title: Immunohistochemical expression of HER1, HER3, and HER4 in HER2-positive breast cancer patients treated with trastuzumab-containing neoadjuvant chemotherapy.
abstract: OBJECTIVE
  The aim of the present study was to examine the association between the expression of human epidermal receptor (HER) 1, HER3, and HER4 and pathologic complete response (pCR) in HER2-positive patients treated with trastuzumab-containing neo-adjuvant chemotherapy.
  
  
  METHODS
  Immunohistochemical analyses of HER1, HER3, and HER4 were performed using tumor specimens obtained from patients treated with trastuzumab-containing neoadjuvant chemotherapy. The staining intensity of each biomarker was evaluated, and the correlations between the immunohistochemical profiles and pCR were examined.
  
  
  RESULTS
  The present study included 44 patients with HER2-positive breast cancer treated with trastuzumab-containing neo-adjuvant chemotherapy. Seventeen patients achieved a pCR. The expressions of HER1, HER3, and HER4 were observed in 18.2%, 27.3%, and 18.2% of the specimens, respectively. A marginally significant negative correlation between the expression of HER1 and pCR was observed, irrespective of the expression of HER3 and HER4, whereas the expressions of HER3 and HER4 were not significantly correlated with pCR.
  
  
  CONCLUSIONS
  The expression of HER1 might be an independently negative predictor of pCR in HER2-positive breast cancer patients treated with trastuzumab-containing neoadjuvant chemotherapy.
authors.affiliation: Breast and Medical Oncology Division, National Cancer Center Hospital, Chuo-ku, Tokyo, Japan. kyonemor@ncc.go.jp
authors.forename: Kan
authors.initials: K
authors.lastname: Yonemori
authors.forename: Koji
authors.initials: K
authors.lastname: Tsuta
authors.forename: Chikako
authors.initials: C
authors.lastname: Shimizu
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Hatanaka
authors.forename: Akihiro
authors.initials: A
authors.lastname: Hirakawa
authors.forename: Makiko
authors.initials: M
authors.lastname: Ono
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kouno
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Katsumata
authors.forename: Masashi
authors.initials: M
authors.lastname: Ando
authors.forename: Kenji
authors.initials: K
authors.lastname: Tamura
authors.forename: Tadashi
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kinoshita
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujiwara
mesh_terms: D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal / Q000008:administration & dosage*; D061067:Antibodies, Monoclonal, Humanized; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy*; D017024:Chemotherapy, Adjuvant; D066246:ErbB Receptors / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis* / Q000037:antagonists & inhibitors; D020893:Receptor, ErbB-3 / Q000032:analysis*; D066247:Receptor, ErbB-4; D000068878:Trastuzumab
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D066246:ErbB Receptors; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; D066247:Receptor, ErbB-4; D000068878:Trastuzumab; C512478:EGFR protein, human; C508053:ERBB2 protein, human; C587689:ERBB4 protein, human