Postoperative radiotherapy with modern techniques does not improve survival for operable stage IIIA-N2 non-small cell lung cancer

Abstract

Objectives: This study aims to evaluate whether postoperative radiotherapy using newer techniques (intensity-modulated radiotherapy [IMRT]) is associated with improved survival for patients with stage IIIA-N2 non-small cell lung cancer (NSCLC) who underwent complete resection.

Methods: The overall survival of patients with stage IIIA-N2 NSCLC who received postoperative IMRT versus no postoperative IMRT following induction chemotherapy and lobectomy in the National Cancer Database from 2010-2018 was assessed via Kaplan-Meier analysis, Cox proportional hazards analysis and propensity score-matched analysis. Additional survival analyses were also conducted in patients with completely resected stage IIIA-pN2 NSCLC who had upfront lobectomy (without induction therapy) followed by adjuvant chemotherapy alone or adjuvant chemotherapy with postoperative IMRT. Only patients receiving IMRT, which is a newer, more conformal radiotherapy technique, were included. Patients with positive surgical margins were excluded.

Results: A total of 3203 patients with stage IIA-N2 NSCLC who underwent lobectomy were included. Five hundred eighty-eight (18.4%) patients underwent induction chemotherapy followed by lobectomy, and 2615 (82%) underwent lobectomy followed by chemotherapy. In unadjusted, multivariable-adjusted, and propensity score--matched analyses, there were no significant differences in overall survival between the patients who also received postoperative IMRT versus those who did not.

Conclusions: In this national analysis, the use of postoperative IMRT was not associated with improved survival in patients with completely resected stage IIIA-N2 NSCLC with or without induction chemotherapy.

Trial registration: ClinicalTrials.gov NCT00410683.

Keywords: 3-dimensional conformal radiation therapy; intensity-modulated radiation therapy; lobectomy; non–small cell lung cancer; postoperative radiation; resection; stage III; stage IIIA-N2; surgery.