Post-diagnostic metformin and statin use and risk of biochemical recurrence in Veterans diagnosed with prostate cancer.

OBJECTIVE: To evaluate the impact of post-diagnostic metformin or statin use and duration on risk of biochemical recurrence in a racially-diverse cohort of Veterans. METHODS: The population consisted of men diagnosed with prostate cancer in the Veterans Health Administration and treated with either radical prostatectomy or radiation (Full cohort n = 65,759, Black men n = 18,817, White men n = 46,631, Other = 311). The association between post-diagnostic (1) metformin and (2) statin use with biochemical recurrence was assessed using multivariable, time-varying Cox Proportional Hazard Models for the overall cohort and by race. In a secondary analysis, metformin and statin duration were evaluated. RESULTS: Post-diagnostic metformin use was not associated with biochemical recurrence (multivariable-adjusted hazard ratio [aHR]: 1.01; 95% confidence interval [CI]: 0.94, 1.09), with similar results observed for both Black and White men. However, duration of metformin use was associated with a reduced risk of biochemical recurrence in the cohort overall (HR: 0.94; 95% CI: 0.92, 0.95) as well as both Black and White men. By contrast, statin use was associated with a reduced risk of biochemical recurrence (HR: 0.83; 95% CI: 0.79, 0.88) in the overall cohort as well as both White and Black men. Duration of statin use was also inversely associated with biochemical recurrence in all groups. CONCLUSION: Post-diagnostic metformin and statin use have the potential to prevent biochemical recurrence in men diagnosed with prostate cancer.

NCCN Guidelines® Insights: Prostate Cancer Early Detection, Version 1.2023.

The NCCN Guidelines for Prostate Cancer Early Detection provide recommendations for individuals with a prostate who opt to participate in an early detection program after receiving the appropriate counseling on the pros and cons. These NCCN Guidelines Insights provide a summary of recent updates to the NCCN Guidelines with regard to the testing protocol, use of multiparametric MRI, and management of negative biopsy results to optimize the detection of clinically significant prostate cancer and minimize the detection of indolent disease.

Adapting a Research and Community Capacity-Building Program to Address Rural Cancer Burden and Facilitate Partnership Development Between Rural Community Stakeholders and an Urban Comprehensive Cancer Center.

While rural-urban cancer disparities persist, the research building capacity between rural communities and high-quality cancer centers remains limited. Thus, we describe how a National Cancer Institute-designated cancer center partnered with rural community stakeholders to adapt a cancer prevention-focused research and community capacity-building workshop. The workshop's goal was to strengthen community-academic partnerships and facilitate the development of sustainable well-resourced rural cancer-focused research. Researchers from the Siteman Cancer Center partnered with community leaders from rural counties in southern Illinois. We adapted the workshop from an existing evidence-based program. We analyzed changes in knowledge and research capacity and relevance to their community work. From February to May 2019, community partners guided all elements of the workshop development. Workshop participants were mostly White race (93%), had a college degree or beyond (75%), reported living in a rural community (93%), and represented an academic, faith-based, or healthcare institution (78%). Participants' mean knowledge scores of the presented content increased significantly after each session, from 9.3 to 9.9 for session 1 (p = 0.05) and 6.8 to 9.7 (p < 0.001) for session two. Through the workshop, participant scores also increased in research capacity skills, confidence, and their understanding of conducting research in the community. The workshop, co-curated and led by rural community leaders and researchers from Siteman Cancer Center, successfully increased knowledge of and interest in building cancer research capacity. Lessons from our work can inform the implementation of similar programs that address rural cancer health through research and community capacity building between rural community partners and urban cancer centers.

Employment Loss and Food Insecurity - Race and Sex Disparities in the Context of COVID-19.

