title: Continuation of epidermal growth factor receptor tyrosine kinase inhibitor treatment prolongs disease control in non-small-cell lung cancers with acquired resistance to EGFR tyrosine kinase inhibitors.
abstract: OBJECTIVE
  Patients with non-small-cell lung cancer (NSCLC) develop acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKIs) after tumor regression. No approved targeted therapies are currently available after initial EGFR TKI treatment. This study investigated the efficacy of continuing EGFR TKI therapy with local treatments for patients with NSCLC and local progression or minimal/slow progression on TKI therapy.
  
  
  METHODS
  Fifty-five patients with NSCLC treated with EGFR TKIs and developed acquired resistance to the drug were included. Initial response to target therapy, median progression free survival (PFS1), progression pattern, and first progression site were assessed. Median progression free survival to physician assessment progression (PFS2) and difference between PFS1 and PFS2 (PFS difference) were also recorded.
  
  
  CONCLUSIONS
  PFS1 was 11.2 months, PFS2 was 20.3 months, and PFS difference was 8.3 months. Nineteen patients (34.5%) who manifested progression received local therapy, and 16 (28.6%) underwent rebiopsy after progression with six positive EGFR T790M mutations detected. Cox proportional hazards regression model showed that only the first line of treatment was significantly correlated with PFS difference. NSCLC patients with acquired resistance to EGFR TKIs could benefit from the same TKI therapy through months to years of disease control.
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, China.|Department of Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, China.|Collaborative Innovation Center of Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, China.|Department of Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, China.|Collaborative Innovation Center of Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Quan
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, China.|Department of Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, China.|Collaborative Innovation Center of Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
authors.forename: Lingyu
authors.initials: L
authors.lastname: Ding
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, China.|Department of Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, China.|Collaborative Innovation Center of Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
authors.forename: Xiangchan
authors.initials: X
authors.lastname: Hong
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, China.|Department of Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, China.|Collaborative Innovation Center of Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
authors.forename: Ningning
authors.initials: N
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, China.|Department of Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, China.|Collaborative Innovation Center of Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Liang
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, China.|Department of Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, China.|Collaborative Innovation Center of Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, China.
authors.forename: Haiying
authors.initials: H
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D043844:Crown Ethers / Q000009:adverse effects / Q000627:therapeutic use; D018450:Disease Progression; D018572:Disease-Free Survival; D019008:Drug Resistance, Neoplasm / Q000187:drug effects / Q000235:genetics; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D000069347:Erlotinib Hydrochloride / Q000009:adverse effects / Q000627:therapeutic use; D005076:Exanthema / Q000139:chemically induced; D005260:Female; D000077156:Gefitinib; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009154:Mutation; D017063:Outcome Assessment, Health Care / Q000379:methods / Q000706:statistics & numerical data; D016016:Proportional Hazards Models; D047428:Protein Kinase Inhibitors / Q000009:adverse effects / Q000627:therapeutic use*; D011799:Quinazolines / Q000009:adverse effects / Q000627:therapeutic use; D013997:Time Factors
chemical_list: D043844:Crown Ethers; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; C531470:icotinib; D000069347:Erlotinib Hydrochloride; D066246:ErbB Receptors; D000077156:Gefitinib
keywords: acquired resistance; beyond PD; continuation of epidermal growth factor receptor tyrosine kinase inhibitors; local treatment; non-small-cell lung cancer