Practice patterns in metastatic castration-resistant prostate cancer (mCRPC): Evidence from the veterans health administration

6582 Background: Skeletal related events (SREs) are a known complication for the 80% of men with metastatic prostate cancer who have bone metastases. Previous studies have demonstrated that bone modifying agents (BMAs) such as zoledronic acid and denosumab reduce SREs in men with metastatic castration-resistant prostate cancer who have bone metastases and are now recommended by national guidelines. We sought to investigate factors associated with use of BMAs in Veterans with CRPC across the Veterans Health Administration (VA). Methods: Using the VA Corporate Data Warehouse, consisting of aggregated medical record data from 130 facilities, we used an algorithm previously published to identify men with a diagnosis of castration-resistant prostate cancer (CRPC) based on rising prostate specific antigen (PSA) levels while on androgen deprivation therapy and who received systemic treatment for CRPC with one of the commonly used therapies: abiraterone, enzalutamide, docetaxel, ketoconazole between 2010 and 2017. To account for clustering among facilities, we used a multilevel multivariable logistic regression to determine the association of patient and disease-specific variables on the odds of a patient receiving a BMA after they started treatment for CRPC. Results: Of 4,998 patients with CRPC in our cohort, 2223 (44%) received either zoledronic acid or denosumab at some point after they were initiated on treatment for CRPC. After adjusting for other variables and accounting for a facility, the odds of receiving a BMA decreased by 3% for every additional year of age (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.96-0.98), and decreased significantly with increasing comorbid conditions (OR 0.94, 95% CI 0.72-0.98 for Charlson Comorbidity Index [CCI] of 1; OR 0.69, 95% CI 0.59-0.81 for CCI 2+). Patients who were Black had 25% lower odds of receiving a BMA than patients who were White (OR 0.75, 95% CI 0.65-0.87). PSA at time of CRPC treatment start had a small but not significant effect on receipt of a BMA (OR 1.04, 95% CI 1.00-1.08) for every unit increase of PSA on the log scale. PSA doubling time was not associated with receipt of a BMA. The presence of a diagnosis code for bone metastases was far lower than expected in this cohort of patients with CRPC (40.7%), and thus was not included in the model. We did not expect the presence of bone metastases to vary significantly among the other independent variables. Conclusions: Despite most patients with CRPC historically having bone metastases, less than half of patients with CRPC received a BMA. Patients who are older, had more comorbidities, or were Black were less likely to receive a BMA after starting treatment for CRPC. Understanding factors that lead to different patterns of treatment can guide initiatives toward more guideline-concordant care.

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Survival by race in men with chemotherapy-naive enzalutamide- or abiraterone-treated metastatic castration-resistant prostate cancer

Prostate Cancer and Prostatic Diseases ◽

10.1038/s41391-021-00463-9 ◽

2021 ◽

Author(s):

Daniel J. George ◽

Krishnan Ramaswamy ◽

Ahong Huang ◽

David Russell ◽

Jack Mardekian ◽

...

Keyword(s):

Prostate Cancer ◽

Black Men ◽

White Men ◽

Subsequent Treatment ◽

Veterans Health ◽

Health Administration ◽

Castration Resistant Prostate Cancer ◽

Cox Models ◽

Black And White ◽

Castration Resistant

Abstract Background Black men are more likely to be diagnosed with aggressive prostate cancer (PC) and die from PC than white men. However, black men with metastatic castration-resistant PC (mCRPC) had longer overall survival (OS) than white men when treated with certain agents in clinical trials. We analyzed claims data from the Veterans Health Administration (VHA) database to evaluate OS in black and white men treated with enzalutamide or abiraterone (novel hormonal therapy [NHT]) for chemotherapy-naïve mCRPC. Methods Patients with mCRPC aged ≥18 years were identified in the VHA database by diagnosis codes, evidence of surgical/medical castration, and a prescription claim for enzalutamide or abiraterone after castration from April 2014–March 2017. Cox models assessed associations between race and OS. Unadjusted and multivariable analyses were performed on the entire population and subsets based on the type of therapy received (if any) after NHT. Results In total, 2910 patients were identified (787 black, mean 71.7 years; 2123 white, mean 74.0 years). Median follow-up was 19.0 and 18.7 months in blacks and whites, respectively. Black men had better survival versus white men: hazard ratios (95% CIs) were 0.89 (0.790–0.996; P = 0.044) and 0.67 (0.592–0.758; P < 0.0001) in the unadjusted and multivariable models, respectively. Statistically significantly longer OS was seen in black versus white men regardless of subsequent treatment, including no subsequent treatment. Conclusions In the VHA, black men with chemotherapy-naïve mCRPC initiating NHT may have better outcomes than similarly treated white men.

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Survival outcomes in patients with chemotherapy-naive metastatic castration-resistant prostate cancer treated with enzalutamide or abiraterone acetate

Prostate Cancer and Prostatic Diseases ◽

10.1038/s41391-021-00318-3 ◽

2021 ◽

Author(s):

Scott T. Tagawa ◽

Krishnan Ramaswamy ◽

Ahong Huang ◽

Jack Mardekian ◽

Neil M. Schultz ◽

...

