ERG Fusion Research Articles

Upregulation of PTTG1 is associated with poor prognosis in prostate cancer.

Pituitary tumor-transforming gene 1 (PTTG1) is a regulator of chromosome stability. PTTG1 overexpression had been associated with tumor aggressiveness in several cancer types. To examine its prognostic utility in prostate cancer, a tissue microarray including 12 427 tumors with clinical and molecular data was analyzed by immunohistochemistry. PTTG1 immunostaining was largely absent in normal prostate epithelial cells. In cancers, staining was considered weak in 5.4%, moderate in 5.6% and strong in 0.8%. Strong staining was linked to advanced pT stage, high classical and quantitative Gleason grade, high Ki67-labeling index (all P < 0.0001) and lymph node metastasis (P = 0.0083). The prognostic impact of PTTG1 expression was independent of established preoperative and postoperative prognostic features. Comparison with molecular features revealed that PTTG1 upregulation was associated with nine of 12 common genomic deletions (P < 0.05), p53 alterations and high androgen receptor levels (P < 0.001 each), but was unrelated to the TMPRSS2:ERG fusion status. In conclusion, these data identify PTTG1 as a strong and independent prognostic feature in prostate cancer. PTTG1 measurement, either alone or in combination with other biomarkers might be instrumental for determining prostate cancer aggressiveness.

High CHK2 protein expression is a strong and independent prognostic feature in ERG negative prostate cancer

Checkpoint kinase 2 (CHK2) is a serine-threonine kinase with a role in DNA repair, cell cycle arrest or apoptosis in response to DNA damage. Both reduced and increased CHK2 expression has been described in different tumour types with impact on patient prognosis. To evaluate prevalence and significance of altered CHK2 expression in prostate cancer, a tissue microarray containing 17,747 tumours was analysed by immunohistochemistry. Nuclear CHK2 immunostaining was absent or weak in benign prostate epithelium but often more prominent in cancers. CHK2 immunostaining was considered weak in 38.8%, moderate in 33.6% and strong in 11.2% of prostate cancers. High CHK2 expression was strongly associated with TMPRSS2:ERG fusions (p<0.0001). Subgroup analysis of ERG positive and negative cancers revealed that high CHK2 staining was significantly linked to advanced tumour stage, high Gleason score, positive nodal status, positive surgical margin, high preoperative PSA (p<0.0001 each) and early prostate-specific antigen (PSA) recurrence (p=0.0001) in the subset of ERG negative cancers, while most of these associations were absent in ERG positive cancers. In ERG negative cancers, high CHK2 expression was an independent predictor of patient prognosis, even if parameters were included that were only available postoperatively. High CHK2 expression was also linked to presence of chromosomal deletions, high level of androgen receptor expression, positive p53 immunostaining, and high Ki-67 labelling index. These provide further invivo evidence for previously described functional interactions. In summary, high CHK2 expression is linked to adverse tumour features and independently predicts early biochemical recurrence in ERG negative prostate cancer. CHK2 measurement, either alone or in combination, might be of clinical utility in this prostate cancer subgroup.

Association of germline genetic variants with TMPRSS2-ERG fusion status in prostate cancer.

Introduction: Oncogenic activation of ERG resulting from TMPRSS2-ERG gene fusion is a key molecular genetic alteration in prostate cancer (CaP). The frequency of ERG fusion is variable by race; however, there are limited data available on germline polymorphisms associating with ERG fusion status. The goal of this study is to identify the inherited risk variants associating with ERG status of CaP.Materials and Methods: SNP genotyping was performed on the Illumina platform using Infinium Oncoarray SNP chip on blood derived genomic DNA samples from 400 patients treated by radical prostatectomy at a single military institution. ERG status was determined in whole mounted prostate specimens by immuno-histochemistry (IHC) for ERG protein expression. Data analysis approaches included association analyses based on EMMAX and imputation by IMPUTE2. Imputed SNPs were validated by ddPCR.Results: SNP genotyping analysis using imputation identified rs34349373 (p 4.68 × 10-8) and rs2055272 (p 5.62 × 10-8) in TBC1D22B to be significantly associated with ERG fusion status in index tumor and non-index tumor foci. Imputed SNP rs2055272 was further experimentally validated by ddPCR with 98.04% (100/102) concordance. Initial discovery analysis based on SNPs on Oncoarray SNP chip, showed significant (p 10-5) association for SNPs (rs6698333, rs1889877, rs3798999, rs10215144, rs3818136, rs9380660 and rs1792695) with ERG fusion status. The study also replicated two previously known ERG fusion associated SNPs (rs11704416 in chromsome 22; rs16901979 in chromosome 8).Conclusions: This study identified SNPs associated with ERG status of CaP.Impact: The findings may contribute towards defining the underlying genetics of ERG positive and ERG negative CaP patients.

