Addressing racial disparities in prostate cancer pathology prediction models: external validation and comparison of four models of pathological outcome prediction before radical prostatectomy in the multiethnic SEARCH cohort.

BACKGROUND: Certain widely used pathological outcome prediction models that were developed in tertiary centers tend to overpredict outcomes in the community setting; thus, the Michigan Urological-Surgery Improvement Collaborative (MUSIC) model was developed in general urology practice to address this issue. Additionally, the development of these models involved a relatively small proportion of Black men, potentially compromising the accuracy of predictions in this patient group. We tested the validity of the MUSIC and three widely used nomograms to compare their overall and race-stratified predictive performance. METHODS: We extracted data from 4139 (1138 Black) men from the Shared Equal Access Regional Cancer Hospital (SEARCH) database of the Veterans Affairs health system. The predictive performance of the MUSIC model was compared to the Memorial-Sloan Kettering (MSK), Briganti-2012, and Partin-2017 models for predicting lymph-node invasion (LNI), extra-prostatic extension (EPE), and seminal vesicle invasion (SVI). RESULTS: The median PSA of Black men was higher than White men (7.8 vs. 6.8 ng/ml), although they were younger by a median of three years and presented at a lower-stage disease. MUSIC model showed comparable discriminatory capacity (AUC:77.0%) compared to MSK (79.2%), Partin-2017 (74.6%), and Briganti-2012 (76.3%), with better calibration for LNI. AUCs for EPE and SVI were 72.7% and 76.9%, respectively, all comparable to the MSK and Partin models. LNI AUCs for Black and White men were 69.6% and 79.6%, respectively, while EPE and SVI AUCs were comparable between races. EPE and LNI had worse calibration in Black men. Decision curve analysis showed MUSIC superiority over the MSK model in predicting LNI, especially among Black men. CONCLUSION: Although the discriminatory performance of all models was comparable for each outcome, the MUSIC model exhibited superior net benefit to the MSK model in predicting LNI outcomes among Black men in the SEARCH population.

Do Hispanic Puerto Rican men have worse outcomes after radical prostatectomy? Results from SEARCH.

BACKGROUND: We previously reported that outcomes after radical prostatectomy (RP) were similar among non-Hispanic Black, non-Hispanic White, and Hispanic White Veterans Affairs (VA) patients. However, prostate cancer (PC) mortality in Puerto Rican Hispanics (PRH) may be higher than in other Hispanic groups. Data focused on PRH patients is sparse; thus, we tested the association between PR ethnicity and outcomes after RP. METHODS: Analysis included men in SEARCH cohort who underwent RP (1988-2020, n = 8311). PRH patients (n = 642) were treated at the PR VA, and outcomes were compared to patients treated in the Continental US regardless of race. Logistic regression was used to test the associations between PRH and PC aggressiveness, adjusting for demographic and clinicopathological features. Multivariable Cox models were used to investigate PRH versus Continental differences in biochemical recurrence (BCR), metastases, castration-resistant PC (CRPC), and PC-specific mortality (PCSM). RESULTS: Compared to Continental patients, PRH patients had lower adjusted odds of pathological grade group ≥2 (p < 0.001), lymph node metastasis (p < 0.001), and positive margins (p < 0.001). In contrast, PRH patients had higher odds of extracapsular extension (p < 0.001). In Cox models, PRH patients had a higher risk for BCR (HR = 1.27, p < 0.001), metastases (HR = 1.49, p = 0.014), CRPC (HR = 1.80, p = 0.001), and PCSM (HR = 1.74, p = 0.011). Further adjustment for extracapsular extension and other pathological variables strengthened these findings. CONCLUSIONS: In an equal access setting, PRH RP patients generally had better pathological features, but despite this, they had significantly worse post-treatment outcomes than men from the Continental US, regardless of race. The reasons for the poorer prognosis among PRH men require further research.

Effect of omega-3 fatty acid diet on prostate cancer progression and cholesterol efflux in tumor-associated macrophages-dependence on GPR120.

