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BACKGROUND: There is an unmet clinical need for interventions to prevent disease progression in patients with localized prostate cancer on active surveillance (AS). OBJECTIVE: To determine the immunologic response to the PROSTVAC vaccine and the clinical indicators of disease progression in patients with localized prostate cancer on AS. DESIGN, SETTING, AND PARTICIPANTS: This was a phase 2, double-blind, randomized controlled trial in 154 men with low- or intermediate-risk prostate cancer on AS. INTERVENTION: Participants were randomized (2:1) to receive seven doses of subcutaneous PROSTVAC, a vaccinia/fowlpox viral vector-based immunotherapy containing a prostate-specific antigen (PSA) transgene and three T-cell co-stimulatory molecules, or an empty fowlpox vector (EV) over 140 d. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome was the change from baseline in CD4 and CD8 T-cell infiltration in biopsy tumor tissue. Key secondary outcomes were safety and changes in prostate biopsy tumor pathology, peripheral antigen-specific T cells, and serum PSA. Continuous variables were compared using nonparametric tests. Categorical variables were compared using Fishers exact test. RESULTS AND LIMITATIONS: The PROSTVAC/EV vaccination was well tolerated. All except one participant completed the vaccination series. Changes in CD4 or CD8 density in biopsy tumor tissue did not differ between the PROSTVAC and EV arms. The proportions of patients with Gleason upgrading to grade group 3 after treatment was similar between the arms. There were no differences in postvaccination peripheral T-cell responses or the PSA change from baseline to 6-mo post-treatment follow-up between the groups. CONCLUSIONS: In this first-of-kind trial of immunotherapy in patients on AS for prostate cancer, PROSTVAC did not elicit more favorable prostate tissue or peripheral T-cell responses than the EV. There was no difference between the arms in clinicopathologic effects. Despite the null findings, this is the first study reporting the feasibility and acceptability of an immunotherapy intervention in the AS setting. PATIENT SUMMARY: We looked at responses after an experimental prostate cancer vaccine in patients with prostate cancer on active surveillance (AS). Participants who received the vaccine did not show more favorable outcomes than those receiving the control. Despite these findings, this is the first report showing the feasibility and acceptability of immunotherapy for prostate cancer in patients on AS.

Men diagnosed with low-risk prostate cancer (PC) are increasingly electing active surveillance (AS) as their initial management strategy. While this may reduce the side effects of treatment for prostate cancer, many men on AS eventually convert to active treatment. PC is one of the most heritable cancers, and genetic factors that predispose to aggressive tumors may help distinguish men who are more likely to discontinue AS. To investigate this, we undertook a multi-institutional genome-wide association study (GWAS) of 5,222 PC patients and 1,139 other patients from replication cohorts, all of whom initially elected AS and were followed over time for the potential outcome of conversion from AS to active treatment. In the GWAS we detected 18 variants associated with conversion, 15 of which were not previously associated with PC risk. With a transcriptome-wide association study (TWAS), we found two genes associated with conversion (MAST3, p = 6.9×10-7 and GAB2, p = 2.0×10-6). Moreover, increasing values of a previously validated 269-variant genetic risk score (GRS) for PC was positively associated with conversion (e.g., comparing the highest to the two middle deciles gave a hazard ratio [HR] = 1.13; 95% Confidence Interval [CI]= 0.94-1.36); whereas, decreasing values of a 36-variant GRS for prostate-specific antigen (PSA) levels were positively associated with conversion (e.g., comparing the lowest to the two middle deciles gave a HR = 1.25; 95% CI, 1.04-1.50). These results suggest that germline genetics may help inform and individualize the decision of AS-or the intensity of monitoring on AS-versus treatment for the initial management of patients with low-risk PC.

PurposeWe examined the demographic and clinicopathological parameters associated with the time to convert from active surveillance to treatment among men with prostate cancer.Materials and methodsA multi-institutional cohort of 7,279 patients managed with active surveillance had data and biospecimens collected for germline genetic analyses.ResultsOf 6,775 men included in the analysis, 2,260 (33.4%) converted to treatment at a median followup of 6.7 years. Earlier conversion was associated with higher Gleason grade groups (GG2 vs GG1 adjusted hazard ratio [aHR] 1.57, 95% CI 1.36-1.82; ≥GG3 vs GG1 aHR 1.77, 95% CI 1.29-2.43), serum prostate specific antigen concentrations (aHR per 5 ng/ml increment 1.18, 95% CI 1.11-1.25), tumor stages (cT2 vs cT1 aHR 1.58, 95% CI 1.41-1.77; ≥cT3 vs cT1 aHR 4.36, 95% CI 3.19-5.96) and number of cancerous biopsy cores (3 vs 1-2 cores aHR 1.59, 95% CI 1.37-1.84; ≥4 vs 1-2 cores aHR 3.29, 95% CI 2.94-3.69), and younger age (age continuous per 5-year increase aHR 0.96, 95% CI 0.93-0.99). Patients with high-volume GG1 tumors had a shorter interval to conversion than those with low-volume GG1 tumors and behaved like the higher-risk patients. We found no significant association between the time to conversion and self-reported race or genetic ancestry.ConclusionsA shorter time to conversion from active surveillance to treatment was associated with higher-risk clinicopathological tumor features. Furthermore, patients with high-volume GG1 tumors behaved similarly to those with intermediate and high-risk tumors. An exploratory analysis of self-reported race and genetic ancestry revealed no association with the time to conversion.

