3D-printed soft-tissue physical models of renal malignancies for individualized surgical simulation: a feasibility study

To construct patient-specific physical three-dimensional (3D) models of renal units with materials that approximates the properties of renal tissue to allow pre-operative and robotic training surgical simulation, 3D physical kidney models were created (3DSystems, Rock Hill, SC) using computerized tomography to segment structures of interest (parenchyma, vasculature, collection system, and tumor). Images were converted to a 3D surface mesh file for fabrication using a multi-jet 3D printer. A novel construction technique was employed to approximate normal renal tissue texture, printers selectively deposited photopolymer material forming the outer shell of the kidney, and subsequently, an agarose gel solution was injected into the inner cavity recreating the spongier renal parenchyma. We constructed seven models of renal units with suspected malignancies. Partial nephrectomy and renorrhaphy were performed on each of the replicas. Subsequently all patients successfully underwent robotic partial nephrectomy. Average tumor diameter was 4.4 cm, warm ischemia time was 25 min, RENAL nephrometry score was 7.4, and surgical margins were negative. A comparison was made between the seven cases and the Tulane Urology prospectively maintained robotic partial nephrectomy database. Patients with surgical models had larger tumors, higher nephrometry score, longer warm ischemic time, fewer positive surgical margins, shorter hospitalization, and fewer post-operative complications; however, the only significant finding was lower estimated blood loss (186 cc vs 236; p = 0.01). In this feasibility study, pre-operative resectable physical 3D models can be constructed and used as patient-specific surgical simulation tools; further study will need to demonstrate if this results in improvement of surgical outcomes and robotic simulation education.

A Whole Blood Assay for AR-V7 and ARv567es in Patients with Prostate Cancer

PURPOSE

Most prostate cancer mortality can be attributed to metastatic castration resistant prostate cancer, an advanced stage that remains incurable despite recent advances. The AR (androgen receptor) signaling axis remains active in castration resistant prostate cancer. Recent studies suggest that expression of the AR-V (AR splice variant) AR-V7 may underlie resistance to abiraterone and enzalutamide. However, controversy exists over the optimal assay. Our objective was to develop a fast and sensitive assay for AR-Vs in patients.

MATERIALS AND METHODS

Two approaches were assessed in this study. The first approach was based on depletion of leukocytes and the second one used RNA purified directly from whole blood preserved in PAXgene® tubes. Transcript expression was analyzed by quantitative reverse transcription-polymerase chain reaction.

RESULTS

Through a side-by-side comparison we found that the whole blood approach was suitable to detect AR-Vs. The specificity of the assay was corroborated in a cancer-free cohort. Using the PAXgene assay samples from a cohort of 46 patients with castration resistant prostate cancer were analyzed. Overall, AR-V7 and ARv567es were detected in 67.53% and 29.87% of samples, respectively. Statistical analysis revealed a strong association of AR-V positivity with a history of second line hormonal therapies.

CONCLUSIONS

To our knowledge this is the first study to demonstrate that PAXgene preserved whole blood can be used to obtain clinically relevant information regarding the expression of 2 AR-Vs. These data on a castration resistant prostate cancer cohort support a role for AR-Vs in resistance to therapies targeting the AR ligand-binding domain.

Active surveillance of prostate cancer in African American men

Active surveillance (AS) is a treatment strategy for prostate cancer (PCa) whereby patients diagnosed with PCa undergo ongoing characterization of their disease with the intent of avoiding radical treatment. Previously, AS has been demonstrated to be a reasonable option for men with low-risk PCa, but existing cohorts largely consist of Caucasian Americans. Because African Americans have a greater incidence, more aggressive, and potentially more lethal PCa than Caucasian Americans, it is unclear if AS is appropriate for African Americans. We performed a review of the available literature on AS with a focus on African Americans.

Clinical Use of PCA3 and TMPRSS2:ERG Urinary Biomarkers in African-American Men Undergoing Prostate Biopsy

PURPOSE

Prostate specific antigen has decreased performance characteristics for the detection of prostate cancer in African-American men. We evaluated urinary PCA3 and TMPRSS2:ERG in a racially diverse group of men.

MATERIALS AND METHODS

After institutional review board approval, post-examination urine was prospectively collected before prostate biopsy. PCA3 and TMPRSS2:ERG RNA copies were quantified using transcription mediated amplification assays (Hologic, San Diego, California). Prediction models were created using standard of care variables (age, race, family history, prior biopsy, abnormal digital rectal examination) plus prostate specific antigen. Decision curve analysis was performed to compare the net benefit of PCA3 and TMPRSS2:ERG.

