Researchers affiliated with an international multicenter trial have reported that Zometa® (zoledronic acid) may prevent bone loss in postmenopausal women treated early with Femara® (letrozole) for early-stage breast cancer. These findings were published in the March, 2008 issue of Cancer.

Femara is an aromatase inhibitior that is more effective than tamoxifen (Nolvadex®) in preventing recurrences in postmenopausal women with hormone responsive localized breast cancer. One of the major side effects of Femara is bone loss leading and subsequent osteoporosis. Zometa is a new generation bisphosphonate that inhibits osteoclast bone resorption. The FDA has approved Zometa for treatment of patients with metastatic bone disease. In this study the goal was to determine if Zometa could prevent the bone loss associated with Femara.

The current multicenter study examined two strategies for treating women with Zometa: 1) beginning Zometa as soon as they begin treatment with Femara or 2) delaying use of Zometa until the patient had experienced a loss of bone density or a fracture. The study included 1,065 post-menopausal patients with early breast cancer. Participants received either immediate or delayed treatment with Zometa twice a year for five years. Researchers evaluated changes in bone mass by analyzing bone mineral density scores.

• Women receiving immediate treatment had an increase in their bone density compared with women who received delayed treatment; the latter group had a loss in bone density.
• After 12 months of follow-up, women who had received immediate treatment had a 5.7% advantage in bone density compared with women who received delayed treatment.
• Both treatment strategies were well tolerated with few serious side effects. Bone pain, the most frequent side effect, was more common among patients receiving immediate treatment.
• After 12 months immediate treatment with Zometa was found to prevent bone loss in postmenopausal breast cancer patients receiving Femara.

Comments: These data confirm previous observations that Zometa can prevent bone loss in post-menopausal women taking Femara for breast cancer.

Related News:

Zometa® Prevents Bone Loss in Pre and Postmenopausal Breast Cancer Patients (12/19/2007)

Zometa® Prevents Bone Loss in Premenopausal Breast Cancer Patients (1/17/2007)

Patients with Breast Cancer Bone Metastasis Failing Bonefos® or Aredia® Benefit From Zometa® (10/31/2006)

Zometa® Reduces Bone Loss from Adjuvant Femara® In Early Breast Cancer (6/15/2005)

Reference:  Bundred, N., Campbell, I., Davidson, N., et al.  Effective inhibition of aromatase inhibitor associated bone loss by zoledronic acid in post menopausal women with early breast cancer receiving adjuvant letrozole. Cancer. 2008; 112(5):1001-1010.