Pretreatment Clinical Mediastinal Nodal Bulk and Extent do not Influence Survival in N2-Positive Stage IIIA Non-small Cell Lung Cancer Patients Treated with Trimodality Therapy

Treatment for patients with N2-positive stage IIIA non-small cell lung cancer has been a controversial issue. The current study evaluated the outcomes in patients treated with trimodality therapy, which consisted of neoadjuvant radiation therapy concurrent with chemotherapy followed by surgical resection, with emphasis on clinical and pathologic nodal status. We reviewed the records of 355 patients who were treated with trimodality therapy between 1997 and 2011. After completion of neoadjuvant chemoradiation, overall down-staging and complete response rates were 50.4 % (179 patients), and 13.2 % (47 patients), respectively. With median follow-up of 35.3 months, median times of progression-free survival (PFS) and overall survival (OS) were 16.3 months and 45.5 months, respectively. Seventeen patients (4.8 %) died of postoperative complications, and the remaining 338 patients were analyzed on prognostic factors. Old age (p = 0.032), pneumonectomy (p < 0.001), and ypN+ (p < 0.001) were found to be the significant prognosticators for worse PFS, and old age (p = 0.013), pneumonectomy (p < 0.001), and ypN+ (p < 0.001) were related to worse OS. Clinical N2 status did not influence either OS or PFS: the number of involved stations (single station vs. multi-station; p = 0.187 for PFS; p = 0.492 for OS), and bulk (clinically evident vs. microscopic; p = 0.902 for PFS; p = 0.915 for OS). ypN stage was the most important prognosticator for both PFS and OS; however, neither initial bulk nor extent of cN2 disease influenced prognosis. Surgery following neoadjuvant chemoradiation should have contributed to improved clinical outcomes regardless of clinical nodal bulk and extent.