title: Shear-wave elastography and immunohistochemical profiles in invasive breast cancer: evaluation of maximum and mean elasticity values.
abstract: OBJECTIVE
  To evaluate the correlations of maximum stiffness (Emax) and mean stiffness (Emean) of invasive carcinomas on shear-wave elastography (SWE) with St. Gallen consensus tumor phenotypes.
  
  
  METHODS
  We used an ultrasound system with SWE capabilities to prospectively study 190 women with 216 histologically confirmed invasive breast cancers. We obtained one elastogram for each lesion. We correlated Emax and Emean with tumor size, histologic type and grade, estrogen and progesterone receptors, HER2 expression, the Ki67 proliferation index, and the five St. Gallen molecular subtypes: luminal A, luminal B without HER2 overexpression (luminal B HER2-), luminal B with HER2 overexpression (luminal B HER2+), HER2, and triple negative.
  
  
  RESULTS
  Lesions larger than 20 mm had significantly higher Emax (148.04 kPa) and Emean (118.32 kPa) (P=0.005) than smaller lesions. We found no statistically significant correlations between elasticity parameters and histologic type and grade or molecular subtypes, although tumors with HER2 overexpression regardless whether they expressed hormone receptors (luminal B HER2+ and HER2 phenotypes) and triple-negative tumors had lower Emax and Emean than the others. We assessed the B-mode ultrasound findings of the lesions with some of the Emax or Emean values less than or equal to 80 kPa; only four of these had ultrasound findings suggestive of a benign lesion (two with luminal A phenotype and two with HER2 phenotype).
  
  
  CONCLUSIONS
  We were unable to demonstrate statistically significant differences among the subtypes of invasive tumors, although there appears to be a trend toward lower Emax and Emean in the aggressive phenotypes.
authors.affiliation: Women's Imaging Department, UDIAT-Centre Diagnòstic, Institut Universitari Parc Taulí - UAB, Parc Taulí, 1, 08205 Sabadell, Barcelona, Spain. Electronic address: sganau@tauli.cat.
authors.forename: Sergi
authors.initials: S
authors.lastname: Ganau
authors.affiliation: Pathology Department, UDIAT-Centre Diagnòstic, Institut Universitari Parc Taulí - UAB, Parc Taulí, 1, 08205 Sabadell, Barcelona, Spain. Electronic address: xandreu@tauli.cat.
authors.forename: Francisco Javier
authors.initials: FJ
authors.lastname: Andreu
authors.affiliation: Women's Imaging Department, UDIAT-Centre Diagnòstic, Institut Universitari Parc Taulí - UAB, Parc Taulí, 1, 08205 Sabadell, Barcelona, Spain. Electronic address: fescribano@tauli.cat.
authors.forename: Fernanda
authors.initials: F
authors.lastname: Escribano
authors.affiliation: Women's Imaging Department, UDIAT-Centre Diagnòstic, Institut Universitari Parc Taulí - UAB, Parc Taulí, 1, 08205 Sabadell, Barcelona, Spain. Electronic address: amartino@tauli.cat.
authors.forename: Amaya
authors.initials: A
authors.lastname: Martín
authors.affiliation: Women's Imaging Department, UDIAT-Centre Diagnòstic, Institut Universitari Parc Taulí - UAB, Parc Taulí, 1, 08205 Sabadell, Barcelona, Spain. Electronic address: ltortajada@tauli.cat.
authors.forename: Lidia
authors.initials: L
authors.lastname: Tortajada
authors.affiliation: Women's Imaging Department, UDIAT-Centre Diagnòstic, Institut Universitari Parc Taulí - UAB, Parc Taulí, 1, 08205 Sabadell, Barcelona, Spain. Electronic address: mvillajos@tauli.cat.
authors.forename: Maite
authors.initials: M
authors.lastname: Villajos
authors.affiliation: Cancer Screening and Epidemiology, UDIAT-Centre Diagnòstic, Institut Universitari Parc Taulí - UAB, Parc Taulí, 1, 08205 Sabadell, Barcelona, Spain. Electronic address: mbare@tauli.cat.
authors.forename: Marisa
authors.initials: M
authors.lastname: Baré
authors.affiliation: Radiology Department, Consorci Sanitari de Terrassa, Carretera Torrebonica S/N, 08227 Terrassa, Barcelona, Spain. Electronic address: mteixido@cst.cat.
authors.forename: Milagros
authors.initials: M
authors.lastname: Teixidó
authors.affiliation: Radiology Department, Consorci Hospitalari de Vic, Carrer Francesc Pla "El Vigatà", 1, 08500 Vic, Barcelona, Spain. Electronic address: jribe@chv.cat.
authors.forename: Judit
authors.initials: J
authors.lastname: Ribé
authors.affiliation: Women's Imaging Department, UDIAT-Centre Diagnòstic, Institut Universitari Parc Taulí - UAB, Parc Taulí, 1, 08205 Sabadell, Barcelona, Spain. Electronic address: msentis@tauli.cat.
authors.forename: Melcior
authors.initials: M
authors.lastname: Sentís
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000648:ultrastructure*; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results
keywords: Breast cancer molecular subtypes; Elastography; Shear-wave; Ultrasound