Analysis of Survival of the Patients with Brain Metastases from Lung Cancer according to Treatment Modalities and Prognostic Indexes

Abstract

This study aimed to retrospectively evaluate overall survival (OS) of the patients with brain metastases (BM) from lung cancer who had been treated with whole-brain radiotherapy (WBRT) and gamma knife (GK) according to prognostic factors and prognostic score indexes. METHODS Ninety-five patients with brain metastases from lung cancer were retrospectively evaluated using age, sex, lung cancer histological type, extracranial metastases, primary tumor control, number of brain metastases, total brain metastases volume, brain metastasectomy, chemotherapy, EGFR mutation, EGFR-TKI therapy, Karnofsky Performance Status (KPS), Recursive Partitioning Analysis (RPA) Class, Basic Score for Brain Metastases (BS-BM), Graded Prognostic Assessment Index (DS-GPA) and Modified Lung-Specific between 2015 and 2018. Univariate analysis of OS was performed using the Kaplan-Meier method supplemented by the log-rank test. We also applied multivariate survival analysis using the Cox Regression Model. RESULTS The median OS for all patients with brain metastases from lung cancer was six months± SE: 0.807 (range: 1-42 months; 95% CI: 4.419-7.581) and one-year overall survival rate was 25.3%. The median OS was four months, four months, 12 months in the WBRT arm, the GK arm and the combined WBRT-GK arm, respectively (p=0.004). In multivariate analysis, treatment with WBRT-GK (p=0.030), brain metastasectomy (p=0.019), controlled primary tumor (p=0.004), chemotherapy (p=0.001) were significantly correlated with overall survival. BS-BM (p=0.033) was closely related to overall survival compared to other prognostic score indexes on the multivariate analysis. CONCLUSION The patients with BM benefited from WBRT and GK combined therapy. BS-BM for the survival of patients with BM from lung cancer is the most appropriate prognostic index.