RESULTS

Of 304 patients 182 (60%) were African-American and 139 (46%) were diagnosed with prostate cancer (69% African-American). PCA3 and TMPRSS2:ERG scores were greater in men with prostate cancer, 3 or more cores, 33.3% or more cores, greater than 50% involvement of greatest biopsy core and Epstein significant prostate cancer (p <0.01). PCA3 added to the standard of care plus prostate specific antigen model for the detection of any prostate cancer in the overall cohort (0.747 vs 0.677, p <0.0001) in African-American men only (0.711 vs 0.638, p=0.0002) and nonAfrican-American men (0.781 vs 0.732, p=0.0016). PCA3 added to the model for the prediction of high grade prostate cancer for the overall cohort (0.804 vs 0.78, p=0.0002) and African-American men only (0.759 vs 0.717, p=0.0003) but not nonAfrican-American men. Decision curve analysis demonstrated improvement with the addition of PCA3. For African-American men TMPRSS2:ERG did not improve concordance statistics for the detection of prostate cancer.

CONCLUSIONS

For African-American men urinary PCA3 improves the ability to predict the presence of any and high grade prostate cancer. However, the TMPRSS2:ERG urinary assay does not add significantly to standard tools.

Clinical Characteristics and Outcomes Based on Race of Hospitalized Patients With COVID-19 in a New Orleans Cohort

Background

In Louisiana, deaths related to COVID-19 have disproportionately occurred in Black persons. Granular data are needed to better understand inequities and develop prevention strategies to mitigate further impact on Black communities.

Methods

We conducted a retrospective study of patients admitted to an urban safety net hospital in New Orleans, Louisiana, with reactive SARS-CoV-2 testing from March 9 to 31, 2020. Clinical characteristics of Black and other racial/ethnic group patients were compared using Wilcoxon rank-sum test and Fisher exact tests. The relationship between race and outcome was assessed using day 14 status on an ordinal scale.

Results

This study included 249 patients. The median age was 59, 44% were male, and 86% were age ≥65 years or had ≥1 comorbidity. Overall, 87% were Black, relative to 55% Black patients typically hospitalized at our center. Black patients had longer symptom duration at presentation (6.41 vs 5.88 days; P = .05) and were more likely to have asthma (P = .008) but less likely to have dementia (P = .002). There were no racial differences in initial respiratory status or laboratory values except for higher lactate dehydrogenase in Black patients. Patient age and initial oxygen requirement, but not race (adjusted proportional odds ratio, 0.92; 95% CI, 0.70–1.20), were associated with worse day 14 outcomes.

Conclusions

Our results demonstrate minor racial differences in comorbidities or disease severity at presentation, and day 14 outcomes were not different between groups. However, Black patients were disproportionately represented in hospitalizations, suggesting that prevention efforts should include strategies to limit SARS-CoV-2 exposures and transmission in Black communities as one step toward reducing COVID-19-related racial inequities.

Prospective Observational Study of a Racially Diverse Group of Men on Active Surveillance for Prostate Cancer

OBJECTIVE

To evaluate the risk upgrading of active surveillance (AS), we reviewed the outcomes of African American men (AA) after electing AS. AS is the standard of care for men with low-grade prostate cancer (PCa). AA are known to have more advanced PCa features and are more likely to die from PCa, thus subsequent disease progression for AA on AS is unclear.

METHODS

A prospectively maintained AS database from the Southeast Louisiana Veterans Administration Medical Center, New Orleans, Lousiana was queried. We identified men with low- and very low-risk PCa (Gleason 3 + 3, PSA <10, ≤CT2a) who had undergone at least 2 prostate biopsies, including initial diagnostic and subsequent confirmatory prostate biopsies. Descriptive and comparative statistical analysis was performed using R version 3.5.1.

RESULTS

From a total of 274 men on AS (70% AA), 158 men met inclusion criteria (104 AA [66%]). All patients underwent at least 2 biopsies, and 29% underwent 3 or more biopsies. The median follow-up was 2.7 years. At 3 years on AS protocol, 57% AA and 61% Caucasians demonstrated no evidence of upgrading or treatment. No significant difference was observed between upgrading or progression to treatment when comparing racial groups. Seven (4%) patients in this cohort died from non PCa-specific causes, but no patients demonstrated metastasis or death from PCa over the course of study.

CONCLUSION

AA men with low-risk PCa can be safely followed with the same AS protocol as non-AA men. Further analysis with longer follow up is ongoing.

