A multicenter, Phase III study conducted by researchers at Columbia University Medical Center in New York City showed that the osteoporosis drug zoledronic acid prevents bone loss at 12 months in premenopausal women undergoing chemotherapy following surgery for early-stage breast cancer. The study was published online August 18, 2008, in the Journal of Clinical Oncology.

This is the first study to evaluate the use of the drug in premenopausal breast cancer patients, but previous studies have shown that similar drugs prevent bone loss during and following chemotherapy in this group. Zoledronic acid has been shown to prevent bone loss in postmenopausal women, and recent findings have indicated that it reduces risk of recurrence in women with breast cancer.

"Our study confirms that women experience significant bone loss due to cancer treatments and that zoledronic acid can prevent this loss," said Dawn L. Hershman, MD, MS, assistant professor of medicine at Columbia University's College of Physicians and Surgeons and the study's lead author. "While our findings are promising, it's too early for us to recommend this drug for all premenopausal women undergoing chemotherapy for breast cancer because we don't yet have all the information we need on dosing, cost effectiveness, and whether this drug actually prevents bone fractures. However, this research does show we need to be more vigilant about monitoring patients' bone densities before and during treatment so we can protect bone health and offset bone fracture or osteoporosis risk."

The study was a randomized, double-blind, multicenter phase III trial comparing treatment with zoledronic acid or placebo every three months for one year; 101 patients were enrolled in the trial and 85 completed it. All patients in the trial were given oral vitamin D and calcium supplements. Primary measure of bone loss was change in bone mineral density (BMD), measured via scans of the lower spine and hip. Scans were performed prior to chemotherapy and at six and 12 months.

Patients who received zoledronic acid had stable BMDs at both six and 12 months. Patients who received placebo showed a significant decline in spine BMD: 2.4 percent at six months and 4.1 percent at 12 months. In the hip, BMD declines were 0.8 percent at six months and 2.6 percent at 12 months.

Side effects did not differ significantly between the two groups.

"Bone loss can be a problem for premenopausal women undergoing breast cancer treatment because it can lead to bone fractures and osteoporosis later in life." Said Lori Pierce, MD, a breast cancer and radiation oncology expert at the Univ. of Michigan. "These early results demonstrating prevention in bone loss at 12 months are particularly encouraging in light of data from other studies suggesting a reduction in breast cancer recurrence following treatment with zoledronic acid."