Survival and effective prognostic factors in lung cancer patients with brain metastases treated with whole brain radiotherapy

Abstract

ObjectiveTo evaluate the outcomes and explore the risk factors for survival of lung cancer patients with brain metastases (BMs) who were treated with whole brain radiotherapy (WBRT) and to identify the significance of the risk factors. MethodsA retrospective analysis was carried out for lung cancer patients with BMs who were treated with WBRT in the Second Affiliated Hospital of Soochow University from January 2014 to December 2017. Their survival time was calculated using the Kaplan-Meier method. Meanwhile, the neutrophil-lymphocyte ratio (NLR) cutoff values were defined using the receiver operating characteristic (ROC) curve analysis, and the characteristics of different NLR groups were compared using the Wilcoxon Rank Sum Test. ResultsA total of 179 patients were assessed. Their median overall survival (OS) was 9.9 (95% CI 7.08–12.72) months. As shown by univariate analyses, their OS was significantly affected by histology (P ​< ​0.001), number of BMs (P ​= ​0.009), local treatment of BMs (P ​= ​0.019), Karnofsky Performance Status score (P ​= ​0.001), Graded Prognostic Assessment (GPA) score (P ​< ​0.001), hemoglobin level (P ​= ​0.002), lymphocyte count (P ​= ​0.006), albumin level (P ​= ​0.001), and NLR (P ​< ​0.001). Meanwhile, according to multivariate analyses, independent risk factors for OS included non-adenocarcinoma (ADCA) histology (P ​< ​0.001) and high NLR (P ​= ​0.006). Moreover, the optimal NLR cutoff value was determined to be 7.0. The patients in this study were divided into three categories based on their total score determined by assigning each risk factor of histology and NLR one point. The median survival in the patients with scores of 0, 1, and 2 was 19.6 months, 8.5 months, and 2.2 months, respectively (P ​= ​0.001). The survival time and prognostic factors of different pathological types of patients were further analyzed. As a result, the median OS of patients with small-cell lung cancer (SCLC), ADCA patients receiving targeted therapy, and ADCA patients not receiving targeted therapy was 10.9 months, 13.2 months, and 9.5 months, respectively. The results of multivariate analyses all showed that NLR was an independent risk factor for OS of these three pathological types of patients. ConclusionsNon-ADCA histology and high NLR serve as independent prognostic factors for survival of lung cancer patients with BMs who have been treated with WBRT. A prognostic model comprising histological type and NLR can be used to evaluate the survival.