title: Relationship between intrinsic subtypes and tumor responses to neoadjuvant chemotherapy in patients with locally advanced breast cancer.
abstract: BACKGROUND
  For locally advanced breast cancer, neoadjuvant chemotherapy (NAC) is the standard of care for downstaging the tumor prior to surgery, and improved prognoses that are associated with pathological complete responses (pCR) have been noted, particularly in patients with human epidermal growth factor receptor 2 (HER2)-positive and triple negative (TN) tumors.
  
  
  OBJECTIVE
  The aim of this study was to assess the differences in pathological responses among intrinsic subtypes of local lesions and status of axillary lymph nodes (Ax LN).
  
  
  METHODS
  A consecutive series of 134 patients with locally advanced breast cancer who were treated with NAC was analyzed. Tumors were classified into the following 5 subtypes according to immunohistochemical staining results: Luminal A type, Luminal B type (HER2-negative and HER2-positive), HER2 type, and TN type.
  
  
  RESULTS
  In Luminal A, Luminal B (HER2-negative), Luminal B (HER2-positive), HER2, and TN tumors, the pCR rates were 10% (4 of 40), 19% (8 of 42), 42% (8 of 19), 59% (10 of 17), and 38% (6 of 16), respectively. HER2-positive tumors showed good therapeutic effects, while Luminal A tumors showed less therapeutic effects.
  
  
  CONCLUSIONS
  Strategies that are determined according to intrinsic subtypes are becoming very important in the treatment of locally advanced breast cancer.
authors.affiliation: Osaka Breast Clinic, Osaka, Japan. obc@osaka-breast-clinic.com
authors.forename: Asako
authors.initials: A
authors.lastname: Ooe
authors.forename: Sachiko
authors.initials: S
authors.lastname: Takahara
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sumiyoshi
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Jun
authors.initials: J
authors.lastname: Kawai
authors.forename: Eiichi
authors.initials: E
authors.lastname: Shiba
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis
chemical_list: D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human