TRBC1-targeting antibody-drug conjugates for the treatment of T cell cancers.

Antibody and chimeric antigen receptor (CAR) T cell-mediated targeted therapies have improved survival in patients with solid and haematologic malignancies1-9. Adults with T cell leukaemias and lymphomas, collectively called T cell cancers, have short survival10,11 and lack such targeted therapies. Thus, T cell cancers particularly warrant the development of CAR T cells and antibodies to improve patient outcomes. Preclinical studies showed that targeting T cell receptor ß-chain constant region 1 (TRBC1) can kill cancerous T cells while preserving sufficient healthy T cells to maintain immunity12, making TRBC1 an attractive target to treat T cell cancers. However, the first-in-human clinical trial of anti-TRBC1 CAR T cells reported a low response rate and unexplained loss of anti-TRBC1 CAR T cells13,14. Here we demonstrate that CAR T cells are lost due to killing by the patient's normal T cells, reducing their efficacy. To circumvent this issue, we developed an antibody-drug conjugate that could kill TRBC1+ cancer cells in vitro and cure human T cell cancers in mouse models. The anti-TRBC1 antibody-drug conjugate may provide an optimal format for TRBC1 targeting and produce superior responses in patients with T cell cancers.

Predicting Prostate Cancer Molecular Subtype With Deep Learning on Histopathologic Images.

Microscopic examination of prostate cancer has failed to reveal a reproducible association between molecular and morphologic features. However, deep-learning algorithms trained on hematoxylin and eosin (H&E)-stained whole slide images (WSI) may outperform the human eye and help to screen for clinically-relevant genomic alterations. We created deep-learning algorithms to identify prostate tumors with underlying ETS-related gene (ERG) fusions or PTEN deletions using the following 4 stages: (1) automated tumor identification, (2) feature representation learning, (3) classification, and (4) explainability map generation. A novel transformer-based hierarchical architecture was trained on a single representative WSI of the dominant tumor nodule from a radical prostatectomy (RP) cohort with known ERG/PTEN status (n = 224 and n = 205, respectively). Two distinct vision transformer-based networks were used for feature extraction, and a distinct transformer-based model was used for classification. The ERG algorithm performance was validated across 3 RP cohorts, including 64 WSI from the pretraining cohort (AUC, 0.91) and 248 and 375 WSI from 2 independent RP cohorts (AUC, 0.86 and 0.89, respectively). In addition, we tested the ERG algorithm performance in 2 needle biopsy cohorts comprised of 179 and 148 WSI (AUC, 0.78 and 0.80, respectively). Focusing on cases with homogeneous (clonal) PTEN status, PTEN algorithm performance was assessed using 50 WSI reserved from the pretraining cohort (AUC, 0.81), 201 and 337 WSI from 2 independent RP cohorts (AUC, 0.72 and 0.80, respectively), and 151 WSI from a needle biopsy cohort (AUC, 0.75). For explainability, the PTEN algorithm was also applied to 19 WSI with heterogeneous (subclonal) PTEN loss, where the percentage tumor area with predicted PTEN loss correlated with that based on immunohistochemistry (r = 0.58, P = .0097). These deep-learning algorithms to predict ERG/PTEN status prove that H&E images can be used to screen for underlying genomic alterations in prostate cancer.

Cell Cycle Progression Score, but Not Phosphatase and Tensin Homolog Loss, Is an Independent Prognostic Factor for Metastasis in Intermediate- and High-risk Prostate Cancer in Men Treated With and Without Salvage Radiotherapy.

