Breast Cancer Tumor Heterogeneity

Breast cancer biomarkers are usually performed on core needle biopsy (CNB) specimens and are not routinely repeated on surgical specimens (SS). However, preliminary data suggests that testing these biomarkers, on SS when compared to CNB samples can lead to different results. Our hypothesis is that The aim of this study is to identify a group of women with invasive breast cancer who may benefit from additional HER2 testing on their SS to ensure that areas of HER2 amplification are not missed. Another aim is to determine whether further HER2 testing on the SS in select patients would lead to changes in breast cancer treatment options.