title: HER2/CEP17 ratio and HER2 immunohistochemistry predict clinical outcome after first-line trastuzumab plus taxane chemotherapy in patients with HER2 fluorescence in situ hybridization-positive metastatic breast cancer.
abstract: OBJECTIVE
  This study aimed to elucidate the clinical implication of human epidermal growth factor receptor 2/centromeric probe for chromosome 17 (HER2/CEP17) ratio and HER2 immunohistochemistry (IHC) results in patients with HER2 fluorescence in situ hybridization (FISH)-positive metastatic breast cancer (MBC) who received first-line trastuzumab plus taxane chemotherapy.
  
  
  METHODS
  Using clinical data of patients with HER2 FISH-positive MBC who received first-line trastuzumab plus taxane chemotherapy, we analyzed the clinical outcome according to the HER2/CEP17 ratio and HER2 IHC analysis.
  
  
  RESULTS
  Fifty-two women were analyzed. The median age was 50 years (range 27-69 years). Patients with a HER2/CEP17 ratio ≥3.0 had significantly longer progression-free survival (PFS) (17.2 vs. 7.4 months; p = 0.002) with a tendency toward higher response rate (RR) (p = 0.325) and longer overall survival (OS) (p = 0.129). Patients with HER2 IHC 1+ had significantly shorter OS (14.0 vs. 42.4 months; p = 0.013) along with a tendency toward lower RR (p = 0.068) and shorter PFS (p = 0.220). In the multivariate analysis, HER2/CEP17 ratio <3.0 (p = 0.004) and Eastern Cooperative Oncology Group (ECOG) PS 2 (p = 0.015) were significant factors for shorter PFS, and HER2 IHC 1+ (p = 0.015) and ECOG PS 2 (p = 0.036) were significant factors for poor OS.
  
  
  CONCLUSIONS
  Our data support that HER2/CEP17 ratios and HER2 IHC scores may predict clinical outcome after first-line trastuzumab plus taxane chemotherapy in patients with HER2 FISH-positive MBC.
authors.affiliation: Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, Korea.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Kim
authors.forename: Jee Hyun
authors.initials: JH
authors.lastname: Kim
authors.forename: Seock-Ah
authors.initials: SA
authors.lastname: Im
authors.forename: Yu Jung
authors.initials: YJ
authors.lastname: Kim
authors.forename: Hye-Suk
authors.initials: HS
authors.lastname: Han
authors.forename: Jin-Soo
authors.initials: JS
authors.lastname: Kim
authors.forename: Kyung-Hun
authors.initials: KH
authors.lastname: Lee
authors.forename: Tae-Yong
authors.initials: TY
authors.lastname: Kim
authors.forename: Sae-Won
authors.initials: SW
authors.lastname: Han
authors.forename: Yoon Kyung
authors.initials: YK
authors.lastname: Jeon
authors.forename: Do-Youn
authors.initials: DY
authors.lastname: Oh
authors.forename: Tae-You
authors.initials: TY
authors.lastname: Kim
authors.forename: In Ae
authors.initials: IA
authors.lastname: Park
mesh_terms: D000328:Adult; D000368:Aged; D000465:Algorithms; D061067:Antibodies, Monoclonal, Humanized / Q000008:administration & dosage / Q000627:therapeutic use*; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage; D014408:Biomarkers, Tumor / Q000378:metabolism; D001859:Bone Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000556:secondary; D001943:Breast Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D001952:Bridged-Ring Compounds / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000188:drug therapy / Q000556:secondary; D008207:Lymphatic Metastasis / Q000175:diagnosis; D042361:Mammary Glands, Human / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D012189:Retrospective Studies; D016019:Survival Analysis; D043823:Taxoids / Q000008:administration & dosage / Q000627:therapeutic use*; D000068878:Trastuzumab
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D014408:Biomarkers, Tumor; D001952:Bridged-Ring Compounds; D009363:Neoplasm Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; D043823:Taxoids; D000068878:Trastuzumab; C080625:taxane; C508053:ERBB2 protein, human