US Pharm. 2012;37(9)(Oncology/Hematology suppl):19.

Women who are postmenopausal and suffer from the most common type of metastatic breast cancer have a new treatment option that lengthens their lives, according a study led by University of California–Irvine oncologist Rita Mehta, MD, and conducted by the Southwest Oncology Group. The findings appear in the August 2 issue of the New England Journal of Medicine.

Compared to the standard treatment with anastrozole alone, a combination of the two antiestrogen drugs anastrozole and fulvestrant extended the median survival time of women with stage IV hormone receptor–positive metastatic breast cancer by more than 6 months. Dr. Mehta said the results of the phase 3 trial are important because “these patients have not had a new treatment that gave them an overall survival benefit in more than a decade.”

Both drugs are currently used to treat breast cancer, but not together. Anastrozole reduces the production of tumor-promoting estrogen, while fulvestrant inhibits the receptors that allow estrogen to signal cells to grow and reproduce and also accelerates the degradation of these receptors.