Impact of main bronchial lymph node involvement in pathological T1-2N1M0 non-small-cell lung cancer: multi-institutional survey by the Japan National Hospital Study Group for Lung Cancer

Abstract

Purpose: According to the TNM classification revised in 1997, stage II non-small-cell lung cancer (NSCLC) has an unfavorable prognosis. The purpose of this study was to analyze the prognostic factors for pathological T1-2N1M0 patients with NSCLC and elucidate the significance of main bronchial lymph nodes involvement.

Methods: This retrospective study analyzed patients in a prospective database of cases from an 11-year period (operations from 1992 to 2002, follow-up data until March 2008) obtained from the Japan National Hospital Study Group for Lung Cancer. Among them, a total of 319 patients with pathological T1-2N1M0 disease were identified, and all dissected lymph nodes were classified using the Naruke map.

Results: The cumulative overall 5-year survival rate for patients with intralobar or interlobar lymph node involvement (n = 266) was 56.8%, and that for those with main bronchial lymph node involvement (n = 53) was 40.4% (P = 0.002). Among patients with multiple-station N1 nodal involvement including the main bronchial lymph nodes, patients with a lower lobe tumor (n = 12) had a significantly worse prognosis than those with an upper lobe tumor (n = 9) (13.3% vs. 55.6%, P = 0.033). Multivariate analysis demonstrated that age, histology, tumor size, and main bronchial lymph node involvement were independent prognostic factors for patients with pathological T1-2N1M0 disease.

Conclusion: Involvement of the main bronchial lymph nodes is a significant factor to predict a worse prognosis in pathological T1-2N1M0 patients with NSCLC.