Bone Health and Falls: Fracture Risk in Breast Cancer Survivors With Chemotherapy-Induced Amenorrhea.

Purpose/
Objectives: To describe risk factors for fracture-bone health and falls-among breast cancer survivors with chemotherapy-induced amenorrhea.Design: Cross-sectional and prospective cohort.Setting: National Cancer Institute-designated cancer center in the Pacific northwest region of the United States.Sample: Breast cancer survivors with chemotherapy-induced amenorrhea (N = 35; X age = 46 years; one year after chemotherapy) compared to cancer-free controls (N = 26; X age = 41 years).
Methods: One two-hour testing session at baseline, 12-month follow-up, monthly postcards.Main Research Variables: Clinical characteristics and number of falls, leg strength, bone mineral density (BMD), body composition, and bone turnover.Findings: No significant differences between groups for BMD at either time point. Significantly more breast cancer survivors had low-spine BMD based on T scores and elevated bone turnover versus controls at baseline and follow-up. Breast cancer survivors with low-spine BMD have significantly lower body mass index, lean mass, and leg strength, and had stage II disease more often than breast cancer survivors with normal BMD. Significantly more breast cancer survivors (75%) experienced at least one fall compared to 46% of controls. Among breast cancer survivors, those who had fallen had significantly lower leg strength and calcium intakes than those who had not.Conclusions: Breast cancer survivors with chemotherapy-induced amenorrhea, particularly those with muscle weakness, may be at increased risk of fracture.Implications for Nursing: Breast cancer survivors with chemotherapy-induced amenorrhea should be evaluated for low bone mass and fall risk and considered for therapeutic intervention to lower fracture risk.