Critical appraisal of primary systemic endocrine therapy in receptor-positive postmenopausal breast cancer: an update

Even in elderly patients, greater consideration is now being given to tumor volume reduction in locally advanced breast cancer, with increased subsequent breast-conserving surgery. Neoadjuvant endocrine therapy offers the possibility of testing therapeutic efficacy in vivo, which is of great importance for optimal adjuvant treatment. Resulting therapy modifications can be expected to increase disease-free as well as overall survival. Recent results indicate that remission rates with primary chemotherapy are significantly lower in receptor-positive than in receptor-negative breast cancer and that efficacy parameters in receptor-positive tumors tend to favor primary endocrine therapy, highlighting the increased importance of this type of treatment. Aromatase inhibitors are superior to tamoxifen in terms of clinical response as well as breast conservation rate. Results from a small number of studies suggest that prolonged preoperative aromatase inhibitor therapy for up to 12 months can increase the rate of clinical and pathological complete remissions. In conclusion, primary endocrine therapy is a valid therapeutic option for postmenopausal patients with locally advanced hormone receptor-positive breast cancer and significant comorbidity, increased risk of complications with regard to anesthesia and surgery, desire for breast-conserving surgery and/or reduced suitability for chemotherapy, as well as in very old patients.