Validation of the Disease-Specific GPA for Patients With 1 to 3 Synchronous Brain Metastases in Newly Diagnosed NSCLC

Abstract

BackgroundThe disease-specific graded prognostic assessment (DS-GPA) for brain metastases is a powerful prognostic tool but has not been validated for patients with synchronous brain metastases (SBM) in newly diagnosed non–small-cell lung cancer (NSCLC). Patients and MethodsWe identified patients with newly diagnosed NSCLC with 1 to 3 SBM treated with stereotactic radiosurgery (SRS) between 1997 and 2012. We included patients whose brain metastases were treated with SRS alone or combined SRS and whole-brain radiotherapy (WBRT). Patients were stratified according to NSCLC DS-GPA to evaluate the accuracy of survival estimates. ResultsOne hundred sixty-four patients were treated with either SRS alone (n = 85; 52%) or SRS and WBRT (n = 79; 48%). Median overall survival (OS) stratified according to DS-GPA of 0 to 1, 1.5 to 2, 2.5 to 3, and 3.5 to 4 were 2.8, 6.7, 9.8, and 13.2 months, respectively, consistent with OS reported for brain metastases in NSCLC DS-GPA (3.0, 6.5, 11.3, and 14.8 months, respectively). No difference in median progression-free survival or OS was noted with combined use of SRS and WBRT: 6.0 versus 6.1 months (P = .81) and 8.5 versus 9.1 months (P = .093), respectively. In multivariable analysis, Karnofsky performance status (hazard ratio [HR], 0.98; P = .008), extracranial metastases (HR, 0.498; P = .0003), squamous histology (HR, 1.81; P = .02), and number of brain metastases (2 vs. 1; HR, 1.504; P = .04, and 3 vs. 1; HR, 1.66; P = .05) were significant predictors of OS. ConclusionThe DS-GPA accurately estimates the prognosis of patients with SBM in newly diagnosed NSCLC. Patients with synchronous brain metastasis in newly diagnosed NSCLC should be carefully stratified for consideration of aggressive therapy.