Cancer Research Lab

Once-weekly treatment with risedronate prevents bone loss in breast cancer survivors who underwent chemotherapy, according to the results of a new study, suggesting that early bisphosphonate treatment be considered for these patients.

Previous research has shown bone loss and fractures in women with chemotherapy-induced early menopause, the authors explain, but few studies have examined prevention of chemotherapy-induced bone loss.

Dr. Susan L. Greenspan from University of Pittsburgh, Pennsylvania, and other members of the Risedronate’s Effect on Bone Loss in Breast Cancer (ReBBeCa) Study investigated the effects of risedronate, 35 mg once weekly, on bone mass in 87 newly postmenopausal women with breast cancer who finished chemotherapy (with or without tamoxifen or aromatase inhibitors).

The findings are published in the January issue of The Journal of Clinical Endocrinology & Metabolism.

Bone mineral density (BMD) in the spine increased by 1.2% after 1 year of treatment with risedronate, the authors report, but BMD in the spine decreased by 0.9% in the placebo group. Results were similar for BMD for the total hip. BMD remained stable in the distal radius and total body among risedronate-treated women, the results indicate, but both decreased in the placebo group.

The changes did not differ significantly between women taking tamoxifen and women not taking tamoxifen, the researchers note. Markers of bone formation and resorption decreased significantly in the treatment group compared with the placebo group, the report indicates.

Adverse events did not differ significantly between the risedronate and placebo groups, the investigators say.

“These results have important clinical ramifications for breast cancer survivors who go into remission after early, aggressive therapy,” the authors conclude. “Because of the long-term survival of this cohort, they are at risk for bone loss and osteoporosis. Skeletal integrity needs to be assessed and considered as part of their long-term management.”

“The ReBBeCa study provides evidence that bisphosphonate therapy is likely to be useful in preventing chemotherapy-induced bone loss,” writes Dr. Richard Eastell from University of Sheffield, UK, in a related editorial.

The results of ongoing studies “should inform us whether bisphosphonates can be used to prevent bone loss due to aromatase inhibitors,” he added.