Prognostic Importance of the Lymph Node Factor in Surgically Resected Non-Small Cell Lung Cancer

Abstract

Background Patients with N1 non-small cell lung cancer represent a heterogeneous population. The aim of this study is to determine the difference of survival rate between subtypes of N1 disease in surgically resected non-small cell lung cancer patients and to compare the survival in these patients with multi-N1 and single N2 (skip metastasis) disease. Methods Patients who underwent anatomical pulmonary resection in our institution between 2007 and 2014 with a pathological diagnosis of N1 and single N2 positive non-small cell lung cancer were included in the study. N1 positive patients were divided into three groups as single hilar; single interlobar, lobar, or segmental; and multiple N1 positive patients. These groups were compared among themselves as well as with incidentally found single N2 patients. Results A total of 1,742 patients who had non-small cell lung cancer underwent anatomical lung resection. The survival was better in single hilar lymph nodes than other subtypes of N1 disease (p = 0.015). There was no statistically significant difference in terms of survival between the other subtypes of N1 disease (p = 0.332). The difference in survival for single N2 disease compared with multi-N1 was not statistically significant (p = 0.054). Also, when we divided the groups as single and multi-N1, there was a significant difference in survival (p = 0.025). Conclusion Single hilar lymph nodes with direct invasion have better survival rate than other subtypes of N1. Also, patients with multiple N1 positive lymph nodes have similar survival results compared with single N2 patients. Our results should be confirmed with larger series to better explain N1 disease.

Unforeseen N2 Disease after Negative Endosonography Findings with or without Confirmatory Mediastinoscopy in Resectable Non–Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

“…In addition, several studies showed 5-year overall survival rates in patients with occult single-level N2 disease treated with curative-intent resection and adjuvant chemoradiotherapy that were comparable to those in patients with N1 disease. 55,56 The extensiveness of N2 nodal metastasis, however, remains important because significant differences in overall survival were found between patients with single-and multiple-station N2 disease and between patients with microscopic (0.2-2 mm) and macroscopic N2 disease. 57,58 In the ASTER trial, mediastinoscopy-diagnosed N2/N3 disease after negative endosonography findings was found in 9.2% of patients.…”

Postoperative Radiotherapy Option Based on Mediastinal Lymph Node Reclassification for Patients with pN2 Non-small-Cell Lung Cancer

“…Moreover, multivariate analysis revealed that port was an independent predictive factor for adverse os (hr: 2.618; 95% ci: 1.185 to 5.785; p = 0.017). Numerous studies have proposed that the prognosis for patients with nsclc having single-station skip mediastinal ln metastasis (N2a1) is close to that for patients with pN1 disease 14,24,25 . Thus, it could be speculated that nsclc at the N2a1 pathologic stage might exhibit biologic behaviours similar to those at the N1 stage.…”

Genetic Clonality as the Hallmark Driving Evolution of Non-Small Cell Lung Cancer

“…This confirms that lymph node metastases are seeded a long before clinical detection and, at that moment, they do not contribute to migration to other sites; however, they evolve in parallel with primary tumors sharping the genetic divergence [ 116 , 122 ]. Primary NSCLC, and its corresponding lymph node metastases, present high concordance in clonal alterations, indicating that local metastases may arise from the major clone of primary tumor [ 114 , 123 ]. Moreover, the NPIPA1 gene mutation and NKX2/1 gene amplification are evident drivers of lymph nodes metastases [ 116 ].…”

“…Due to a common ancestor, primary NSCLC and its lymph node metastases should be susceptible to the same treatment regimen. However, the genetic heterogeneity between both lesions seems to be the main reason for recurrence after surgical resection [ 123 , 124 ]. Lymph nodes metastases may be considered a reservoir for distant spreading of NSCLC; however, distant metastases that were seeded from the primary tumor or metastatic lymph nodes indicated divergent evolutionary trajectories [ 114 , 116 , 125 ].…”