Use of frailty to predict survival in elderly patients with early stage non-small-cell lung cancer treated with stereotactic body radiation therapy

Objectives: Frailty has been shown to increase morbidity and mortality independent of age, but studies are lacking in radiation oncology. This study evaluates a modified frailty index (mFI) in predicting overall survival (OS) and non-cancer death for Stage I/II [N0M0] Non-Small-Cell Lung Cancer (NSCLC) patients treated with Stereotactic Body Radiation Therapy (SBRT). Materials and Methods: Medical records for all patients with Stage I/II NSCLC treated at our institution with SBRT from 2009 to 2014 were reviewed. A validated mF1 score, consisting of 11 variables was calculated, classifying patients as non-frail (0-1) or frail (>= 2). Primary endpoint (OS) was analyzed using Kaplan-Meier method and log-rank. Secondary endpoint, non-cancer death, was analyzed using Fine-Gray's method, with death from lung cancer as a competing risk. Results: Patient cohort consisted of 38 (27.3%) non-frail and 101 (72.7%) frail [median total mFI score 3.0 (range 0-7)]. Median age and pack-year history was 74 and 46 years, respectively. Median follow-up among survivors was 38.5 months (range 4.0-74.1 months). Frailty was associated with a lower 3-year OS (37.3% vs. 74.7%; p = 0.003) and 3-year cumulative incidence of non-cancer death (36.7% vs. 12.5%; p = 0.02). Frailty remained significant in the multivariate model [OS HR for mFI 225 (1.14-4.44); p = 0.02]. Conclusion: Frailty is associated with lower OS in older patients with early stage NSCLC treated with SBRT, yet frail patients survived a median 2.5 years, and were more likely to die of causes unrelated to the primary lung cancer, suggesting SBRT should be considered even in older patients deemed unfit for surgery. (C) 2017 Elsevier Ltd. All rights reserved.