Magnetic resonance imaging radiomic features for recurrent prostate cancer following proton radiation therapy-A pilot study

OBJECTIVE

The role of multiparametric MRI (mp-MRI) for postproton radiation evaluation is unclear. In this pilot study, we characterize the mp-MRI features using the Prostate Imaging-Reporting and Data System (PI-RADS) for recurrent prostate cancer (PCa) following proton radiation therapy.

METHODS

After obtaining IRB approval, we identified 163 consecutive cases who underwent MRI-fusion prostate biopsy at our institution from November 2017 to May 2020. This study evaluated patients with prostate cancer (PCa) with biochemical recurrence following proton radiation. Patients were excluded if they had grossly metastatic disease, metal fragments, implanted devices, or with surgically removed prostates. The mpMRI studies were reviewed in depth and scored by 2 fellowship-trained radiologists. Following MRI-fusion biopsy of lesions of interest (LOI), slides were read by fellowship-trained pathologists.

RESULTS

We found 14 patients with 16 lesions who met the study inclusion criteria. The median age was 69 years (range 57-79) and median time to biochemical recurrence was 7.3 years (range 3-13). On post-treatment imaging, decreases in prostate size and diffusely decreased T2 signal intensity were observed, making the use of apparent diffusion coefficient (ADC) and early enhancement at dynamic contrast enhanced (DCE) imaging often necessary for diagnosis of disease recurrence. We identified a total of 16 lesions with PIRADS scores of 3 or higher. Of these lesions, there were 5 PIRADS 3 lesions (4/5 (80%) without prostate cancer), 7 PIRADS 4-5 lesions (6 (86%) had high risk Pca), and 4 lesions with unassigned PIRADS scores (100% had high risk cancers). Among the MRI variables, diffusion weighted imaging (DWI) heterogeneity had the strongest association with recurrence of PCa (P < 0.001).

CONCLUSIONS

Results of our pilot study showed that the PIRADS scoring system in the postproton radiation therapy setting has some correlations with prostate cancer recurrence; However, the clinical value of these findings are unclear. While definitive PIRADS categorization of lesions demonstrated expected frequency of cancer consistent with the scoring system, all unassigned lesions also harbored malignancy suggesting a cautious approach to PIRADS scoring system in postproton radiation setting. The findings from this study may be validated using a larger cohort.

Racial variation in prostate needle biopsy templates directed anterior to the peripheral zone

OBJECTIVES

African Americans (AA) have been reported to have both increased incidence and increased aggressiveness of prostate cancer (PCa) located anterior to the peripheral zone (APZ). We sought to evaluate the utility of prostate biopsies directed toward the APZ in a predominantly AA cohort.

METHODS AND MATERIALS

We reviewed all patients with PCa found on biopsy schema that included needle biopsies directed at both the peripheral zone (PZ) and APZ from 2010 to 2014. Self-identified race was recorded for all patients. To evaluate the reliability of APZ-directed prostate biopsies, we performed pathologic secondary review of 25 radical prostatectomy specimens. A series of the Mann-Whitney U and Chi-square tests were used to compare variables.

RESULTS

We identified 398 men, of which 277 (70%) were AA. Compared with non-AA, AA had more National Comprehensive Cancer Network-defined intermediate or high-risk (50% vs. 39%, P = 0.25) PCa. Most patients had PCa limited to the PZ only (n = 190) or in both the PZ and APZ (n = 191). For 17 patients (4%), PCa was limited only to the APZ core(s), 14 (5%) AA vs. 3 (2%) non-AA (P = 0.24). Most of these 17 patients (n = 14, 82%) had Gleason 6 disease. Patients with PCa in both the PZ and APZ had higher serum prostate-specific antigen, prostate-specific antigen density, volume of disease, and increased grade and National Comprehensive Cancer Network category (all P<0.01). Of these patients, there were no differences in race (AA = 135, 71% vs. non-AA = 56, 29%; P = 0.48). In only 21 men (11%), without racial variation, APZ tumor grade was greater than PZ. Radical prostatectomy and APZ-directed biopsies demonstrated a concordance rate of 80% (20/25), false positive rate of 8% (2/25), and false negative rate of 12% (3/25).

CONCLUSIONS

APZ-directed prostate biopsies are rarely the sole location of PCa and do not show a clear racial predilection. In those men with PCa identified in both regions, the APZ biopsy did not frequently change treatment recommendations. Biopsies directed at the APZ are not of greater benefit to AA than non-AA.