PURPOSE: The prognostic value for metastasis of the cell-cycle progression score and phosphatase and tensin homolog haven't been evaluated jointly in contemporary men with exclusively intermediate- or high-risk prostate cancer. We evaluated associations of cell-cycle progression and phosphatase and tensin homolog with metastasis-free survival in contemporary intermediate/high-risk prostate cancer patients overall, and intermediate/high-risk men receiving salvage radiotherapy. MATERIALS AND METHODS: In a case-cohort of 209 prostatectomy patients with intermediate/high-risk prostate cancer, and a cohort of 172 such men who received salvage radiotherapy, cell-cycle progression score was calculated from RNA expression, and phosphatase and tensin homolog was analyzed by immunohistochemistry. Proportional hazards regression, weighted for case-cohort design or unweighted for the salvage radiotherapy cohort, was used to evaluate associations of cell-cycle progression, phosphatase and tensin homolog with metastasis-free survival. Improvement in model discrimination was evaluated with the concordance index. RESULTS: In the case-cohort 41 men had metastasis, and 17 developed metastasis in the salvage radiotherapy cohort, at median follow-up of 3 and 4 years, respectively. For both case-cohort and salvage radiotherapy cohort, cell-cycle progression was independently associated with metastasis-free survival after adjustment for Cancer of the Prostate Risk Assessment Post-Surgical: hazard ratio (95% confidence interval) = 3.11 (1.70-5.69) and 1.85 (1.19-2.85), respectively. Adding cell-cycle progression to Cancer of the Prostate Risk Assessment Post-Surgical increased the concordance index from 0.861 to 0.899 (case-cohort), and 0.745 to 0.819 (salvage radiotherapy cohort). Although statistically significant in univariate analyses, phosphatase and tensin homolog was no longer significant after adjustment for Cancer of the Prostate Risk Assessment Post-Surgical. Analysis of interaction with National Comprehensive Cancer Network risk group showed that cell-cycle progression had the strongest effect among unfavorable intermediate-risk men. CONCLUSIONS: In the first study to evaluate metastasis risk associated with cell-cycle progression and phosphatase and tensin homolog in exclusively intermediate/high-risk prostate cancer, and in such men with salvage radiotherapy, cell-cycle progression but not phosphatase and tensin homolog was associated with significantly increased 2- to 3-fold risk of metastasis after Cancer of the Prostate Risk Assessment Post-Surgical adjustment.

Heart neurons use clock genes to control myocyte proliferation.

Neurons can regulate the development, pathogenesis, and regeneration of target organs. However, the role of neurons during heart development and regeneration remains unclear. We genetically inhibited sympathetic innervation in vivo, which resulted in heart enlargement with an increase in cardiomyocyte number. Transcriptomic and protein analysis showed down-regulation of the two clock gene homologs Period1/Period2 (Per1/Per2) accompanied by up-regulation of cell cycle genes. Per1/Per2 deletion increased heart size and cardiomyocyte proliferation, recapitulating sympathetic neuron­deficient hearts. Conversely, increasing sympathetic activity by norepinephrine treatment induced Per1/Per2 and suppressed cardiomyocyte proliferation. We further found that the two clock genes negatively regulate myocyte mitosis entry through the Wee1 kinase pathway. Our findings demonstrate a previously unknown link between cardiac neurons and clock genes in regulation of cardiomyocyte proliferation and heart size and provide mechanistic insights for developing neuromodulation strategies for cardiac regen5eration.

GSTP1 positive prostatic adenocarcinomas are more common in Black than White men in the United States.

GSTP1 is a member of the Glutathione-S-transferase (GST) family silenced by CpG island DNA hypermethylation in 90-95% of prostate cancers. However, prostate cancers expressing GSTP1 have not been well characterized. We used immunohistochemistry against GSTP1 to examine 1673 primary prostatic adenocarcinomas on tissue microarrays (TMAs) with redundant sampling from the index tumor from prostatectomies. GSTP1 protein was positive in at least one TMA core in 7.7% of cases and in all TMA cores in 4.4% of cases. The percentage of adenocarcinomas from Black patients who had any GSTP1 positive TMA cores was 14.9%, which was 2.5 times higher than the percentage from White patients (5.9%; P < 0.001). Further, the percentages of tumors from Black patients who had all TMA spots positive for GSTP1 (9.5%) was 3-fold higher than the percentage from White patients (3.2%; P<0.001). In terms of association with other molecular alterations, GSTP1 positivity was enriched in ERG positive cancers among Black men. By in situ hybridization, GSTP1 mRNA expression was concordant with protein staining, supporting the lack of silencing of at least some GSTP1 alleles in GSTP1-positive tumor cells. This is the first report revealing that GSTP1-positive prostate cancers are substantially over-represented among prostate cancers from Black compared to White men. This observation should prompt additional studies to determine whether GSTP1 positive cases represent a distinct molecular subtype of prostate cancer and whether GSTP1 expression could provide a biological underpinning for the observed disparate outcomes for Black men.

Circulating Tumor Cell and Circulating Tumor DNA Assays Reveal Complementary Information for Patients with Metastatic Urothelial Cancer.

