Purpose: This study was conducted to accurately define the N status of non-small cell lung carcinoma (NSCLC).
Methods: We retrospectively reviewed 147 patients with NSCLC and pathologically positive regional lymph nodes who underwent major pulmonary resections with complete mediastinal lymph node dissections.
Results: The overall 5-year survival rate was 41% after a median follow-up period of 33 months. The survival rate of patients with hilar N1 disease (26%) was significantly lower (P = 0.002) than that of those with interlobar and intrapulmonary N1 disease (60%). The survival rate of patients with hilar N1 disease (26%) was similar to that of those with N2 disease (33%; P = 0.56). Cox proportional hazards analysis with the covariates of age, sex, cell type, site of resection, pathological T factor, and pathological N factor revealed that pathological N factor indicated a relative risk for N2 disease of 1.76 (P = 0.028). Grouping hilar N1 disease with N2 disease showed that the relative risk of this "new N2 disease" with the same covariates was 2.65 (P = 0.002).
Conclusion: According to our data, hilar N1 disease should be grouped with N2 disease because this combined category accurately reflects surgical outcome.