Association between epidermal growth factor receptor mutation subtypes and the prognosis of brain metastases in patients with lung adenocarcinoma

Abstract

Objective To explore the association between epidermal growth factor receptor (EGFR) mutation subtypes and the prognosis of brain metastasis in patients with lung adenocarcinoma. Methods A retrospective analysis was performed on the clinical data of 256 patients who were admitted to our hospital and confirmed with brain metastases of lung adenocarcinoma by EGFR mutation detection from 2010 to 2015. The prognostic factors for brain metastases were analyzed. The survival rate was calculated by the Kaplan-Meier method and analyzed by the log-rank test. The univariate and multivariate prognostic analyses were performed by the log-rank test and the Cox proportional hazards model. Results The median survival time was 10.13 months in all patients. The univariate analysis showed that sex, EGFR mutation status, exon 19 deletion, the Karnofsky Performance Status (KPS) score of brain metastases, and targeted therapy were prognostic predictors (P=0.006, 0.001, 0.010, 0.000, 0.003). The multivariate analysis showed that the KPS score and exon 19 deletion were prognostic factors for brain metastases (P=0.000, 0.045). When grouped into the recursive partitioning analysis classes, all the patients were split into three subgroups with significantly different prognosis (P=0.000). Conclusions Exon 19 deletion is a prognostic predictor of brain metastases in patients with lung adenocarcinoma, which can be integrated into the prognosis scoring system for brain metastases of lung adenocarcinoma. EGFR tyrosine kinase inhibitors improve the survival in patients with brain metastases of lung adenocarcinoma and EGFR mutation, particularly, in those with exon 19 deletion. Key words: Neoplasm metastasis, brain; Lung neoplasms; Epidermal growth factor receptor; Prognosis