Despite considerable advances in the management of urothelial carcinoma (UC), better risk stratification and enhanced detection of minimal residual disease are still urgent priorities to prolong survival while avoiding the morbidity of overtreatment. Circulating tumor cells and DNA (CTCs, ctDNA) are two biologically distinct "liquid biopsies" that may potentially address this need, although they have been understudied in UC to date and their relative utility is unknown. To this end, matched CTC and ctDNA samples were collected for a head-to-head comparison in a pilot study of 16 patients with metastatic UC. CTCs were defined as cytokeratin- and/or EpCAM-positive using the RareCyte direct imaging platform. ctDNA was assayed using the PlasmaSelect64 probe-capture assay. 75% of patients had detectable CTCs, and 73% had detectable somatic mutations, with no correlation between CTC count and ctDNA. 91% of patients had tissue confirmation of at least one plasma mutation and, importantly, several clinically actionable mutations were detected in plasma that were not found in the matching tumor. A ctDNA fraction of >2% was significantly associated with worse overall survival (p=0.039) whereas CTC detection was not (p=0.46). Notably, using a predefined gene panel for ctDNA detection had a high but not complete detection rate in metastatic UC, similar to what has been described for a custom tissue-personalized assay approach. In sum, both liquid biopsies show promise in UC and deserve further investigation. PATIENT SUMMARY: New "liquid biopsy" blood tests are emerging for urothelial cancer aimed at early detection and avoiding overtreatment. Our results suggest that two such tests provide complementary information: circulating tumor cells may be best for studying the biological features of a person's cancer, whereas circulating tumor DNA may be better for early detection.

Genome-wide association and multi-omic analyses reveal ACTN2 as a gene linked to heart failure.

Heart failure is a major public health problem affecting over 23 million people worldwide. In this study, we present the results of a large scale meta-analysis of heart failure GWAS and replication in a comparable sized cohort to identify one known and two novel loci associated with heart failure. Heart failure sub-phenotyping shows that a new locus in chromosome 1 is associated with left ventricular adverse remodeling and clinical heart failure, in response to different initial cardiac muscle insults. Functional characterization and fine-mapping of that locus reveal a putative causal variant in a cardiac muscle specific regulatory region activated during cardiomyocyte differentiation that binds to the ACTN2 gene, a crucial structural protein inside the cardiac sarcolemma (Hi-C interaction p-value = 0.00002). Genome-editing in human embryonic stem cell-derived cardiomyocytes confirms the influence of the identified regulatory region in the expression of ACTN2. Our findings extend our understanding of biological mechanisms underlying heart failure.

Combining immune check-point blockade and cryoablation in an immunocompetent hormone sensitive murine model of prostate cancer.

BACKGROUND: Prostate cancer remains the second leading cause of cancer related death in men. Immune check point blocking antibodies have revolutionized treatment of multiple solid tumors, but results in prostate cancer remain marginal. Previous reports have suggested that local therapies, in particular cryoablation might increase tumor immunogenicity. In this work, we examine potential synergism between tumor cryoabalation and check point blocking antibodies. METHODS: FVB/NJ mice were injected subcutaneously into each flank with either 1 × 106 or 0.2 × 106 isogenic hormone sensitive Myc-Cap cells to establish synchronous grafts. Mice were treated with four intraperitoneal injections of anti-PD-1 (10 mg/kg), anti-CTLA-4 (1 mg/kg), or isotype control antibody with or without adjuvant cryoablation of the larger tumor graft and with or without neo-adjuvant androgen deprivation with degarelix (ADT). Mouse survival and growth rates of tumor grafts were measured. The immune dependency of observed oncological effects was evaluated by T cell depletion experiments. RESULTS: Treatment with anti-CTLA-4 antibody and cryoablation delayed the growth of the distant tumor by 14.8 days (p = 0.0006) and decreased the mortality rate by factor of 4 (p = 0.0003) when compared to cryoablation alone. This synergy was found to be dependent on CD3+ and CD8+ cells. Combining PD-1 blockade with cryoablation did not show a benefit over use of either treatment alone. Addition of ADT to anti-PD1 therapy and cryoablation doubled the time to accelerated growth in the untreated tumors (p = 0.0021) and extended survival when compared to cryoablation combined with ADT in 25% of the mice. Effects of combining anti-PD1 with ADT and cryoablation on mouse survival were obviated by T cell depletion. CONCLUSION: Trimodal therapy consisting of androgen deprivation, cryoablation and PD-1 blockade, as well as the combination of cryoablation and low dose anti-CTLA-4 blockade showed that local therapies with cryoablation could be considered to augment the effects of checkpoint blockade in prostate cancer.

