Title: Estrogen receptor variants in ER-positive basal-type breast cancers responding to therapy like ER-negative breast cancers

Publication: NPJ Breast Cancer, April 2019

Authors: Groenendijk, et al.

Introduction: To examine how MammaPrint (MP) and BluePrint (BP) results affected treatment decisions (Neoadjuvant chemotherapy (NAC) vs surgery first) and tumor response in a Black patient population. Diagnostic testing of breast cancers for hormone receptor (HR) and HER2 status by immunohistochemistry and/or in-situ hybridization is routinely performed as an integral step to clinically define tumor characteristics and predict tumor behavior.1,2
Advancement of technology has made it possible to molecularly characterize these tumors at the genomic level by evaluating underlying and intrinsic differences in tumor biology.3,4 Although clinical subtypes overlap with these molecular subtypes, a significant number of patients will be reclassified based on the functionality of molecular pathways.5,6 This reclassification may have important consequences for treatment allocation, response and clinical outcome.