INTRODUCTION: Applying an intersectional framework, we examined sex and racial inequality in COVID-19-related employment loss (ie, job furlough, layoff, and reduced pay) and food insecurity (ie, quality and quantity of food eaten, food worry, and receipt of free meals or groceries) among residents in Saint Louis County, Missouri. METHODS: We used cross-sectional data from adults aged 18 or older (N = 2,146), surveyed by using landlines or cellular phones between August 12, 2020, and October 27, 2020. We calculated survey-weighted prevalence of employment loss and food insecurity for each group (Black female, Black male, White female, White male). Odds ratios for each group were estimated by using survey-weighted binary and multinomial logistic regression models. RESULTS: Black female residents had higher odds of being laid off, as compared with White male residents (OR = 2.61, 95% CI, 1.24-5.46). Both Black female residents (OR = 4.13, 95% CI, 2.29-7.45) and Black male residents (OR = 2.41, 95% CI, 1.15-5.07) were more likely to receive free groceries, compared with White male residents. Black female (OR = 4.25, 95% CI, 2.28-7.94) and White female residents (OR = 1.93, 95% CI, 1.04-3.60) had higher odds of sometimes worrying about food compared with White male residents. Black women also had higher odds of always or nearly always worrying about food, compared with White men (OR = 2.99, 95% CI, 1.52-5.87). CONCLUSION: Black women faced the highest odds of employment loss and food insecurity, highlighting the disproportionate impact of COVID-19 among people with intersectional disadvantages of being both Black and female. Interventions to reduce employment loss and food insecurity can help reduce the disproportionately negative social effects among Black women.

African-specific improvement of a polygenic hazard score for age at diagnosis of prostate cancer.

Polygenic hazard score (PHS) models are associated with age at diagnosis of prostate cancer. Our model developed in Europeans (PHS46) showed reduced performance in men with African genetic ancestry. We used a cross-validated search to identify single nucleotide polymorphisms (SNPs) that might improve performance in this population. Anonymized genotypic data were obtained from the PRACTICAL consortium for 6253 men with African genetic ancestry. Ten iterations of a 10-fold cross-validation search were conducted to select SNPs that would be included in the final PHS46+African model. The coefficients of PHS46+African were estimated in a Cox proportional hazards framework using age at diagnosis as the dependent variable and PHS46, and selected SNPs as predictors. The performance of PHS46 and PHS46+African was compared using the same cross-validated approach. Three SNPs (rs76229939, rs74421890 and rs5013678) were selected for inclusion in PHS46+African. All three SNPs are located on chromosome 8q24. PHS46+African showed substantial improvements in all performance metrics measured, including a 75% increase in the relative hazard of those in the upper 20% compared to the bottom 20% (2.47-4.34) and a 20% reduction in the relative hazard of those in the bottom 20% compared to the middle 40% (0.65-0.53). In conclusion, we identified three SNPs that substantially improved the association of PHS46 with age at diagnosis of prostate cancer in men with African genetic ancestry to levels comparable to Europeans.

The association of weight change in young adulthood and smoking status with risk of prostate cancer recurrence.

The decades before prostate cancer diagnosis represent an etiologically relevant time period for prostate cancer carcinogenesis. However, the association of weight gain in young adulthood with subsequent biochemical recurrence among men with prostate cancer is not well studied, particularly among smokers. We conducted a prospective cohort study of 1,082 men with prostate cancer and treated with either radical prostatectomy or radiation between 2003 and 2010. The association of weight at age 20, weight at age 50 and weight change from age 20 to age 50 with biochemical recurrence was assessed using Cox Proportional Hazards with adjustment for confounders. Stratum-specific hazard ratio (HR) estimates by smoking status were evaluated. In the overall cohort, weight at age 20 (HR per 30 kg: 1.56, 95% confidence interval (CI): 1.02, 2.38, p-trend: 0.039), weight at age 50 (HR per 30 kg: 1.80, 95% CI: 1.32, 2.47, p-trend: <0.001) and weight change from age 20 to age 50 (HR per 30 kg: 1.84, 95% CI: 1.24, 2.74, p-trend: 0.003) were associated with biochemical recurrence. In stratified analyses, weight change from age 20 to age 50 was significantly associated with biochemical recurrence only in former smokers (HR per 30 kg: 3.87, 95% CI: 1.88, 8.00, p-trend: <0.001) and ever smokers (HR per 30 kg: 2.38, 95% CI: 1.27, 4.45, p-trend: 0.007). No significant association was observed between weight gain in young adulthood and biochemical recurrence in never smokers. Our study adds further evidence that weight gain during early adult years conveys long-term risk for adverse cancer outcomes.

