LAUSR

Initially, neoadjuvant chemotherapy (NAC) was predominantly used in locally advanced disease. However, NAC is now considered for any patient who would be recommended adjuvant chemotherapy based on clinical and histological examination at diagnosis. NAC may downstage disease in both the breast and axilla, as well as allow the assessment of in vivo response to therapy. While tumor size and nodal involvement were the dominant factors in considering NAC initially, currently tumor biology is a key factor. Response rates to NAC are highest in HER2? disease and in triple-negative breast cancer. Additionally, neoadjuvant endocrine therapy is increasingly considered for hormone receptor-positive disease. Our hypothesis was that use of NAC had changed over time with higher use in triple-negative and HER2? disease than in hormone receptor (HR)?/HER2disease.