The metastatic breast cancer arena is rapidly evolving, and endocrine resistant mutations are now known to be strongly associated with aromatase inhibitor therapy and disease progression. Novel treatment combinations are being utilized to achieve greater progression-free survival. To date, patients on aromatase inhibitor treatments continue to develop resistance, recurrence, and have poor preservation of bones, fractures, diminished quality of life in vaginal and sexual health. With 70% of all breast cancers being estrogen receptor positive and in need of some form of anti-estrogen treatment during the course of therapy, lasofoxifene is well-positioned to fulfill an unmet need in this arena.

Treatment and survivorship will likely overlap considerably in the future with greater and longer remission rates. There is an unmet need for oral anti-estrogens that can contribute to the treatment armamentarium and help with progression–free survival. Many breast cancer treatments may have deleterious effects on bone health, so there are survivors who, for this reason as well as natural aging, are at increased risk for osteoporosis, osteoporotic fractures, and—when bone metastases are present—skeletal related events. The economic burden of metastatic breast cancer in human, direct and indirect costs is a challenge. A well-tolerated, potent, efficacious oral SERM such as lasofoxifene with its unique tissue-selectivity may offer multiple health and quality of life and provide significant value to the patient, provider, the healthcare system and society.