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

Author(s):  
Daniel J. George ◽  
Krishnan Ramaswamy ◽  
Ahong Huang ◽  
David Russell ◽  
Jack Mardekian ◽  
...  

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.

2019 ◽  
Vol 37 (5) ◽  
pp. 403-410 ◽  
Author(s):  
Susan Halabi ◽  
Sandipan Dutta ◽  
Catherine M. Tangen ◽  
Mark Rosenthal ◽  
Daniel P. Petrylak ◽  
...  

Purpose Several studies have reported that among patients with localized prostate cancer, black men have a shorter overall survival (OS) time than white men, but few data exist for men with advanced prostate cancer. The primary goal of this analysis was to compare the OS in black and white men with metastatic castration-resistant prostate cancer (mCRPC) who were treated in phase III clinical trials with docetaxel plus prednisone (DP) or a DP-containing regimen. Methods Individual participant data from 8,820 men with mCRPC randomly assigned in nine phase III trials to DP or a DP-containing regimen were combined. Race was based on self-report. The primary end point was OS. The Cox proportional hazards regression model was used to assess the prognostic importance of race (black v white) adjusted for established risk factors common across the trials (age, prostate-specific antigen, performance status, alkaline phosphatase, hemoglobin, and sites of metastases). Results Of 8,820 men, 7,528 (85%) were white, 500 (6%) were black, 424 (5%) were Asian, and 368 (4%) were of unknown race. Black men were younger and had worse performance status, higher testosterone and prostate-specific antigen, and lower hemoglobin than white men. Despite these differences, the median OS was 21.0 months (95% CI, 19.4 to 22.5 months) versus 21.2 months (95% CI, 20.8 to 21.7 months) in black and white men, respectively. The pooled multivariable hazard ratio of 0.81 (95% CI, 0.72 to 0.91) demonstrates that overall, black men have a statistically significant decreased risk of death compared with white men ( P < .001). Conclusion When adjusted for known prognostic factors, we observed a statistically significant increased OS in black versus white men with mCRPC who were enrolled in these clinical trials. The mechanism for these differences is not known.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 6582-6582
Author(s):  
Jordan Bauman ◽  
Kyle Kumbier ◽  
Jennifer A. Burns ◽  
Jordan Sparks ◽  
Phoebe A. Tsao ◽  
...  

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.


Author(s):  
Scott T. Tagawa ◽  
Krishnan Ramaswamy ◽  
Ahong Huang ◽  
Jack Mardekian ◽  
Neil M. Schultz ◽  
...  

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.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e18680-e18680
Author(s):  
Phoebe A. Tsao ◽  
Jennifer A. Burns ◽  
Shami Entenman ◽  
Kyle Kumbier ◽  
Jordan Sparks ◽  
...  

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]


2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 18-18 ◽  
Author(s):  
Heather H. Cheng ◽  
Rosa Nadal ◽  
Roman Gulati ◽  
Arun Azad ◽  
Przemyslaw Twardowski ◽  
...  

18 Background: Enzalutamide (Enza) and abiraterone (Abi) are next generation hormonal agents for metastatic castration resistant prostate cancer (mCRPC). Whether these agents can be effectively sequenced is not yet well understood. Results of retrospective analyses of Abi after prior Enza have demonstrated modest responses of brief duration, suggesting common resistance pathways. Here, we retrospectively analyze response to Enza with or without prior Abi treatment. Methods: We retrospectively reviewed 195 patients from seven academic centers treated with Enza between January 2009 and August 2013. Data were collected on disease characteristics, prior therapies, and prostate-specific antigen (PSA) values at baseline and while on treatment. Logistic regression was used to evaluate association between 30% or greater PSA decline on Enza and either prior Abi treatment or 30% or greater PSA decline on prior Abi after accounting for potential confounders. Results: One hudred eighty three patients had non-missing PSA starting and nadir values on Enza, with starting PSA median 102.0 (range 1.1–5007.0) ng/mL. Overall, 42% (76 of 183) of Enza-treated patients achieved a 30% or greater PSA decline, with 39% (58 of 150) response among prior Abi-treated patients and 55% (18 of 33) response among Abi-naïve patients. Of 79 patients who lacked significant response to prior Abi, 30% (25 of 79) achieved a 30% or greater PSA decline and 19% (15 of 79) achieved a 50% or greater PSA decline with subsequent Enza. Odds of achieving a 30% or greater PSA response on Enza was 2.3 times higher for Abi-naïve patients versus prior Abi-treated patients (95% CI 1.0–5.5, P=0.06) and 1.9 times higher for Abi-responders vs Abi-non-responders (95% CI 1.0–3.7, P=0.06) after adjusting for prior docetaxel and concurrent steroid use. Conclusions: In this multi-center retrospective study, 39% of patients achieved a 30% or greater PSA decline with Enza after prior Abi treatment. While the activity of Enza appears to be blunted in the post-Abi setting, PSA declines still occur in a meaningful proportion of patients. Notably, 30% of patients without significant response to prior Abi responded to subsequent treatment with Enza, suggesting a subset of men with distinct biological resistance pathways. Data will be updated at the time of presentation.


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