POS0292 OSTEOPOROSIS IN BREAST CANCER PATIENTS ON AROMATASE INHIBITORS THERAPY: ABOUT 200 CASES
Authors: R. Assadi, K. Nassar, S. Janani
Journal: Annals of the Rheumatic Diseases (2021)

Background: Breast cancer is the most common cancer affecting women both before and after the menopause. Aromatase inhibitors (AIs) used as adjuvant therapy cause bone loss and increase the risk of osteoporosis (OP) (1). Objectives: To assess the bone status and the frequency of OP in breast cancer patients using AIs. Methods: We conducted a retrospective study in the rheumatology department, over 5 years (2016-2020). Inclusion criteria: patients followed for breast neoplasm in oncology department on AIs therapy and referred to rheumatology department for bone evaluation. All of these patients underwent an evaluation of bone mineral density (BMD) and phosphocalcic assessment. Exclusion criteria: patients treated by another type of hormone therapy and having other risk factors for OP. Results: 200 breast cancer women were enrolled for the study, 92 patients (46%) were treated with AIs, the average age was 58.22 years (41 - 75 years) with an average age of discovery of the breast cancer of 46.75 years and the average time between the start of AIs therapy and the diagnosis of OP was 21.6 months. the characteristics of the patients are summed up in Table 1. 97% of patients were postmenopausal and 38% of them had menopause secondary to treatment. In AIs users, 85 patients (92.3%) were osteoporotic, and 11% had bone fractures. In regard to osteodensitometry measurement, lumbar spine was the most affected site (88%) with mean T score of -2.98 and mean BMD of 0.854, followed by femoral neck (17%) with mean T score of - 2.8 and mean BMD of 0.740 and total hip (14%) with mean T score of -3.10 and mean BMD of 0.497. The cancer was metastatic in 15.18% patients, 75% of the group had bone metastasis and 25% had visceral metastasis. The phosphocalcic status of the osteoporotic patients was: mean calcemia: 92.83 mg / l, mean calciuria: 131.8 mg / 24h, mean phosphatemia: 48.09 mg / l, mean 25 OH Vit D level: 19.78 ng / ml, mean PTH: 79 pg / ml. Osteoporotic patients were treated with bisphosphonates, 60% women had received Alendronate, 17% Risedronate and 12% Zoledronate in addition to dietary measures and correction of calcium and vitamin D deficiency. Conclusion: AIs are correlated with a high risk of OP and fractures in 30% of patients (2), the frequency of OP in our series is estimated at 42.5%. Assessment of bone status and OP clinical risk factors should be systematic in all breast cancer patients receiving adjuvant AIs therapy. Bisphosphonates appear to be beneficial in treating secondary OP, in preventing bone fractures, and in reducing the incidence of breast cancer bone metastases. References: [1]Aromatase Inhibitor-Associated Bone Loss Clinical Considerations P Shubham, L. Shapiro Drugs 2008; 68 (18): 2591-2600 [2]Aromatase inhibitor-associated bone loss and its management with bisphosphonates in patients with breast cancer M.Bauer, J. Bryce, P.Hadji Breast Cancer. 2012; 4: 91–101 Table 1. Characteristics of osteoporotic patients using AIs therapy Results Total of patients 92 (46%) Mean age 58.22 years Mean age of breast cancer diagnosis 46.75 years Delay between AIs therapy and OP 21.6 months Post menopausal patients 97% Menopausis due to AIs 38% Osteoporotic patients 85 (92.3%) Fractures 11% Sites of OP in osteodensitometry lumbar spine 88% femoral neck 17% total hip 14% Cancer metastasis 15.18% Bone 75% Visceral 25% Phosphocalcic status (mean values) calcemia 92.83 mg / l calciuria 131.8 mg / 24h phosphatémie 48.09 mg / l 25 OH vitaminD 19.78 ng / ml PTH 79 pg / ml Biphosphanates therapy Alendronate 60% Risedronate 17% Zoledronate 12% Disclosure of Interests: None declared