Bone Rx Boosted Breast Cancer Survival

Denosumab may improve survival of early-stage HR+ breast cancer, reduce fractures in postmenopausal women

(RxWiki News) Nearly all postmenopausal women with early-stage HR+ breast cancer are treated with aromatase inhibitors. But these drugs can significantly compromise bone health and up the risk of fractures.

For this reason, high-risk patients are often prescribed the osteoporosis drug denosumab (brand name Prolia) to reduce their risk of fractures. But denosumab may have another benefit, a new study found. Adding denosumab to aromatase inhibitor therapy may improve disease-free survival in postmenopausal women with early-stage HR+ breast cancer.

Because denosumab is currently only approved by the US Food and Drug Administration (FDA) for breast cancer patients who are at high risk for fractures, the drug is typically only added to the treatment regimens of patients with established osteoporosis.

DeLinda McDaniel, RPh, CCDM, a clinical pharmacist and founder of Rx-Consultant, told RxWiki News that "not only is bone preserved, but denosumab may prolong disease-free status of the HR+ breast cancer, as well. When started as an adjuvant dose of 60 mg every six months, at the start of the chemotherapy. Benefits may be increased with patients who have larger tumors and positive ductal histology."

Osteoporosis is a condition that causes the bones to become weak and brittle. But the authors of the current study said denosumab may have big benefits beyond osteoporosis patients.

"Our new data suggest that this treatment should be offered to all patients with HR-positive breast cancer who are receiving adjuvant aromatase inhibitor therapy, irrespective of their bone health status," said lead study author Michael Gnant, MD, a professor of surgery at the Medical University of Vienna in Austria, in a press release.

For this study, Dr. Gnant and team looked at 3,425 postmenopausal women with early-stage HR+ breast cancer. About half of these women were randomly assigned to 60 milligrams of denosumab given by injection once every six months. The other half were given a placebo. All patients were treated with aromatase inhibitor therapy throughout.

After an average of four years, the patients on denosumab had an 18 percent reduced risk of cancer recurrence compared with the patients on placebo.

This study was presented Dec. 9 at the 2015 San Antonio Breast Cancer Symposium. Research presented at conferences may not have been peer-reviewed.

This research was supported by Amgen, which makes Prolia. Several study authors disclosed ties to companies that make products used in the treatment of breast cancer.

Review Date: 
December 9, 2015