SUN-787 - Are Men with Prostate Cancer Treated with Androgen Deprivation Therapy Being Appropriately Screened for Bone Loss?

Introduction
Patients with high and very high-risk prostate cancer, and those with metastatic castrate-sensitive prostate cancer without bony metastases, are treated with androgen deprivation therapy (ADT). Loss of bone mineral density can be seen after 6-9 months of ADT. American Society of Clinical Oncology (ASCO) recommends those with prostate cancer with planned ADT should have a baseline DXA scan performed before treatment, and repeat DXA every 2 years if results do not show osteoporosis. ASCO recommends treatment with an osteoclast inhibitor, either denosumab or bisphosphonate, if patients meet a clinical diagnosis of osteoporosis, or a T-score <-2.5 or T-score <-1.0 and >-2.5 and a FRAX score 10-year probability of a major osteoporotic fracture >20% or hip fracture >3%. We hypothesized that men with prostate cancer are not being appropriately screened with baseline DXA scan prior to receiving ADT or with follow up DXA scans according to the guidelines.

Methods
We conducted a retrospective chart review of 850 patients with ICD-10 code C61 (prostate cancer) and NDC code for leuprolide, 0074-3642-03, that were seen in the primary care, endocrinology, oncology, or urology clinics in our hospital system July 2020-July 2025. The primary outcome was the rate of having a baseline DXA scan in patients with prostate cancer who were treated with leuprolide. Secondary outcomes included the rate of antiresorptive therapy for those who met guideline criteria and the fracture rates in the group with and without screening baseline DXA scan with subgroup analyses across clinics.

Results
Of the 850 charts reviewed, 218 (25.6%) had baseline DXA performed, and 48 (7.5%) had follow-up DXA performed 18-30 months after the baseline DXA scan. Compared to patients seen only in oncology clinics, those seen in primary care had 2.88 OR (95% CI: 1.83-4.53, p-value < 0.001), and those seen in urology clinics had 0.35 OR (95% CI: 0.19-0.65, p-value < 0.001) of receiving baseline DXA. Overall,44 ( 66%) of patients meeting criteria for treatment with an osteoclast inhibitor received antiresorptive therapy, with 22 (50%) receiving denosumab and 22 (50%) receiving bisphosphonate. No difference in fracture rates was found between those with and without baseline DXA scan.

Conclusion
Only 25% of men with prostate cancer starting ADT were screened for osteoporosis via baseline DXA scan. Those seen in primary care clinics were more likely to receive a baseline DXA compared to those seen in specialty clinics, highlighting the importance of primary care involvement in screening for osteoporosis. Unlike previous studies, our study did not show a reduction in fracture rates in those receiving baseline DXA scan. Further education for those that treat men with prostate cancer after ADT is needed to improve screening rates and treatment of osteoporosis in these patients.

*Unless otherwise noted, all abstracts presented at ENDO must not be released to the press or the public until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.*