3:10 PM Abstract No. 44 Thermal ablation and stereotactic radiation therapy for stage I NSCLC: contemporary trends and outcomes from the National Cancer Database

Abstract

To investigate utilization of thermal ablation for management of stage I non–small cellular lung cancer (NSCLC) compared to stereotactic radiation and evaluate associated outcomes. Patients treated with thermal ablation or stereotactic radiation for stage I NSCLC diagnosed between 2004 and 2013 were retrospectively studied using the National Cancer Database (NCDB). Patients were excluded if receiving chemotherapy or immunotherapy. Propensity score models (nearest neighbour method) were used to 1:1 match patients receiving ablation and radiation, resulting in a cohort with balanced distribution of baseline variables. Overall survival was analyzed using Kaplan Meier plots and Cox proportional hazard models in the matched cohort. 1,058 patients receiving thermal ablation and 22,415 patients receiving stereotactic radiation fulfilled the inclusion criteria. Thermal ablation patients were in general older and had more comorbidities. Sociodemographic factors associated with thermal ablation treatment were white race, private insurance or Medicare, high median household income, rural residency, smaller tumor size and treatment in an academic center. Patients residing in Middle Atlantic or New England states had a higher likelihood of treatment by thermal ablation. In the 1:1 matched cohort with balanced distribution of baseline variables (including age, gender, comorbidities, socio-demographic and cancer factors), overall survival was comparable for both treatment subgroups with a median survival for thermal ablation of 36.4 months versus 35.3 months for patients receiving stereotactic radiation (log rank p-value 0.939). Cox proportional hazards regression showed a survival benefit for patients treated by thermal ablation, although results did not reach statistical significance (HR = 0.97, 95% CI: 0.87-1.08, p = 0.57). NSCLC treatment by thermal ablation shows substantial variation depending on patient characteristics and socio-demographic factors. Overall survival for thermal ablation is comparable with stereotactic radiation. In light of these findings, further studies should evaluate whether thermal ablation is a cost-effective alternative to stereotactic radiation.