Survival Outcomes by Race and Ethnicity in Veterans With Nonmetastatic Castration-Resistant Prostate Cancer.

Importance: Racial and ethnic disparities in prostate cancer are poorly understood. A given disparity-related factor may affect outcomes differently at each point along the highly variable trajectory of the disease. Objective: To examine clinical outcomes by race and ethnicity in patients with nonmetastatic castration-resistant prostate cancer (nmCRPC) within the US Veterans Health Administration. Design, Setting, and Participants: A retrospective, observational cohort study using electronic health care records (January 1, 2006, to December 31, 2021) in a nationwide equal-access health care system was conducted. Mean (SD) follow-up time was 4.3 (3.3) years. Patients included in the analysis were diagnosed with prostate cancer from January 1, 2006, to December 30, 2020, that progressed to nmCRPC defined by (1) increasing prostate-specific antigen levels, (2) ongoing androgen deprivation, and (3) no evidence of metastatic disease. Patients with metastatic disease or death within the landmark period (3 months after the first nmCRPC evidence) were excluded. Main Outcomes and Measures: The primary outcome was time from the landmark period to death or metastasis; the secondary outcome was overall survival. A multivariate Cox proportional hazards model, Kaplan-Meier estimates, and adjusted survival curves were used to evaluate outcome differences by race and ethnicity. Results: Of 12 992 patients in the cohort, 826 patients identified as Hispanic (6%), 3671 as non-Hispanic Black (28%; henceforth Black), 7323 as non-Hispanic White (56%; henceforth White), and 1172 of other race and ethnicity (9%; henceforth other, including American Indian or Alaska Native, Asian, Native Hawaiian or Other Pacific Islander, unknown by patient, and patient declined to answer). Median time elapsed from nmCRPC to metastasis or death was 5.96 (95% CI, 5.58-6.34) years for Black patients, 5.62 (95% CI, 5.11-6.67) years for Hispanic patients, 4.11 (95% CI, 3.96-4.25) years for White patients, and 3.59 (95% CI, 3.23-3.97) years for other patients. Median unadjusted overall survival was 6.26 (95% CI, 6.03-6.46) years among all patients, 8.36 (95% CI, 8.0-8.8) years for Black patients, 8.56 (95% CI, 7.3-9.7) years for Hispanic patients, 5.48 (95% CI, 5.2-5.7) years for White patients, and 4.48 (95% CI, 4.1-5.0) years for other patients. Conclusions and Relevance: The findings of this cohort study of patients with nmCRPC suggest that differences in outcomes by race and ethnicity exist; in addition, Black and Hispanic men may have considerably improved outcomes when treated in an equal-access setting.

Biomarker-Directed Therapy in Black and White Men With Metastatic Castration-Resistant Prostate Cancer.

Importance: Black men have higher incidence and mortality from prostate cancer. Whether precision oncology disparities affect Black men with metastatic castration-resistant prostate cancer (mCRPC) is unknown. Objective: To compare precision medicine data and outcomes between Black and White men with mCRPC. Design, Setting, and Participants: This retrospective cohort study used data collected by the Prostate Cancer Precision Medicine Multi-Institutional Collaborative Effort (PROMISE) consortium, a multi-institutional registry with linked clinicogenomic data, from April 2020 to December 2021. Participants included Black and White patients with mCRPC with molecular data. Data were analyzed from December 2021 to May 2023. Exposures: Database-reported race and ethnicity. Main Outcomes and Measures: The primary outcome was the frequency of actionable molecular data, defined as the presence of mismatch repair deficiency (MMRD) or high microsatellite instability (MSI-H), homologous recombination repair deficiency, or tumor mutational burden of 10 mutations per megabase or greater. Secondary outcomes included the frequency of other alterations, the type and timing of genomic testing performed, and use of targeted therapy. Efficacy outcomes were prostate-specific antigen response rate, site-reported radiographic response, and overall survival. Results: A total of 962 eligible patients with mCRPC were identified, including 204 Black patients (21.2%; median [IQR] age at diagnosis, 61 [55-67] years; 131 patients [64.2%] with Gleason scores 8-10; 92 patients [45.1%] with de novo metastatic disease) and 758 White patients (78.8%; median [IQR] age, 63 [57-69] years; 445 patients [58.7%] with Gleason scores 8-10; 310 patients [40.9%] with de novo metastatic disease). Median (IQR) follow-up from mCRPC was 26.6 (14.2-44.7) months. Blood-based molecular testing was more common in Black men (111 men [48.7%]) than White men (317 men [36.4%]; P < .001). Rates of actionable alterations were similar between groups (65 Black men [32.8%]; 215 White men [29.1%]; P = .35), but MMRD or MSI-H was more common in Black men (18 men [9.1]) than White men (36 men [4.9%]; P = .04). PTEN alterations were less frequent in Black men than White men (31 men [15.7%] vs 194 men [26.3%]; P = .003), as were TMPRSS alterations (14 men [7.1%] vs 155 men [21.0%]; P < .001). No other differences were seen in the 15 most frequently altered genes, including TP53, AR, CDK12, RB1, and PIK3CA. Matched targeted therapy was given less frequently in Black men than White men (22 men [33.5%] vs 115 men [53.5%]; P = .008). There were no differences in response to targeted therapy or survival between the two cohorts. Conclusions and Relevance: This cohort study of men with mCRPC found higher frequency of MMRD or MSI-H and lower frequency of PTEN and TMPRSS alterations in Black men compared with White men. Although Black men received targeted therapy less frequently than White men, no differences were observed in clinical outcomes.

