Incidence and Distribution of Lobe-Specific Mediastinal Lymph Node Metastasis in Non-small Cell Lung Cancer: Data from 4511 Resected Cases
- 256 Downloads
We aimed to investigate the incidence and distribution of mediastinal lymph node metastases (MLNM) in operable non-small cell lung cancer (NSCLC) with the purpose of guiding mediastinal lymph node dissection (MLND).
A total of 4511 NSCLC patients who underwent resection between January 2001 and December 2014 were included. These patients were preoperatively untreated and grouped according to the primary tumor lobes. The incidence and distribution of pathologic MLNM were compared among groups, and multivariate analysis was conducted to find the independent factors impacting MLNM.
Lymph node involvement was observed in 1784 patients (39.5%). A total of 628 cases (13.9%) were N1-positive only, 752 cases (16.7%) were both N1- and N2-positive, and 404 cases (9.0%) were N2-positive only. The most common sites of mediastinal metastasis for different primary tumor lobes were the right upper lobe, station 4R (21.5%, 192/893); right middle lobe, station 7 (21.1%, 69/327); right lower lobe, station 7 (24.1%, 212/878); left upper lobe, station 5 (22.2%, 224/1008); and left lower lobe, station 7 (21.7%, 136/628). However, when only N2 cases were considered, each mediastinal lymph node zone can be involved with metastasis to a high proportion (> 5%). Multivariable analyses showed that poor cell differentiation, adenocarcinoma, larger tumor size, central type, and younger age were independent factors favoring MLNM.
Different primary tumor locations have a different propensity to be sites of MLNM; however, once MLNM occurs, each zone can be involved and should not be neglected. Systematic MLND is the preferred procedure for operable NSCLC.
This work was supported by the Science and Technology Planning Project of Guangdong Province (2013B021800147), the Natural Science Foundation of Guangdong Province (2016A030313857), the Guangdong Provincial Medical Scientific Funds (2016114134515565), and the National Natural Science Foundation of China (81501986).
Run-Bin Liang, Jie Yang, Tai-Shan Zeng, Hao Long, Jian-Hua Fu, Lan-Jun Zhang, Peng Lin, Xin Wang, Tie-Hua Rong, Xue Hou, and Hao-Xian Yang have no conflicts of interest to disclose.
- 6.Lardinois D, Suter H, Hakki H, Rousson V, Betticher D, Ris HB. Morbidity, survival, and site of recurrence after mediastinal lymph-node dissection versus systematic sampling after complete resection for non-small cell lung cancer. Ann Thorac Surg. 2005;80:268–74; discussion 274–265.CrossRefGoogle Scholar
- 9.Darling GE, Allen MS, Decker PA, et al. Randomized trial of mediastinal lymph node sampling versus complete lymphadenectomy during pulmonary resection in the patient with N0 or N1 (less than hilar) non-small cell carcinoma: results of the American College of Surgery Oncology Group Z0030 Trial. J Thorac Cardiovasc Surg. 2011;141:662–70.CrossRefGoogle Scholar