AB1002 Differences in bone metabolism between intermittent and continuous treatment with lhrh agonists in prostate cancer patients
Authors: K.R. Arevalo, J. Ivorra, C. Vera, E. Grau, I. Chalmeta, L. Gonzalez, R. Negueroles, C. Alcañiz, I. Canovas, C. Feced, J.J. Fragio, R. Gonzalez, E. Labrador, I. Martinez, C. Najera, J.E. Oller, F.M. Ortiz, E. Vicens, M. De la Rubia, D. Hervas, J.A. Roman
Journal: Annals of the Rheumatic Diseases (2018)

<h3>Background</h3> Prostate cancer is an hormone dependent neoplasia, therefore androgenic inhibition by LHRH agonists is the mainstay of treatment. There are different treatment regimen options: continuous or intermittent in order to decrease side effects. As for the bone effects, therapy with LHRH agonists increases bone resorption and decreases bone mineral density (BMD) all together increasing the risk of fracture. The influence of the different treatment regimen in bone metabolism has not been studied enough. <h3>Objectives</h3> To evaluate the effect of the LHRH agonists therapy different regimens on bone metabolism in prostate cancer patients, and whether antiresorptive treatment influences the evolution of BMD according to LHRH agonists treatment regimen. <h3>Methods</h3> We recruited patients from the Prostate Cancer Protocol of Osteoporotic Risk Assessment in our institution. The patients were evaluated in a basal visit (month 0) and 6–12–18–24 months after basal evaluation. Data of bone metabolism biomarkers, BMD values, LHRH agonists regimen and antiresorptive treatment was collected. Biostatistical analysis with software R was performed. <h3>Results</h3> We reviewed 69 patients and 52 prostate cancer patients without bone metastasis with 12 months follow up were selected. The mean age at cancer diagnosis was 68.92 (8.44) years old, with a mean Gleason score of 7.<sup>1</sup> 81% of patients had LHRH agonists active treatment, 81% of them were under continuous treatment scheme. 39% of patients initiated antiresorptive therapy, 24% with intermittent LHRH agonists and 76% with continuous LHRH agonists. At the basal evaluation 12% of patients had osteoporosis and the 32% had osteopenia. 43% of patients displayed vitD values under 20 ng/mL. Antiresorptive treatment influenced lumbar spine, femoral neck and hip BMD values (p&lt;0.001). In patients with antiresorptive treatment, LHRH agonists intermittent scheme did not have an independent effect in any locations of BMD. In patients without antiresorptive therapy, intermittent LHRH agonists regimen have a positive effect on BMD in total hip and lumbar spine increasing their values compared to those on continuous LHRH agonists regimen. The effect in lumbar spine depends on the time of the intermittency. LHRH agonist intermittent therapy showed no significant influence on T score values of femoral neck, this effect was independent of antiresorptive therapy. In patients without antiresorptive treatment elevated beta-CTX levels were related to a decrease of BMD values (p=0.017). No fractures were reported during the follow up period. <h3>Conclusions</h3> In our patients there is a high prevalence of vitD deficiency. Antiresortive therapy had a positive effect in the BMD on both LHRH agonists treatment schemes. Patients without antiresorptive treatment under an intermittent LHRH agonists scheme display a better evolution in BMD values compared to those under a continuous scheme. In patients without antiresorptive treatment the evolution of BMD values was related to beta-CTX levels during follow up. <h3>Disclosure of Interest</h3> None declared