Comparison of circulating tumor DNA between African American and Caucasian patients with metastatic castrate-resistant prostate cancer post-abiraterone and/or enzalutamide.

BACKGROUND: African American men are much more likely than Caucasian men to be diagnosed with and to die of prostate cancer. Genetic differences likely play a role. The cBioPortal database reveals that African American men with prostate cancer have higher rates of CDK12 somatic mutations compared to Caucasian men. However, this does not account for prior prostate cancer treatments, which are particularly important in the castrate-resistant setting. We aimed to compare somatic mutations based on circulating tumor DNA (ctDNA) in metastatic castration-resistant prostate cancer (mCRPC) between African American and Caucasian men after exposure to abiraterone and/or enzalutamide. METHODS: This single-institution retrospective study characterizes the somatic mutations detected on ctDNA for African American and Caucasian men with mCRPC who had progressed after abiraterone and/or enzalutamide from 2015 through 2022. We evaluated the gene mutations and types of mutations in this mCRPC cohort. RESULTS: There were 50 African American and 200 Caucasian men with CRPC with available ctDNA data. African American men were younger at the time of diagnosis (p = 0.008) and development of castration resistance (p = 0.006). African American men were more likely than Caucasian men to have pathogenic/likely pathogenic (P/LP) mutations in CDK12 (12% vs. 1.5%; p = 0.003) and copy number amplifications and P/LP mutations in KIT (8.0% vs. 1.5%; p = 0.031). African American men were also significantly more likely to have frameshift mutations (28% vs. 14%; p = 0.035). CONCLUSIONS: Compared to Caucasian men, African American men with mCRPC after exposure to abiraterone and/or enzalutamide had a higher incidence of somatic CDK12 P/LP mutations and KIT amplifications and P/LP mutations based on ctDNA. African American men also had more frameshift mutations. We hypothesize that these findings have potential implications for tumor immunogenicity.

Overall and progression-free survival of Afro-Caribbean men with metastatic castration-resistant prostate cancer (mCRPC).

INTRODUCTION: Several studies in the Caucasian population have shown the benefit of using docetaxel, abiraterone, or enzalutamide for patients with metastatic prostate cancer at the castration-resistant stage (mCRPC). However, there are no strong data for men of African ancestry. The objective of this study was to estimate the overall and progression-free survival of patients according to these treatments at the mCRPC stage. PATIENTS AND METHODS: This was a monocentric retrospective study that consecutively included 211 men with mCRPC between June 1, 2009 and August 31, 2020. The primary end point was overall survival (OS). The secondary end point was progression-free survival. Kaplan-Meier survival and Cox proportional hazard analyses were performed. RESULTS: The present study included 180 patients for analyses. There was no difference in OS (log-rank test = 0.73), with a median follow-up of 20.7 months, regardless of the treatment administered in the first line. Men with mCRPC who received hormonotherapy (abiraterone or enzalutamide) showed better progression-free survival than those who received docetaxel (log-rank test = 0.004), with a particular interest for abiraterone hazard ratio (HR) = 0.51 (95% confidence interval: 0.39-0.67). The patient characteristics were similar, except for bone lesions, irrespective of the treatment administered in the first line. After univariate then multivariate analysis, only World Health Organization status and metastases at diagnosis were significantly associated with progression. CONCLUSION: Our results suggest the use of hormonotherapy (abiraterone or enzalutamide) with a tendency for abiraterone in first line for men with African ancestry at the mCRPC stage.

