Background:
Lymph node status is of utmost importance in determining prognosis and planning therapy for patients with non-small cell lung cancer (NSCLC). Due to methodological difficulties no changes were made to the nodal (N) descriptors in the 8th edition of NSCLC staging. It is recommended, however, that clinicians record more detailed information about nodal metastases, so that more prognostically discriminative subcategories may be established. Here we analyzed surgical patients with N1 lymph node metastases to determine whether the number and station of lymph node metastases had an effect on long-term survival.
Materials and methods:
We retrospectively analyzed patients with NSCLC who had been treated with pulmonary resection (lobectomy, pneumonectomy, or sublobar resection) and systematic lymph node dissection at our institution between 2008 and 2012. We included patients with N1 lymph node involvement and a tumor size corresponding to T1 or T2. In all cases patients had been treated in curative intent and the tumor had been removed in toto (R0).
Results:
We found 92 patients (61 men, 29 women), who fit our inclusion criteria. The overall 5-year survival rate was 56.3%. In the univariate analysis solitary N1 lymph node metastasis was associated with a better disease free survival rate than multiple N1 metastases, but this relationship was no longer significant in the multivariate analysis. There was no significant difference in outcome between N1 involvement due to direct extension and N1 involvement due to metastasis. A multivariate survival model using Cox's regression analysis revealed that in patients with N1 lymph node metastases, large cell carcinoma and higher tumor stage were associated with worse outcomes, while pneumonectomy (compared to smaller resections) was associated with a better outcome.
Conclusion:
Our study could not confirm a relationship between subcategories of N1 lymph node involvement and long term survival. Further investigations are warranted.