Detailed Molecular and Immune Marker Profiling of Archival Prostate Cancer Samples Reveals an Inverse Association between TMPRSS2:ERG Fusion Status and Immune Cell Infiltration

Prostate cancer is a significant global health issue, and limitations to current patient management pathways often result in overtreatment or undertreatment. New ways to stratify patients are urgently needed. We conducted a feasibility study of such novel assessments, looking for associations between genomic changes and lymphocyte infiltration. An innovative workflow using an in-house targeted sequencing panel, immune cell profiling using an image analysis pipeline, RNA sequencing, and exome sequencing in select cases was tested. Gene fusions were profiled by RNA sequencing in 27 of 27 cases, and a significantly higher tumor-infiltrating lymphocyte (TIL) count was noted in tumors without a TMPRSS2:ERG fusion compared with those with the fusion (P=0.01). Although this finding was not replicated in a larger validation set (n=436) of The Cancer Genome Atlas images, there was a trend in the same direction. Differential expression analysis of TIL-high and TIL-low tumors revealed the enrichment of both innate and adaptive immune response pathways. Mutations in mismatch repair genes (MLH1 and MSH6 mutations in 1 of 27 cases) were identified. We describe a potential immune escape mechanism in TMPRSS2:ERG fusion-positive tumors. Detailed profiling, as shown herein, can provide novel insights into tumor biology. Likely differences with findings with other cohorts are related to methods used to define region of interest, but this warrants further study in a larger cohort.

Inferring Personalized and Race-Specific Causal Effects of Genomic Aberrations on Gleason Scores: A Deep Latent Variable Model.

Extensive research has examined socioeconomic factors influencing prostate cancer (PCa) disparities. However, to what extent molecular and genetic mechanisms may also contribute to these inequalities still remains elusive. Although various in vitro, in vivo, and population studies have originated to address this issue, they are often very costly and time-consuming by nature. In this work, we attempt to explore this problem by a preliminary study, where a joint deep latent variable model (DLVM) is proposed to in silico quantify the personalized and race-specific effects that a genomic aberration may exert on the Gleason Score (GS) of each individual PCa patient. The core of the proposed model is a deep variational autoencoder (VAE) framework, which follows the causal structure of inference with proxies. Extensive experimental results on The Cancer Genome Atlas (TCGA) 270 European-American (EA) and 43 African-American (AA) PCa patients demonstrate that ERG fusions, somatic mutations in SPOP and ATM, and copy number alterations (CNAs) in ERG are the statistically significant genomic factors across all low-, intermediate-, and high-grade PCa that may explain the disparities between these two groups. Moreover, compared to a state-of-the-art deep inference method, our proposed method achieves much higher precision in causal effect inference in terms of the impact of a studied genomic aberration on GS. Further validation on an independent set and the assessment of the genomic-risk scores along with corresponding confidence intervals not only validate our results but also provide valuable insight to the observed racial disparity between these two groups regarding PCa metastasis. The pinpointed significant genomic factors may shed light on the molecular mechanism of cancer disparities in PCa and warrant further investigation.

Upregulation of the transcription factor TFAP2D is associated with aggressive tumor phenotype in prostate cancer lacking the TMPRSS2:ERG fusion