Race does not predict skeletal-related events and all-cause mortality in men with castration-resistant prostate cancer.

BACKGROUND: The impact of race on prostate cancer skeletal-related events (SREs) remains understudied. In the current study, the authors tested the impact of race on time to SREs and overall survival in men with newly diagnosed, bone metastatic castration-resistant prostate cancer (mCRPC). METHODS: The authors performed a retrospective study of patients from 8 Veterans Affairs hospitals who were newly diagnosed with bone mCRPC in the year 2000 or later. SREs comprised pathologic fracture, spinal cord compression, radiotherapy to the bone, or surgery to the bone. Time from diagnosis of bone mCRPC to SREs and overall mortality was estimated using the Kaplan-Meier method. Cox models tested the association between race and SREs and overall mortality. RESULTS: Of 837 patients with bone mCRPC, 232 patients (28%) were black and 605 (72%) were nonblack. At the time of diagnosis of bone mCRPC, black men were found to be more likely to have more bone metastases compared with nonblack men (29% vs 19% with ≥10 bone metastases; P = .021) and to have higher prostate-specific antigen (41.7 ng/mL vs 29.2 ng/mL; P = .005) and a longer time from the diagnosis of CRPC to metastasis (17.9 months vs 14.3 months; P < .01). On multivariable analysis, there were no differences noted with regard to SRE risk (hazard ratio [HR], 0.80; 95% CI, 0.59-1.07) or overall mortality (HR, 0.87; 95% CI, 0.73-1.04) between black and nonblack people, although the HRs were <1, which suggested the possibility of better outcomes. CONCLUSIONS: No significant association between black race and risk of SREs and overall mortality was observed in the current study. These data have suggested that efforts to understand the basis for the excess risk of aggressive prostate cancer in black men should focus on cancer development and progression in individuals with early-stage disease.

Prognostic value of the bone scan index in patients with metastatic castration-resistant prostate cancer: a systematic review and meta-analysis.

BACKGROUND: Many studies have reported the prognostic significance of the bone scan index (BSI) for metastatic castration-resistant prostate cancer (mCRPC); however, these reports are controversial. This study investigated the BSI in mCRPC and its relationship with prognosis. METHODS: The PubMed, Cochrane, and Embase databases were searched systematically for relevant articles published before September 1, 2019. Hazard ratios (HRs) were used to investigate the prognostic value. RESULTS: This study finally identified 9 eligible studies. The results suggested that high baseline BSI predicted poor OS (HR = 1.331, 95% CI: 1.081-1.640) and that elevated ΔBSI also predicted poor OS (HR = 1.220, 95% CI: 1.015-1.467). The subgroup analysis stratified by ethnicity showed that the baseline BSI and ΔBSI predicted poor OS in the Asian population but not in the Caucasian population. We also performed a subgroup analysis based on the different cut-off values of baseline BSI. The subgroup of ≤1 showed a significant association with OS in mCRPC patients. CONCLUSION: Our study demonstrated that high baseline BSI and elevated ΔBSI predicted poor OS in patients with mCRPC. Hence, the BSI can serve as a prognostic indicator for mCRPC patients and may therefore guide clinical treatment in the future.

Population Pharmacokinetics of Apalutamide and its Active Metabolite N-Desmethyl-Apalutamide in Healthy and Castration-Resistant Prostate Cancer Subjects.

