion: For stage III (N2) NSCLC patients, PORT can help reduce the locoregional mediastinal recurrence rate,while the supraclavicular lymph node recurrence rate is significantly higher in LNS 2 positive patients. Therefore, for patients with NSCLC and positive LNS2, the CTV of PORT should consider including bilateral supraclavicular lymph nodes (SLN), but large-sample prospective clinical studies are warranted to further confirm.
