Ultrasound is a useful adjunct to mammography for the characterisation and biopsy of solid breast lesions.
Protein expression profiling of
breast cancer has identified specific subgroups with potential clinical, biological and therapeutic implications. The aim of this study was to determine the ultrasound correlates of these novel molecular classes of invasive
breast cancer. The ultrasound findings in 358 patients with operable
breast cancer were correlated with the previously described
protein expression classes identified by our group using immunohistochemical (IHC) assessment of a large series of
breast cancer cases in which 25
proteins of known relevance in
breast cancer were assessed, including
hormone receptors, HER2 status, basal and
luminal markers, p53 and
e-cadherin. The proportion of occult lesions was not significantly different in the two groups. Significant differences were noted between the two groups expressing
luminal epithelial markers and
hormone receptors (1 and 2), including a greater proportion of ill-defined, irregular and distally attenuating tumours in group 2. Tumours characterised by c-erbB2/MUC1 expression, with weak
hormone receptor positivity (group 3) were also more likely to be ill defined. Tumours expressing basal markers (group 5) were less likely to have an echogenic halo. The ultrasound features of
breast cancer show areas of significant correlation with molecular classes of invasive
breast cancer identified by IHC analysis. The biological reasons for these findings and their implications regarding imaging protocols require further study and may enable improved detection of these lesions.