Postmenopausal Fracture History and Survival After Reproductive Cancer Diagnosis

Abstract

Abstract Background Postmenopausal bone fracture's have been proposed as a marker of lifetime estrogen exposure and have been associated with decreased risk of breast and endometrial cancer. It is plausible that prediagnostic fractures may be related to survival of estrogen-sensitive cancers. Methods We evaluated a cohort of breast (n = 6411), endometrial (n = 1127), and ovarian (n = 658) cancer cases diagnosed between 1992 and 2010 while participating in the Women’s Health Initiative. Postmenopausal fracture history was assessed from baseline reports of fractures after age 55 years and incident fractures that occurred at least one year prior to cancer diagnosis during study follow-up. Using Cox regression, we compared women with and without a history of fractures with respect to overall and cancer-specific survival. Estimates were adjusted for participant factors, including hormone therapy use; hormone receptor status was not included in our analysis. Results Among women with breast cancer, a history of prediagnostic fractures at any site was associated with poorer overall survival (hazard ratio [HR] = 1.22, 95% confidence interval [CI] = 1.05 to 1.43). A history of hip, forearm, or spine fractures, or hip fracture alone, was associated with increased risk of mortality (HR = 1.26, 95% CI = 1.01 to 1.58, and HR = 2.05, 95% CI = 1.27 to 3.32, respectively). Fracture history was associated neither with cancer-specific survival among breast cancer survivors, nor with overall or disease-specific mortality among endometrial and ovarian cancer survivors. Conclusions Postmenopausal breast cancer patients with a history of fractures, especially of the hip, are more likely to die of any cause than breast cancer survivors without a fracture history. Identifying and intervening in fracture risk factors should be standard of care for all women diagnosed with breast cancer.