title: Radiotherapy for asymptomatic brain metastasis in epidermal growth factor receptor mutant non-small cell lung cancer without prior tyrosine kinase inhibitors treatment: a retrospective clinical study.
abstract: BACKGROUND
  Non-small cell lung cancer (NSCLC) with brain metastasis (BM) harboring an epidermal growth factor receptor (EGFR) mutation shows good response to tyrosine kinase inhibitors (TKIs). This study is to assess the appropriate timing of brain radiotherapy (RT) for asymptomatic BM in EGFR mutant NSCLC patients.
  
  
  METHODS
  There were 628 patients diagnosed with EGFR mutant NSCLC between October 2005 and December 2011. Treatment outcomes had been retrospectively evaluated in 96 patients with asymptomatic BM without prior TKI treatment. 39 patients received first-line brain RT, 23 patients received delayed brain RT, and 34 patients did not receive brain RT.
  
  
  RESULTS
  With a median follow-up of 26 months, the 2-year OS was 40.6 %. Univariate analyses revealed that ECOG performance status (p = 0.006), other distant metastases (p = 0.002) and first line systemic treatment (p = 0.032) were significantly associated with overall survival (OS). Multivariate analyses revealed that other sites of distant metastases (p = 0.030) were prognostic factor. The timing of brain RT was not significantly related to OS (p = 0.246). The 2-year BM progression-free survival (PFS) was 26.9 %. Brain RT as first-line therapy failed to demonstrate a significant association with BM PFS (p = 0.643).
  
  
  CONCLUSIONS
  First-line brain RT failed to improve long-term survival in TKI-naïve EGFR mutant NSCLC patients with asymptomatic BM. Prospective studies are needed to validate these clinical findings.
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. liusr@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. liusr@sysucc.org.cn.|Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. liusr@sysucc.org.cn.
authors.forename: SongRan
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. qiubo@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. qiubo@sysucc.org.cn.|Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. qiubo@sysucc.org.cn.
authors.forename: Bo
authors.initials: B
authors.lastname: Qiu
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. chenlk@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. chenlk@sysucc.org.cn.|Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China. chenlk@sysucc.org.cn.
authors.forename: LiKun
authors.initials: L
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. wangf@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. wangf@sysucc.org.cn.|Department of Molecular Diagnosis, Sun Yat-sen University Cancer Center, Guangzhou, China. wangf@sysucc.org.cn.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. liangying@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. liangying@sysucc.org.cn.|Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China. liangying@sysucc.org.cn.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. caipq@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. caipq@sysucc.org.cn.|Department of Radiology, Sun Yat-sen University Cancer Center, Guangzhou, China. caipq@sysucc.org.cn.
authors.forename: PeiQiang
authors.initials: P
authors.lastname: Cai
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. zhangli@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. zhangli@sysucc.org.cn.|Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou, China. zhangli@sysucc.org.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. christyfeel@hotmail.com.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. christyfeel@hotmail.com.|Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. christyfeel@hotmail.com.
authors.forename: ZhaoLin
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. liushil@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. liushil@sysucc.org.cn.|Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. liushil@sysucc.org.cn.
authors.forename: ShiLiang
authors.initials: S
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. liumzh@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. liumzh@sysucc.org.cn.|Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. liumzh@sysucc.org.cn.
authors.forename: MengZhong
authors.initials: M
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. liuhui@sysucc.org.cn.|Guangdong Esophogeal Cancer Research Institute, Guangzhou, China. liuhui@sysucc.org.cn.|Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China; Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China. liuhui@sysucc.org.cn.
authors.forename: Hui
authors.initials: H
authors.lastname: Liu
mesh_terms: D000230:Adenocarcinoma / Q000201:enzymology / Q000235:genetics / Q000532:radiotherapy / Q000556:secondary*; D000328:Adult; D000368:Aged; D058070:Asymptomatic Diseases; D001932:Brain Neoplasms / Q000201:enzymology / Q000235:genetics / Q000532:radiotherapy*; D002289:Carcinoma, Non-Small-Cell Lung / Q000201:enzymology / Q000235:genetics / Q000532:radiotherapy / Q000556:secondary*; D016371:Cranial Irradiation / Q000009:adverse effects / Q000379:methods*; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D018773:Genes, erbB-1; D005838:Genotype; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000201:enzymology / Q000235:genetics / Q000628:therapy; D008297:Male; D008875:Middle Aged; D058990:Molecular Targeted Therapy; D009154:Mutation; D011379:Prognosis; D047428:Protein Kinase Inhibitors; D012189:Retrospective Studies; D013997:Time Factors; D017211:Treatment Failure
chemical_list: D047428:Protein Kinase Inhibitors; D066246:ErbB Receptors