Extent of Removal for Mediastinal Nodal Stations for Patients with Clinical Stage I Non-Small Cell Lung Cancer: Effect on Outcome

Background Lobectomy and mediastinal lymph node dissection comprise the standard surgical treatment for non-small cell lung cancer (NSCLC). Although complete mediastinal lymph node dissection has been recommended as part of the procedure for achieving complete resection, the benefits for early lung cancer are unclear. The purpose of this study was to determine the effects of different degrees of mediastinal lymph node dissection on the clinical outcomes of patients with clinical stage I NSCLC. Materials and Methods The records of patients with clinical stage I NSCLC treated between January 2000 and September 2010 were reviewed retrospectively. This study consisted of 211 patients who underwent lobectomy plus mediastinal lymph node dissection and sampling. Patients were divided into a group who underwent lymphadenectomy (LA) including complete mediastinal node dissection or lobe-specific lymph node dissection and a group who underwent selective lymph node sampling (LS). Clinical outcomes, including survival, and prognostic factors were determined. Results The mean (+/-) number of extracted lymph nodes for the LS and LA patients was 7.50 +/- 5.44 and 14.09 +/- 7.57, respectively (p < 0.001). Male and diabetes mellitus patients were more associated with LS. Survival of the LA patients was significantly longer (p = 0.029). By multivariate analysis, extent of mediastinal nodal sampling (p = 0.029) and positive for mediastinal nodal (N2-positive) disease (p = 0.046) were significant predictors for survival. Conclusions The extent of dissection of mediastinal lymph nodes affected the clinical outcomes of our study patients with clinical stage I NSCLC. At least evaluation of lobe-specific lymph node dissection is required.