The association of metformin use with prostate cancer aggressiveness among Black Americans and White Americans in a population-based study.

PURPOSE: Metformin has been associated with a reduced incidence of prostate cancer and improved prostate cancer outcomes. However, whether race modifies the association between metformin use and prostate cancer aggressiveness remains uncertain. The association between metformin use and prostate cancer aggressiveness was examined separately in Black Americans (Blacks) and White Americans (Whites). METHODS: The study population consisted of 305 Black and 195 White research participants with incident prostate cancer and self-reported diabetes from the North Carolina-Louisiana Prostate Cancer Project. High-aggressive prostate cancer was defined using a composite measure of Gleason sum, prostate-specific antigen, and clinical stage. Multivariable logistic regression was used to assess the association between metformin use and high-aggressive prostate cancer at diagnosis, separately among Whites and Blacks, with adjustment for age, screening history, site, education, insurance, and body mass index. RESULTS: Metformin use was associated positively with high-aggressive prostate cancer in Blacks (OR 2.01; 95% CI 1.05, 3.83). By contrast, a weak inverse association between metformin use and high-aggressive prostate cancer was found in Whites (OR 0.80, 95% CI 0.34, 1.85). CONCLUSIONS: The association between metformin use and prostate cancer aggressiveness may be modified by race.

The burden of prostate cancer in Trinidad and Tobago: one of the highest mortality rates in the world.

PURPOSE: In Trinidad and Tobago (TT), prostate cancer (CaP) is the most commonly diagnosed malignancy and the leading cause of cancer deaths among men. TT currently has one of the highest CaP mortality rates in the world. METHODS: 6,064 incident and 3,704 mortality cases of CaP occurring in TT from January 1995 to 31 December 2009 reported to the Dr. Elizabeth Quamina Cancer population-based cancer registry for TT, were analyzed to examine CaP survival, incidence, and mortality rates and trends by ancestry and geography. RESULTS: The age-standardized CaP incidence and mortality rates (per 100,000) based on the 1960 world-standardized in 2009 were 64.2 and 47.1 per 100,000. The mortality rate in TT increased between 1995 (37.9 per 100,000) and 2009 (79.4 per 100,000), while the rate in the US decreased from 37.3 per 100,000 to 22.1 per 100,000 over the same period. Fewer African ancestry patients received treatment relative to those of Indian and mixed ancestry (45.7%, 60.3%, and 60.9%, respectively). CONCLUSIONS: Notwithstanding the limitations surrounding data quality, our findings highlight the increasing burden of CaP in TT and the need for improved surveillance and standard of care. Our findings highlight the need for optimized models to project cancer rates in developing countries like TT. This study also provides the rationale for targeted screening and optimized treatment for CaP to ameliorate the rates we report.

Physician role in physical activity for African-American males undergoing radical prostatectomy for prostate cancer.

