Abstract P6-11-01: Adherence to guidelines for bone health in a predominantly Hispanic cohort of breast cancer patients receiving aromatase inhibitors
Authors: Bright Tamis M. , Mcalice Meghan K. , Escriba-Omar Abelardo , Gaur Sumit , Philipovskiy Alexander V. 
Published: March 2020

Introduction: Aromatase inhibitors (AI), by reducing estrogen levels, decrease the risk of recurrence of hormone receptor positive breast cancer but also lead to accelerated bone loss and increased fracture risk. This has led to guidelines for treating women on AIs with bone antiresorptive agents earlier in order to avoid fractures. The 2017 joint position statement from the International Osteoporosis Foundation, Cancer and Bone Society, European Calcified Tissue Society, International Expert Group for AI Bone Loss, European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Disease, International Menopause Society, and the International Society for Geriatric Oncology recommends treating patients on AI with either denosumab or bisphosphonates with BMD T-scores &lt; -2.0, T-scores &lt; -1.5 with one additional risk factor, or with ≥ 2 risk factors even without a BMD for the duration of AI therapy.

The Garbar Breast Care Center at TTUHSC-El Paso serves a predominantly Hispanic patient population. As disparities in cancer care have been well documented amongst minorities, we sought to determine the adherence to the current guidelines for fracture prevention in this group.

Methods: Post-menopausal women diagnosed with non-metastatic breast cancer and receiving adjuvant AIs who had a BMD done were included. Patients with pre-existing osteoporosis or already receiving antiresorptive therapy prior to cancer diagnosis were excluded. Electronic medical records of patients seen in clinic between 9/2015 and 3/2018 were reviewed to extract data regarding bone mineral density (T score, Z score), risk factors, and use of antiresorptive therapies. Study was approved by the institutional IRB.

Results: A total of sixty patients were included. Median age was 65 years and 92% were Hispanic. Stage distribution was as follows: I, 40%, II, 43% and III, 17%. Thirty-eight (63%) met criteria to be treated with an antiresorptive agent. Thirty-two (53%) had T-scores &lt; -2.0 and 6 (10%) had a T-score &lt; -1.5 with at least 1 additional risk factor. Only 15 (39%) of the 38 patients who met guidelines for treatment were on antiresorptive therapy. Of the 15 patients who were on treatment, 10 had osteoporosis (T-score &lt; -2.5), and 5 had osteopenia (T-score -2 to -2.5). Two additional patients were on antiresorptive therapy that did not meet the guidelines. Of the remaining 23 patients who met guidelines for treatment but were not treated, 6 had frank osteoporosis, 11 had a T-score between -2.0 and -2.5, and 6 had T-scores &lt; -1.5 with at least one additional risk factor. Perceived barriers to appropriate institution of anti-resorptive therapy amongst oncologists were a) lack of timely dental evaluation and risk of osteonecrosis, b) cost of denosumab and zoledronic acid c) risk of myalgias and arthralgias with anti-resorptive agents potentially affecting compliance with AI therapy.

Conclusion: In a predominantly Hispanic population, we found that only 39% of patients with indications for anti-resorptive therapy were on appropriate treatment. This has important implications for long term bone health amongst these cancer survivors. As adjuvant bisphosphonates have also been associated with a decrease in bone metastases and improvement of breast cancer specific survival, the low rate of adherence to guidelines can potentially contribute to inferior long-term survival. Timely access to dental services can potentially improve compliance rates.

Citation Format: Tamis M. Bright, Meghan K. Mcalice, Abelardo Escriba-Omar, Sumit Gaur, Alexander V. Philipovskiy. Adherence to guidelines for bone health in a predominantly Hispanic cohort of breast cancer patients receiving aromatase inhibitors [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P6-11-01.