Survival of patients with resected N2 non-small-cell lung cancer: Evidencefor a subclassification and implications

Purpose: Patients who suffer from non-small-cell lung cancer (NSCLC) with i psilateral mediastinal lymph node involvement (N2) belong to a heterogeneou s subgroup of patients. We analyzed the prognosis of patients with resected N2 NSCLC to propose homogeneous patient subgroups. Patients and Methods: The present study comprised 702 consecutive patients from six French centers who underwent surgical resection of N2 NSCLC, Initi ally, two groups of patients were defined: patients with clinical N2 (cN2) and those with minimal N2 (mN2) disease were patients in whom N2 disease wa s and was not detected preoperatively at computed tomographic scan, respect ively. Results: The median duration of follow-up was 52 months (range, 18 to 120 m onths). A multivariate analysis using Cox regression identified four negati ve prognostic factors, namely, cN2 status (P < .0001), involvement of multi ple lymph node levels (L2+; P < .0001), pT3 to T4 stage (P < .0001), and no preoperative chemotherapy (P < .01). For patients treated with primary sur gery, 5-year survival rates were as follows: mN2, one level involved (mN2L1 , n = 244): 34%; mN2, multiple level involvement (mN2L2+, n = 78): 11%; cN2 L1 (n = 118): 8%; and cN2L2+ (n = 122): 3%. When only patients with mN2L1 d isease were considered, the sire of lymph node involvement according to the American Thoracic Society numbering system had no prognostic significance (P = .14). Preoperative chemotherapy was associated with a better prognosis for those with cN2 (P < .0001). Five-year survival rates were 18% and 5% f or cN2 patients treated with and without preoperative chemotherapy, respect ively. Conclusion: This study has identified homogeneous N2 NSCLC prognostic subgr oups and suggests different therapeutic approaches according to the subgrou p profile. (C) 2000 by American Society of Clinical Oncology.