title: Differential pathological response to preoperative chemotherapy across breast cancer intrinsic subtypes.
abstract: BACKGROUND
  Breast cancer is a heterogeneous disease with a diversity of clinical behaviors. The purpose of this study was to evaluate the utility of breast cancer intrinsic subtypes in the prediction of pathological complete response (pCR) in a cohort of breast cancer patients receiving preoperative chemotherapy.
  
  
  METHODS
  Patients with stage II/III breast cancer received 4 cycles of XT (capecitabine and docetaxel) followed by 4 cycles of FEC (fluorouracil, epirubicin, and cyclophosphamide) as preoperative chemotherapy. Tumors were classified as luminal A, luminal B, luminal/HER2, HER2, basal-like, or non-basal-like triple negative by immunohistochemical analysis in core needle biopsy samples at baseline.
  
  
  RESULTS
  The overall pCR rate was 11.9% (12/101). Multivariate analysis showed that intrinsic subtype was an independent factor to predict pCR. With luminal A patients as the reference group, luminal B (OR = 16.39; 95% CI 1.44-185.88; p = 0.024), HER2 (OR = 14.73; 95% CI 1.19-180.84; p = 0.035), and basal-like (OR = 13.27; 95% CI 1.27-138.79; p = 0.031) patients had a significantly higher likelihood of pCR.
  
  
  CONCLUSIONS
  The present data indicate that intrinsic subtypes may be useful predictive biomarkers of pCR in breast cancer patients treated with preoperative chemotherapy.
authors.affiliation: Department of Surgery, Keio University School of Medicine, Tokyo, Japan. jinno@z7.keio.jp
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Jinno
authors.forename: Sachiko
authors.initials: S
authors.lastname: Matsuda
authors.forename: Tetsu
authors.initials: T
authors.lastname: Hayashida
authors.forename: Maiko
authors.initials: M
authors.lastname: Takahashi
authors.forename: Shigemichi
authors.initials: S
authors.lastname: Hirose
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ikeda
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kitagawa
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D000069287:Capecitabine; D003520:Cyclophosphamide / Q000008:administration & dosage; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives; D000077143:Docetaxel; D015251:Epirubicin / Q000008:administration & dosage; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D005472:Fluorouracil / Q000008:administration & dosage / Q000031:analogs & derivatives; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D043823:Taxoids / Q000008:administration & dosage
chemical_list: D000069287:Capecitabine; D003520:Cyclophosphamide; D003841:Deoxycytidine; D000077143:Docetaxel; D015251:Epirubicin; D066246:ErbB Receptors; D005472:Fluorouracil; D018719:Erb-b2 Receptor Tyrosine Kinases; D043823:Taxoids