Characterization of Urothelial Cancer Circulating Tumor Cells with a Novel Selection-Free Method.

OBJECTIVE: To investigate circulating tumor cells (CTCs) as biomarkers of urothelial carcinoma (UC). To date, the majority of work on this topic has utilized the CellSearch test, which has limited sensitivity due to reliance on positive selection for the cell surface protein epithelial cell adhesion molecule (EpCAM). We used a novel selection-free method to enumerate and characterize CTCs across a range of UC stages. MATERIALS AND METHODS: Blood samples from 38 patients (9 controls, 8 nonmuscle invasive bladder cancer [NMIBC], 12 muscle-invasive bladder cancer [MIBC], and 9 metastatic UC) were processed with the AccuCyte-CyteFinder system. Slides were stained for the white blood cell markers CD45 and CD66b and the epithelial markers EpCAM and pancytokeratin. CTCs were defined as any cytokeratin postive and white blood cell marker negative cell. Separately, the more restrictive CellSearch definition was applied, with the additional requirement of EpCAM positivity. The Kruskal-Wallis ANOVA test compared CTC counts by stage. RESULTS: Greater than or equal to 1 CTC was detected in 2 of 8 (25%) patients with NMIBC, 7 of 12 (58%) with MIBC, and 6of 9 (67%) with metastatic disease. No control had CTCs. Comparing CTC counts between groups, the only statistically significant comparison was between controls and patients with metastatic UC (P = .009). With EpCAM positivity as a CTC requirement, no CTCs were detected in any patient with NMIBC, and only 2 (17%) patients with MIBC had CTCs. CTCs tended to be larger in metastatic patients. CONCLUSION: CTCs were detected at all UC stages and exhibited phenotypic diversity of cell size and EpCAM expression. EpCAM negative CTCs that would be missed with the CellSearch test were detected in patients with NMIBC and patients with MIBC.

Prostate Cancer Disseminated Tumor Cells are Rarely Detected in the Bone Marrow of Patients with Localized Disease Undergoing Radical Prostatectomy across Multiple Rare Cell Detection Platforms.

PURPOSE: Prostate circulating tumor cells escape into peripheral blood and enter bone marrow as disseminated tumor cells, representing an early step before conventionally detectable metastasis. It is unclear how frequently this occurs in localized disease and existing detection methods rely on epithelial markers with low specificity and sensitivity. We used multiple methodologies of disseminated tumor cell detection in bone marrow harvested at radical prostatectomy. MATERIALS AND METHODS: Bone marrow was harvested from 208 clinically localized cases, 16 controls and 5 metastatic cases with peripheral blood obtained from 37 metastatic cases. Samples were evaluated at 4 centers with 4 distinct platforms using antibody enrichment with the AdnaTest (Qiagen®) or VERSA (versatile exclusion based rare sample analysis), or whole sample interrogation with the RareCyte platform (Seattle, Washington) or HD-SCA (high definition single cell assay) using traditional epithelial markers and prostate specific markers. We investigated the sensitivity and specificity of these markers by evaluating expression levels in control and metastatic cases. RESULTS: EpCAM, NKX3.1 and AR were nonspecifically expressed in controls and in most samples using AdnaTest with no relation to perioperative variables. Only 1 patient with localized disease showed positive results for the prostate specific marker PSA. With the VERSA platform no localized case demonstrated disseminated tumor cells. With the RareCyte and HD-SCA platforms only a single patient had 1 disseminated tumor cell. CONCLUSIONS: Evaluation across multiple platforms revealed that epithelial markers are nonspecific in bone marrow and, thus, not suitable for disseminated tumor cell detection. Using prostate specific markers disseminated tumor cells were typically not detected in patients with localized prostate cancer.

Analogous detection of circulating tumor cells using the AccuCyte® -CyteFinder® system and ISET system in patients with locally advanced and metastatic prostate cancer.

