title: Clinical efficacy of erlotinib, a salvage treatment for non-small cell lung cancer patients following gefitinib failure.
abstract: OBJECTIVE
  The purpose of this study was to identify predictive factors for erlotinib treatment in non-small cell lung cancer (NSCLC) patients following gefitinib failure.
  
  
  METHODS
  Forty-five patients with NSCLC who were treated with erlotinib following gefitinib failure at Seoul National University Hospital between August 2005 and November 2011 were enrolled. Epidermal growth factor receptor (EGFR) mutation status, pathologic findings and other clinical factors, including response to tyrosine kinase inhibitors (TKIs) and progression-free survival (PFS), were evaluated.
  
  
  RESULTS
  Of the 45 patients, 40 patients (88.8%) had adenocarcinoma. The following EGFR mutations were observed: five patients with a deletion of exon 19, six patients with an L858R mutation, three patients with wild-type EGFR, and 31 patients with unknown mutations. The response rate of erlotinib was 4.4%, and stable disease was 42.2%. The median PFS for erlotinib was 2.6 months (95% confidence interval, 1.4 to 3.7). Patients with a PFS ≥ 4 months during previous gefitinib treatment had a significantly longer PFS with erlotinib (3.3 months vs. 1.6 months, respectively; p < 0.01) than patients with PFS < 4 months with gefitinib. According to multivariate analyses, PFS ≥ 4 months for previous gefitinib treatment was significantly associated with prolonged PFS with erlotinib (p = 0.04). However, the response rate of gefitinib and treatment sequence were not associated with prolonged PFS with erlotinib (p = 0.28 and p = 0.67, respectively).
  
  
  CONCLUSIONS
  Following rechallenge with the EGFR TKI erlotinib following gefitinib failure, patients who showed prolonged PFS with gefitinib benefit from erlotinib. However, further prospective studies are needed to confirm these findings.
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.|Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Kyoung Min
authors.initials: KM
authors.lastname: Cho
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.|Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Bhumsuk
authors.initials: B
authors.lastname: Keam
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.|Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Tae Min
authors.initials: TM
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.|Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Se-Hoon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.|Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Dong-Wan
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.|Cancer Research Institute, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Dae Seog
authors.initials: DS
authors.lastname: Heo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D016009:Chi-Square Distribution; D018572:Disease-Free Survival; D066246:ErbB Receptors / Q000037:antagonists & inhibitors / Q000235:genetics; D000069347:Erlotinib Hydrochloride / Q000627:therapeutic use*; D005260:Female; D000077156:Gefitinib; D006785:Hospitals, University; D006801:Humans; D053208:Kaplan-Meier Estimate; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009154:Mutation; D016016:Proportional Hazards Models; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use*; D011799:Quinazolines / Q000627:therapeutic use*; D056910:Republic of Korea; D012189:Retrospective Studies; D012307:Risk Factors; D016879:Salvage Therapy; D013997:Time Factors; D017211:Treatment Failure
chemical_list: D000970:Antineoplastic Agents; D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D000069347:Erlotinib Hydrochloride; C512478:EGFR protein, human; D066246:ErbB Receptors; D000077156:Gefitinib
keywords: Carcinoma, non-small-cell lung; Disease-free survival; Erlotinib; Gefitinib; Prognostic factor