Neoadjuvant chemoradiotherapy is superior to chemotherapy alone in surgically treated stage III/N2 non-small-cell lung cancer: a retrospective single-center cohort study

BACKGROUND: There is lack of consensus whether neoadjuvant chemoradiotherapy (CHT/RT) is superior to neoadjuvant chemotherapy (CHT) alone in patients with potentially resectable stage III/N2 non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: We retrospectively evaluated clinical parameters and outcomes in patients with clinical stage III/N2 NSCLC treated with neoadjuvant CHT/RT versus CHT followed by surgery. Nearest-neighbor propensity score (PS) matching was used to correct for pretreatment differences. RESULTS: A total of 84 patients were enrolled. Thirty-four (40%) and 50 (60%) patients received CHT/RT or CHT followed by curative-intent surgery, respectively. Overall 90-day mortality and morbidity were 0% versus 0.04% and 21% versus 18%, respectively, with no significant difference between the CHT/RT and the CHT-alone cohorts (P = 0.51 and P = 0.70). In the PS-matched cohort, complete pathological response was recorded in 25% after CHT/RT versus 0% after CHT at the time of surgery. Patients receiving neoadjuvant CHT/RT exhibited significantly better 5-year disease-free survival (DFS) [45% versus 16% CHT group; hazard ratio (HR) 0.43, P = 0.04]; 5-year overall survival (OS) was 75% after CHT/RT and 21% after CHT (HR 0.37, P = 0.001). CHT/RT more often induced pathological mediastinal downstaging (P = 0.007), but CHT/RT remained the only independent factor for DFS and OS and did not depend on mediastinal downstaging. CONCLUSIONS: In this retrospective PS-matched long-term analysis, neoadjuvant CHT/RT conferred improved DFS and OS compared with CHT alone in stage III/N2 NSCLC. These highly challenging results require confirmation in well-designed randomized controlled trials conducted at highly specialized thoracic oncology centers.