Impact of Metabolizing Enzymes on Drug Response of Endocrine Therapy in Breast Cancer

Pilar H Saladores; Jana C Precht; Werner Schroth; Hiltrud Brauch; Matthias Schwab


Expert Rev Mol Diagn. 2013;13(4):349-65. 

In This Article

Aromatase Inhibitors

The third-generation AIs letrozole, anastrozole and exemestane are frequently used as adjuvant therapy for ER-positive breast cancer in the postmenopausal setting. Large clinical studies have shown an improved disease-free survival for AI therapy in comparison to tamoxifen,[5–7] a reason why AI use has been on the rise. The current ASCO guidelines recommend the use of an AI as upfront therapy or sequential to tamoxifen. Still, optimal timing and duration of AI therapy remains unclear.[8] The patients' individual risk profile, including familial predisposition to particular side effects (e.g., thromboembolism or osteoporosis) and the adverse effect profiles of the drugs are considered in the treatment decision between tamoxifen and AI.