New findings about endocrine therapy for breast cancer

For over a decade, the selective estrogen receptor modulator, tamoxifen, has been the primary agent for adjuvant endocrine therapy for steroid receptor-positive breast cancer. New data over the last 2 years now suggest that its primacy may be challenged by strategies that lower circulating and/or intratumoral estrogens. Recent trials support the use of ovarian suppression approaches with or without tamoxifen in place of chemotherapy in premenopausal women. A large randomized trial has also established the short-term efficacy and safety of the aromatase inhibitor, anastrozole, in postmenopausal women. How and when to integrate these new approaches into standard practice are topics of debate. Ongoing research is focused on choice of endocrine approach, duration and sequencing of endocrine treatment, identification of better predictive markers for hormone response, and assessment of long-term risks and benefits.