BACKGROUND: Apalutamide is a next-generation androgen receptor inhibitor approved for treatment of subjects with high-risk, non-metastatic, castration-resistant prostate cancer (NM-CRPC). OBJECTIVE: The objective of this study was to characterize the population pharmacokinetics of apalutamide and its metabolite N-desmethyl-apalutamide in healthy male and castration-resistant prostate cancer subjects. METHODS: Plasma concentration data for apalutamide and N-desmethyl-apalutamide from 1092 subjects (seven clinical studies) receiving oral apalutamide (30-480 mg) once daily were pooled for a population pharmacokinetic analysis using a non-linear mixed-effect modelling approach. The impact of clinically relevant covariates was also assessed. RESULTS: Apalutamide absorption was rapid, and the apparent steady-state volume of distribution was large (276 L), reflecting a wide body distribution. Apalutamide was eliminated slowly, with its apparent clearance increasing from 1.31 L/h after the first dose to 2.04 L/h at steady state. No evidence of time-dependent disposition was observed for N-desmethyl-apalutamide, which was also widely distributed and slowly cleared (1.5 L/h). After 4 weeks of treatment, more than 95% of steady-state exposure of apalutamide and N-desmethyl-apalutamide was reached. At a dose of apalutamide 240 mg/day, apalutamide and N-desmethyl-apalutamide exposure exhibited 5.3- and 85.2-fold accumulation in plasma, respectively. Inter-individual variability in apalutamide apparent clearance is low (< 20%). Among the covariates evaluated, apalutamide and N-desmethyl-apalutamide exposure were statistically associated only with health status, body weight, and albumin concentration, and the effect was low (< 25%). CONCLUSIONS: A population pharmacokinetic modelling approach was successfully applied to describe the pharmacokinetics of apalutamide and N-desmethyl-apalutamide. No clinically relevant covariates were identified as predictors of apalutamide and N-desmethyl-apalutamide pharmacokinetics.

Does race predict the development of metastases in men who receive androgen-deprivation therapy for a biochemical recurrence after radical prostatectomy?

BACKGROUND: In this study among men who underwent radical prostatectomy (RP), African American men (AAM) were 28% more likely to develop recurrent disease compared with Caucasian men (CM). However, among those who had nonmetastatic, castration-resistant prostate cancer (CRPC), race did not predict metastases or overall survival. Whether race predicts metastases among men who receive androgen-deprivation therapy (ADT) after a biochemical recurrence (BCR) (ie, before CRPC but after BCR) is untested. METHODS: The authors identified 595 AAM and CM who received ADT for a BCR that developed after RP between 1988 and 2015 in the Shared Equal-Access Regional Cancer Hospital (SEARCH) database. Univariable and multivariable Cox models were used to test the association between race and the time from ADT to metastases. Secondary outcomes included the time to CRPC, all-cause mortality, and prostate cancer-specific mortality. RESULTS: During a median follow-up of 66 months after ADT, 62 of 354 CM (18%) and 38 of 241 AAM (16%) developed metastases. AAM were younger at the time they received ADT (63 vs 67 years; P < .001), had received ADT in a more recent year (2008 vs 2006; P < .001), had higher prostate-specific antigen levels at RP (11.1 vs 9.2 ng/mL; P < .001), lower pathologic Gleason scores (P = .004), and less extracapsular extension (38% vs 48%; P = .022). On multivariable analysis, there was no association between race and metastases (hazard radio, 1.20; P = .45) or any of the other secondary outcomes (all P > .5). CONCLUSIONS: Among veterans who received ADT post-BCR after RP, race was not a predictor of metastases or other adverse outcomes. The current findings suggest that research efforts to understand racial differences in prostate cancer biology should focus on early stages of the disease (ie, closer to the time of diagnosis).

Overall Survival of Black and White Men With Metastatic Castration-Resistant Prostate Cancer Treated With Docetaxel.

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.

In Men with Castration-Resistant Prostate Cancer, Visceral Metastases Predict Shorter Overall Survival: What Predicts Visceral Metastases? Results from the SEARCH Database.