BACKGROUND: Preclinical and clinical translational research supports the role of an ω-3 fatty acid diet for prostate cancer prevention and treatment. The anti-prostate cancer effects of an ω-3 diet require a functional host g-protein coupled receptor 120 (GPR120) but the underlying effects on the tumor microenvironment and host immune system are yet to be elucidated. METHODS: Friend leukemia virus B (FVB) mice received bone marrow from green fluorescent protein (GFP) labeled GPR120 wild-type (WT) or knockout (KO) mice followed by implanting Myc-driven mouse prostate cancer (MycCap) allografts and feeding an ω-3 or ω-6 diet. Tumor associated immune cells were characterized by flow cytometry, and CD206+ tumor infiltrating M2-like macrophages were isolated for gene expression studies. MycCap prostate cancer cell conditioned medium (CM) was used to stimulate murine macrophage cells (RAW264.7) and bone marrow-derived (BMD) macrophages to study the effects of docosahexanoic acid (DHA, fish-derived ω-3 fatty acid) on M2 macrophage function and cholesterol metabolism. RESULTS: The bone marrow transplantation study showed that an ω-3 as compared to an ω-6 diet inhibited MycCaP allograft tumor growth only in mice receiving GPR120 WT but not GPR120 KO bone marrow. In the ω-3 group, GPR120 WT BMD M2-like macrophages infiltrating the tumor were significantly reduced in number and gene expression of cholesterol transporters Abca1, Abca6, and Abcg1. RAW264.7 murine macrophages and BMDMs exposed to MycCaP cell CM had increased gene expression of cholesterol transporters, depleted cholesterol levels, and were converted to the M2 phenotype. These effects were inhibited by DHA through the GPR120 receptor. CONCLUSION: Host bone marrow cells with functional GPR120 are essential for the anticancer effects of dietary ω-3 fatty acids, and a key target of the ω-3 diet are the M2-like CD206+ macrophages. Our preclinical findings provide rationale for clinical trials evaluating ω-3 fatty acids as a potential therapy for prostate cancer through inhibition of GPR120 functional M2-like macrophages.

Are associations between obesity and prostate cancer outcomes following radical prostatectomy the same in smokers and non-smokers? Results from the SEARCH Cohort.

PURPOSE: Obesity and smoking have been associated with poor prostate cancer (PC) outcomes. We investigated associations between obesity and biochemical recurrence (BCR), metastasis, castrate resistant-PC (CRPC), PC-specific mortality (PCSM), and all-cause mortality (ACM) and examined if smoking modified these associations. METHODS: We analyzed SEARCH Cohort data from men undergoing RP between 1990 and 2020. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between body mass index (BMI) as a continuous variable and weight status classifications (normal: 18.5 ≤ 25 kg/m2; overweight: 25-29.9 kg/m2; obese: ≥ 30 kg/m2) and PC outcomes. RESULTS: Among 6,241 men, 1,326 (21%) were normal weight, 2,756 (44%) overweight and 2159 (35%) obese; 1,841 (30%) were never-smokers, 2,768 (44%) former and 1,632 (26%) current-smokers. Among all men, obesity was associated with non-significant increased risk of PCSM, adj-HR = 1.71; 0.98-2.98, P = 0.057, while overweight and obesity were inversely associated with ACM, adj-HR = 0.75; 0.66-0.84, P < 0.001 and adj-HR = 0.86; 0.75-0.99, P = 0.033, respectively. Other associations were null. BCR and ACM were stratified for smoking status given evidence for interactions (P = 0.048 and P = 0.054, respectively). Among current-smokers, overweight was associated with an increase in BCR (adj-HR = 1.30; 1.07-1.60, P = 0.011) and a decrease in ACM (adj-HR = 0.70; 0.58-0.84, P < 0.001). Among never-smokers, BMI (continuous) was associated with an increase in ACM (adj-HR = 1.03; 1.00-1.06, P = 0.033). CONCLUSIONS: While our results are consistent with obesity as a risk factor for PCSM, we present evidence of effect modification by smoking for BCR and ACM highlighting the importance of stratifying by smoking status to better understand associations with body weight.

