title: Quantitative MRI morphology of invasive breast cancer: correlation with immunohistochemical biomarkers and subtypes.
abstract: BACKGROUND
  Breast cancer is a heterogeneous disease with intrinsic molecular subtypes. The different biology and histology of breast cancer exhibit different tumor morphology at breast magnetic resonance imaging (MRI). However, few studies have examined the quantitative relationship between the MRI morphological and immunohistochemical features in breast cancer.
  
  
  OBJECTIVE
  To investigate the correlations between tumor roundness, as quantitatively assessed with MRI and biomarkers or subtypes of breast cancer.
  
  
  METHODS
  A total of 280 women (mean age, 51 years; range, 28-79 years) with 282 invasive breast cancers (<5 cm) were included. The associations between the tumor roundness (1-100%), as measured using MRI software, and immunohistochemical (e.g. estrogen receptor [ER], progesterone receptor [PR], human epidermal growth factor receptor 2 [HER2], and Ki67) features were evaluated using Pearson's or Spearman's rank correlation coefficients and multiple linear regression analysis.
  
  
  RESULTS
  An inverse correlation was observed between the ER (r = -0.408, P < 0.001) or PR (r = -0.248, P < 0.001) scores and tumor roundness, whereas a positive correlation was observed between the Ki67 index and tumor roundness (r = 0.354, P < 0.001). In multiple linear regression, the ER score (P < 0.001) and Ki67 index (P = 0.003) were independent factors determining tumor roundness. Triple-negative tumors (ER, PR, and HER2 negative) showed the highest mean roundness scores compared with the other subtypes (e.g. 67.3% for triple-negative, relative to 55.9% for HER2-enriched, 53.8% for luminal B, and 51.7% for luminal A, P < 0.001).
  
  
  CONCLUSIONS
  Our results suggest that breast tumors with lower ER expression and higher cellular proliferation or biologically aggressive triple-negative tumors are likely to manifest with relatively benign morphologic features.
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Min Sun
authors.initials: MS
authors.lastname: Bae
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Mirinae
authors.initials: M
authors.lastname: Seo
authors.affiliation: Biomedical Engineering Branch, Division of Convergence Technology, National Cancer Center, Gyeonggi-do, Republic of Korea.
authors.forename: Kwang Gi
authors.initials: KG
authors.lastname: Kim
authors.affiliation: Department of Pathology, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: In-Ae
authors.initials: IA
authors.lastname: Park
authors.affiliation: Department of Radiology, Seoul National University College of Medicine, Seoul, Republic of Korea moonwk@snu.ac.kr.
authors.forename: Woo Kyung
authors.initials: WK
authors.lastname: Moon
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism / Q000473:pathology*; D003287:Contrast Media; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008536:Meglumine / Q000031:analogs & derivatives; D008875:Middle Aged; D015588:Observer Variation; D009942:Organometallic Compounds; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D012189:Retrospective Studies; D047368:Tumor Burden
chemical_list: D014408:Biomarkers, Tumor; D003287:Contrast Media; D019394:Ki-67 Antigen; D008536:Meglumine; D009942:Organometallic Compounds; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; C064572:gadobenic acid; C508053:ERBB2 protein, human
keywords: Breast neoplasm; Ki67; breast cancer subtype; estrogen receptor; magnetic resonance imaging (MRI)