POS1421 AROMATASE INHIBITORS AND SKELETAL HEALTH – NATURAL HISTORY AND INTERVENTIONAL EPIDEMIOLOGY

Background Breast cancer remains the most common diagnosed in women worldwide. Aromatase inhibitors (AI) are employed for hormone sensitive disease mainly postmenopausal women. AI related bone loss (AIBL) is a known complication; although data regarding natural history real-world, long-term outcomes and role of active therapy fracture prevention sparse. Objectives Our aim was to determine real-world impact AIBL whether sparing utilising standard risk stratification model sufficient prevention. Methods We undertook longitudinal study patients prescribed breast over seven-year period at our university teaching hospital. All recorded electronically with full access demographics, parameters, investigations drug management. DEXA scans performed prior initiation were compared subsequent imaging mean follow up 3 years. Outcome all fractures collected. Statistical analysis done investigate significant relationships amongst variables interest. Results 1001 identified during period. The age cohort 64 years (range 29-93). 929 (93%) Caucasian, 57 (6%) Asian 15 (1%) Afro-Caribbean. 723 (72%) invasive ductal carcinoma 863 (86%) postmenopausal. At diagnosis, 428 (43%) had node positive 35 (4%) metastases. 91 (9%) sustained their diagnosis. baseline DEXA: 496 (49.6%) osteopenia, 151 (15%) osteoporosis 354 (35.4%) normal result. 478 (48%) repeat scan available. Overall, there decline (from 0.888 g/cm2 0.858 g/cm2, p<0.0001) left neck femur (LNOF) mineral density (BMD) time (mean years, range 1-6). 334 (33%) 276 (83%) given oral bisphosphonates. This group an improvement BMD by 0.4% (LNOF 0.785 LNOF 0.788 DEXA, p=0.82). Women who not offered any treatment (n=667, 66%), showed being -5%. 0.939 p< 0.0001). rate remained same between (19 fractures, 5.67%) non-treatment (38 5.70%) Conclusion provides long term confirms seven It that effective reducing pace BMD. However such as FRAX based intervention thresholds those WHO defined (T ≤-2.5) ineffective keeping literature. Since overlaps publication newer guidelines recommending different T score-based model, further studies required confirm utility. References [1] https://www.wcrf.org/dietandcancer/worldwide-cancer-data/ . Date accessed: 26.01.2022 [2]R. Coleman, J.J. Body, M. Aapro, et al., Bone health patients: ESMO clinical practice guidelines, Ann. Oncol. 25 (Suppl 3) (2014) iii124–iii137. [3]E. Amir, B. Seruga, S. Niraula, Toxicity adjuvant endocrine systematic review meta-analysis, J. Natl. Cancer Inst. 103 (2011) 1299–1309. Disclosure Interests None declared