Diabetes and Prostate Cancer Outcomes in Men with Nonmetastatic Castration-Resistant Prostate Cancer: Results from the SEARCH Cohort.

BACKGROUND: The prognosis of diabetic men with advanced prostate cancer is poorly understood and understudied. Hence, we studied associations between diabetes and progression to metastases, prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM) in men with nonmetastatic castration-resistant prostate cancer (nmCRPC). METHODS: Data from men diagnosed with nmCRPC between 2000 and 2017 at 8 Veterans Affairs Health Care Centers were analyzed using Cox regression to determine HRs and 95% confidence intervals (CI) for associations between diabetes and outcomes. Men with diabetes were classified according to: (i) ICD-9/10 codes only, (ii) two HbA1c values > 6.4% (missing ICD-9/10 codes), and (iii) all diabetic men [(i) and (ii) combined]. RESULTS: Of 976 men (median age: 76 years), 304 (31%) had diabetes at nmCRPC diagnosis, of whom 51% had ICD-9/10 codes. During a median follow-up of 6.5 years, 613 men were diagnosed with metastases, and 482 PCSM and 741 ACM events occurred. In multivariable-adjusted models, ICD-9/10 code-identified diabetes was inversely associated with PCSM (HR, 0.67; 95% CI, 0.48-0.92) while diabetes identified by high HbA1c values (no ICD-9/10 codes) was associated with an increase in ACM (HR, 1.41; 95% CI, 1.16-1.72). Duration of diabetes, prior to CRPC diagnosis was inversely associated with PCSM among men identified by ICD-9/10 codes and/or HbA1c values (HR, 0.93; 95% CI, 0.88-0.98). CONCLUSIONS: In men with late-stage prostate cancer, ICD-9/10 'code-identified' diabetes is associated with better overall survival than 'undiagnosed' diabetes identified by high HbA1c values only. IMPACT: Our data suggest that better diabetes detection and management may improve survival in late-stage prostate cancer.

Time from biopsy to radical prostatectomy by race in an equal-access healthcare system: Results from the SEARCH cohort.

BACKGROUND: We previously showed that within an equal-access health system, race was not associated with the time between prostate cancer (PC) diagnosis and radical prostatectomy (RP). However, in the more recent time-period of the study (2003-2007), Black men had significantly longer times to RP. We sought to revisit the question in a larger study population with more contemporary patients. We hypothesized that time from diagnosis to treatment would not differ by race, even after accounting for active surveillance (AS) and the exclusion of men at very low to low risk of PC progression. METHODS: We analyzed data from 5885 men undergoing RP from 1988 to 2017 at eight Veterans Affairs Hospitals from SEARCH. Multiple linear regression was used to compare time from biopsy to RP and to examine the risk of delays (>90 and >180 days) between races. In sensitivity analyses we excluded men deemed to have initially chosen AS based on having >365 days from biopsy to RP and men at very low to low PC risk for progression according to National Comprehensive Cancer Network Clinical Practice Guidelines. RESULTS: At biopsy, Black men (n = 1959) were younger, had lower body mass index, and higher prostate specific antigen levels, (all p < 0.02), compared to White men (n = 3926). Time from biopsy to RP was longer in Black men (mean days: 98 vs. 92; adjusted ratio of mean number of days, 1.07 [95% confidence interval: 1.03-1.11], p < 0.001); however, there were no differences in delays >90 or >180 days after adjusting for confounders (all p ≥ 0.286). Results were similar following the exclusion of men potentially under on AS and at very low and low risk. CONCLUSIONS: In an equal-access healthcare system, we did not find evidence of clinically relevant differences in time from biopsy to RP in Black versus White men.

A modeling study to estimate prostate cancer-specific mortality on active surveillance for men with favorable intermediate-risk prostate cancer: Results from the SEARCH cohort.