Deep learning (DL)–based algorithms to determine prostate cancer (PCa) Grade Group (GG) on biopsy slides have not been validated by comparison to clinical outcomes. We used a DL-based algorithm, AIRAProstate, to regrade initial prostate biopsies in 2 independent PCa active surveillance (AS) cohorts. In a cohort initially diagnosed with GG1 PCa using only systematic biopsies (n = 138), upgrading of the initial biopsy to ≥GG2 by AIRAProstate was associated with rapid or extreme grade reclassification on AS (odds ratio = 3.3, P  =  .04), whereas upgrading of the initial biopsy by contemporary uropathologist reviews was not associated with this outcome. In a contemporary validation cohort that underwent prostate magnetic resonance imaging before initial biopsy (n = 169), upgrading of the initial biopsy (all contemporary GG1 by uropathologist grading) by AIRAProstate was associated with grade reclassification on AS (hazard ratio = 1.7, P  =  .03). These results demonstrate the utility of a DL-based grading algorithm in PCa risk stratification for AS. [ABSTRACT FROM AUTHOR]

Purpose: Indeterminate renal masses are increasingly incidentally found on cross-sectional imaging. 99mTc-sestamibi single-photon emission computed tomography/computed tomography (SPECT/CT) scans can be used to identify oncocytomas and oncocytic renal neoplasms, including a subset of chromophobe renal cell carcinomas (chRCCs), which are viewed as false-positive. Procedure: Patients imaged with renal sestamibi scans between 2014 and 2023 were reviewed. Those patients with solitary tumors that were originally classified as chRCC were included in the analysis. Imaging with SPECT/CT from the liver dome down had been carried out 75 min after the administration of 925 MBq of 99mTc-sestamibi. All available H&E and immunostained slides were re-reviewed and classified according to WHO 2022 criteria. Confirmatory immunohistochemical stains were performed in tumors considered morphologically suspicious for non-chRCC entities. Result: A total of 18 patients with solitary tumors were included in the final analysis. 13/18 (72.2%) tumors in this cohort remained classified as chRCC, with 4/18 (22.2%) being eosinophilic-variant chRCC. The reclassified tumors (5/18 [27.8%]) included 2/18 (11.1%) low-grade oncocytic tumor (LOT), 1/18 (5.5%) eosinophilic vacuolated tumor (EVT), and 2/18 (11.1%) unclassified low-grade oncocytic neoplasms. As such, only 2/9 (22.2%) qualitatively "hot" tumors were chRCC other than eosinophilic-variant and only 1/9 (11.1%) "cold" tumors was a histology other than chRCC. Conclusion: Based on current histopathologic classification methods, it is likely that the "false-positive" rate of uptake on renal sestamibi scans with chRCC has been over-stated. Further study is warranted to better refine the optimal utility of renal sestamibi scans for non-invasive risk stratification of indeterminate renal masses. [ABSTRACT FROM AUTHOR]