PURPOSE: Physical activity is recognized as a complementary therapy to improve physical and physiological functions among prostate cancer survivors. Little is known about communication between health providers and African-American prostate cancer patients, a high risk population, regarding the health benefits of regular physical activity on their prognosis and recovery. This study explores African-American prostate cancer survivors' experiences with physical activity prescription from their physicians. METHODS: Three focus group interviews were conducted with 12 African-American prostate cancer survivors in May 2014 in St. Louis, MO. Participants' ages ranged from 49 to 79 years, had completed radical prostatectomy, and their time out of surgery varied from 7 to 31 months. RESULTS: Emerged themes included physician role on prescribing physical activity, patients' perceived barriers to engaging in physical activity, perception of normalcy following surgery, and specific resources survivors' sought during treatment. Of the 12 men who participated, 8 men (67%) expressed that their physicians did not recommend physical activity for them. Although some participants revealed they were aware of the importance of sustained physical activity on their prognosis and recovery, some expressed concerns that urinary dysfunction, incontinence, and family commitments prevented them from engaging in active lifestyles. CONCLUSIONS: Transitioning from post radical prostatectomy treatment to normal life was an important concern to survivors. These findings highlight the importance of physical activity communication and prescription for prostate cancer patients.

African American prostate cancer survivorship: Exploring the role of social support in quality of life after radical prostatectomy.

PURPOSE: The aim of this study was to explore the African American prostate cancer survivorship experience following radical prostatectomy and factors contributing to quality of life during survival. DESIGN: African American men who were part of a larger prostate cancer cohort were invited to participate in a focus group. Eighteen open-ended questions were designed by the study team and an experienced moderator to elicit participants' survivorship experiences. RESULTS: Twelve men consented to participate in the study. Emergent themes included views of prostate cancer in the African American community, perceptions of normalcy, emotional side effects following radical prostatectomy, and social support involvement and impact during recovery. CONCLUSIONS: Previous findings suggest that African American men may experience more distress than Caucasian men when facing typical prostate cancer side effects. Traditional masculine role norms and negative perceptions of "disease disclosure" in the African American community could be contributing to the distress reported by some in this study. Strengthening social support systems by promoting more prosocial coping and help-seeking behaviors early in the survivorship journey may help bypass the detrimental health effects associated with masculine role identification, resulting in improved quality of life throughout the lengthy survival period anticipated for these men.

Barriers and Strategies to Participation in Tissue Research Among African-American Men.

Before the burgeoning field of biospecimen collection can advance prevention and treatment methods, researchers must access diverse molecular data samples. However, minorities, especially African-American men, remain reticent to join these studies. This study, using theory-based approaches, investigated African-American men's barriers to participating in biorepository research. Fourteen focus groups were conducted among 70 African-American men (ages 40 to 80). The groups were stratified by prostate cancer history and educational attainment background. Participants identified perceived factors that promoted or hindered study participation when questioned about their knowledge and attitudes about biospecimen research. Ninety-four percent of participants indicated never participating in a study that collected biological samples. Barriers to their participation included lack of knowledge and understanding regarding biospecimen research practices and uses. In addition, they extensively cited a prevalent mistrust of the medical community and discomfort with study recruitment practices. African-American males were more willing to participate in biorepository studies with physician endorsement or if they understood that participation could benefit future generations. Men also wanted more recruitment and advertising done in familiar places.

Development of Plain Language Supplemental Materials for the Biobank Informed Consent Process.

The US Department of Health and Human Services addresses clear communication in the informed consent process as part of the Notice of Proposed Rulemaking for revisions to the Common Rule. However, prior research has shown that participants may not fully comprehend research studies despite completion of an informed consent process. Our main goal was to provide plain language information about donation processes to a cancer biobank to supplement an informed consent form. We developed and conducted cognitive testing with supplemental brochures that clearly communicated information about three different models for consent (notice, broad and study-specific) to future use of biospecimens. During the brochure development process, we conducted qualitative, semi-structured, individual, in-person cognitive interviews among 14 women to examine participants' perceptions of the brochures. Each participant provided feedback regarding the understandability, graphics and layout, and cultural appropriateness of the brochures. Our findings demonstrate that these methods may be used to tailor consent form brochures, such as the ones developed here, to other populations. This study therefore adds to our understanding of how best to present content to help women from two different racial groups make informed decisions about participation in a cancer biobank.

A Community-Based Partnership to Successfully Implement and Maintain a Breast Health Navigation Program.