PURPOSE: Limited data exist to help surgeons decide between active surveillance (AS) versus treatment for men with favorable intermediate risk (FIR) prostate cancer. To estimate the theoretical excess risk of prostate cancer-specific mortality (PCSM) with AS versus radical prostatectomy (RP), we determined the risk of PCSM in FIR men undergoing RP and modeled the PCSM risk for AS using a range of increased PSCM scenarios ranging from 1.25x to 2x higher relative to RP. MATERIALS AND METHODS: We retrospectively reviewed data from men undergoing RP from 1988 to 2017 at 8 Veterans Affairs hospitals within the SEARCH cohort. Men with FIR PC were identified using the NCCN risk criteria. Risk of PCSM at 5, 10, and 15 years after RP was estimated. Using these estimates, PCSM was then modeled for AS using a range of increased risk of PCSM relative to RP ranging from 1.25x to 2x higher. RESULTS: For the 920 FIR men identified, 5-, 10-, and 15-year survival estimates for PCSM after RP were 99.9%, 99.0%, and 97.8%, respectively. If the risk of PCSM on AS were 1.25-2x greater than RP, there would be 0.54%-2.17% excess risk of PCSM at 15 years. CONCLUSIONS: The risk of death for FIR after RP is very low. Assuming even modestly increased PCSM with AS versus RP, the excess risk of death for AS in FIR is low even up to 15 years. These data support the consideration of AS as a relatively safe alternative to RP in FIR men, though prospective randomized trials are needed to validate these findings.

Is time to castration resistant prostate cancer a potential intermediate end-point for time to metastasis among men initiating androgen deprivation therapy for non-metastatic prostate cancer with rapid PSA doubling time (<9 months)?

PURPOSE: Metastasis-free survival (MFS) is a surrogate for overall survival (OS) in men with non-metastatic castration-resistant prostate cancer (CRPC), but this endpoint may take years to develop in men with non-metastatic castrate-sensitive disease. The study objective was to examine whether progression to CRPC is a potential intermediate endpoint for developing metastatic disease in patients with biochemical recurrence (BCR) after radical prostatectomy (RP). MATERIALS AND METHODS: Men with BCR following RP who had PSA doubling times (PSADT) < 9 months and no metastasis at the time of initiating androgen deprivation therapy (ADT) (n = 210) were included. The primary objective was to assess the correlation between CRPC-free survival (CRPC-FS) and MFS, and the secondary objective was to assess the correlation between time to metastasis and time to CRPC. Kendall's Tau was used to test the correlation for the primary and secondary outcomes. RESULTS: The median MFS was 104 months (95% CI: 83-114) and median CRPC-FS was 100 months (95% CI: 80-114). Based on the Kaplan-Meier curve, the greatest difference in time to MFS and CRPC-FS was around 70% free survival, which was reached at 61.2 months for MFS and 49.6 months for CRPC-FS. Kendall's Tau for the correlation between CRPC-FS and MFS and between time to CRPC and time to metastasis was 0.867 (95% CI: 0.765-0.968) and 0.764 (95% CI: 0.644-0.884), respectively. CONCLUSIONS: Given the high correlation between CRPC-FS and MFS, after validation, CRPC-FS may serve as a potential intermediate endpoint in trials for men with BCR initiating ADT following local therapy.

Impact of darolutamide on local symptoms: pre-planned and post hoc analyses of the ARAMIS trial.