Keyword(s):

Prostate Cancer ◽

Retrospective Analysis ◽

Index Date ◽

Abiraterone Acetate ◽

Cox Proportional Hazards ◽

Veterans Health ◽

Health Administration ◽

Castration Resistant Prostate Cancer ◽

Risk Of Death ◽

Castration Resistant

Abstract Objective Evaluation of the comparative effectiveness of enzalutamide and abiraterone in patients with metastatic castration-resistant prostate cancer (mCRPC) is limited to meta-analyses of randomized trials that exclude patients with significant comorbidities. We evaluated overall survival (OS) in patients with chemotherapy-naive mCRPC treated with enzalutamide or abiraterone acetate (abiraterone) in a real-world single payer setting. Methods A retrospective analysis (4/1/2014–3/31/2018) of the Veterans Health Administration (VHA) database was conducted. Patients with mCRPC had ≥1 pharmacy claim for enzalutamide or abiraterone (first claim date = index date) following disease progression on surgical/medical castration, without chemotherapy <12 months prior to index date. Patients had continuous VHA enrollment for ≥12 months pre-index date and were followed until death, disenrollment, or end of study. Kaplan–Meier analysis and multivariable Cox proportional hazards regression models examined the OS treatment effect. Results Patients with chemotherapy-naive mCRPC (N = 3174; enzalutamide, n = 1229; abiraterone, n = 1945) had mean ages of 74 and 73 years, respectively. Median follow-up was 18.27 and 19.07 months with enzalutamide and abiraterone, respectively. Enzalutamide-treated patients had longer median treatment duration than abiraterone-treated patients (9.93 vs 8.47 months, respectively, p = 0.0008). After baseline comorbidity adjustment, enzalutamide-treated patients had a 16% reduced risk of death (hazard ratio [HR] = 0.84; 95% CI, 0.76–0.94; p = 0.0012). For patients who remained on first line-therapy only, enzalutamide-treated patients had improved OS versus abiraterone-treated patients (HR = 0.71; 95% CI, 0.62–0.82). Enzalutamide-treated patients who crossed over to abiraterone had a comparable risk of death versus abiraterone-treated patients who crossed over to enzalutamide (HR = 0.91; 95% CI, 0.74–1.13). These results were confirmed by sensitivity analysis, which considered prognostic variables. Conclusions Retrospective analysis of the VHA database indicated that chemotherapy-naive patients with mCRPC initiating therapy with enzalutamide had improved survival versus abiraterone.

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Mental health care utilization among veterans with castration-resistant prostate cancer receiving abiraterone or enzalutamide.

Journal of Clinical Oncology ◽

10.1200/jco.2021.39.15_suppl.e18680 ◽

2021 ◽

Vol 39 (15_suppl) ◽

pp. e18680-e18680

Author(s):

Phoebe A. Tsao ◽

Jennifer A. Burns ◽

Shami Entenman ◽

Kyle Kumbier ◽

Jordan Sparks ◽

...

Keyword(s):

Mental Health ◽

Prostate Cancer ◽

Health Care ◽

Mental Health Care ◽

Health Administration ◽

Castration Resistant Prostate Cancer ◽

First Line ◽

Castration Resistant ◽

Diagnostic Characteristics ◽

Comorbidity Burden

e18680 Background: Abiraterone and enzalutamide are oral therapies widely used to treat men with castration-resistant prostate cancer (CRPC). Recent data have suggested potentially worsened quality of life and depression with use of enzalutamide compared to abiraterone. Because Veterans are at a higher risk for mental health conditions, we sought to compare mental health service utilization in Veterans with CRPC receiving enzalutamide to those receiving abiraterone. Methods: The Veterans Health Administration Corporate Data Warehouse was used to identify men with CRPC who received abiraterone or enzalutamide for ≥ 30 days as first-line treatment between 2010-2017. We compared the rate of mental health visits per 100 patient-months for men on abiraterone versus enzalutamide using an exact rate ratio test, assuming Poisson counts. Results: Among 2902 male Veterans, 68.6% (n=1992) received abiraterone and 31.4% (n=910) enzalutamide as first-line therapy. Men who received enzalutamide were older (76 vs 74, p<0.01) and had a higher comorbidity burden (Charlson Comorbidity Index [CCI] ≥ 2 in 28.7% vs 21.6%, p<0.01); no differences were noted in race or prevalence of preexisting documented mental health diagnoses. Median time on drug was 8 months for both medications. There was no difference in the rate of mental health visits per 100 patients-months on enzalutamide versus abiraterone (6.6 v. 6.7, p=0.66). However, within patient sub-groups, men who were age 75 or older, not married, or without notable comorbidities had lower rates of mental health visits with enzalutamide compared to abiraterone; whereas those who were younger than 75, married, had higher comorbidities, or a preexisting mental health diagnosis had higher rates of mental health visits with enzalutamide (Table). Conclusions: Among Veterans with CRPC who received a novel antiandrogen therapy first-line, there was no difference in engagement in mental health care between those who received abiraterone versus enzalutamide. Sub-group analysis revealed significant differences between patients on the two medications in demographic and diagnostic characteristics associated with number of visits, suggesting that vulnerability for mental health symptoms may vary by medication type. Further work in understanding the long-term impact of novel antiandrogens on mental health is needed.[Table: see text]

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