2026 Southeastern Residency Conference

Title: Assessment of Antiresorptive Therapy Utilization in Prostate Cancer Patients Receiving Abiraterone with Prednisone + Androgen Deprivation Therapy

Authors: Makenzie Boyd & Barbie Gleaton

Background: Abiraterone is an oral anticancer agent widely used for the treatment of metastatic prostate cancer in combination with prednisone and androgen deprivation therapy (ADT). One of the adverse effects associated with this regimen is bone density loss, leading to an increased risk of fractures and skeletal-related events. Bone health is critically important in these patients to maintain quality of life and reduce morbidity. The veteran population may be at greater risk of bone density loss due to multiple factors, including advanced age, higher comorbidity burden, and potential exposure to hazardous substances during military service, which could contribute to decreased bone health. Rapid bone loss without preventive measures can lead to severe complications, including pathological fractures, spinal cord compression, and reduced mobility. Assessing the current practices regarding the use of antiresorptive therapies in this high-risk population is essential to improving care and outcomes.

Methods: This study is a retrospective chart review of veterans with metastatic prostate cancer treated at the Birmingham VA Medical Center between January 1, 2024, and July 31, 2025. Patients were identified via fill history for active prescriptions of abiraterone. Included patients were at least 18 years old with a documented diagnosis of metastatic castrate-resistant prostate cancer who received at least 3 months of treatment and had at least 30 days of follow-up in the VA electronic medical record. Patients were excluded if they were followed by non-VA providers, had secondary malignancies, used steroids chronically for other comorbidities, had less than 180 days of life expectancy at the initiation of treatment, or had unspecified metastatic disease. The primary data point of this study was the appropriate utilization of antiresorptive treatment. Other data points included analysis of adjunctive supportive therapy for bone health and examination of pharmacist intervention in initiating supportive care. Baseline demographics and comorbidities were also collected to describe the study population and identify risk factors for bone mineral density loss.

Results: There were 131 patients reviewed, of which 38 met inclusion criteria. Of these, 12 patients had metastatic castration-resistant prostate cancer (mCRPC) and 26 had metastatic castration-sensitive prostate cancer (mCSPC). All patients with mCRPC were receiving appropriate antiresorptive therapy, including zoledronic acid or denosumab. In contrast, three patients in the mCSPC group received inappropriate bone-modifying therapy based on current guideline recommendations. At baseline, 86.8% of patients had a vitamin D level <30 ng/mL, indicating a high prevalence of vitamin D deficiency. Despite this, 65.3% of patients did not undergo bone mineral density screening with DEXA. Additionally, clinical pharmacists initiated 65.8% of vitamin D monitoring and prescribed 55.3% of supportive care supplementation.

Conclusions: Overall, it was determined that antiresorptive therapies were used appropriately for patients with mCRPC. However, inappropriate use of these therapies for patients with mCSPC, highlighting the need for review of current guideline recommendations. Gaps in supportive care were also identified, particularly in the underutilization of bone mineral density screening. Limited use of DEXA scanning restricted the ability to fully assess fracture risk and identify patients who may benefit from additional bone-modifying therapy while on this treatment regimen. Pharmacists played a significant role in driving laboratory monitoring and supportive care interventions. Future efforts should focus on implementing standardized bone health screening for all patients receiving androgen deprivation therapy to improve early identification and prevention of skeletal-related events in this high-risk population.