Introduction: Renal cell carcinoma (RCC) represents cancer originating from the renal epithelium and accounts for > 90% of cancers in the kidney. Prostatespecific membrane antigen (PSMA) is overexpressed in tumor-associated neovascular endothelial cells of many solid tumors, including metastatic RCC. Although studied in several small clinical studies, PSMA-based imaging and therapy have not been pursued rigorously in preclinical RCC. This study aimed to evaluate the preclinical performance of PSMA-based radiotheranostic agents in a relevant murine model. Methods: A PSMA-overexpressing murine cell line, PSMA+ RENCA, was developed by lentiviral transduction. PSMA-based theranostic agents, 68Ga-L1/177Lu-L1/225Ac-L1, were synthesized in high radiochemical yield and purity following our reported methods. Immunocompetent BALB/c mice were used for flank and orthotopic tumor inoculation. 68Ga-L1 was evaluated in small animal PET/CT imaging in flank and PET/MR imaging in orthotopic models. Cell viability studies were conducted for 177Lu-L1 and 225Ac-L1. Proof-of-concept treatment studies were performed using 225Ac-L1 (0, 37 kBq, 2 kBq × 37 kBq, 1 week apart) using PSMA+ RENCA in the flank model. Results: Cellular uptake of 68Ga-L1, 177Lu-L1, and 225Ac-L1 confirmed the specificity of the agents to PSMA+ RENCA cells rather than to RENCA (wt) cells, which are low in PSMA expression. The uptake in PSMA+ RENCA cells at 1 h for 68Ga-L1 (49.0% incubated dose [ID] ± 3.6%ID/million cells), 177Lu-L1 (22.1% ID ± 0.5%ID)/million cells), and 225Ac-L1 (4.1% ± 0.2% ID)/million cells), respectively, were higher than the RENCA (wt) cells (~ 1%ID-2%ID/million cells). PET/CT images displayed > 7-fold higher accumulation of 68Ga-L1 in PSMA+ RENCA compared to RENCA (wt) in flank implantation at 1 h. A twofold higher accumulation of 68Ga-L1 was observed in orthotopic tumors than in normal kidneys during 1-3 h postinjection. High lung uptake was observed with 68Ga-L1 PET/MR imaging 3 weeks after orthotopic implantation of PSMA+ RENCA due to spontaneous lung metastases. The imaging data were further confirmed by immunohistochemical characterization. 225Ac-L1 (0-37 kBq) displayed a dose-dependent reduction of cell proliferation in the PSMA+ RENCA cells after 48 h incubation; ~ 40% reduction in the cells with treated 37 kBq compared to vehicle (p < 0.001); however, no effect was observed with 177Lu-L1 (0-3700 kBq) up to 144 h postinoculation, suggesting lower efficacy of β-particle-emitting radiations in cellular studies compared to a-particle-emitting 225Ac-L1. Animals treated with 225Ac-L1 at 1 week posttumor inoculation in flank models displayed significant tumor growth delay (p < 0.03) and longer median survival of 21 days and 24 days for the treatment groups 37 kBq and 2 kBq × 37 kBq, respectively, compared to the vehicle group (12 days). Conclusion: The results suggest that a theranostic strategy targeting PSMA, employing PET and α-emitting radiopharmaceuticals, enabled tumor growth control and enhanced survival in a relevant immunocompetent murine model of RCC. These studies provide the rationale for clinical studies of PSMA-targeted theranostic agents in patients with RCC. [ABSTRACT FROM AUTHOR]

The Immunotherapy to Prevent Progression on Active Surveillance Study is the first trial of immunotherapy for localized prostate cancer. We randomized active surveillance patients to PSA-TRICOM (PROSTVAC) or placebo for 5mo. Final results will be available in 2019.

Purpose Guidelines are limited for genetic testing for prostate cancer (PCA). The goal of this conference was to develop an expert consensus-driven working framework for comprehensive genetic evaluation of inherited PCA in the multigene testing era addressing genetic counseling, testing, and genetically informed management. Methods An expert consensus conference was convened including key stakeholders to address genetic counseling and testing, PCA screening, and management informed by evidence review. Results Consensus was strong that patients should engage in shared decision making for genetic testing. There was strong consensus to test HOXB13 for suspected hereditary PCA, BRCA1/2 for suspected hereditary breast and ovarian cancer, and DNA mismatch repair genes for suspected Lynch syndrome. There was strong consensus to factor BRCA2 mutations into PCA screening discussions. BRCA2 achieved moderate consensus for factoring into early-stage management discussion, with stronger consensus in high-risk/advanced and metastatic setting. Agreement was moderate to test all men with metastatic castration-resistant PCA, regardless of family history, with stronger agreement to test BRCA1/2 and moderate agreement to test ATM to inform prognosis and targeted therapy. Conclusion To our knowledge, this is the first comprehensive, multidisciplinary consensus statement to address a genetic evaluation framework for inherited PCA in the multigene testing era. Future research should focus on developing a working definition of familial PCA for clinical genetic testing, expanding understanding of genetic contribution to aggressive PCA, exploring clinical use of genetic testing for PCA management, genetic testing of African American males, and addressing the value framework of genetic evaluation and testing men at risk for PCA-a clinically heterogeneous disease.

Purpose: We sought to examine the association of extraprostatic extension (EPE) with biochemical recurrence (BCR) separately in men with Grade Group (GG) 1 and GG2 prostate cancer (PCa) treated with radical prostatectomy. Materials and Methods: We reviewed our institutional database of patients who underwent radical prostatectomy for PCa between 2005 and 2022 and identified patients with GG1 and GG2 disease on final pathology. Fine-Gray competing risk models with an interaction between EPE (yes vs no) and GG (GG1 vs GG2) were used to examine the relationship between disease group and BCR-free survival. Results: The cohort consisted of 6309 men, of whom 169/2740 (6.2%) with GG1 disease had EPE while 1013/3569 (28.4%) with GG2 disease had EPE. Median follow-up was 4 years. BCR occurred in 400/6309 (6.3%) patients. For men with GG1, there was no statistically significant difference in BCR-free survival for men with vs without EPE (subdistribution HR = 0.88; 95% CI: 0.37-2.09). However, for GG2 patients BCR-free survival was significantly worse for those with vs without EPE (subdistribution HR = 1.97, 95% CI: 1.54-2.52). Conclusions: Although there is a subset of GG1 PCas capable of invading through the prostatic capsule, patients with GG1 PCa and EPE at prostatectomy experience similar biochemical recurrence and survival outcomes compared to GG1 patients without EPE. However, among men with GG2, EPE connotes a worse prognosis. [ABSTRACT FROM AUTHOR]