Breast cancer screening combined with follow-up and treatment reduces breast cancer mortality. However, in the study clinic, only 12 % of eligible women ≥40 years received a mammogram in the previous year. The objective of this project was to implement patient navigation, in our partner health clinic to (1) identify women overdue for a mammogram; and (2) increase mammography utilization in this population over a 2-year period. Women overdue for a mammogram were identified. One patient navigator made navigation attempts over a 2-year period (2009-2011). Navigation included working around systems- and individual-level barriers to receive a mammogram as well as the appropriate follow-up post screening. Women were contacted up to three times to initiate navigation. The proportion of women navigated and who received a mammogram during the study period were compared to women who did not receive a mammogram using Chi square tests for categorical variables and t tests for continuous variables with an α = 0.05. Barriers to previous mammography were also assessed. With 94.8 % of eligible women navigated and 94 % of these women completing mammography, the implementation project reached 89 % of the target population. This project was a successful implementation of an evidence-based patient navigation program that continues to provide significant impact in a high-need area. Cost was the most commonly cite barrier to mammography. Increasing awareness of resources in the community for mammography and follow-up care remains a necessary adjunct to removing structural and financial barriers to accessing preventive services.

Closing the gap: advancing implementation science through training and capacity building.

In their article on "Navigating the Field of Implementation Science Towards Maturity: Challenges and Opportunities," Chambers and Emmons describe the rapid growth of implementation science along with remaining challenges. A significant gap remains in training and capacity building. Formats for capacity building include university degree programs, summer training institutes, workshops, and conferences. In this letter, we describe and amplify on five key areas, including the need to (1) identify advanced competencies, (2) increase the volume and reach of trainings, (3) sustain trainings, (4) build equity focused trainings, and (5) develop global capacity. We hope that the areas we highlight will aid in addressing several key challenges to prioritize in future efforts to build greater capacity in implementation science.

Alvin J. Siteman Cancer Center: Cancer Prevention Perspective.

We summarize Siteman Cancer Center catchment that covers 82 counties in southern Illinois and eastern Missouri. We note both the high poverty and cancer rates in many rural counties. Siteman Community Outreach and Engagement has developed a number of strategies to move towards achieving health equity. These include NCI-funded research projects in rural clinics and outreach to improve access to cancer prevention services. To increase capacity for community-engaged research, we have developed and refined a Community Research Fellows Training Program.

Racial Variation in the Association Between Domains of Depressive Symptomatology and Functional Recovery in Stroke Survivors.

OBJECTIVE: The purpose of the study was to investigate the relationships between various domains of depressive symptomatology and functional recovery in Black and White stroke survivors. METHODS: Black (n = 181) and White (n = 797) stroke survivors from the Stroke Recovery in Underserved Population database were included. Four domains of depressive symptomatology (depressed affect, positive affect, somatic symptoms, interpersonal difficulties) were measured by the Center for Epidemiologic Studies Depression Scale at discharge; functional recovery was measured by the Functional Independence Measure at discharge and 3-month follow-up. Multivariable linear regression analyses examined the relation between race and functional recovery, and the association between depressive symptomatology and functional recovery by race. RESULTS: Three-month functional recovery was greater among White stroke survivors than Black survivors. Affective symptoms of depression predicted poorer functional recovery of White survivors; whereas somatic symptoms predicted poorer functional recovery of Black survivors. CONCLUSIONS: Domains of depressive symptomatology were differentially associated with poorer functional recovery in Black and White stroke survivors. Psychosocial interventions aimed at alleviating depressive symptomatology have the potential to improve functional recovery in Black and White stroke survivors and should be addressed in planning rehabilitation post-stroke.

Definitive treatment and risk of death among men diagnosed with metastatic prostate cancer at the Veterans Health Administration.