OBJECTIVE: To assess, the effect of darolutamide (a structurally distinct androgen receptor inhibitor) on urinary and bowel symptoms, using data from the phase III ARAMIS trial (NCT02200614) that showed darolutamide significantly reduced the risk of metastasis and death versus placebo. PATIENTS AND METHODS: Patients with non-metastatic castration-resistant prostate cancer (nmCRPC) were randomised 2:1 to darolutamide (n = 955) or placebo (n = 554). Local symptom control was assessed by first prostate cancer-related invasive procedures and post hoc analyses of time to deterioration in quality of life (QoL) using total urinary and bowel symptoms, and individual questions for these symptoms from the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Prostate Cancer Module subscales and Functional Assessment of Cancer Therapy-Prostate prostate cancer subscale. Prostate-specific antigen (PSA) responses were correlated with urinary and bowel adverse events (AEs). RESULTS: Fewer patients receiving darolutamide (4.7%) versus placebo (9.6%) underwent invasive procedures, and time to first procedure was prolonged with darolutamide (hazard ratio 0.42, 95% confidence interval 0.28-0.62). Darolutamide significantly (P < 0.01) delayed worsening of QoL for total urinary and bowel symptoms versus placebo, mostly attributed by individual symptoms of urinary frequency, associated pain, and interference with daily activities. AEs of urinary retention and dysuria were less frequent with darolutamide, and greater PSA response (≥90%, ≥50% and <90%, <50%) among darolutamide-treated patients was associated with lower incidences of urinary retention (2.2%, 4.2%, 5.1%) and dysuria (0.5%, 3.2%, 5.1%), respectively. CONCLUSIONS: Darolutamide demonstrated a positive impact on local disease recurrence and symptom control in patients with nmCRPC, delayed time to deterioration in QoL related to urinary and bowel symptoms, and a favourable safety profile showing similar incidence of urinary- and bowel-related AEs compared with placebo.

Red Blood Cell Distribution Width Is Associated with All-cause Mortality but Not Adverse Cancer-specific Outcomes in Men with Clinically Localized Prostate Cancer Treated with Radical Prostatectomy: Findings Based on a Multicenter Shared Equal Access Regional Cancer Hospital Registry.

BACKGROUND: Recent reports with a small number of patients showed an association of red blood cell distribution width (RDW) with prostate cancer (PCa) progression. OBJECTIVE: To investigate whether preoperative RDW can serve as a prognostic marker in patients with PCa undergoing radical prostatectomy (RP) in a large, equal access, and diverse patient cohort. DESIGN SETTING AND PARTICIPANTS: Data were retrospectively collected on 4756 men treated with RP at eight Veteran Affairs medical centers within the Shared Equal Access Regional Cancer Hospital (SEARCH) database from 1999 through 2017. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Biochemical recurrence (BCR) was the primary outcome, while metastasis, all-cause mortality (ACM), and prostate cancer-specific mortality (PCSM) were secondary outcomes. RESULTS AND LIMITATIONS: The mean (standard deviation) age was 62 yr (6.1), and 1589 (33%) men were black. The median (interquartile range) follow-up was 82 mo (46-127). Preoperative RDW either as a continuous variable or when stratified by quartiles was not associated with BCR. Likewise, preoperative RDW was not associated with metastases or PCSM. However, higher RDW was significantly associated with higher ACM, both as a continuous variable (p < 0.001) and when stratified by quartiles in univariable and multivariable models (p < 0.001). RDW was found to be correlated with D'Amico risk classification of PCa. Study limitations include its retrospective nature and lack of data regarding advanced PCa. CONCLUSIONS: Preoperative RDW was not associated with PCa outcomes in men treated with RP but was associated with ACM. While RDW may be a biomarker of overall health, it is not a biomarker for PCa outcomes. These results emphasize the importance of diverse, larger sized studies in genitourinary cancer research. PATIENT SUMMARY: Prostate cancer includes a wide spectrum of diseases with different genetic, pathological, and oncological behaviors. Red blood cell distribution width is helpful in predicting the overall survival for a localized prostate cancer patient, and hence, it can help inform personalized treatment decisions and operative care.

Effects of dietary omega-3 fatty acids on orthotopic prostate cancer progression, tumor associated macrophages, angiogenesis and T-cell activation-dependence on GPR120.