Characterization of abiraterone responses in African American castrate-resistant prostate cancer

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Background: African American (AA) men have a higher incidence and mortality from prostate cancer (PCa) compared to other racial groups. Abiraterone acetate (Abi) is approved for treatment of mCRPC. While some AA patients were included in Abi trials, the majority of patients have been Caucasian (CA). To date, there have been no reports of Abi responses exclusively in AA men. This study evaluated Abi responses in AA men with mCRPC. Methods: PSA values during Abi treatment as well as baseline hemoglobin (Hgb), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) were tabulated. Prior therapy with docetaxel (Doc) or enzalutamide (Enza) was recorded. PSA response, progression and duration were assessed and compared between racial groups. PSA response, duration of response, and progression were defined by PCWG2 criteria. PSA half-life (PSAHL) based on time to nadir was calculated to assess rate of PSA decline. Results: A total of 74 Abi patients with mCRPC (n = 20 AA; n = 54 CA) were assessed from a single institution. Median AA baseline Hgb, ALP, LDH, and PSA were 11.8 (r = 6.4-15.4), 220 (r = 88-713), 209 (r = 157-401), and 48.41 (r = 4.8-1460) respectively. Median CA baseline Hgb, ALP, LDH, and PSA were 12.35 (r = 7.6-15), 165.5 (r = 70-1699), 218 (r = 133-528), and 44.84 (r = 1.71-2890) respectively. There were no significant differences in baseline labs between AA and CA. Prior use of Doc or Enza was 30% and 5% for AA; 31% and 4% for CA. PSA response was not significant for PSA decline of >30% (>30%: AA = 40%; CA = 44%), >50% (>50%: AA = 35%; CA = 30%), or >90% (>90%: AA = 20%; CA = 9%). In addition, no significant differences between the time to nadir (AA median = 209 days; CA median = 218 days), rate of PSA decline (AA PSAHL median = 72.4 days; CA PSAHL median = 80.1 days), or time to progression was observed. The median treatment length was 278 days and median time to progression was 66 days for AA men; 264 days and 88 days for CA men. Conclusions: Abi response rates, duration of response, and time to progression were not statistically different in AA men compared to CA men in patients with mCRPC. Larger studies are needed to fully evaluate this observation.

Racial Variation in the Outcome of Subsequent Prostate Biopsies in Men With an Initial Diagnosis of Atypical Small Acinar Proliferation

BACKGROUND

African American (AA) men are known to have more aggressive prostate cancer (PCa) compared with Caucasian American men. We sought to determine predictors of subsequent detection and risk stratification of PCa in a racially diverse group of men with atypical small acinar proliferation (ASAP) on initial prostate biopsy.

MATERIALS AND METHODS

A retrospective analysis was conducted on data from men with ASAP on initial prostate biopsy who subsequently received confirmatory biopsies between September 2000 and July 2015. Biopsies with more than 3 years between initial and confirmatory biopsies were excluded. Race, age, body mass index, transrectal ultrasound volume, serum prostate-specific antigen (PSA), PSA velocity, PSA density, and elapsed time between biopsies were assessed for predictive value in subsequent PCa diagnosis after an initial finding of ASAP.

RESULTS

Of 106 men analyzed, 75 (71%) were AA and 31 (29%) were non-AA. Baseline variables revealed AA men had higher PSA levels, PSA velocity, and PSA density (all P < .05). PCa was diagnosed in subsequent biopsy in 42 (40%) patients without significant racial variation; 30 (40%) AA versus 12 (39%) non-AA. Of the 42 PCa patients, 25 (24%) met Epstein criteria for significant disease without racial variation; 18 (24%) AA versus 7 (23%) non-AA. Only 10 (9%) patients had any component of Gleason 4; 7 (9%) AA versus 3 (10%) non-AA. In multivariate analysis, increasing age, PSA level, and PSA density were significant predictors of PCa.

CONCLUSION

AA men diagnosed with ASAP on initial prostate biopsy do not have increased risk of PCa on confirmatory biopsy compared with non-AA men.

Clinical performance of PCA3 and TMPRSS2:ERG urinary biomarkers for African American men undergoing prostate biopsy

