Adherence to bone health guidelines in patients with hormone receptor-positive early breast cancer: Status and clinical impact in a Swiss cohort experience

Evelyne Bischof; Fabienne D Schwab; Elena Laura Georgescu Margarint; Céline Montavon; Iris Zünti; Anna Schollbach; Andreas Schötzau; Anna Hirschmann; Julia Landin; Christian Meier; Kurzeder Christian; Marcus Vetter

doi:10.1016/j.bonr.2021.101160

Adherence to bone health guidelines in patients with hormone receptor-positive early breast cancer: Status and clinical impact in a Swiss cohort experience

Bone Rep. 2021 Dec 11:16:101160. doi: 10.1016/j.bonr.2021.101160. eCollection 2022 Jun.

Authors

Affiliations

¹ Shanghai University of Medicine and Health Sciences, Department of Basic and Clinical Medicine, Shanghai, China.
² Department of Medical Oncology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
³ Department of Gynaecologic Oncology, Women's Hospital, University Hospital Basel, Basel, Switzerland.
⁴ Shanghai East International Medical Center, Shanghai, China.
⁵ Department of Medical Oncology, University Hospital Basel, Basel, Switzerland.
⁶ Department of Radiology, University Hospital Basel, Basel, Switzerland.
⁷ Department of Endocrinology, Diabetology and Metabolism, University Hospital Basel, Basel, Switzerland.
⁸ Medical University Clinic, Canton Hospital Baselland, Liestal, Switzerland.

Abstract

Aim: In patients with postmenopausal hormone receptor-positive breast cancer (ER + eBC), aromatase inhibitors (AIs) are widely used for effective relapse prevention. However, AIs reduce bone density and increase bone-related events (BREs). Alongside calcium and vitamin D3 supplementation, bisphosphonates and denosumab are well-known options for improving outcomes in bone health and breast cancer prognosis. This study aimed to evaluate the practice patterns of bone health guideline-based management in real-world patients with ER + eBC.

Material and methods: In total, 68 patients with ER + eBC treated between 2009 and 2014 at the University Hospital Basel were included in this retrospective cohort study. Chart reviews were analyzed. Baseline, clinicopathological, treatment, and BRE data were extracted. Each patient was specifically reviewed for therapy adherence to the Swiss bone health guidelines (Swiss Association against Osteoporosis 2010 [SVGO]).

Results: The mean patient age was 66.5 (range, 56-74) years, all post-menopausal. The most frequent tumor characteristics were tumor size of pT1-pT2 (N = 53, 77.9%) and treatment with letrozole (N = 35, 51.5%), followed by tamoxifen as a switch strategy (N = 27, 40.3%). The median treatment time with AIs was 47 (range, 30-60) months. Five patients (7.8%) experienced a fracture during or after AI treatment. Moreover, 51 (75%) patients were treated according to the SVGO recommendations.

Conclusion: The fracture rate in our retrospective cohort was comparable to that in the larger phase III randomized trials. The adherence to bone health guidelines was satisfactory but still suboptimal. Clinicians should strictly adhere to the current bone health guidelines to ensure the best possible prevention of BREs and maintain bone health and cancer prognosis in patients with ER + eBC.

Keywords: Aromatase inhibitor; Bisphosphonates; Bone targeted therapies; Breast cancer; Calcium; Denosumab; Oncology; Osteoporosis; Postmenopause; Public health; Vitamin D.