BACKGROUND: The antiprostate cancer effects of dietary ω-3 fatty acids (FAs) were previously found to be dependent on host G-protein coupled receptor 120 (GPR120). Using an orthotopic tumor model and an ex-vivo model of bone marrow derived M2-like macrophages, we sought to determine if ω-3 FAs inhibit angiogenesis and activate T-cells, and if these effects are dependent on GPR120. METHODS: Gausia luciferase labeled MycCaP prostate cancer cells (MycCaP-Gluc) were injected into the anterior prostate lobe of FVB mice. After established tumors were confirmed by blood luminescence, mice were fed an ω-3 or ω-6 diet. Five weeks after tumor injection, tumor weight, immune cell infiltration and markers of angiogenesis were determined. An ex-vivo co-culture model of bone marrow derived M2-like macrophages from wild-type or GPR120 knockout mice with MycCap prostate cancer cells was used to determine if docosahexanoic acid (DHA, ω-3 FA) inhibition of angiogenesis and T-cell activation is dependent on macrophage GPR120. RESULTS: Feeding an ω-3 diet significantly reduced orthotopic MycCaP-Gluc tumor growth relative to an ω-6 diet. Tumors from the ω-3 group had decreased M2-like macrophage infiltration and decreased expression of angiogenesis factors. DHA significantly inhibited M2 macrophage-induced endothelial tube formation and reversed M2 macrophage-induced T-cell suppression, and these DHA effects were mediated, in part, by M2 macrophage GPR120. CONCLUSION: Omega-3 FAs delayed orthotopic tumor growth, inhibited M2-like macrophage tumor infiltration, and inhibited M2-like macrophage-induced angiogenesis and T-cell suppression. Given the central role of M2-like macrophages in prostate cancer progression, GPR120-dependent ω-3 FA inhibition of M2-like macrophages may play an important role in prostate cancer therapeutics.

Association between Delay to Radical Prostatectomy and Clinically Meaningful Outcomes among Patients with Intermediate and High-Risk Localized Prostate Cancer.

PURPOSE: There are limited data regarding the effect of treatment delays on important long-term outcomes among men with intermediate/high-risk prostate cancer (PC). MATERIALS AND METHODS: We identified 3,962 men with intermediate/high-risk disease from the SEARCH cohort treated with radical prostatectomy (RP) from 1988 to 2018. Cox proportional hazard models assessed the association between time from biopsy to RP (up to 1 year) and time to castration-resistant PC (CRPC), metastasis and all-cause mortality. Interaction terms were used to test for effect modification by risk group. RESULTS: Of the 3,962 men, 167 developed CRPC, 248 developed metastases and 884 died after a median followup of 85 months. Longer delays between biopsy and RP were associated with a decreased risk of CRPC (adjusted HR=0.88, 95% CI: 0.80-0.98, p=0.02), independent of D'Amico risk group (interaction p >0.05). In men with intermediate and high-risk disease, we found no statistically significant association between length of time to RP and risk of developing metastases (p=0.5 and 0.9, respectively) or all-cause mortality (p=0.1 and 0.1, respectively). CONCLUSIONS: Among men with intermediate and high-risk PC, we found no statistically significant increased risk of adverse long-term outcomes, including CRPC, metastasis and death, for men who had treatment delays up to 1 year following PC diagnosis.

Prostate weight and prostate cancer outcomes after radical prostatectomy: Results from the SEARCH cohort study.

BACKGROUND: Smaller prostates have been linked to unfavorable clinical characteristics and poor short-term outcomes following radical prostatectomy (RP). We examined the relation between prostate weight at RP and prostate cancer (PC) outcomes post-RP. METHODS: Men in the SEARCH cohort undergoing RP between 1988 and 2017 (N = 6242) were studied for PC-specific mortality (PCSM) as the primary outcome, and for biochemical recurrence (BCR), castration-resistant PC (CRPC) and metastasis as secondary outcomes. Hazard ratios (HR) and 95% confidence intervals (CI) were determined for associations between prostate weight and outcomes using Fine-Gray competing risk regression multivariable analyses. Sensitivity analyses were also carried out following exclusion of: (i) men with extreme prostate weights (<20 g and ≥100 g); and (ii) men with elevated prostate specific antigen (PSA) levels. RESULTS: Median values for age, pre-RP PSA and prostate weight were 63 years, 6.6 ng/ml, and 42.0 g, respectively. During a median follow-up of 7.9 years, 153 (3%) died from PC, 2103 (34%) had BCR, 203 (3%) developed CRPC, and 289 (5%) developed metastases. Prostate weight was not associated with PCSM in the main analyses (multivariable HR = 1.43; 95% CI: 0.87-2.34) or in sensitivity analyses. Prostate weight was inversely associated with BCR in the main analyses (multivariable HR = 0.70; 95%CI: 0.61-0.79) which was unchanged in sensitivity analyses. HRs for prostate weight and CRPC and metastasis were elevated but statistical significance was not attained. Similar results were observed in sensitivity analyses. CONCLUSIONS: Inconsistent results for prostate weight and short-term vs longer-term outcomes highlight the need to better understand the complex biology leading to prostate size and the relevance of prostate size as a predictor of PC outcomes.

