Surgery on unfavourable persistent N2/N3 non-small-cell lung cancer after trimodal therapy: do the results justify the risk?

OBJECTIVES: Persistent mediastinal lymph node metastasis after neoadjuvant therapy is a significant negative indicator for survival. Even though there is still no consensus on the matter, some authors advocate a thorough restaging prior to surgery and deny surgery in cases of persistent N2 because of the poor outcome. We analysed our results after trimodal therapy in pN2/N3 stage III non-small-cell lung cancer (NSCLC) and persistent mediastinal lymph node metastasis after neoadjuvant chemoradiotherapy. METHODS: We conducted a retrospective cohort analysis of 167 patients who received trimodal therapy for stage III NSCLC. Progression-free interval and survival were calculated. T-stage, N-stage, ypT-stage, ypN2/3-stage and surgical procedure were tested as risk factors. RESULTS: Eighty-three patients with potentially resectable initial pN2/3 underwent 44 pneumonectomies and 76% extended resections. Thirty-five patients showed persistent mediastinal lymph node metastasis after trimodal therapy. Treatment-related comorbidity after an operative therapy was 58%. Hospital mortality was 2.4%. The ypT- and ypN2/N3 stages were significant risk factors and, in the case of persistent mediastinal lymph node metastasis, median progression-free period was 17 months and median survival time was 21 months. CONCLUSIONS: Persistent but resectable N2/N3 after chemoradiotherapy in stage III NSCLC is the least favourable subgroup of patients in neoadjuvant approaches. If surgery can be carried out with curative intent and low morbidity, completing trimodal therapy is justified, with an acceptable outcome.