Surgical multimodality treatment for baseline resectable stage IIIA-N2 non-small cell lung cancer. Degree of mediastinal lymph node involvement and impact on survival.

OBJECTIVE

Analysis of single centre results and identification of prognostic factors of surgical combined modality treatment in pathological proven stage IIIA-N2 non-small cell lung cancer (NSCLC).

METHODS

Out of a total of 996 resections for NSCLC between 2000 and 2006, 92 patients with radiological response or stable disease after induction chemotherapy for pathologically proven ipsilateral positive lymph nodes (N2-disease) underwent surgical exploration with the aim of complete resection. Adenocarcinoma and squamous cell carcinomas were equally present (48% vs 43%). Median follow-up of surviving patients (n=36) was 51 (10-94) months.

RESULTS

Complete resection (i.e., tumour with free margins and negative highest mediastinal lymph nodes, R0) was achieved in 68% (n=63), resection was uncertain or incomplete in 24% (n=22), while surgery was explorative in 8% (n=7). Pneumonectomy was performed in 24%, (bi)lobectomy in 62%, and sleeve lobectomy in 13% of patients. In-hospital mortality was 2.3%. Overall need for ICU stay was 18% (30% after pneumonectomy). Median hospital stay was 10 days (6-157). Downstaging of mediastinal lymph nodes (ypN0-1) was found in 43% (n=40). Overall survival at 5 years (5YS) was 33% (n=92), and after complete resection 43% (n=63). Detection of multilevel compared to single level positive nodes at initial mediastinoscopy was related to lower 5YS (17% vs 39%; p<0.005), and this was identified as an independent prognostic factor in a multivariate analysis of the examined presurgical variables. We found a trend for a better 5YS in patients with mediastinal nodal downstaging compared to patients with persistent N2 disease (49% vs 27%; p=0.095). In the subgroup with persistent N2 disease, single level disease has a significantly better survival (37% vs 7% 5YS, p<0.005). Multivariate survival analysis of the examined surgical variables identified completeness of resection and classification of ypN category (ypN0-1 and ypN2-single level vs multilevel-ypN2 and ypN3) as independent prognostic factors.

CONCLUSIONS

Surgery after induction chemotherapy for stage IIIA-N2 NSCLC can be performed with an acceptable mortality and morbidity. Baseline single level N2 disease is an independent prognostic factor for long-term survival. Patients with mediastinal downstaging, but also a subgroup of patients with single level persistent N2 disease, after induction therapy have a rewarding survival.