Efficacy and safety of darolutamide in Black/African-American patients from the phase III ARAMIS study.

Aim: Darolutamide significantly improved metastasis-free survival (MFS) and overall survival (OS) versus placebo in the phase III ARAMIS study. We evaluated outcomes in Black/African-American patients in ARAMIS. Materials & methods: Patients with nonmetastatic castration-resistant prostate cancer were randomized 2:1 to darolutamide (n = 955) or placebo (n = 554) plus androgen-deprivation therapy. The primary end point was MFS. Secondary end points included OS and safety. Results: In 52 (3.4%) Black/African-American patients, darolutamide improved MFS (median: not reached vs 12.4 months) and OS (3-year survival rates: 100 vs 71%) versus placebo. The safety profile of darolutamide in Black/African-American patients was consistent with that of all ARAMIS patients. Conclusion: In Black/African-American patients, darolutamide improved MFS and OS and was well tolerated, consistent with the overall ARAMIS population.

In patients with prostate cancer that has stopped responding to androgen-deprivation therapy, or 'ADT,' and has not spread to other parts of the body (known as nonmetastatic castration-resistant prostate cancer, or 'nmCRPC'), darolutamide is an oral treatment option. Darolutamide added to ADT was tested in patients with nmCRPC in a large international study called ARAMIS and was found to prolong the time that patients were free from their cancer spreading compared with patients who received ADT alone. This report provides information on the effect of darolutamide in the 52 Black/African­American patients who took part in ARAMIS. In these patients, darolutamide showed similar effects on lowering the risk of their cancer spreading and was well tolerated.

Radium-223 Utilization Patterns and Outcomes in Clinical Practice.

INTRODUCTION: Radium-223 was approved for metastatic castration-resistant prostate cancer based on the ALSYMPCA trial. We characterize radium-223 treatment patterns and overall survival (OS) in a large equal access health system. METHODS: We identified all men within the Veterans Affairs (VA) Healthcare System who received radium-223 between January 2013 and September 2017. Patients were followed until death or last followup. We abstracted all treatments received prior to radium; no treatments after radium were abstracted. Our primary aim was understanding practice patterns, and secondary outcome was the association between treatment pattern and OS measured using Cox models. RESULTS: We identified 318 bone metastatic castration-resistant prostate cancer patients who received radium-223 within the VA Healthcare System. Of these patients 277 (87%) died during followup. The 5 predominant treatment patterns that encompassed 88% of patients (279/318) were 1) androgen receptor-targeted agent (ARTA)-radium, 2) docetaxel-ARTA-radium, 3) ARTA-docetaxel-radium, 4) docetaxel-ARTA-cabazitaxel-radium and 5) radium alone. Median OS was 11 months (95% CI 9.7-12.5). Men who received ARTA-docetaxel-radium had the worst survival. All other treatments had similar outcomes. Only 42% of patients completed the full 6 injections; 25% received only 1 or 2 injections. CONCLUSIONS: We identified the most common radium-223 treatment patterns and their association with OS within the VA population. The better survival in ALSYMPCA (14.9 months) vs our study (11 months) along with 58% of patients not receiving the full radium-223 course suggests radium is being used later in the disease course in the real world in a more heterogeneous population.