INTRODUCTION: Circulating tumor cells (CTCs) can provide important information on patient's prognosis and treatment efficacy. Currently, a plethora of methods is available for the detection of these rare cells. We compared the outcomes of two of those methods to enumerate and characterize CTCs in patients with locally advanced and metastatic prostate cancer (PCa). First, the selection-free AccuCyte® - CyteFinder® system (RareCyte® , Inc., Seattle, WA) and second, the ISET system (Rarecells Diagnostics, France), a CTC detection method based on cell size-exclusion. METHODS: Peripheral blood samples were obtained from 15 patients with metastatic PCa and processed in parallel, using both methods according to manufacturer's protocol. CTCs were identified by immunofluorescence, using commercially available antibodies to pancytokeratin (PanCK), EpCAM, CD45/CD66b/CD34/CD11b/CD14 (AccuCyte® - CyteFinder® system), and pancytokeratin, vimentin (Vim) and CD45 (ISET system). RESULTS: The median CTC count was 5 CTCs/7.5 mL (range, 0-20) for the AccuCyte® - CyteFinder® system and 37 CTCs/7.5 mL (range, 8-139) for the ISET system (P < 0.001). Total CTC counts obtained for the two methods were correlated (r = 0.750, P = 0.001). When separating the total CTC count obtained with the ISET system in PanCK+/Vim- and PanCK+/Vim+ CTCs, the total CTC count obtained with the AccuCyte® - CyteFinder® system was moderately correlated with the PanCK+/Vim- CTCs, and strongly correlated with the PanCK+/Vim+ CTCs (r = 0.700, P = 0.004 and r = 0.810, P < 0.001, respectively). CONCLUSION: Our results highlight significant disparities in the enumeration and phenotype of CTCs detected by both techniques. Although the median amount of CTCs/7.5 mL differed significantly, total CTC counts of both methods were strongly correlated. For future studies, a more uniform approach to the isolation and definition of CTCs based on immunofluorescent stains is needed to provide reproducible results that can be correlated with clinical outcomes.

Pharmacodynamic and pharmacokinetic neoadjuvant study of hedgehog pathway inhibitor Sonidegib (LDE-225) in men with high-risk localized prostate cancer undergoing prostatectomy.

PURPOSE: To determine the pharmacodynamic effects of Sonidegib (LDE-225) in prostate tumor tissue from men with high-risk localized prostate cancer, by comparing pre-surgical core-biopsy specimens to tumor tissue harvested post-treatment at prostatectomy. METHODS: We conducted a prospective randomized (Sonidegib vs. observation) open-label translational clinical trial in men with high-risk localized prostate cancer undergoing radical prostatectomy. The primary endpoint was the proportion of patients in each arm who achieved at least a two-fold reduction in GLI1 mRNA expression in post-treatment versus pre-treatment tumor tissue. Secondary endpoints included the effect of pre-surgical treatment with Sonidegib on disease progression following radical prostatectomy, and safety. RESULTS: Fourteen men were equally randomized (7 per arm) to either neoadjuvant Sonidegib or observation for 4 weeks prior to prostatectomy. Six of seven men (86%) in the Sonidegib arm (and none in the control group) achieved a GLI1 suppression of at least two-fold. In the Sonidegib arm, drug was detectable in plasma and in prostatic tissue; and median intra-patient GLI1 expression decreased by 63-fold, indicating potent suppression of Hedgehog signaling. Sonidegib was well tolerated, without any Grade 3-4 adverse events observed. Disease-free survival was comparable among the two arms (HR = 1.50, 95% CI 0.26-8.69, P = 0.65). CONCLUSIONS: Hedgehog pathway activity (as measured by GLI1 expression) was detectable at baseline in men with localized high-risk prostate cancer. Sonidegib penetrated into prostatic tissue and induced a >60-fold suppression of the Hedgehog pathway. The oncological benefit of Hedgehog pathway inhibition in prostate cancer remains unclear.

MSH2 Loss in Primary Prostate Cancer.