BACKGROUND: Although visceral metastases (VMs) are widely recognized to portend worse prognoses compared with bone and lymph metastases in men with metastatic castration-resistant prostate cancer (mCRPC), little is known about what predicts VMs and the extent to which men with VMs do worse. OBJECTIVE: To determine whether men with VMs at initial mCRPC diagnosis have worse overall survival (OS) and identify predictors of VMs. DESIGN, SETTING, AND PARTICIPANTS: We analyzed 494 men diagnosed with castration-resistant prostate cancer post-1999 and no known metastases from five Veterans Affairs hospitals of the Shared Equal Access Regional Cancer Hospital (SEARCH) database who later developed metastases. Radiology scans within 30 d of initial metastasis diagnosis were reviewed to collect information on bone, visceral, and lymph node metastases. We analyzed the 236 men who had a computed tomography scan performed. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Predictors of VMs and OS were evaluated using logistic regression and Cox models, respectively. RESULTS AND LIMITATIONS: Of the 236 mCRPC patients, 38 (16%) had VMs. Regarding VMs, 19 patients (50%), 8 patients (21%), and 16 patients (42%) had metastases in the liver, lungs, and other locations, respectively. VMs were a predictor of OS on crude analysis (hazard ratio [HR]: 1.88; 95% confidence interval [CI], 1.30-2.72; p=0.001) and after risk adjustment (HR: 1.84; 95% CI, 1.24-2.72; p=0.002). Age, year, treatment center, prostate-specific antigen (PSA), and time from CRPC to metastases were significant in predicting OS (all p<0.05). None of the variables tested were associated with having VMs (all p > 0.09). Prospective studies and larger cohorts are needed to validate our findings. CONCLUSIONS: Demographic, tumor, and PSA kinetic characteristics were not predictive of having VMs, but VMs predicted worse OS. PATIENT SUMMARY: Because patients with VMs have worse overall survival, further research is needed to develop better biomarkers and thus diagnose those with VMs at earlier stages in their disease course.

68Ga-PSMA-11 PET/CT for prostate cancer staging and risk stratification in Chinese patients.

We evaluated the clinical utility of 68Ga-PSMA-11 PET/CT for staging and risk stratification of treatment-naïve prostate cancer (PCa) and metastatic castrate-resistant prostate cancer (mCRPC). Twenty-two consecutive patients with treatment-naïve PCa and 18 with mCRPC were enrolled. 68Ga-PSMA-11 PET/CT and magnetic resonance imaging (MRI) were performed for the evaluation of primary prostatic lesions, and bone scans were used for evaluation bone metastasis. Among the 40 patients, 37 (92.5% [22 treatment-naïve PCa, 15 mCRPC]) showed PSMA-avid lesions on 68Ga-PSMA-11 images. Only 3 patients with stable mCRPC after chemotherapy were negative for PSMA. The sensitivity, specificity and accuracy of 68Ga-PSMA-11 imaging were 97.3%, 100.0% and 97.5%, respectively. The maximum standardized uptake (SUVmax) of prostatic lesions was 17.09 ± 11.08 and 13.33 ± 12.31 in treatment-naïve PCa and mCRPC, respectively. 68Ga-PSMA-11 revealed 105 metastatic lymph nodes in 15 patients; the SUVmax was 16.85 ± 9.70 and 7.54 ± 5.20 in treatment-naïve PCa and mCRPC, respectively. 68Ga-PSMA-11 PET/CT also newly detected visceral metastasis in 9 patients (22.5%) and bone metastasis in 29 patients (72.5%). 68Ga-PSMA-11 PET/CT exhibits potential for staging and risk stratification in naïve PCa, as well as improved sensitivity for detection of lymph node and remote metastasis.

Prostate-specific antigen response in black and white patients treated with abiraterone acetate for metastatic castrate-resistant prostate cancer.

