Endocrine therapy considerations in postmenopausal patients with hormone receptor positive, human epidermal growth factor receptor type 2 negative advanced breast cancers

The standard of care for patients with hormone receptor positive, human epidermal growth factor receptor type 2 negative advanced breast cancer is endocrine therapy. Endocrine agents, including aromatase inhibitors, tamoxifen, and fulvestrant, are often administered alone as first line treatment and demonstrate durable responses with limited side effects. Endocrine resistance represents a major clinical problem. In the future, poly-endocrine therapy and combination therapies with biological agents might become valuable options for the first line treatment of hormone receptor-positive advanced breast cancer. However, it will be critical to develop clinical tools that can reliably identify the subgroup of patients most likely to benefit from endocrine therapy alone, and those who might benefit from alternative approaches.