PURPOSE: To assess the potential survival benefit associated with receipt of definitive treatment (radical prostatectomy or radiation), compared to non-definitive treatment (hormonal therapy or chemotherapy) among men with metastatic prostate cancer. METHODS: A cohort of men diagnosed with metastatic (T4/M1/N1 or T4/M1) prostate cancer from 1999 to 2013 in the Veterans Health Administration were identified and followed to December 28, 2014. All-cause and prostate cancer-specific mortality were evaluated at 10 years for the T4/M1/N1 cohort and 8 years for the T4/M1/ cohort. The association of definitive treatment (radical prostatectomy or radiation), compared to non-definitive (hormonal therapy or chemotherapy) with both all-cause and prostate cancer-specific mortality was assessed using inverse probability of treatment weighted (IPTW) multivariable survival analyses. RESULTS: The cohort included 2919 with T4/M1/N1 disease and 1479 men with T4/M1 disease. Receipt of definitive treatment was associated with a reduced risk of 10-year all-cause (Hazard Ratio (HR): 0.61; 95% Confidence Interval (CI): 0.57-0.65) and prostate cancer-specific mortality (HR: 0.50; 95% CI: 0.46-0.55) among men diagnosed with T4/M1/N1 met-astatic disease. Definitive treatment was similarly associated with a reduced risk of all-cause (HR: 0.84; 95% CI: 0.77-0.91) and prostate cancer-specific (HR: 0.81; 95% CI: 0.73-0.90) mortality among men diagnosed with T4/M1 only metastatic disease. CONCLUSIONS: Definitive treatment may improve survival in men diagnosed with metastatic prostate cancer.

Local Treatment and Treatment-Related Adverse Effects Among Patients With Advanced Prostate Cancer.

Importance: Recent data suggest that local treatment with radical prostatectomy or radiation may improve survival outcomes in men with advanced prostate cancer. However, evidence is lacking on treatment-related adverse effects among men with advanced prostate cancer. Objective: To assess the association of local treatment on treatment-related adverse effects among men diagnosed with advanced prostate cancer. Design, Setting, and Participants: This cohort study assessed men diagnosed with advanced prostate cancer (defined as T4, N1, and/or M1 prostate cancer) between January 1, 1999, and December 31, 2013, with follow-up through December 31, 2021, who were treated at Veterans Health Administration medical centers. Exposure: Local treatment with radical prostatectomy or radiation. Main Outcomes and Measures: Main outcomes were treatment-related adverse effects, including constitutional, gastrointestinal, pain, sexual function, and urinary function conditions, at 3 intervals after initial treatment (≤1 year, >1 to ≤2 years, and >2 to ≤5 years) after initial treatment. Results: This cohort study consisted of 5502 men (mean [SD] age, 68.7 [10.3] years) diagnosed with advanced prostate cancer. Of the cohort, 1705 men (31.0%) received local treatment. There was a high prevalence of adverse conditions in men receiving both local and nonlocal treatment, and these adverse conditions persisted for more than 2 years to 5 years or less after initial treatment. A total of 916 men (75.2%) with initial local treatment and 897 men (67.1%) with initial nonlocal treatment reported the presence of at least 1 adverse condition for more than 2 years to 5 years or less after initial treatment. In the first year, local treatment (vs nonlocal) was associated with adverse gastrointestinal (multivariable-adjusted odds ratio [AOR], 4.08; 95% CI, 3.06-5.45), pain (AOR, 1.57; 95% CI, 1.35-1.83), sexual (AOR, 2.96; 95% CI, 2.42-3.62), and urinary (AOR, 2.25; 95% CI, 1.90-2.66) conditions. Local treatment (without secondary treatment) remained significantly associated with adverse gastrointestinal (AOR, 2.39; 95% CI, 1.52-3.77), sexual (AOR, 3.36; 95% CI, 2.56-4.41), and urinary (AOR, 1.39; 95% CI, 1.09-1.78) conditions at more than 2 years to 5 years or less after treatment. Conclusions and Relevance: In this cohort study of men with advanced prostate cancer, local treatment was associated with persistent treatment-related adverse effects across multiple domains. These results suggest that patients and clinicians should consider the adverse effects of local treatment when making treatment decisions in the setting of advanced prostate cancer.

