Improved Survival Outcomes in Medically Fit Patients With Early-Stage Non–Small-Cell Lung Cancer Undergoing Stereotactic Body Radiotherapy

Abstract

IntroductionStereotactic body radiotherapy (SBRT) has been shown to result in excellent disease control rates for early-stage non–small-cell lung cancer (NSCLC). It remains unknown which patients would most benefit from SBRT in treating NSCLC. Patients and MethodsWe conducted a retrospective analysis of 346 patients treated with SBRT for early-stage NSCLC at 2 institutions (86 patients from City of Hope National Medical Center and 260 patients from The Newport Beach Radiosurgery Center/Hoag Hospital) from February 2010 to July 2019. The primary endpoint was overall survival (OS). The omnibus test of model coefficients was performed to study the associations between clinical factors and OS. Survival analyses were performed by the log-rank test and Cox proportional hazards regression. ResultsUnder the univariate analysis, variables associated with a decreased likelihood of death included age < 65 years (P = .040) and being a surgical candidate (P = .010). Multivariate analysis found that surgical candidates still had a significantly decreased likelihood of death compared to nonsurgical candidates (Hazard ratio 0.360, 95% confidence interval 0.153-0.848, P = .019). Median OS was significantly increased for surgical candidates versus nonsurgical candidates (83 vs 53 months, P = .017). The local failure rate was 9.1%, the locoregional failure rate was 12.7%, and the distant failure rate was 10.7%. ConclusionPatients who are deemed to be candidates for surgery have improved OS compared to those who are not when treated with SBRT. This raises the question of selection bias in trials comparing surgery with SBRT in NSCLC, as patients who are deemed to be surgical candidates and then go on to undergo surgery may have an inherent OS benefit.