ER-poor and HER2-positive: a potential subtype of breast cancer to avoid axillary dissection in node positive patients after neoadjuvant chemo-trastuzumab therapy

PLoS One. 2014 Dec 11;9(12):e114646. doi: 10.1371/journal.pone.0114646. eCollection 2014.

Abstract

Purpose: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Antibodies, Monoclonal, Humanized / therapeutic use*
  • Axilla / pathology
  • Breast Neoplasms / classification
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / metabolism
  • Breast Neoplasms / pathology*
  • Chemotherapy, Adjuvant
  • Female
  • Humans
  • Lymphatic Metastasis
  • Middle Aged
  • Neoadjuvant Therapy*
  • Neoplasm Staging
  • Receptor, ErbB-2 / metabolism*
  • Receptors, Estrogen / deficiency*
  • Retrospective Studies
  • Trastuzumab
  • Young Adult

Substances

  • Antibodies, Monoclonal, Humanized
  • Receptors, Estrogen
  • ERBB2 protein, human
  • Receptor, ErbB-2
  • Trastuzumab

Grants and funding

This research is supported by the Shanghai Committee of Science and Technology, China (grant 12DZ2260100), and the Shanghai United Developing Technology Project of Municipal Hospitals (SHDC12010116), the Key Clinical Program of the Ministry of Health (2010–2012). The research funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. No other potential confict of interest relevant to this article was reported.