Financial burden of men with localized prostate cancer: a process paper.

Background: Many individuals undergoing cancer treatment experience substantial financial hardship, often referred to as financial toxicity (FT). Those undergoing prostate cancer treatment may experience FT and its impact can exacerbate disparate health outcomes. Localized prostate cancer treatment options include: radiation, surgery, and/or active surveillance. Quality of life tradeoffs and costs differ between treatment options. In this project, our aim was to quantify direct healthcare costs to support patients and clinicians as they discuss prostate cancer treatment options. We provide the transparent steps to estimate healthcare costs associated with treatment for localized prostate cancer among the privately insured population using a large claims dataset. Methods: To quantify the costs associated with their prostate cancer treatment, we used data from the Truven Health Analytics MarketScan Commercial Claims and Encounters, including MarketScan Medicaid, and peer reviewed literature. Strategies to estimate costs included: (1) identifying the problem, (2) engaging a multidisciplinary team, (3) reviewing the literature and identifying the database, (4) identifying outcomes, (5) defining the cohort, and (6) designing the analytic plan. The costs consist of patient, clinician, and system/facility costs, at 1-year, 3-years, and 5-years following diagnosis. Results: We outline our specific strategies to estimate costs, including: defining complex research questions, defining the study population, defining initial prostate cancer treatment, linking facility and provider level related costs, and developing a shared understanding of definitions on our research team. Discussion and next steps: Analyses are underway. We plan to include these costs in a prostate cancer patient decision aid alongside other clinical tradeoffs.

Survival of veterans treated with enzalutamide and abiraterone for metastatic castrate resistant prostate cancer based on comorbid diseases.

BACKGROUND: Comorbid diseases influence patient outcomes, yet little is known about how comorbidities interact with treatments for metastatic castrate-resistant prostate cancer (mCRPC). No head-to-head trials have compared the efficacy of abiraterone and enzalutamide - oral androgen-receptor targeted agents (ARTAs) for mCRPC. In patients with comorbid disease, outcomes with ARTAs may differ due to disparate mechanisms of action, adverse events, and drug interactions. METHODS: Retrospective observational study of US veterans initiating treatment for mCRPC with abiraterone or enzalutamide between September 2014 and June 2017. Treatment duration and overall survival (OS) was compared based on age and comorbid diseases. The association between ARTA and OS was assessed using Cox proportional hazards and propensity-score matched modeling while adjusting for potential confounders. Sensitivity analyses were performed based on patient age, comorbidities, and subsequent treatments for mCRPC. RESULTS: Of 5822 veterans treated for mCRPC, 43.0% initially received enzalutamide and 57.0% abiraterone. Veterans initially treated with enzalutamide versus abiraterone were older (mean 75.8 vs. 75.0 years) with higher mean Charlson comorbidity index (4.4 vs. 4.1), and higher rates of cardiovascular disease or diabetes (74.2% vs. 70.6%). In the entire population, veterans initially treated with enzalutamide had longer median OS compared to those initially treated with abiraterone (24.2 vs. 22.1 months, p = 0.001). In veterans with cardiovascular disease or diabetes, median treatment duration with enzalutamide was longer (11.4 vs. 8.6 months, p < 0.001) with longer median OS compared to abiraterone (23.2 vs. 20.5 months, p < 0.001). In a propensity score matched cohort, enzalutamide was associated with decreased mortality compared to abiraterone (HR 0.90, 95% CI 0.84-0.96). CONCLUSIONS: Veterans with cardiovascular disease or diabetes had longer treatment duration and OS with enzalutamide compared to abiraterone. Further study of ARTA selection may benefit men with metastatic castrate resistant prostate cancer and likely hormone sensitive prostate cancer, especially among patients with comorbid diseases.