Nomogram Predicting Overall Survival Benefit of Stereotactic Ablative Radiotherapy for Early-Stage Non-Small Cell Lung Cancer.

Abstract Objectives To develop and validate a nomogram that predicts overall survival (OS) for patients with early-stage non-small cell lung cancer (NSCLC) treated with stereotactic ablative radiotherapy (SABR) vs. observation. Materials and Methods Adults with biopsy-proven T1-T2N0 NCSLC treated with SABR (30-70 Gy in 1-10 fractions with biologically effective dose ≥100 Gy10) or observation between 2004 and 2015 in the National Cancer Database (NCDB) were identified. Propensity score was used to match SABR and observation cohorts on prognostic demographic and clinicopathologic factors identified by logistic regression. Using backward selection, a multivariable Cox proportional hazard was identified predicting 2- and 5-year OS via a nomogram. Model prediction accuracy was assessed by time-dependent receiver operating characteristic (ROC) curves and integrated area under the ROC curve (AUC) analysis. Results A total of 22,073 adults met inclusion criteria and 4418 matched pairs (total n = 8836) were identified for nomogram development. The factors most strongly associated with improved OS on multivariable analysis included younger age (HR 0.82 by decade, P Conclusion This nomogram estimates OS at 2 and 5 years based on whether medically inoperable early-stage NSCLC patients receive SABR or elect for observation. Incorporation of other variables not captured within the NCDB may improve the model accuracy.