Tumor morphology and expression of ER, PgR, HER2, Ki67, CK5/6, E-cadherin, vimentin and EGFR were assessed in a tissue microarray containing cores from 174 BBC, 23 BOCS and 2 BBC?+?BOCS.
BOCS tumors were characterized by higher incidence of EGFR expression, HER2 negativity and lower incidence of intraductal component. HER2-positive phenotypes were marginally more frequent in the BBC group and triple negative tumors - in BOCS.
Breast cancers from BOCS patients are characterized by more aggressive phenotype, most probably related to their more frequent association with BRCA1 mutation.