The osteoporosis drug raloxifene, primarily prescribed for post-menopausal women, may also be able to treat triple-negative breast cancer, according to research published in Cell Death and Disease.
In lab tests, researchers found that the drug, marketed under the brand name Evista, killed human TNBC cells as well as liver cancer cells. Raloxifene binds with a protein called the aryl hydrocarbon receptor (AhR) and kills cancer cells that do not have receptors for estrogen. Included in the study was an analysis of data on women who had estrogen-negative breast cancers, in which researchers found increased survival rates in the women whose breast cancers had higher levels of the AhR protein.
Raloxifene would have to go through clinical trials, showing its effects on women rather than just on cells in the lab, before it can become an approved therapy, but, under the Affordable Care Act, most health insurance plans are now required to offer raloxifene at no cost to women who have an increased risk of developing breast cancer.
Raloxifene belongs to a class of drugs called selective estrogen receptor modulators (SERMs). Research presented at the San Antonio Breast Cancer Symposium in December 2013 demonstrated that a different class of osteoporosis drugs, bisphosphonates, can reduce the risk of breast cancer recurrence in all types of breast cancer.
SOURCE: “The aryl hydrocarbon receptor mediates raloxifene-induced apoptosis in estrogen receptor-negative hepatoma and breast cancer cells.” O’Donnell EF, Koch DC, Bisson WH, Jang HS, Kolluri SK. Cell Death Dis. 2014 Jan 30;5:e1038.DOI: 10.1038/cddis.2013.549.