Diabetes and Prostate Cancer Outcomes in Obese and Nonobese Men After Radical Prostatectomy.

Background: The link between diabetes and prostate cancer progression is poorly understood and complicated by obesity. We investigated associations between diabetes and prostate cancer-specific mortality (PCSM), castrate-resistant prostate cancer (CRPC), and metastases in obese and nonobese men undergoing radical prostatectomy (RP). Methods: We included 4688 men from the Shared Equal Access Regional Cancer Hospital cohort of men undergoing RP from 1988 to 2017. Diabetes prior to RP, anthropometric, and clinical data were abstracted from 6 Veterans Affairs Medical Centers electronic medical records. Primary and secondary outcomes were PCSM and metastases and CRPC, respectively. Multivariable-adjusted hazard ratios (adj-HRs) and 95% confidence intervals (CIs) were estimated for diabetes and PCSM, CRPC, and metastases. Adjusted hazard ratios were also estimated in analyses stratified by obesity (body mass index: nonobese <30 kg/m2; obese ≥30 kg/m2). All statistical tests were 2-sided. Results: Diabetes was not associated with PCSM (adj-HR = 1.38, 95% CI = 0.86 to 2.24), CRPC (adj-HR = 1.05, 95% CI = 0.67 to 1.64), or metastases (adj-HR = 1.01, 95% CI = 0.70 to 1.46), among all men. Interaction terms for diabetes and obesity were statistically significant in multivariable models for PCSM, CRPC, and metastases (P ≤ .04). In stratified analyses, in obese men, diabetes was associated with PCSM (adj-HR = 3.06, 95% CI = 1.40 to 6.69), CRPC (adj-HR = 2.14, 95% CI = 1.11 to 4.15), and metastases (adj-HR = 1.57, 95% CI = 0.88 to 2.78), though not statistically significant for metastases. In nonobese men, inverse associations were suggested for diabetes and prostate cancer outcomes without reaching statistical significance. Conclusions: Diabetes was associated with increased risks of prostate cancer progression and mortality among obese men but not among nonobese men, highlighting the importance of aggressively curtailing the increasing prevalence of obesity in prostate cancer survivors.

Safety of concomitant therapy with radium-223 and abiraterone or enzalutamide in a real-world population.

BACKGROUND: Real-world utilization and outcomes of combination therapy for men with metastatic castrate-resistant prostate cancer (mCRPC) are largely unknown. We evaluated the overall survival (OS) and skeletal-related events (SREs) among men who received radium-223 with or without concomitant abiraterone or enzalutamide in the Veterans Affairs (VA) Health System. METHODS: We reviewed charts of all mCRPC patients who received radium-223 in the VA from January 2013 to September 2017. We used Cox models to test the association between concomitant therapy versus radium-223 alone on OS and SRE. Sensitivity analyses were performed for concomitant use of denosumab/bisphosphonates. RESULTS: Three hundred and eighteen patients treated with radium-223 were identified; 116/318 (37%) received concomitant abiraterone/enzalutamide. Two hundred and seventy-seven (87%) patients died during follow-up. Patients who received concomitant therapy were younger at radium-223 initiation (median age 68 vs. 70, p = .027) and had a longer follow-up (median 29.5 vs. 17.9 months, p = .030). There was no OS benefit for those on concomitant therapy (hazard ratio [HR]: 0.87, 95% confidence interval [CI]: 0.67-1.12, p = .28). There was a trend for an increased SRE risk for patients on concomitant therapy (HR: 1.87, 95% CI: 0.96-3.61, p = .066), but this was not significant. When analyses were limited to men using bone heath agents, similar results were seen for OS (HR: 0.86, 95% CI 0.64-1.15, p = .30) and SRE (HR: 2.36, 95% CI: 0.94-5.94, p = .068). CONCLUSIONS: Despite the common use of concomitant therapy in this real-world study, there was no difference in OS among mCRPC patients. A nonsignificant increased SRE risk was observed. Further work needs to evaluate the optimal sequence, timing, and safety of combination therapies.