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Background: Urinary assaysfor PCA3 and TMPRSS2:ERG (T2:ERG) fusion are established biomarkers for the detection of prostate cancer (PCa). However few African Americans (AA) have been included in previous studies. We sought to determine the performance characteristics of these assays in a racially diverse group of men who elected to undergo prostate biopsy. Methods: Following IRB approval, from 12/2013-10/2014, post digital rectal exam urine was collected in 152 patients without a diagnosis of PCa, prior to biopsy. PCA3 and T2:ERG RNA copies were quantified using transcription-mediated amplification assays and normalized to PSA mRNA copies. Results: Of the 152 patients who met study inclusion, 93 (61%) were AA, 59 were non-AA (39%); 72(47%) were diagnosed with PCa (55% AA, 36% non-AA). Both PCA3 and T2:ERG scores were greater in men with biopsy-proven PCa, those with ≥3 PCa cores, ≥33.3% PCa cores, >50% PCa involvement of greatest biopsy core and Epstein significant PCa (all p-values ≤ 0.02). PCA3 but not T2:ERG scores were greater in men with Gleason grade ≥7 (p = 0.0003). ROC analyses for prediction of biopsy outcome resulted in AUCs of 0.7, 0.61 and 0.59 for PCA3, T2:ERG and serum PSA. For the subgroup of AA, PCA3 and T2:ERG scores were greater in men with biopsy-proven PCa, those with ≥3 PCa cores, ≥33.3% PCa cores, >50% PCa involvement of greatest biopsy core and Epstein significant PCa (all p-values ≤0.01). Both PCA3 and T2:ERG scores were greater in men with Gleason grade ≥7 (p ≤ 0.03). ROC analyses for prediction of biopsy outcome for AA only resulted in AUCs of 0.66, 0.66 and 0.58 for PCA3, T2:ERG and serum PSA. For the non-AA cohort, PCA3 scores were greater in men with biopsy-proven PCa, those with ≥3 PCa cores, ≥33.3% PCa cores, >50% PCa involvement of greatest biopsy core, Epstein significant PCa and Gleason grade ≥7 (all p-values ≤ 0.03). T2:ERG did not reach significance for any of these variables. In this subgroup, ROC analyses for prediction of biopsy outcome resulted in AUCs of 0.73, 0.54 and 0.56 for PCA3, T2:ERG and serum PSA. Conclusions: In AA men undergoing prostate biopsy, both PCA3 and T2:ERG urinary assays demonstrate clinical utility in predicting biopsy outcome and PCa disease characteristics.

Early assessment of PSA response in patients with mCRPC treated with enzalutamide and abiraterone

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Background: Abiraterone (Abi) and enzaleutamide (Enza) are first-line agents for the treatment of metastatic castrate-resistant prostate cancer (mCRPC). Primary resistance is well-documented, but little data exists for rapid treatment responders. This study intended to further characterize patients with early prostate-specific antigen (PSA) decline. Methods: A single-institution retrospective review was performed on 123 mCRPC patients treated with Abi and/or Enza. PSA was recorded every 4 weeks for the duration of treatment. The primary endpoint was to describe PSA response, including sensitivities and specificities, as a predictor of later treatment response (defined as ≥50% decrease in PSA from baseline). Additional clinical covariates were also evaluated as treatment-response predictors. Results: A PSA response to Abi was achieved in 52/123 (42%) of patients. Median time to PSA nadir was 37 days. 30/52 (58%) patients responded to the drug within 4 weeks. Median length of time on drug was 110 days. A PSA response to Enza was achieved in 21/123 (17%) of patients. Median time to PSA nadir was 140 days. 18/21 (86%) of patients responded to the drug within 4 weeks. Median length of time on drug was 161 days. Conclusions: Percentage of PSA decline and time to drug response for Enza and Abi are important variables that can serve as reliable way for clinicians to predict long-term PSA response. It is vital to make appropriate treatment modifications for patients that do not display early PSA response. [Table: see text]

Evaluating abiraterone responses in African Americans with metastatic CRPC

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Background: A disparity between African American (AA) and other racial groups is documented in prostate cancer incidence and mortality. For metastatic CRPC, abiraterone (Abi) showed improvement in overall survival and gained FDA approval. However, Phase III trials enrolled mostly Caucasian (CA) patients. Documentation of Abi response rates in AA men is scant. Further characterization of Abi responses in AA men was the objective of this study. Methods: Age at diagnosis, prior enzalutamide (Enza) and/or docetaxel (Doc), and duration of Abi treatment were assessed. Baseline values at Abi initiation for alkaline phosphatase (ALP), hemoglobin (Hgb), and lactate dehydrogenase (LDH) were recorded. PSA values at baseline and throughout treatment were also logged. The velocity of PSA decline was determined by the PSA half-life (PSAHL) based on time to nadir. PCWG2 criteria were used to define PSA response and progression. Results: This was a single institution, retrospective cohort of 103 patients with mCRPC treated with Abi (n = 24 AA; n = 79 CA). Median age at diagnosis was 61.8 years and 62.4 years for AA and CA respectively. Prior Enza/Doc was 4.2%/33.3% for AA and 6.3%/29.1% for CA. Median duration of Abi therapy in AA was 207 days and 253 days for CA; neither median age or duration were statistically distinct. Median AA baseline ALP, Hgb, LDH, and PSA was 136 (range (r) = 59-653), 11.8 (r = 8.9-15.4), 256 (r = 157-401), and 59.9 (r = 4.8-1658) respectively. Median CA baseline ALP, Hgb, LDH, and PSA were 88 (r = 51-1600), 12.4 (r = 8.4-15.0), 204 (r = 100-528), and 40.6 (r = 2.5-2890) respectively. The difference in baseline lab values between AA and CA were insignificant. No statistical difference was seen in median PSAHL (AA = 55 days; CA = 64 days), or PSA decline of > 30% (AA = 50%; CA = 52%), > 50% (AA = 46%; CA = 39%), or > 90% (AA = 21%; CA = 14%). Finally, neither the median time to nadir (AA = 119 days; CA = 137 days) or progression (AA = 157 days; CA = 131 days) were significantly different. Conclusions: Comparison between AA men and CA men in mCRPC patients being treated with Abi showed no statistical difference in response rates, duration of response, or time to progression. Prospective, multi-institutional studies are needed to further assess these findings.

