Impacts of EGFR 19 exon mutations on brain metastases in treatment-naïve patients with lung adenocarcinoma

Abstract

Objective: To investigate the relationship between the status of epidermal growth factor receptor (EGFR) mutations and brain metastases in patients with lung adenocarcinoma. Methods: From August 2010 to May 2015, a total of 1 063 lung adenocarcinoma patients with identified status of EGFR mutations in Shanxi Cancer Hospital were enrolled, of which 456 patients had EGFR mutations. Multivariate Logistic regression model was used to analyze the correlation between EGFR mutation status and brain metastases in patients with lung adenocarcinoma. Results: In 125 patients with brain metastases before initial treatment, 65 patients had EGFR mutations, including 36 patients with deletion mutations in exon 19. The frequency of EGFR 19 exon mutation was 28.8% (36/125). Among 456 patients with EGFR mutations, 65(14.3%) patients were with brain metastases, in which 36(55.0%) had deletion mutations in exon 19. The multivariate analysis showed that age, Eastern Cooperative Oncology Group (ECOG) score, EGFR mutations and N staging were associated with brain metastases(P<0.05). Further subgroup multivariate analyses showed that age, ECOG score, mutation status in exon 19 and N staging were associated with brain metastases (P<0.05). Conclusions: EGFR mutation status is related to brain metastases. Mutations in EGFR exon 19 is an independent risk factor for brain metastases.