title: Diagnostic performance of magnetic resonance imaging for assessing tumor response in patients with HER2-negative breast cancer receiving neoadjuvant chemotherapy is associated with molecular biomarker profile.
abstract: BACKGROUND
  This study aimed to evaluate the influence of hormone receptor (HR) and Ki-67 proliferation markers in predicting the accuracy of magnetic resonance imaging (MRI) for measuring residual tumor size in patients with HER2-negative (HER2(-)) breast cancer receiving neoadjuvant chemotherapy (NAC).
  
  
  METHODS
  Fifty-four women were studied. Patients received AC (doxorubicin (Adriamycin)/cyclophosphamide) and/or taxane-based regimens. The accuracy of MR-determined clinical complete response (CCR) was compared to pathological complete response (pCR). The size of detectable residual tumor on MRI was correlated with pathologically diagnosed tumor size using the Pearson correlation.
  
  
  RESULTS
  MRI correctly diagnosed 16 of the 17 cases of pCR. There were 8 false-negative diagnoses: 7 HR(+) and 1 HR(-). The overall sensitivity, specificity, and accuracy of MRI were 78%, 94%, and 83%, respectively. The positive predictive value was 97% and the negative predictive value was 67%. For MRI vs. pathologically determined tumor size correlation, HR(-) cancers showed a higher correlation (R = 0.79) than did HR(+) cancers (R = 0.58). A worse MRI/pathology size discrepancy was found in HR(+) cancer than in HR(-)cancer (1.6 ± 2.8 cm vs. 0.56 ± 0.9 cm; P = .05). Tumors with low Ki-67 proliferation (< 40%) showed a larger size discrepancy than did those with high Ki-67 proliferation (≥ 40%) (1.2 ± 2.0 cm vs. 0.4 ± 0.8 cm; P = .05).
  
  
  CONCLUSIONS
  The results showed that the diagnostic performance of MRI for patients with breast cancer undergoing NAC is associated with a molecular biomarker profile. Among HER2(-)tumors, the accuracy of MRI was worse in HR(+)cancers than in HR(-)cancers and was also worse in low-proliferation tumors than in high-proliferation tumors. These findings may help in surgical planning.
authors.affiliation: John Tu and Thomas Yuen Center for Functional Onco Imaging of Department of Radiological Sciences, University of California, Irvine, California, USA.
authors.forename: Aida
authors.initials: A
authors.lastname: Kuzucan
authors.forename: Jeon-Hor
authors.initials: JH
authors.lastname: Chen
authors.forename: Shadfar
authors.initials: S
authors.lastname: Bahri
authors.forename: Rita S
authors.initials: RS
authors.lastname: Mehta
authors.forename: Philip M
authors.initials: PM
authors.lastname: Carpenter
authors.forename: Peter T
authors.initials: PT
authors.lastname: Fwu
authors.forename: Hon J
authors.initials: HJ
authors.lastname: Yu
authors.forename: David J B
authors.initials: DJ
authors.lastname: Hsiang
authors.forename: Karen T
authors.initials: KT
authors.lastname: Lane
authors.forename: John A
authors.initials: JA
authors.lastname: Butler
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Feig
authors.forename: Min-Ying
authors.initials: MY
authors.lastname: Su
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D014408:Biomarkers, Tumor / Q000032:analysis; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy* / Q000378:metabolism*; D017024:Chemotherapy, Adjuvant; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis; D011960:Receptors, Estrogen / Q000096:biosynthesis; D011980:Receptors, Progesterone / Q000096:biosynthesis; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone