Surgery following neoadjuvant chemotherapy for non-small-cell lung cancer patients with unexpected persistent pathological N2 disease.

Patients with mediastinal lymph node (LN) downstaging following neoadjuvant chemotherapy exhibit improved outcomes compared with patients with persistent N2 disease. The aim of this study was to compare clinicopathological characteristics and survival between patients with unexpected and expected persistent N2 disease following surgery for non-small-cell lung cancer (NSCLC). This retrospective analysis included 348 patients with NSCLC who underwent surgery following chemotherapy at the Shanghai Pulmonary Hospital, Tongji University School of Medicine, between 1995 and 2012. According to the results of the imaging examinations and postoperative pathology, the patients were divided into three groups, namely groups I (nodal downstaging, pN0-1), II (expected persistent N2 disease) and III (unexpected persistent N2 disease). The rates of overall survival (OS) and disease-free survival (DFS) were estimated by the Kaplan-Meier method. Univariate and multivariate analyses were performed to identify the independent risk factors for OS and DFS. The mortality rate was 1.1% during the postoperative period. Perioperative complications occurred in 45 patients (12.9%). The 5-year OS rate was 32.2, 6.3 and 25.9% in groups I, II and III, respectively (group I vs. III, P=0.023; and group III vs. II, P<0.001). The 5-year DFS rate was 30.1, 5.1 and 22.4% in groups I, II and III, respectively (group I vs. III, P=0.012; and group III vs. II, P<0.001). Grouping, predicted forced expiratory volume in 1 sec, N downstaging and skip N2 metastasis were identified as independent predictive factors associated with OS, whereas the independent risk factors associated with DFS were grouping and N downstaging. Patients with unexpected persistent N2 disease exhibited better survival compared with those with expected persistent N2 disease. Surgery following chemotherapy remains the optimal approach for a proportion of patients with persistent N2 disease.