The Importance of Monitoring Bone Density in Survivors of Breast Cancer

Despite the fact that aging and aromatase inhibitor (AI) therapy can increase fracture risk, the older women get, the less likely they are to have baseline bone density testing before going on AI therapy after breast cancer treatment, according to a recent study.

NCCN Guidelines recommend that patients have bone mineral density testing before treatment with an AI begins, as well as antiresorptive therapy such as a bisphosphonate to slow down bone loss. These recommendations are not widely followed in practice, however, as researchers from the Medical College of Wisconsin discovered.

The retrospective study searched claims data for Medicare Parts A, B and D to identify women aged 67 years and older with incident breast cancer in 2006 and 2007 who started AI therapy. The claims data provided the researchers with information on patient demographics, bone density testing, as well as other treatments that they would have received through 2012. Additionally, information on treatment with bisphosphonates, as recommended by NCCN, was included in the evaluation.

Overall, they found that baseline bone density testing was noted in two-thirds of the women, but the rate of testing dwindled with age: 73 percent of women in the 67- to 70-year age bracket were tested for bone density, compared with only 51 percent who had crossed the 85-year mark. Treatment with a bisphosphonate to promote resorption also decreased with age, the authors reported.

“This study highlights suboptimal US compliance with guideline recommendations for baseline [bone mineral density] testing when starting AI therapy,” said lead study author John Alan Charlson, in a statement.

Charlson, an associate professor of medicine in the Division of Hematology and Oncology at the Medical College of Wisconsin, added that, “While a larger number of older patients did receive bisphosphonates, this does not explain the disparities in bone density findings, or even substantially change our finding that attending to [bone mineral density] was higher in lower risk, younger women.”

Steven J. Isakoff, a member of the NCCN Guidelines Panel for Breast Cancer, said the findings are especially important when seen in the context of other studies now suggesting that the risk of bone fracture is even higher in women using AIs than previously recognized:

“Many women may now be using aromatase inhibitors beyond five years, which may further increase the risk of fractures,” Isakoff said in a statement.

“This study highlights that, as a breast cancer community, we need to do a better job screening for bone health, because with proper screening and treatment, many of these fractures can be prevented, particularly in the older patients at highest risk for fractures but who have the lowest rates of bone health screening.”

Surabhi Dangi-Garimella, PhD, is a writer and editor for the American Journal of Managed Care, Evidence-Based Oncology. Read more at AJMC.com.