The Features Of Brain Metastases From Non-small Cell Lung Cancer According To Epidermal Growth Factor Receptor Mutation Status

ObjectTo explore the relationship between epidermal growth factor receptor(EGFR)mutation status and clinical characteristics in patients with non-small cell lung cancer(NSCLC).We also compare the imaging features of brain metastases according to EGFR mutation status in those with brain involvement.MethodsPatients diagnosed with NSCLC who underwent EGFR mutation status testing at our institution between October 2012 and March 2016 were retrospectively reviewed.Clinical characteristics and the imaging features of brain metastasis were compared among different EGFR mutation groups.ResultsEGFR mutation occurred more frequently in female(76%vs 37.8%,p<0.001),never smoker(69.1%vs 35.1%,p<0.001),never drinker(61.4%vs 44.1%,p<0.001),and those with adenocarcinoma(60%vs 17.2%,p<0.001).The mutation rate was significantly lower among the patients with poor differentiation(p=0.001).The incidence of brain metastasis was significantly higher in patients with exon 19 mutation both at initial diagnosis(23.6%vs 12.1%,p=0.003)and at subsequent follow-up(30.7%vs 17.0%,p=0.002).Patients with exon 19 mutation status had a lower rate of adrenal metastasis(2.9%vs 8.6%,p=0.043).In addition,among the patients with brain metastasis,no significant difference was found in number and size of the largest brain metastatic tumor according to EGFR mutations.ConclusionOur study showed that EGFR mutation was seen in greater percentage of female patients,never smokers,never drinkers,and those with adenocarcinoma.Patients with exon 19 mutated had a higher likelihood of suffering from brain metastasis and a lower rate of adrenal metastasis.No significant difference was found in the number or size of the largest brain metastatic tumor among patients with exon 19 mutation,exon 21 mutation and EGFR wild type.