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

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.

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.

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).

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.