Purpose: Inactivation of mismatch repair (MMR) genes may predict sensitivity to immunotherapy in metastatic prostate cancers. We studied primary prostate tumors with MMR defects.Experimental Design: A total of 1,133 primary prostatic adenocarcinomas and 43 prostatic small cell carcinomas (NEPC) were screened by MSH2 immunohistochemistry with confirmation by next-generation sequencing (NGS). Microsatellite instability (MSI) was assessed by PCR and NGS (mSINGS).Results: Of primary adenocarcinomas and NEPC, 1.2% (14/1,176) had MSH2 loss. Overall, 8% (7/91) of adenocarcinomas with primary Gleason pattern 5 (Gleason score 9-10) had MSH2 loss compared with 0.4% (5/1,042) of tumors with any other scores (P < 0.05). Five percent (2/43) of NEPC had MSH2 loss. MSH2 was generally homogenously lost, suggesting it was an early/clonal event. NGS confirmed MSH2 loss-of-function alterations in all (12/12) samples, with biallelic inactivation in 83% (10/12) and hypermutation in 83% (10/12). Overall, 61% (8/13) and 58% (7/12) of patients had definite MSI by PCR and mSINGS, respectively. Three patients (25%) had germline mutations in MSH2 Tumors with MSH2 loss had a higher density of infiltrating CD8+ lymphocytes compared with grade-matched controls without MSH2 loss (390 vs. 76 cells/mm2; P = 0.008), and CD8+ density was correlated with mutation burden among cases with MSH2 loss (r = 0.72, P = 0.005). T-cell receptor sequencing on a subset revealed a trend toward higher clonality in cases versus controls.Conclusions: Loss of MSH2 protein is correlated with MSH2 inactivation, hypermutation, and higher tumor-infiltrating lymphocyte density, and appears most common among very high-grade primary tumors, for which routine screening may be warranted if validated in additional cohorts. Clin Cancer Res; 23(22); 6863-74. ©2017 AACR.

Nucleolin Staining May Aid in the Identification of Circulating Prostate Cancer Cells.

INTRODUCTION: Circulating tumor cells (CTCs) have great potential as circulating biomarkers for solid malignancies. Currently available assays for CTC detection rely on epithelial markers with somewhat limited sensitivity and specificity. We found that the staining pattern of nucleolin, a common nucleolar protein in proliferative cells, separates CTCs from white blood cells (WBCs) in men with metastatic prostate cancer. PATIENTS AND METHODS: Whole peripheral blood from 3 men with metastatic prostate cancer was processed with the AccuCyte CTC system (RareCyte, Seattle, WA). Slides were immunostained with 4',6-diamidino-2-phenylindole (DAPI), anti-pan-cytokeratin, anti-CD45/CD66b/CD11b/CD14/CD34, and anti-nucleolin antibodies and detected using the CyteFinder system. DAPI nucleolin colocalization and staining pattern wavelet entropy were measured with novel image analysis software. RESULTS: A total of 33,718 DAPI-positive cells were analyzed with the novel imaging software, of which 45 (0.13%) were known CTCs based on the established AccuCyte system criteria. Nucleolin staining pattern for segmentable CTCs demonstrated greater wavelet entropy than that of WBCs (median wavelet entropy, 6.86 × 107 and 3.03 × 106, respectively; P = 2.92 × 10-22; approximated z statistic = 9.63). Additionally, the total nucleolin staining of CTCs was greater than that of WBCs (median total pixel intensity, 1.20 × 105 and 2.55 × 104 integrated pixel units, respectively; P = 2.40 × 10-21; approximated z statistic = 9.41). CONCLUSION: Prostate cancer CTCs displayed unique nucleolin expression and localization compared to WBCs. This finding has the potential to serve as the basis for a sensitive and specific CTC detection method.

Prevalence and Prognostic Significance of PTEN Loss in African-American and European-American Men Undergoing Radical Prostatectomy.

African-American (AA) men have a higher risk of lethal prostate cancer (PCa) compared to European-American (EA) men. However, the molecular basis of this difference, if any, remains unclear. In EA PCa, PTEN loss, but not ERG rearrangement, has been associated with poor outcomes in most studies. Although ERG rearrangement is less common in AA compared to EA PCa, the relative frequency of PTEN loss and the association of PTEN/ERG molecular subtypes with outcomes is unknown for AA PCa. We examined PTEN/ERG status by immunohistochemistry in self-identified AA patients undergoing radical prostatectomy at Johns Hopkins with tumor tissue available on tissue microarray (TMA; n=169) and matched these cases by pathologic parameters to 169 EA patients from the same TMAs. The rate of PTEN loss was significantly lower in AA compared to EA PCa (18% vs 34%; p=0.001), similar to the lower rate of ERG expression (25% vs 51%; p<0.001). To examine the association of PTEN/ERG status with oncologic outcomes, we created an additional TMA of 87 AA tumors with Gleason score > 4 + 3 = 7. Among the total population of AA men with outcome data from all TMAs (n=222), PTEN loss was associated with higher risk of biochemical recurrence (hazard ratio [HR] 2.25, 95% confidence interval [CI] 1.33-3.82) and metastasis (HR 3.90, 95% CI 1.46-10.4) in multivariable models. PATIENT SUMMARY: PTEN and ERG alterations in prostate cancer are less likely in African-American than in European-American men. However, PTEN loss remains associated with poor prostate cancer outcomes among African-American men.

