Molecular profiling of aromatase inhibitor-treated post-menopausal breast tumors identifies immunerelated correlates of resistance

To identify in clinical breast cancer those genes and pathways most associated with resistance to aromatase inhibitors by examining the global transcriptional effects of aromatase inhibitor (AI) treatment. Analysis of gene-expression measured in core-cut biopsies at baseline and surgery from patients received 2-week’s presurgical AI revealed: i) the molecular response to AI treatment varies greatly between patients, consistent with the variable clinical benefit from AI treatment; ii) higher baseline expression of an inflammatory signature is associated with poor antiproliferative response, and should be assessed further as a novel biomarker and potential target for AI-treated patients. Global gene-expression measured in core-cut biopsies, from 112 postmenopausal women with stage I to IIIB ER+ early breast cancer before and after two-weeks’ anastrozole monotherapy in a neoadjuvant trial.