Changes in Bone Mineral Density in Women With Breast Cancer: A Prospective Cohort Study.

Background: Cancer treatment-induced bone loss is an important long-term effect among breast cancer survivors. Little is known, however, about the pattern of bone loss and the factors associated with it.

Objective: The aim of this study was to examine annual bone health changes and factors associated with bone loss for 3 years after diagnosis among women with breast cancer.

Methods: Ninety-nine newly diagnosed women with breast cancer (mean age, 51.1 years) were enrolled in a prospective longitudinal study. Bone mineral density (BMD) was measured with dual-energy x-ray absorptiometry at baseline and yearly for 3 years.

Results: During the 3-year follow-up, the proportion of women who had osteopenia or osteoporosis increased from 33.3% to 62.5%. The BMD of the participants significantly decreased 6.8% in the lumbar spine, 4.6% in the femur neck, and 3.5% in the total hip, with bone loss the greatest in the first year. In multiple linear regression analysis, chemotherapy was significantly associated with bone loss at all sites, and premenopausal status at diagnosis was significantly related to bone loss at the lumbar spine. We found no significant relationship between health behavior status and BMD change at any site.

Conclusion: Women newly diagnosed with breast cancer can lose up to 6.8% of BMD during a 3-year follow-up. Chemotherapy and premenopausal status are important risk factors for bone loss.

Implications For Practice: Identification of premenopausal women at diagnosis and monitoring BMD before and after chemotherapy are key for promoting bone health in women with breast cancer.