In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 41, No. 16_suppl ( 2023-06-01), p. e18878-e18878
Abstract:
e18878 Background: Bone metastases occur in up to 90% of men with metastatic prostate cancer and cause skeletal-related events (SREs) such as fracture and spinal cord compression. Although bone modifying agents (BMAs) have been shown to decrease the risk of SREs in men with metastatic castration-resistant prostate cancer (mCRPC), BMAs are not widely used in this patient population. In this retrospective study, we report the prescribing patterns of BMAs and predictors of BMA use in a large national cohort. Methods: We used the VA corporate data warehouse to identify patients with mCRPC who were treated with first-line mCRPC therapy (abiraterone, enzalutamide, docetaxel, or ketoconazole) between 2010 and 2017. BMA prescribing frequency and patterns were analyzed. Multivariable regression analysis was used to evaluate clinical and disease-specific factors associated with BMA use which are presented as adjusted odds ratios (OR) with 95% confidence intervals (CI). Results: In the final cohort of 4,079 patients, the median age at mCRPC diagnosis was 73 years (IQR 66-81). 29% of patients in the cohort were Black. Diagnosis codes identified bone metastases at mCRPC diagnosis in 48% of the cohort (ICD-9 and 10 coding for sites of metastases are known to underestimate the actual incidence of metastases). Only 48% of patients received a BMA following initiation of treatment for mCRPC, 47% of which had already received a BMA 6 months prior to mCRPC diagnosis. For those who were new BMA starts, the median time to BMA administration from mCRPC treatment was 3.4 months (IQR 1.2-8.8). Factors associated with BMA use were having an ICD-9 or 10 diagnosis code for bone metastases at time of mCRPC treatment (OR 1.28, 95% CI 1.10-1.48), concurrent corticosteroid use (OR 1.90, 95% CI 1.53-2.38), and docetaxel use as first-line mCRPC therapy (OR 1.78, 95% CI 1.45-2.18). Factors associated with decreased BMA use were Charlson comorbidity index score of ≥ 2 (OR 0.75, 95% CI 0.62-0.90), advancing age (OR 0.86 per 10 years, 95% CI 0.79-0.94), and decreased eGFR (eGFR 30-59, OR 0.81, 95% CI 0.68-0.96; eGFR 0-29, OR 0.23, 95% CI 0.14-0.37). Having a diagnosis code for a SRE before mCRPC diagnosis (e.g., bone fracture and cord compression) did not impact BMA use, but the incidence of those events was low. Conclusions: Less than half of this VA cohort received a BMA after starting therapy for mCRPC. Key factors associated with BMA use were corticosteroid use and first-line docetaxel use, which likely represented more aggressive disease. Notably, patients who were older and had more comorbid conditions were less likely to receive a BMA despite being highest risk for frailty and SREs. Future quality improvement efforts aimed at increasing BMA use may address the needs of the geriatric mCRPC patient population.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2023.41.16_suppl.e18878
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2023
detail.hit.zdb_id:
2005181-5
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