Xin Li1, Xiaofei Li2, Xiangning Fu3, Lunxu Liu4, Yang Liu5, Heng Zhao6, Yin Li7, Jian Hu8, Lin Xu9, Deruo Liu10, Haiying Yang11, Xun Zhang12. 1. Department of Thoracic Surgery, Tianjin Chest Hospital, Tianjin, 300051, China. 2. Department of Thoracic Surgery, Tangdu Hospital, Fourth Military Medical University, Xi'an, 710038, China. 3. Department of Thoracic Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China. 4. Department of Thoracic Surgery, West China Hospital, Sichuan University, Chengdu, 610041, China. 5. Department of Thoracic Surgery, Chinese People's Liberation Army General Hospital, Beijing, 1000853, China. 6. Department of Thoracic Surgery, Shanghai Chest Hospital, Shanghai, 200030, China. 7. Department of Thoracic Surgery, Henan Cancer Hospital, Zhengzhou, 450008, China. 8. Department of Thoracic Surgery, First Hospital Affiliated to Medical College of Zhejiang University, Hangzhou, 310000, China. 9. Department of Thoracic Surgery, Jiangsu Cancer Hospital, Nanjing, 210009, China. 10. Department of Thoracic Surgery, China-Japan Friendship Hospital, Beijing, 100029, China. 11. Medical Affairs, Linkdoc Technology Co, Ltd, Beijing, 100080, China. 12. Department of Thoracic Surgery, Tianjin Chest Hospital, Tianjin, 300051, China. Electronic address: zhangxun69@163.com.
Abstract
INTRODUCTION: N2 non-small cell lung cancer (NSCLC) without N1 involvement, also known as skip metastases (pN0N2), has been suggested as a subgroup of heterogeneous N2 disease with better survival. This real-world observational study aimed to elucidate the prognostic impacts of skip N2 metastases using a large number of pathologic N2 NSCLC from 10 participating centers in China. MATERIALS AND METHODS: Medical records of pN2 NSCLC patients after surgical resection at 10 thoracic surgery centers between January 2014 and September 2017 were retrospectively reviewed based on the LinkDoc database. Clinical data on patient demographics, tumor characteristics, treatments and clinical outcomes were collected. Overall survival of patients with and without skip metastases was evaluated and compared by Kaplan-Meier method and Log-rank test. Cox proportional hazard model was established to identify potential prognostic predictors. Subgroup analysis was carried out to further explore the prognostic significance of skip metastases. RESULTS: Among 2653 surgically resected N2 patients, 881 (33.2%) had skip metastases. Patients with skip N2 had a significant better overall survival (P = 0.0019). Multivariate COX regression analysis showed borderline significance of skip metastases (HR = 0.81, 95%CI: 0.645-1.017, P = 0.0698) after adjustment for other covariates. Other independent prognostic predictors included smoking history, tumor location, stage and N2 station involved (P < 0.05). Subgroup analysis demonstrated significant survival benefits of skip N2 in most subpopulations. CONCLUSIONS: This study suggested a prognostic benefit of skip N2 metastases in real world practice. Further subdivision of N2 disease is warranted for better patient management and prognostic prediction (NCT03429192).
INTRODUCTION: N2 non-small cell lung cancer (NSCLC) without N1 involvement, also known as skip metastases (pN0N2), has been suggested as a subgroup of heterogeneous N2 disease with better survival. This real-world observational study aimed to elucidate the prognostic impacts of skip N2 metastases using a large number of pathologic N2 NSCLC from 10 participating centers in China. MATERIALS AND METHODS: Medical records of pN2 NSCLCpatients after surgical resection at 10 thoracic surgery centers between January 2014 and September 2017 were retrospectively reviewed based on the LinkDoc database. Clinical data on patient demographics, tumor characteristics, treatments and clinical outcomes were collected. Overall survival of patients with and without skip metastases was evaluated and compared by Kaplan-Meier method and Log-rank test. Cox proportional hazard model was established to identify potential prognostic predictors. Subgroup analysis was carried out to further explore the prognostic significance of skip metastases. RESULTS: Among 2653 surgically resected N2 patients, 881 (33.2%) had skip metastases. Patients with skip N2 had a significant better overall survival (P = 0.0019). Multivariate COX regression analysis showed borderline significance of skip metastases (HR = 0.81, 95%CI: 0.645-1.017, P = 0.0698) after adjustment for other covariates. Other independent prognostic predictors included smoking history, tumor location, stage and N2 station involved (P < 0.05). Subgroup analysis demonstrated significant survival benefits of skip N2 in most subpopulations. CONCLUSIONS: This study suggested a prognostic benefit of skip N2 metastases in real world practice. Further subdivision of N2 disease is warranted for better patient management and prognostic prediction (NCT03429192).