title: ER-poor and HER2-positive: a potential subtype of breast cancer to avoid axillary dissection in node positive patients after neoadjuvant chemo-trastuzumab therapy.
abstract: OBJECTIVE
  The study was to estimate the likelihood of axillary downstaging and to identify the factors predicting a pathologically node negative status after neoadjuvant chemotherapy (NAC) with or without trastuzumab in HER2-positive breast cancer.
  
  
  METHODS
  Patients with HER2-positive, stage IIa-IIIc breast cancer were enrolled. Axillary status was evaluated by palpation and fine needle aspiration (FNA) before NAC. All patients received 4-6 cycles of PCrb (paclitaxel 80 mg/m2 and carboplatin AUC = 2 d1, 8, and 15 of a 28-day cycle, or paclitaxel 175 mg/m2 and carboplatin AUC = 6 every-3-week) and were non-randomly administered trastuzumab (2 mg/kg weekly or 6 mg/kg every-3-week) or not. After NAC, each patient underwent standard axillary lymph node dissection and breast-conserving surgery or mastectomy. And some patients received sentinel lymph node biopsy (SLNB) before axillary dissection.
  
  
  RESULTS
  Between November-2007 and June-2013, 255 patients were enrolled. Of them, 157 were confirmed as axillary node positive by FNA (group-A) and 98 as axillary node negative either by FNA or impalpable (group-B). After axillary dissection, the overall pathologically node negative rates (pNNR) were 52.9% in group-A and 69.4% in group-B. The ER-poor/HER2-positive subtype acquired the highest pNNR (79.6% in group-A and 87.9% in group-B, respectively) and the lowest rate of residual with ≥4 nodes involvement (1.9% and 3%, respectively) after PCrb plus trastuzumab. In multivariate analysis, trastuzumab added and ER-poor status were independent factors in predicting a higher pNNR in HER2-positive breast cancer. Forty-six tested patients showed that the ER-poor/HER2-positive subtype acquired a considerable high pNNR and axillary status with SLNB was well macthed with the axillary dissection.
  
  
  CONCLUSIONS
  ER-poor/HER2-positive subtype of breast cancer is a potential candidate for undergoing sentinel lymph node biopsy instead of regional node dissection for accurate axillary evaluation after effective downstaging by neoadjuvant chemo-trastuzumab therapy.
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Li
authors.affiliation: Clinical Statistics Center, Fudan University Shanghai Cancer Center, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Miao
authors.initials: M
authors.lastname: Mo
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Ke-da
authors.initials: KD
authors.lastname: Yu
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Can-Ming
authors.initials: CM
authors.lastname: Chen
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Hu
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Yi-Feng
authors.initials: YF
authors.lastname: Hou
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Gen-Hong
authors.initials: GH
authors.lastname: Di
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Jiong
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Zhen-Zhou
authors.initials: ZZ
authors.lastname: Shen
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Shao
authors.affiliation: Department of Breast Surgery, Shanghai Cancer Center/Cancer Institute, Fudan University, Shanghai, P. R. China and Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P. R. China.
authors.forename: Guang-Yu
authors.initials: GY
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D001365:Axilla / Q000473:pathology; D001943:Breast Neoplasms / Q000145:classification / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000172:deficiency*; D012189:Retrospective Studies; D000068878:Trastuzumab; D055815:Young Adult
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D000068878:Trastuzumab; C508053:ERBB2 protein, human