PURPOSE: Evidence suggests differences in androgen receptor AR signaling between black (B) and white (W) patients with prostate cancer, but pivotal trials of abiraterone acetate (AA) for patients with metastatic castration-resistant prostate cancer (mCRPC) enrolled few black patients, a population with a higher mortality from prostate cancer. Our primary objective was to determine differences in response to AA between B and W patients. METHODS: We performed a retrospective case-control study of B vs. W patients treated with AA between May 1, 2008 and June 16, 2015 at Duke University Medical Center. Patients were identified (W control patients were matched 2:1 to B patients stratified based on previous docetaxel exposure) through pharmacy records and were eligible if treated with AA for metastatic castration-resistant prostate cancer. Patients with previous enzalutamide use were excluded. The primary objective was to compare the rate of≥90% prostate-specific antigen (PSA) decline from baseline between B vs. W patients. Secondary outcomes included comparing time on therapy, time to PSA progression, and overall survival among groups. RESULTS: Baseline characteristics among patients (n = 45 B, n = 90 W) were identified; these included Karnofsky performance status, PSA, Gleason score, alkaline phosphatase, albumin, hemoglobin, lactate dehydrogenase, opiate use for pain, and metastatic sites. Baseline characteristics among groups were similar except for median hemoglobin (B = 11.4g/dl, W = 12.3g/dl). The proportion of B patients achieving a≥90% PSA level decline was 37.8% vs. 28.9% for W patients (P = 0.296). Statistically significant differences were found in the proportion of patients achieving a≥50% PSA level decline (B = 68.9%, W = 48.9% [P = 0.028]) and≥30% PSA level decline (B = 77.8%, W = 54.4% [P = 0.008]). Rates of primary abiraterone-refractory disease (PSA increase as best response) trended higher in W (31.1%) than in B (15.6%) patients (P = 0.052). Median treatment duration (B = 9.4 mo, W = 8.3 mo) did not differ (Wilcoxon P = 0.444). Median overall survival (B = 27.3 mo [95% CI: 13.9, not estimable], W = 24.8 mo [95% CI: 19, 31.6] [P = 0.669]) and median time to PSA progression (B = 11.0 mo [95% CI: 4.3, 18.0], W = 9.4 mo [95% CI: 6.2, 13.0] [P = 0.917]) did not differ. CONCLUSIONS: Black patients may have a higher PSA response to AA than white patients. An ongoing prospective clinical study (NCT01940276) is evaluating outcomes between black and white patients treated with AA.

Phase II Trial of Abiraterone Acetate Plus Prednisone in Black Men With Metastatic Prostate Cancer.

LESSONS LEARNED: The safety and activity findings of abiraterone acetate plus prednisone treatment in black men with mCRPC were similar to results from previously conducted studies with largely white populations.Poor trial accrual continues to be a challenge in black men with mCRPC and further efforts are needed to address such underrepresentation. BACKGROUND: Self-identified black men have higher incidence and mortality from prostate cancer in the United States compared with white men but are dramatically underrepresented in clinical trials exploring novel therapies for metastatic castration-resistant prostate cancer (mCRPC). METHODS: Black men with mCRPC were treated with abiraterone acetate (AA), 1,000 mg daily, and prednisone (P), 5 mg twice daily. The primary objective was to determine antitumor activity (defined by a ≥30% decline in prostate-specific antigen [PSA] level) and to correlate germline polymorphisms in androgen metabolism genes with antitumor activity. Secondary objectives included determining safety, post-treatment changes in measurable disease, and time to disease progression. RESULTS: From April 2013 to March 2016, a total of 11 black men were enrolled and received AA plus P (AA+P); 7 of 10 evaluable patients were docetaxel naive. Post-treatment declines in PSA level of ≥30% were achieved in 90% of patients. The side effect profile was consistent with prior clinical trials exploring AA+P in mCRPC. Due to poor accrual, the study was closed prematurely with insufficient sample size for the planned pharmacogenetic analyses. CONCLUSION: In this small prospective study terminated for poor accrual, the safety and activity of AA+P in black men with mCRPC was similar to that reported in prior studies exploring AA in largely white populations. Further efforts are needed to address underrepresentation of black men in mCRPC trials.

Radium-223 in Heavily Pretreated Metastatic Castrate-Resistant Prostate Cancer.

