Greenspan SL et al. (2008) Risedronate prevents bone loss in breast cancer survivors: a 2-year, randomized, double-blind, placebo-controlled clinical trial. J Clin Oncol 26: 2644–2652

In women with breast cancer, chemotherapy might induce early menopause, which is associated with bone loss and increased risk of fractures. Risedronate, a bisphosphonate that is used to treat osteoporosis, might reduce bone loss in affected patients; therefore, Greenspan and colleagues conducted a randomized, placebo-controlled clinical trial to investigate the efficacy of oral risedronate in this setting.

The study included 87 women with stage I–III breast cancer who underwent chemotherapy and had recently (≤8 years previously) entered menopause. Patients were randomly allocated to receive once-weekly oral risedronate 35 mg (n = 43) or placebo (n = 44) for 24 months following chemotherapy. Concomitant treatment with tamoxifen or aromatase inhibitors was permitted.

At 24 months, BMD had decreased at most of the spine and hip sites assessed in patients who received placebo, whereas BMD generally remained stable in women treated with risedronate. Patients who were receiving concomitant aromatase inhibitors had greater BMD reductions than those who were not taking this therapy. Patients who received risedronate but no aromatase inhibitors showed the greatest BMD increases and a trend for reduced bone-turnover markers.

The authors conclude that once-weekly oral risedronate, with or without concomitant aromatase-inhibitor therapy, was beneficial for postmenopausal breast-cancer survivors in terms of spine and hip BMD and bone turnover.