Fracture incidence in pre- and postmenopausal women after completion of adjuvant hormonal therapy for breast cancer

Introduction: Although the effect of hormonal therapy (HT) on fracture risk during treatment of breast cancer is established, information about fracture incidence after completion of HT is scarce. In this hospital based observational study we evaluated fracture rates after completion of HT in pre- and postmenopausal women with breast cancer. Methods: All women diagnosed with breast cancer in the VieCuri Medical Center between 1998 and 2005 who started adjuvant HT with aromatase inhibitors or tamoxifen were included (n=289). Data on fracture rate, fracture type and risk factors for fracture after completion of HT were collected. Results: The overall fracture rate was 12% in pre- and 15% in postmenopausal women respectively during an average follow-up of 3.1±2.9 years. The number of patients with at least one fracture was 41 (14%). There was no difference in fracture rates between different types of HT (. P=0.15). The most common types of fractures were toe/finger fractures in premenopausal- and hip and major fractures in postmenopausal women. Median time to first fracture was shorter in premenopausal women (1.4 years, IQR 0.2-3.5) than in postmenopausal women (2.4 years, IQR 0.7-5.1, P=0.01). A history of previous fracture was a significant risk factor for fracture in postmenopausal women (HR 3.9, 95% CI 1.3-11.7). Conclusion: Fracture rates in the first years after cessation of HT for breast cancer were 12% and 15% for pre- and postmenopausal women respectively. The most common fractures in postmenopausal women were hip and major fractures.