title: Breast Cancer Index predicts pathological complete response and eligibility for breast conserving surgery in breast cancer patients treated with neoadjuvant chemotherapy.
abstract: BACKGROUND
  The aim of neoadjuvant chemotherapy is to increase the likelihood of successful breast conservation surgery (BCS). Accurate identification of BCS candidates is a diagnostic challenge. Breast Cancer Index (BCI) predicts recurrence risk in estrogen receptor+lymph node-breast cancer. Performance of BCI to predict chemosensitivity based on pathological complete response (pCR) and BCS was assessed.
  
  
  METHODS
  Real-time RT-PCR BCI assay was conducted using tumor samples from 150 breast cancer patients treated with neoadjuvant chemotherapy. Logistical regression and c-index were used to assess predictive strength and additive accuracy of BCI beyond clinicopathologic factors.
  
  
  RESULTS
  BCI classified 42% of patients as low, 35% as intermediate and 23% as high risk. Low BCI risk group had 98.4% negative predictive value (NPV) for pCR and 86% NPV for BCS. High versus low BCI group had a 34 and 5.8 greater likelihood of achieving pCR and BCS, respectively (P=0.0055; P=0.0022). BCI increased c-index for pCR (0.875-0.924; P=0.017) and BCS prediction (0.788-0.843; P=0.027) beyond clinicopathologic factors.
  
  
  CONCLUSIONS
  BCI significantly predicted pCR and BCS beyond clinicopathologic factors. High NPVs indicate that BCI could be a useful tool to identify breast cancer patients who are not eligible for neoadjuvant chemotherapy. These results suggest that BCI could be used to assess both chemosensitivity and eligibility for BCS.
authors: Breast Cancer Unit; INSERM Unit U981; Department of Pathology.
authors: M C
authors: MC
authors: Mathieu
authors: Breast Cancer Unit; Department of Surgery, Institut Gustave Roussy, Villejuif, France.
authors: C
authors: C
authors: Mazouni
authors: bioTheranostics, Inc., San Diego, USA.
authors: N C
authors: NC
authors: Kesty
authors: bioTheranostics, Inc., San Diego, USA.
authors: Y
authors: Y
authors: Zhang
authors: INSERM Unit U981.
authors: V
authors: V
authors: Scott
authors: Department of Pathology.
authors: J
authors: J
authors: Passeron
authors: Breast Cancer Unit; INSERM Unit U981; Department of Medical Oncology; Institut Gustave Roussy, Villejuif, France.
authors: M
authors: M
authors: Arnedos
authors: bioTheranostics, Inc., San Diego, USA.
authors: C A
authors: CA
authors: Schnabel
authors: Breast Cancer Unit; INSERM Unit U981; Department of Medical Oncology; Institut Gustave Roussy, Villejuif, France.
authors: S
authors: S
authors: Delaloge
authors: bioTheranostics, Inc., San Diego, USA.
authors: M G
authors: MG
authors: Erlander
authors: Breast Cancer Unit; INSERM Unit U981; Department of Medical Oncology; Institut Gustave Roussy, Villejuif, France. Electronic address: fandre@igr.fr.
authors: F
authors: F
authors: André
mesh_terms: D000328:Adult; D000368:Aged; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology* / Q000628:therapy*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D060888:Real-Time Polymerase Chain Reaction; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone