Preoperative Endocrine Therapy: Preferred Therapy for Whom?

Abstract

Neoadjuvant endocrine therapy is safe and can be effective in many postmenopausal women with estrogen receptor positive breast cancer. There are limited data available for premenopausal women taking aromatase inhibitors in combination with estrogen suppression. Letrozole, anastrozole, and exemestane have all been shown to be equivalent or superior to tamoxifen in relatively small neoadjuvant trials in postmenopausal women. Tumor factors that appear to have good response are estrogen receptor positivity, characteristics consistent with the so-called Luminal A subtype and lobular carcinomas. Response to neoadjuvant treatment may inform decision making regarding adjuvant treatment, which should include radiotherapy following breast-conserving surgery, or mastectomy, made feasible by neoadjuvant treatment to maintain low local recurrence rates. Chemotherapy may also be required in some cases based on the biological characteristics of the residual tumor and the extent of residual disease.