Pharmacodynamic study of the oral hedgehog pathway inhibitor, vismodegib, in patients with metastatic castration-resistant prostate cancer.

PURPOSE: Hedgehog (Hh) pathway signaling has been implicated in prostate cancer tumorigenesis and metastatic development and may be upregulated even further in the castration-resistant state. We hypothesized that antagonism of the Hh pathway with vismodegib in men with metastatic castration-resistant prostate cancer (mCRPC) would result in pathway engagement, inhibition and perhaps induce measurable clinical responses in patients. METHODS: This is a single-arm study of oral daily vismodegib in men with mCRPC. All patients were required to have biopsies of the tumor and skin (a surrogate tissue) at baseline and after 4 weeks of therapy. Ten patients were planned for enrollment. The primary outcome was the pharmacodynamic assessment of Gli1 mRNA suppression with vismodegib in tumor tissue. Secondary outcomes included PSA response rates, progression-free survival (PFS), overall survival (OS) and safety. RESULTS: Nine patients were enrolled. Gli1 mRNA was significantly suppressed by vismodegib in both tumor tissue (4/7 evaluable biopsies, 57%) and benign skin biopsies (6/8 evaluable biopsies, 75%). The median number of treatment cycles completed was three, with a median PFS of 1.9 months (95% CI 1.3, NA), and a median OS of 7.04 months (95% CI 3.4, NA). No patient achieved a PSA reduction or a measurable tumor response. Safety data were consistent with the known toxicities of vismodegib. CONCLUSIONS: Hh signaling, as measured by Gli1 mRNA expression in mCRPC tissues, was suppressed with vismodegib in the majority of patients. Despite this pharmacodynamic response that indicated target inhibition in some patients, there was no apparent signal of clinical activity. Vismodegib will not be developed further as monotherapy in mCRPC.

Elevated Prostate Health Index (phi) and Biopsy Reclassification During Active Surveillance of Prostate Cancer.

The Prostate Health Index (phi) has been FDA approved for decision-making regarding prostate biopsy. Phi has additionally been shown to positively correlate with tumor volume, extraprostatic disease and higher Gleason grade tumors. Here we describe a case in which an elevated phi encouraged biopsy of a gentleman undergoing active surveillance leading to reclassification of his disease as high risk prostate cancer.

SPINK1 Defines a Molecular Subtype of Prostate Cancer in Men with More Rapid Progression in an at Risk, Natural History Radical Prostatectomy Cohort.

PURPOSE: Prostate cancer is clinically and molecularly heterogeneous. We determined the prognosis of men with ERG-ETS fusions and SPINK1 over expression. MATERIALS AND METHODS: Men were identified with intermediate or high risk localized prostate cancer treated with radical prostatectomy and no therapy before metastasis. A case-cohort design sampled a cohort (262) enriched with metastasis from the entire cohort and a cohort (213) enriched with metastasis from patients with biochemical recurrence. We analyzed transcriptomic profiles and subtyped tumors as m-ERG+, m-ETS+, m-SPINK1+ or Triple Negative (m-ERG─/m-ETS─/m-SPINK1─), and multivariable logistic regression analyses, Kaplan-Meier and multivariable Cox models were used to evaluate subtypes as predictors of clinical outcomes. RESULTS: Overall 36%, 13%, 11% and 40% of prostate cancer was classified as m-ERG+, m-ETS+, m-SPINK1+ and Triple Negative, respectively. Univariable analysis demonstrated that m-SPINK1+ tumors were more common in African-American men (OR 5, 95% CI 1.6-16) but less commonly associated with positive surgical margins (OR 0.16, 95% CI 0.03-0.69) compared to the m-ERG+ group. Compared to the Triple Negative group, m-SPINK1+ showed similar associations with race and surgical margins in univariable and multivariable analyses across the entire cohort. Survival analyses did not show significant differences among m-ERG+, m-ETS+ and Triple Negative cases. m-SPINK1+ independently predicted prostate cancer specific mortality after metastasis (HR 2.48, 95% CI 0.96-6.4) and biochemical recurrence (HR 3, 95% CI 1.1-8). CONCLUSIONS: SPINK1 over expression is associated with prostate cancer specific mortality in at risk men with biochemical and clinical recurrence after prostatectomy. ERG-ETS alterations are not prognostic for outcome.