RESUMO
Objective: We aimed to visualize complicated patterns of lymph node metastases in surgically resected non-small cell lung cancer by applying a data mining technique. Methods: In this retrospective study, 783 patients underwent lobectomy or pneumonectomy with systematic mediastinal lymph node dissection for non-small cell lung cancer between January 2010 and December 2018. Surgically resected lymph nodes were classified according to the International Association for the Study of Lung Cancer lymph node map. Network analysis generated patterns of lymph node metastases from stations 1 to 14, and the degree of connection between 2 lymph node stations was assessed. Results: The median number of lymph nodes examined per patient was 20, and the pathological N category was pN0 in 428 cases, pN1 in 132, pN2 in 221, and pN3 in 2. N1 lymph node stations had strong associations with superior mediastinal lymph node stations for patients with primary tumors in the upper lobes and with station 7 for the lower lobes. There was also a connection from the N1 lymph node stations to superior mediastinal lymph node stations in the lower lobes. In the right middle lobe, an even distribution from station 12m toward stations 2R, 4R, and 7 was noted. We released an interactive web application to visualize these data: http://www.canexapp.com. Conclusions: Lymph node metastasis patterns differed according to the lobe bearing the tumor. Our results support the need for clinical trials to further investigate selective mediastinal lymph node dissection.
RESUMO
OBJECTIVES: The purpose of this study is to assess the clinicopathological characteristics of non-small-cell lung cancer (NSCLC) occurring in the left lingular division (LLD) in association with a proposal of the LLD-specific regional lymph node stations. METHODS: Medical records of patients, who underwent complete tumour resection with mediastinal lymph node dissection (MLND) for LLD-NSCLC from 2000 to 2009 in multiple institutions, were retrospectively examined. We analysed patient clinicopathological characteristics and obtained the LLD-specific regional lymph node stations, and then the validity of intraoperative navigation in lymphadenectomy for LLD-NSCLC was investigated. RESULTS: One hundred and eighty-four LLD-NSCLC patients (97 males and 87 females, and 128 adenocarcinomas and 56 non-adenocarcinomas) were studied. The 5-year overall survival (OS) and disease-free survival (DFS) rates for all LLD-NSCLC patients were 72.9 and 58.3%, respectively. We examined the lymph node metastasis patterns in 42 node-positive tumours. The frequent metastatic lymph node stations were #12u lobar node (n = 22), #5 subaortic node (n = 15) and #11 interlobar node (n = 13) in order. These three node stations were also single metastatic sites in some patients. Metastases to sub-carinal (#7) or inferior mediastinal nodes (#8) were rare. Thus, we assigned the three stations (#5, #11, #12u) as the regional lymph node stations for LLD-NSCLC. If these regional lymph node stations had been examined pathologically during surgery for a total of 160 LLD-NSCLC patients with c-T2N1M0 or lower stage disease, 125 p-N0 and 5 p-N1 patients diagnosed with no metastasis would have been subjected to selective MLND, while 14 p-N1 and all 16 p-N2 patients diagnosed with metastasis would have had complete MLND carried out. As a result, these regional lymph node stations could accurately predict the existence of p-N2 metastasis, and appropriately lead to a selective or complete MLND. CONCLUSIONS: An intraoperative pathological examination using our proposed LLD-specific regional lymph node stations may accurately diagnose the status of node metastasis, and appropriately lead to selective or complete MLND in LLD-NSCLC patients with c-T2N1M0 or lower stage disease.