Bone density in patients with breast cancer

Objective: Because estrogens are important in the pathogenesis of both brea st cancer and osteoporosis, it has been suggested that the risk of osteopor osis and breast cancer are inversely related. The aim of our study was to e valuate bone mineral density in patients with breast cancer. Methods: Speed of sound, broadband ultrasound attenuation, and the stiffnes s index of the calcaneus were measured in 1004 subjects (mean age 53.9 year s) with an Achilles ultrasound bone densitometer. 148 patients had a histor y of breast cancer and 856 did not. Breast cancer patients were compared wi th healthy subjects matched for age, weight, body mass index (BMI), parity, and duration of breast feeding and estrogen exposure. Results: Overall, the patients with breast cancer were 4.4 years older and had higher body weight, BMI and parity, longer duration of breast feeding a nd estrogen exposure, and a significantly higher speed of sound and stiffne ss index than healthy controls. In the matched-pairs analysis, women with b reast cancer had a higher speed of sound and stiffness index than the contr ols. Conclusion: Women with breast cancer have a lower risk of osteoporosis than controls. Although the biologic mechanisms linking bone mass and the risk of breast cancer are not fully understood, factors other than cumulative es trogen exposure may play a role. Studies on larger populations are needed t o evaluate this relationship.