Abstract

Everolimus: finding its place in the treatment of hormone receptor-positive advanced breast cancer

Author(s): Stephen RD Johnston and Belinda Yeo

Despite the various treatment options for patients with advanced hormone receptorpositive breast cancer, progression on endocrine treatment remains a significant problem. Overactivation of certain molecular pathways, including the PI3K/Akt/mTOR pathway, may contribute to such resistance. Everolimus is an mTOR inhibitor that blocks signaling in this pathway and has been shown in clinical studies to improve progression-free survival in patients who have previously responded to endocrine treatment. It provides a new therapeutic option for patients in this setting, ideally prolonging their time to chemotherapy. Here, we discuss the rationale for its use in combination with endocrine therapy in advanced breast cancer. The challenges in using everolimus in this patient population include predicting which patients have the greatest likelihood of benefit, being mindful of its potential toxicities and determining the timing in which it is best introduced into treatment.