Abstract 2475: Bromodomain inhibitor: MT1 and its potential role in modulation of prostate cancer progression

Bromodomains (BD) are epigenetic readers of histone acetylation involved in chromatin remodeling and transcriptional regulation of protooncogene cellular myelocytomatosis (c- Myc) and other genes. Because c-Myc cannot be directly targeted by small molecular inhibitors due to disordered alpha helical structure, epigenetic targeting of c-Myc by BD inhibitors is an attractive therapeutic strategy for diseases such as prostate cancer (PC) associated with increased c-Myc upregulation with advancing disease. We studied the efficacy of MT1, a novel bivalent BD inhibitor that is 100-fold more potent than the first in class BD inhibitor JQ1, at inhibiting PC growth. We tested the effect on viability by MT-1 on PC cell lines, 3D spheroids derived from clinically annotated drug resistant patient derived xenografts (PDX), mice PDX models and corroborated the molecular mechanism of MT1 down regulation of Myc leading to downstream Myc-dependent up regulation of Protein Kinase D1 (PrKD) substrate phosphorylation by western blot. MT-1 inhibited growth of PC in castration sensitive (LNCaP) and resistant PC cells (PC-3). MT-1 treatment upregulated PrKD expression and phosphorylation of known PrKD substrates: threonine 120 (Thr-120) residues in beta-catenin and the serine 216 in Cell Division Cycle 25 (CDC25C) in PC-3 cells. Moreover, MT-1 was effective in inhibition of 3D spheroids growth at IC 50 between 0.27-0.92µM in Abiraterone, Enzalutamide, Docetaxel, Cabazitaxel metastatic castrate resistant PCa patient-derived tumor 3D spheroids. Additionally, MT1 was effective in inhibiting the tumor growth in PDX mice model. A combined intra-peritoneal administration of MT-1 with another c-Myc inhibitor (3JC48-3), an obligate c-Myc and MYC-associated protein X (MAX) heterodimerization inhibitor, increased the efficacy of inhibiting the PDX growth in mice. This study provides strong pre-clinical in vitro and in vivo evidence for advancing MT- 1 as a novel c-Myc targeting drug in PC. The MT-1 drug development will likely be highly impactful as c-Myc is dysregulated in three fourths of men with advanced PC.

Citation Format: Sanjeev Shukla, Mohammed Al-Toubat, Allison H. Feibus, Ahmed Elshafei, Carlos Riveros, Nathalie Meurice, Justyna Gleba, Jonathan Chardon-Robles, Adam M. Kase, John A. Copland III, Joachim L. Petit, Teruko Osumi, K.C. Balaji. Bromodomain inhibitor: MT1 and its potential role in modulation of prostate cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2475.

Extramural venous invasion: a novel magnetic resonance imaging biomarker for adverse pathology in bladder cancer

