title: What are the characteristics of breast cancers misclassified as benign by quantitative ultrasound shear wave elastography?
abstract: OBJECTIVE
  Shear wave elastography (SWE) is a promising adjunct to greyscale ultrasound in differentiating benign from malignant breast masses. The purpose of this study was to characterise breast cancers which are not stiff on quantitative SWE, to elucidate potential sources of error in clinical application of SWE to evaluation of breast masses.
  
  
  METHODS
  Three hundred and two consecutive patients examined by SWE who underwent immediate surgery for breast cancer were included. Characteristics of 280 lesions with suspicious SWE values (mean stiffness >50 kPa) were compared with 22 lesions with benign SWE values (<50 kPa). Statistical significance of the differences was assessed using non-parametric goodness-of-fit tests.
  
  
  RESULTS
  Pure ductal carcinoma in situ (DCIS) masses were more often soft on SWE than masses representing invasive breast cancer. Invasive cancers that were soft were more frequently: histological grade 1, tubular subtype, ≤10 mm invasive size and detected at screening mammography. No significant differences were found with respect to the presence of invasive lobular cancer, vascular invasion, hormone and HER-2 receptor status. Lymph node positivity was less common in soft cancers.
  
  
  CONCLUSIONS
  Malignant breast masses classified as benign by quantitative SWE tend to have better prognostic features than those correctly classified as malignant.
  
  
  CONCLUSIONS
  • Over 90 % of cancers assessable with ultrasound have a mean stiffness >50 kPa. • 'Soft' invasive cancers are frequently small (≤10 mm), low grade and screen-detected. • Pure DCIS masses are more often soft than invasive cancers (>40 %). • Large symptomatic masses are better evaluated with SWE than small clinically occult lesions. • When assessing small lesions, 'softness' should not raise the threshold for biopsy.
authors: Division of Imaging and Technology, Medical Research Institute, Ninewells Hospital Medical School, University of Dundee, Mailbox 4, Dundee, DD1 9SY, UK, s.vinnicombe@dundee.ac.uk.
authors: S J
authors: SJ
authors: Vinnicombe
authors: P
authors: P
authors: Whelehan
authors: K
authors: K
authors: Thomson
authors: D
authors: D
authors: McLean
authors: C A
authors: CA
authors: Purdie
authors: L B
authors: LB
authors: Jordan
authors: S
authors: S
authors: Hubbard
authors: A J
authors: AJ
authors: Evans
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging* / Q000473:pathology; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000000981:diagnostic imaging* / Q000473:pathology; D054459:Elasticity Imaging Techniques; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis; D012189:Retrospective Studies; D016217:Ultrasonography, Mammary / Q000379:methods*; D055815:Young Adult
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases