Prognostic factors in neoadjuvant treatment followed by surgery in stage IIIA-N2 non-small cell lung cancer: a multi-institutional study by the Oncologic Group for the Study of Lung Cancer (Spanish Radiation Oncology Society).

Abstract

To evaluate the prognostic factors associated with survival in patients treated with neoadjuvant treatment [chemoradiotherapy (CRT) or chemotherapy] followed by surgery (CRTS) in patients with stage IIIA-N2 non-small cell lung cancer (NSCLC). A retrospective study was conducted of 118 patients diagnosed with stage T1-T3N2M0 NSCLC and treated with CRTS at 14 hospitals in Spain between January 2005 and December 2014. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method and compared using the log-rank test. Cox regression analysis was performed. Surgery consisted of lobectomy (74.5% of cases), pneumectomy (17.8%), or bilobectomy (7.6%). Neoadjuvant treatment was CRT in 62 patients (52.5%) and chemotherapy alone in 56 patients (47.5%). Median follow-up was 42.5months (5-128months). 5-year OS and PFS were 51.1% and 49.4%, respectively. The following variables were independently associated with worse OS and PFS: pneumonectomy (vs. lobectomy); advanced pathologic T stage (pT3 vs. pT0-pT2); and presence of persistent N2 disease (vs. ypN0-1) in the surgical specimen. In this sample of patients with stage IIIA-N2 NSCLC treated with CRTS, 5-year survival (both OS and PFS) was approximately 50%. After CRTS, the patients with the best prognosis were those whose primary tumour and/or mediastinal nodal metastases were downstaged after induction therapy and those who underwent lobectomy. These findings provide further support for neoadjuvant therapy followed by surgery in selected patients.