Extramural venous invasion (EMVI) recognized on magnetic resonance imaging (MRI) is an unequivocal biomarker for detecting adverse outcomes in rectal cancer: however it has not yet been explored in the area of bladder cancer. In this study, we assessed the feasibility of identifying EMVI findings on MRI in patients with bladder cancer and its avail in identifying adverse pathology. In this single-institution retrospective study, the MRI findings inclusive of EMVI was described in patients with bladder cancer that had available imaging between January 2018 and June 2020. Patient demographic and clinical information were retrieved from our electronic medical records system. Histopathologic features frequently associated with poor outcomes including lymphovascular invasion (LVI), variant histology, muscle invasive bladder cancer (MIBC), and extravesical disease (EV) were compared to MRI-EMVI. A total of 38 patients were enrolled in the study, with a median age of 73 years (range 50-101), 76% were male and 23% were females. EMVI was identified in 23 (62%) patients. There was a significant association between EMVI and MIBC (OR = 5.30, CI = 1.11-25.36; P = 0.036), and extravesical disease (OR = 17.77, CI = 2.37-133; P = 0.005). We found a higher probability of presence of LVI and histologic variant in patients with EMVI. EMVI had a sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) of 90%, 73%, 94% and 63% respectively in detecting extravesical disease. Our study suggests, EMVI may be a useful biomarker in bladder cancer imaging, is associated with adverse pathology, and could be potentially integrated in the standard of care with regards to MRI reporting systems. A larger study sample size is further warranted to assess feasibility and applicability.

Race, inflammation, and prostate cancer: A comparison of African Americans and Caucasians

246

Background: African-Americans (AA) have the highest rate of prostate cancer (PCa) incidence and mortality. Studies have shown higher rates of chronic prostate inflammation in AAs compared to Caucasians (CA). In order to better understand racial disparity in PCa and chronic inflammation (CI), this study examined the effects of race and CI on clinical parameters among PCa patients. Methods: This retrospective study sample consisted of 61 AA and 52 CA PCa patients who underwent radical prostatectomies (RP) at Tulane Hospital between 2013 and 2015. Clinical data was extracted from biopsy and RP pathology reports. The study examined the relationship between CI, race, percent of positive cores, extra-prostatic extension, PSA, PSA density, urinary PCA3 and TMPRSS2, and prostate size (g). Pearson’s chi-square, Fisher’s exact, and Kruskal-Wallis tests were used to analyze categorical, non-continuous data; ANOVA tests were used to analyze continuous data. Differences between biopsy and surgical/pathologic Gleason scores and clinical/pathological stages were also assessed. Results: 94 patients (52 AAs and 42 CAs) had CI to some degree and 19 did not (9 AAs and 10 CAs). There was no difference in rate of CI between AA and CA patients (P = 0.526). Among all patients sampled, AAs had higher percentages of positive cores (P = 0.005), PCA3 copy levels (P =0.004), and PCA3 scores (P <0.001), lower TMPRSS2 scores (P =0.039), and were more likely to have “high” or “intermediate” NCCN risk strata (P =0.010). Among patients with CI, AAs were more likely than CAs to have extra-prostatic extension (P =0.026) and less likely to have undergone a prior prostate biopsy (P =0.043). Patients without CI were more likely than patients with CI to have positive tumor margins (P =0.035) and SV invasion (P =0.013). There were no significant relationships between race and CI, and changes in either total Gleason score or stage from biopsy to RP. Conclusions: This study showed that AAs and patients without CI had more advanced forms of PCa (possibly due to PSA detection biases). Findings did not reveal any significant link between race and CI. Larger studies are needed to confirm these results and better understand the relationship between race, CI, and PCa.

Racial variation in the outcome of subsequent prostate biopsies in men with an initial diagnosis of atypical small acinar proliferation (ASAP)

141

Background: African Americans (AA) are known to have more aggressive prostate cancer (PCa) and a greater probability of death from PCa. We sought to determine predictors of subsequent detection and risk stratification of PCa in a racially diverse group of men who presented with atypical small acinar proliferation (ASAP) on initial prostate biopsy. Methods: Upon receiving IRB approval, a retrospective analysis was performed on men from the Southeast Louisiana Veterans Health Care System and Tulane University Medical Center who presented with ASAP on initial prostate biopsy and subsequently received confirmatory prostate biopsies from September 2000 through July 2015. Confirmatory biopsy with a greater than 3-year interval from the initial were excluded. Self-identified race, age, body mass index (BMI), transrectal ultrasound (TRUS) volume, serum prostate-specific antigen (PSA), PSA velocity (PSAV), PSA density (PSAD), and elapsed time between biopsies were evaluated to determine if they were predictors of subsequent PCa diagnosis in patients with an initial finding of ASAP. Results: Of the 106 men in the analysis cohort, 75 (71%) were AA and 31 (29%) were not African American (non-AA). AA had higher PSA, PSAV, and PSAD (all p < 0.05). Age, BMI and TRUS volume were not statistically different between AA and non-AA. PCa was diagnosed in subsequent biopsy in 42 (40%) patients without significant racial variation; 30 (40%) AA vs 12 (39%) non-AA. Of the 42 men with PCa, 25 (24%) met Epstein pathological criteria for significant disease, although without racial variation; 18 (24%) AA vs 7 (23%) Non-AA. Only 10 (9%) men, again without racial variation, had any component of Gleason 4; 7 (9%) AA vs 3 (10%) non-AA. On multivariate analysis, increasing age, PSA and PSAD were significant predictors of cancer on repeat biopsy while race, BMI, TRUS volume and number of cores with ASAP were not. Conclusions: AA diagnosed with ASAP on initial prostate biopsy do not have increased risk of PCa on confirmatory biopsy compared to non-AA. Regardless of race, most cancers were low grade and lower volume, and AA with ASAP should be managed in a similar manner to non-AA with ASAP.

