Disparity in Bone Density Assessment in Older Women Treated With AI for Breast Cancer

Age is a significant risk factor for fractures in older women who are receiving adjuvant treatment with aromatase inhibitors (AIs) for breast cancer. Despite this knowledge, only half the women over 85 years of age had their baseline bone density tested prior to initiating treatment, according to new research.

AIs are standard adjuvant treatment for post-menopausal women with hormone-receptor positive breast cancer, but have a major effect on bone density—resulting in fractures and complications resulting from the injury. The National Comprehensive Cancer Network (NCCN) Guidelines recommend that patients should undergo bone mineral density testing before treatment with AIs begins. Additionally, the guideline advices antiresorptive therapy to slow down the bone loss. However, these recommendations are not widely followed in practice, as researchers from the Medical College of Wisconsin found out.

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 also included in the evaluation.

The findings were quite surprising. With increasing age, as the risk of bone fractures increases, the rate of testing for bone density decreased in the cohort being studied. Overall, baseline testing was noted in two-thirds of the women, but the rate of testing dwindled with age: 73% of women in the 67 to 70-year age bracket were tested for bone density, as opposed to only 51% who had crossed the 85-year mark (adjusted odds ratio for not being tested, 2.48 [CI, 2.17-2.82]). Treatment with bisphosphonate to promote resorption also decreased with age, the authors report.

“This study highlights sub-optimal US compliance with guideline recommendations for baseline [bone mineral density] testing when starting AI therapy,” said the lead author on the study John Alan Charlson, MD, associate professor of medicine, Division of Hematology and Oncology at the Medical College of Wisconsin. “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,” he added.

Reference

Charlson J, Smith EC, Smallwood AJ, Laud PW, Neuner JM. Bone mineral density testing disparities among patients with breast cancer prescribed aromatase inhibitors. J Natl Compr Canc Netw. 2016;14:875-880.