Breast cancer survivors at increased risk for fractures

June 1, 2005

When compared with postmenopausal women who have never had breast cancer, postmenopausal breast cancer survivors are at greater risk for all types of fractures except those of the hip, according to results from the Women's Health Initiative Observational Study.

When compared with postmenopausal women who have never had breast cancer, postmenopausal breast cancer survivors are at greater risk for all types of fractures except those of the hip, according to results from the Women's Health Initiative Observational Study.

Researchers conducted a prospective cohort study involving approximately 86,000 women. They found that while breast cancer survivors had a lower hazard ratio for hip fracture (0.93), they had HRs of 1.36, 1.31, and 1.31 for forearm/wrist fractures; eligible fractures other than hip, vertebral, and forearm/wrist; and for all of these fractures combined, respectively. They also had a statistically increased risk of a vertebral fracture (HR, 1.78; 95% CI, 1.28–2.46) if they were diagnosed with breast cancer prior to 55 years of age.

Overall, the researchers calculated that postmenopausal breast cancer survivors may sustain 68.6 excess fractures per 10,000 person-years when compared with women of comparable age and no history of breast cancer. Among the likely causes of such fractures, the researchers theorize, are chemotherapy-induced ovarian failure and avoidance of hormone therapy after menopause.