Bone Loss Prevented by Risedronate in Breast Cancer Survivors

NEW YORK JUN 18, 2008 (Reuters Health) - Risedronate is effective in maintaining or improving bone mass in postmenopausal women who have had chemotherapy for breast cancer, researchers report in the June 1st issue of the Journal of Clinical Oncology.

Dr. Susan L. Greenspan of the University of Pittsburgh and colleagues note that adjuvant chemotherapy has prolonged disease-free and overall survival in women with breast cancer. However, chemotherapy-induced early menopause is associated with bone loss and osteoporotic fractures.

To investigate the efficacy of the oral bisphosphonate risedronate in combating these effects, the researchers randomized 87 postmenopausal women who had undergone chemotherapy for breast cancer to risedronate 35 mg once per week or to placebo for 2 years.

At baseline, 13% of the women were taking an aromatase inhibitor. This rose to 44% by the end of the 24-month study.

Women in the placebo group who were also taking an aromatase inhibitor had a significant reduction in bone mineral density (BMD) of 4.8% at the spine and 2.8% at the total hip. Women in the placebo group, not on an aromatase inhibitor, maintained BMD at the spine, but had a significant 1.2% loss at the total hip. In women on an aromatase inhibitor and risedronate, spine BMD fell by 2.4% and remained stable at the hip.

The greatest improvement was seen in women on risedronate who were not taking an aromatase inhibitor. Spine BMD rose by 2.1% and there was a 2.2% increase at the total hip.

Risedronate treatment reduced markers of bone turnover, was well tolerated, and "proved to be effective with or without the use of an aromatase inhibitor," the researchers report.

"Further studies," they add, "are needed to determine whether these improvements in bone mass and decreases in bone turnover translate to fracture reduction for these patients."

SOURCE:

"Reuters content is the intellectual property of Reuters Limited. Any copying, republication or redistribution of Reuters content, including by caching, framing or similar means, is expressly prohibited without the prior written consent of Reuters. Reuters shall not be liable for any errors or delays in content, or for any actions taken in reliance thereon."