Endocrine Abstracts

Introduction: Women prescribed hormonal therapies for breast cancer (eg Aromatase Inhibitors (AI) and ovarian suppression therapy (OST)) are at increased risk of fracture and monitoring of Bone Mineral Density (BMD) is needed. Recommendations for BMD monitoring and treatment interval thresholds differ between guidelines which has implications for management. We compared the outcomes from the application of 3 commonly used guidelines for bone health in women with breast cancer (UK2008^1 and IOF^2 which are based on T-scores and NOGG^3 which is based on FRAX scores)

Methods: Data from 67 women (mean age 53yrs (range 24-82)) with breast cancer that were referred to the Christie for a DXA scan following initiation of hormonal therapy were collected (Treatments: 37 AI, 17 OST, 7 AI+OST and 6 tamoxifen). Each DXA scan was analysed using the 3 different guideline recommendations and the outcomes compared.

Results: Overall in the 67 patients, mean(+/-SD) 10 yr probability for hip fracture was 1.3(2.3)% and 6.1(6.1)% for major osteoporotic fracture. 54/67 patients were >40 yrs; mean(SD) T-score at total hip was -0.45(1.11) and -1.08(1.37) at the lumbar spine. The recommendations from the NOGG guidance, using FRAX based intervention thresholds, differed significantly with regards to recommendations for intervention with bisphosphonate (BP) therapy compared to UK2008 and IOF guidance where intervention is based mainly on T-scores. NOGG2021 recommended BP therapy in only 10% of patients compared to 34% in UK2008 and 40% with IOF.

Conclusion: The results obtained show a discrepancy in recommendations for bone management in women with breast cancer between a FRAX based tool (NOGG2021) and T-score based interventions (UK2008/IOF) which has implications for clinical practice and DXA reporting and may influence fracture prevention in this high risk group.

References: 1- CancerTreatRev2008;34;S3 2- OstInt2019,30;3 3- ArchOst2022,17;58