BACKGROUND: Radium-223 is a bone-targeting radiopharmaceutical that extends survival in mCRPC. Postapproval data are limited, and the value of biochemical and radiologic monitoring during radium therapy is unknown. PATIENTS AND METHODS: We conducted a retrospective study of 29 patients with mCRPC who received radium-223 at 1 of 3 participating institutions between August 2013 and December 2014. Trend of PSA, radiographic changes, and association of biochemical and clinical variables with PSA trend were measured. RESULTS: The median age of patients was 70 years, 79% of patients (N = 23) were European Americans, and 17% of patients (N = 5) were African Americans. Twenty patients (69%) had received at least 3 lines of prior therapies. Some 38% of patients (N = 11) received all 6 cycles of radium-223. Twenty patients (69%) had an increase in PSA during radium therapy, and 4 patients (14%) had a decline in PSA levels. Five patients had visceral metastases on computed tomography imaging performed during the course of radium-223. CONCLUSIONS: Radium therapy in mCRPC was associated with an increase in PSA in the majority of these heavily pretreated patients. The development of visceral disease was not uncommon, suggesting a need for follow-up computed tomography monitoring during radium-223 therapy. The significance of early increases in PSA and pain with radium-223 is still uncertain. Although pain and PSA flare have been reported in patients who subsequently have a dramatic response to therapy, we observed that a PSA increase or pain flare correlates to an improvement in bone scans only in a minority of patients.

Experience with androgen deprivation therapy for prostate cancer in Japan and future perspectives.

Novel anti-androgens and androgen biosynthesis inhibitors have been developed to treat castration-resistant prostate cancer. However, knowledge of androgen deprivation therapy (ADT) has not been developed in the criticism, including information regarding the adverse effects of hormonal therapy. We hypothesize that there are ethnic differences in the efficacy and adverse effects of ADT; therefore, this review summarizes the experience of ADT, mainly in Japan. A risk stratification instrument, the Japan Cancer of the Prostate Risk Assessment (J-CAPRA) score, was developed based on the Japan Study Group of Prostate Cancer registry, which is a large, multicenter, population-based database. It revealed that clinical outcomes were substantially better for males treated with ADT in Japan compared with those in the United States. Moreover, there were small survival differences in patients with localized and locally advanced cancer who received local therapy and primary ADT in another Japanese cohort study. In terms of adverse effects, including bone loss and cardiovascular risk, ADT appears to be better tolerated in Japanese populations than in Western cohorts. An ongoing randomized controlled trial of a trimodality treatment comprising brachytherapy, external beam radiation therapy, and neoadjuvant with or without adjuvant ADT in patients with localized high-risk prostate cancer will provide novel insights regarding adjuvant ADT. As a future perspective, the optimal selection of the type of primary ADT, including combining androgen blockade and novel hormonal compounds, adjusted according to each patient's clinicopathological background, may provide better clinical outcomes in patients with advanced prostate cancer.

Effectiveness and safety of cabazitaxel plus prednisolone chemotherapy for metastatic castration-resistant prostatic carcinoma: data on Korean patients obtained by the cabazitaxel compassionate-use program.

PURPOSE: To report the efficacy and safety of using cabazitaxel plus prednisolone chemotherapy to treat Korean patients with metastatic castration-resistant prostate cancer (mCRPC) following docetaxel therapy. METHODS: This cohort study enrolled 26 mCRPC patients. Treatment consisted of 25 mg/m(2) cabazitaxel that was intravenously administered every 3 weeks, in addition to twice-daily 5 mg prednisolone. RESULTS: The median patient age was 67 years (range = 53-82), median Eastern Cooperative Oncology Group performance status was 1 (range = 0-2), Gleason score was ≥ 8 in 25 patients (96 %), and median serum prostate-specific antigen (PSA) was 95.3 ng/mL (interquartile range = 9.1-297.7). A total of 180 treatment cycles were administered, and a median of five cycles were administered per patient (range = 1-23). A PSA response was observed in 32 % of evaluable patients. Tumor response was evaluated in eight patients, and three and four patients achieved partial response and stable disease, respectively. Over a median follow-up duration of 23.4 months (95 % CI 11.1-35.6), median time to treatment failure was 4.2 months (95 % CI 1.8-6.6) and median time to progression was 8.5 months (95 % CI 3.0-13.1). Median overall survival was 16.5 months (95 % CI 12.1-20.9). Grade 3 or worse febrile neutropenia developed in eight patients (31 %) and neutropenic infection in four patients (15 %). CONCLUSION: Cabazitaxel plus prednisolone chemotherapy can be used to treat Korean mCRPC patients. Prophylactic growth factor support should be considered for patients at high risk of neutropenic fever or infection.