ESR1 and breast carcinoma: Using immunohistochemical (IHC) data for E-cadherin performed centrally using tumor tissue microarrays (TMAs), we performed a large pooled analysis of 12 studies participating in the Breast Cancer Association Consortium (BCAC), and examined whether established breast cancer risk factor associations and survival differed by low vs. high E-cadherin tumor tissue expression, stratified by ER status and histology.