Abstract:
Objective To comprehensively investigate the prognostic significance of nodal skip metastasis and lobe-specific metastasis for patients with IIIa-N2 non-small-cell lung cancer (NSCLC).
Methods A total of 218 completely resected pN2-NSCLC cases with systematic lymph node dissections from 2008 to 2009 at Tianjin Medical University Cancer Hospital were enrolled. Mediastinal lymph node metastasis was subdivided into continuous metastasis and skip metastasis according to whether N1 lymph nodes were involved. Mediastinal lymph node metastasis was also classified into extensive metastasis and lobe-specific metastasis on the basis of whether the lymph nodes involved were within or beyond lobe-specific regions. Overall survival (OS) and disease-free survival (DFS) were compared.
Results For the whole cohort, 5-year OS was 21.6% and 5-year DFS was 16.8%. The 5-year OS for patients with skip metastasis or continuous metastasis were 37.6% and 22.0%, respectively (P =0.008). The 5-year DFS of patients with skip metastasis or continuous metastasis were 29.1% and 15.0%, respectively (P =0.022). The 5-year OS of patients with lobe-specific metastasis and extensive metastasis were 38.3% and 20.4%, respectively (P =0.005). The 5-year DFS of patients with lobe-specific metastasis and extensive metastasis were 28.4% and 15.1%, respectively (P =0.009). According to the two patterns, patients were subdivided into three subgroups: Group A (presence of both skip metastasis and lobe-specific metastasis), Group B (presence of skip metastasis only or lobe-specific metastasis only), and Group C (presence of non-skip metastasis and non-lobe-specific metastasis). The 5-year OS of the three subgroups were 47.1% (Group A), 28.1% (Group B), and 16.6% (Group C) (P =0.001), and the 5-year DFS of these subgroups were 35.2% (Group A), 20.8% (Group B), and 11.2% (Group C), respectively (P =0.002). Multivariate analysis demonstrated that the combined pattern was an independent prognostic factor for both OS and DFS.
Conclusion This combined pattern of lymph node metastasis was a strong prognostic factor for IIIa-N2 NSCLC. This pattern should be considered when predicting prognoses and during the selection of patients that will receive postoperative treatments.