title: Magnetic resonance imaging as a predictor of pathologic response in patients treated with neoadjuvant systemic treatment for operable breast cancer. Translational Breast Cancer Research Consortium trial 017.
abstract: BACKGROUND
  Increased pathologic complete response (pCR) rates observed with neoadjuvant chemotherapy (NCT) for some subsets of patients with invasive breast cancer have prompted interest in whether patients who achieved a pCR can be identified preoperatively and potentially spared the morbidity of surgery. The objective of this multicenter, retrospective study was to estimate the accuracy of preoperative magnetic resonance imaging (MRI) in predicting a pCR in the breast.
  
  
  METHODS
  MRI studies at baseline and after the completion of NCT plus data regarding pathologic response were collected retrospectively from 746 women who received treatment at 8 institutions between 2002 and 2011. Tumors were characterized by immunohistochemical phenotype into 4 categories based on receptor expression: hormone (estrogen and progesterone) receptor (HR)-positive/human epidermal growth factor receptor 2 (HER2)-negative (n = 327), HR-positive/HER2-positive, (n = 148), HR-negative/HER2-positive, (n = 101), and triple-negative (HR-negative/HER2 negative; n = 155). In all, 194 of 249 patients (78%) with HER2-positive tumors received trastuzumab. Univariate and multivariate analyses of factors associated with radiographic complete response (rCR) and pCR were performed.
  
  
  RESULTS
  For the total group, the rCR and pCR rates were 182 of 746 patients (24%) and 179 of 746 patients (24%), respectively, and the highest pCR rate was observed for the triple-negative subtype (57 of 155 patients; 37%) and the HER2-positive subtype (38 of 101 patients; 38%). The overall accuracy of MRI for predicting pCR was 74%. The variables sensitivity, negative predictive value, positive predictive value, and accuracy differed significantly among tumor subtypes, and the greatest negative predictive value was observed in the triple-negative (60%) and HER2-positive (62%) subtypes.
  
  
  CONCLUSIONS
  The overall accuracy of MRI for predicting pCR in invasive breast cancer patients who were receiving NCT was 74%. The performance of MRI differed between subtypes, possibly influenced by differences in pCR rates between groups. Future studies will determine whether MRI in combination with directed core biopsy improves the predictive value of MRI for pathologic response.
authors: Department of Radiation Oncology, University of Alabama at Birmingham Comprehensive Cancer Center, Birmingham, AL, USA. jdelossantos@uabmc.edu
authors: Jennifer F
authors: JF
authors: De Los Santos
authors: Alan
authors: A
authors: Cantor
authors: Keith D
authors: KD
authors: Amos
authors: Andres
authors: A
authors: Forero
authors: Mehra
authors: M
authors: Golshan
authors: Janet K
authors: JK
authors: Horton
authors: Clifford A
authors: CA
authors: Hudis
authors: Nola M
authors: NM
authors: Hylton
authors: Kandace
authors: K
authors: McGuire
authors: Funda
authors: F
authors: Meric-Bernstam
authors: Ingrid M
authors: IM
authors: Meszoely
authors: Rita
authors: R
authors: Nanda
authors: E Shelley
authors: ES
authors: Hwang
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy / Q000473:pathology; D018275:Carcinoma, Lobular / Q000188:drug therapy / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D060828:Induction Chemotherapy; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D011960:Receptors, Estrogen / Q000032:analysis; D011980:Receptors, Progesterone / Q000032:analysis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human