Liver metastases in mCRPC patients post-therapy with abiraterone (Abi) and/or abiraterone/enzalutamide (Enza)

250

Background: Liver metastases (mets) are a particularly poor prognostic group among mCRPC patients. The objective of this study is to characterize mCRPC patients who have had treatment with Abi or Enza to identify risk factors that may be associated with subsequent development of liver mets. Methods: A sample of 67 patients (n = 17 liver mets and 50 non-liver met patients matched by treatment history) seen at Tulane Cancer Center were selected for analysis. All patients had prior Abi and or Abi/Enza. Race, age at PCa diagnosis and Gleason Score at PCa diagnosis were assessed. For patients with liver mets, total liver metastatic volume was measured using CT scans and correlated against PSA, LDH and AST values at the time of the scan. Wilcoxon rank sum tests were run analyzing PSA, LDH and AST at the start of Abi treatment, end of Abi treatment as well the duration of Abi treatment, and the nadir PSA for these patients. Results: Patients were predominantly Caucasian, had a median Gleason Score of 8 at diagnosis and were at a median age of 57 for those with liver mets and 62 for non-liver met at PCa diagnosis. Pearson correlation analysis of the total liver lesion volume and lab values revealed a significant correlation for LDH (R = 0.491, < 0.01) and AST (R = 0.368, p < 0.05), but not for PSA. Further evaluation of PSA and AST values at the start and end of Abi treatment as well as at nadir PSA revealed no statistically significant differences between liver met patients and non-liver met patients. However, there was a significant difference (p = 0.015) between LDH levels at the end of Abi treatment with a median of 347 U/L for liver met and 238 U/L for non-liver met patients. Conclusions: LDH and AST levels correlate with extent of liver metastases. Additionally, elevated LDH at the end of Abi treatment is indicative of an increased risk for developing liver metastases. Larger sample sizes and molecular characterization of these tumors are required to gain more insights into this important patient population.

57. clinical Characteristics and Outcomes of Patients Hospitalized with COVID-19 in New Orleans, LA: A Cohort Study

Background

In Louisiana, deaths related to COVID-19 have disproportionately occurred in Black persons. Granular data are needed to better understand inequities and develop prevention strategies to mitigate further impact on Black communities.

Methods

We conducted a retrospective cohort study of patients admitted to an urban safety net hospital in New Orleans, LA with reactive SARS-CoV-2 testing from March 9–31, 2020. Clinical characteristics and outcomes of Black and other racial/ethnic group patients were compared using Wilcoxon rank-sum test and Fisher’s exact tests. We examined Day-14 status using an ordinal scale to assess race and outcome.

Table 1. Demographics and Comorbidities by Race for Patients Hospitalized with COVID-19

Results

This study included 249 patients. Median age was 59, 44% were male, 86% were age ≥65 years or had ≥1 comorbidity. Overall, 87% were Black, relative to 55% Black patients typically hospitalized at our center. Black patients had longer symptom duration at presentation (6.41 versus 5.88 days, p=0.05), and were more likely to have asthma (p=0.008), but less likely to have dementia (p=0.002). There were no racial differences in initial respiratory status or laboratory values other than higher initial LDH in Black patients. Patient age and initial oxygen requirement, but not race (adjusted proportional odds ratio = 0.92, 95%CI: 0.70–1.20), were associated with worse Day-14 outcomes.

Figure 1: Admissions over time by Race

Conclusion

Our results demonstrate minor racial differences in comorbidities or disease severity at presentation, and Day-14 outcomes were not different between groups. However, Black patients were disproportionately represented in hospitalizations, suggesting that prevention efforts should include strategies to limit SARS-CoV-2 exposures in Black communities as one step towards reducing racial inequities related to COVID-19.

Figure 3a: Logistic Regression for Initial Oxygen Requirement

Disclosures

Meredith E. Clement, MD, FHI360 (Consultant)Gilead (Research Grant or Support)Janssen (Scientific Research Study Investigator)