title: Comparison of clinical outcomes following gefitinib and erlotinib treatment in non-small-cell lung cancer patients harboring an epidermal growth factor receptor mutation in either exon 19 or 21.
abstract: BACKGROUND
  Gefitinib and erlotinib, small-molecule kinase inhibitors that block epidermal growth factor receptor (EGFR) signaling, have demonstrated a dramatic response rate and prolonged progression-free survival (PFS) in patients harboring an activating EGFR mutation. We compared the clinical outcomes in gefitinib- and erlotinib-treated patients harboring EGFR mutations who had recurrent or metastatic non-small-cell lung cancer (NSCLC).
  
  
  METHODS
  A total of 375 patients with recurrent or metastatic stage IIIB/IV NSCLC, who had either exon 19 deletion or the L858R mutation in exon 21, and had received either gefitinib (n = 228) or erlotinib (n = 147), were included in the study. A matched-pair case-control study design was implemented in the analysis, where 121 pairs of gefitinib-treated and erlotinib-treated patients were matched according to sex, smoking history, Eastern Cooperative Oncology Group performance status, and types of EGFR mutation.
  
  
  RESULTS
  The median age of all patients was 58 years (range, 30-84), and more than half of patients had never been smokers (63.6%). Most patients had adenocarcinoma (98.3%) and good Eastern Cooperative Oncology Group performance status (0, 1) (90.9%). The median number of cycles of EGFR tyrosine kinase inhibitor (TKI) treatment was 12.7 in the gefitinib group and 10.8 in the erlotinib group. Of the 242 patients, 63 (26%) received EGFR TKI as first-line therapy. The overall response rates and disease control rates in the gefitinib- or erlotinib-treated groups were 76.9% versus 74.4% (p = 0.575) and 90.1% versus 86.8%, respectively (p = 0.305). There was no statistically significant difference with regard to PFS (median, 11.7 versus 9.6; p = 0.056) between the gefitinib- and erlotinib-treated groups. For patients receiving EGFR TKI as the first-line treatment, there was no significant difference between the two treatment groups in overall response rates (76.7% and 90.0%) (p = 0.431) and median PFS (11.7 versus 14.5 months) (p = 0.507).
  
  
  CONCLUSIONS
  In NSCLC patients harboring EGFR mutation, treatment with gefitinib and erlotinib resulted in similar effectiveness.
authors.affiliation: Division of Hematology-Oncology, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sung Hee
authors.initials: SH
authors.lastname: Lim
authors.forename: Ji Yun
authors.initials: JY
authors.lastname: Lee
authors.forename: Jong-Mu
authors.initials: JM
authors.lastname: Sun
authors.forename: Jin Seok
authors.initials: JS
authors.lastname: Ahn
authors.forename: Keunchil
authors.initials: K
authors.lastname: Park
authors.forename: Myung-Ju
authors.initials: MJ
authors.lastname: Ahn
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000235:genetics / Q000401:mortality / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality / Q000556:secondary; D066246:ErbB Receptors / Q000235:genetics*; D000069347:Erlotinib Hydrochloride; D005091:Exons / Q000235:genetics*; D005260:Female; D005500:Follow-Up Studies; D000077156:Gefitinib; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000235:genetics / Q000401:mortality / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000627:therapeutic use; D011799:Quinazolines / Q000627:therapeutic use*; D012189:Retrospective Studies; D015996:Survival Rate
chemical_list: D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D000069347:Erlotinib Hydrochloride; C512478:EGFR protein, human; D066246:ErbB Receptors; D000077156:Gefitinib