A phase II trial of neoadjuvant aromatase inhibitor therapy and the mTOR inhibitor everolimus in postmenopausal women with hormone receptor positive/HER2 negative breast cancer and a low/intermediate risk Oncotype Dx Recurrence Score (≤ 25).

TPS630 Background: Breast cancer (BC) patients (pts) with low/intermediate Oncotype Dx recurrence scores (RS) ≤ 25 represent a large fraction of BC cases, and a substantial number of distant recurrences occur in this group despite their low to moderate risk and high sensitivity to endocrine therapy. These pts are also the least likely to be sensitive to or benefit from adjuvant chemotherapy. Anatomical risk factors (nodal status, tumor size) continue to define a higher risk group among these endocrine sensitive and molecularly low risk BC pts. The goal of this study is to assess tumor response to a combination of the mTOR inhibitor everolimus and an aromatase inhibitor (AI) in this patient population, utilizing the preoperative endocrine prognostic index (PEPI). Our hypothesis is that everolimus will improve the efficacy of AI in this setting. Methods: This is a phase II study evaluating the efficacy and safety of neoadjuvant AI and everolimus in postmenopausal pts with hormone receptor positive (HR+)/HER...