SAT0469 PROSPECTIVE STUDY ASSESSING BONE MINERAL DENSITY AND RISK FACTORS FOR OSTEOPOROSIS IN PATIENTS WITH ANDROGEN DEPRIVATION THERAPY. PRELIMINARY CROSS-SECTIONAL RESULTS

Background: Few studies have analysed the incidence and risk factors for osteoporosis (OP) development in patients with prostate cancer (PC) and androgen deprivation therapy (ADT). Objectives: To assess risk factors for OP, bone turnover markers (BTM) and bone mineral density (BMD) in a cohort of patients with ADT, as well as the duration of ADT and previous treatments received for PC. Methods: Ongoing prospective study including patients with ADT for PC. Risk factors for OP, BTM (total ALP, bone ALP, CTx), spinal X-Ray and BMD (Lunar, DPX) were assessed yearly since inclusion in the study (April 2018). Patients with known OP or previous antiosteoporotic treatment were excluded. The study was approved by the ethics committee, and all patients gave their signed consent. Herein we present the preliminary cross-sectional study at inclusion. Results: Of the 83 patients attended at the Rheumatology Department during the study period, 75 were included with a mean age 75±5years and median ADT duration of 1 year. 18 were receiving concomitant radiotherapy and 7 docetaxel. When assessing risk factors for OP: 28% had previous fragility fractures and 24% had current alcohol intake. After X-Ray assessment, 14% had morphometric vertebral fractures. Mean 25OHD at inclusion was 19±9ng/ml (73% had 25OHD BMD showed up to 28% with densitometric OP and osteopenia in 56%. Patients with OP were older (83±7 vs 74±8 years, p=0.021), had lower testosterone levels (16 vs 89 ng/dl, p=0.004), as expected lower BMD (at spine, proximal femur and even distal radius) and had more previous fragility fracture (75 vs 19%, p=0.022). But it should be noted that 16% had high bone mass (HBM) mostly affecting spine BMD (in 6 patients combined with femoral osteopenia). All patients with HBM had high bone metastatic disease, and no differences were observed between patients with/without HBM when comparing BTM or calcium-phosphate metabolism. Conclusion: Low bone mass (including osteoporosis and osteopenia) is frequent in patients with ADT as well as previous fragility fractures. Up to 16% had high bone mass, being mostly in patients with high volume metastatic disease. Thus, all patients with ADT should undergo a bone health assessment and start antiosteoporotic treatment if required. Disclosure of Interests: None declared