BackgroundTFAP2D is a transcription factor important for modulating gene expression in embryogenesis. Its expression and prognostic role in prostate cancer has not been evaluated.MethodsTherefore, a tissue microarray containing 17,747 prostate cancer specimens with associated pathological, clinical, and molecular data was analyzed by immunohistochemistry to assess the role of TFAP2D.ResultsTFAP2D expression was typically increased in prostate cancer as compared to adjacent non-neoplastic glands. TFAP2D staining was considered negative in 24.3% and positive in 75.7% of 13,545 interpretable cancers. TFAP2D staining was significantly linked to advanced tumor stage, high classical and quantitative Gleason grade, lymph node metastasis, and a positive surgical margin (p ≤ 0.0045). TFAP2D positivity was more common in ERG fusion positive (88.7%) than in ERG negative cancers (66.8%; p < 0.0001). Subset analyses in 3776 cancers with and 4722 cancers without TMPRSS2:ERG fusion revealed that associations with tumor phenotype and patient outcome were largely driven by the subset of ERG negative tumors. Multivariate analysis did not identify TFAP2D protein expression levels as a robust independent prognostic parameter. Positive TFAP2D immunostaining was significantly associated with 10 of 11 previously analyzed chromosomal deletions in ERG negative cancers (p ≤ 0.0244 each) indicating that elevated TFAP2D expression parallels genomic instability in prostate cancer.ConclusionThese data demonstrate that TFAP2D protein overexpression is linked to prostate cancer progression and genomic instability in ERG negative prostate cancers.

TMPRSS2: ERG expression in prostate cancer—Imaging and clinicopathological correlations.

284 Background: The TMPRSS2:ERG gene fusion (T:E) is found in up to 70% of prostate cancers (PCa) and results in androgen dependent overexpression of ERG, promoting tumor growth. The early identification of T:E may be helpful even in low-risk PCa. Although T:E can be non-invasively detected in urine, its correlation with new imaging tools (MRI and high-frequency ultrasound) and clinical outcome remains vague.This study investigates T:E expression in patients scheduled for random/software-assisted MRI or micro-ultrasound (29Mhz) fusion biopsy. Methods: This is a prospective cohort study in patients with suspected PCa enrolled between 2016 and 2019, approved by local authorities with Prot. N. 336/19, 14/05/2019. Patients underwent systematic US-guided biopsy, plus targeted biopsy if they had ³1 suspicious lesion (PI-RADS V.2 &gt;2) at mpMRI or PRIMUS &gt;2 at MICRO-US. For each patient, 1 prostatic core from the highest PI-RADS or PRIMUS lesion was collected for T:E analysis (a core from the right lobe in negative patients). Histological analyses were performed by experienced genitourinary pathologists. RNA was extracted from a dedicated fresh biopsy and RT-PCR was performed with different primer couples to detect the most frequent T:E fusions. All amplified products were checked by sequencing. Results: The cohort consists of 92 patients (median PSA 7.13 ng/ml, IQR 5.25-11.04 - average age 65ys), 81 with a diagnosis of PCa after biopsy. mpMRI was performed on 63 (68.5%) patients and was positive in 58 (92%), who underwent fusion biopsy. T:E fusion transcripts were detected in 23.5% of individuals with a diagnosis of PCa. Among patients positive for T:E, those analyzed by MRI were 100% positive (73% PI-RADS ≥4), those analyzed by MICRO-US were 83% positive. Sensitivity of the T:E assay for any PCa was 23.5%, specificity 100%, with negative and positive predicting values of 15% and 100%. There was no correlation between T:E and family history, PSA, PIRADS, PRI-MUS and Gleason score. Conclusions: Our finding showed a 100% of specificity making T:E an attractive tool for early cancer detection. In the future, identification of T:E in semen could represent a screening test for clinical stratification of patients with suspected PCa.

Characterization of PSMA and 18F-fluciclovine transporter gene expression in localized prostate cancer.

295 Background: While 18F-fluciclovine PET/CT is approved in the US and recommended by the NCCN, prostate-specific membrane antigen (PSMA) PET/CT is more common in Europe/Australia and recommended by the EAU. Less is known about the biology of lesions detected by either modality. 18F-fluciclovine PET relies on radiotracer uptake by amino acid transporters LAT1-4 and ASCT1-2. PSMA PET is dependent on surface expression of PSMA. We compared relative expression of PSMA and fluciclovine transporter genes in radical prostatectomy (RP) samples to determine their distribution across subtypes and correlation with outcomes. Methods: Gene expression data of 19,102 RP samples were analyzed using the Affymetrix Human Exon 1.0 ST microarray. 1,135 patients had long term follow up. Associations between expression of PSMA and fluciclovine transporter genes (LAT1-4 and ASCT1-2) and pathologic variables, molecular subtypes, and clinical outcomes were conducted. Results: All fluciclovine transporter genes (LAT 1-4, ASCT1-2) were expressed at lower levels than PSMA (p &lt;0.0001). PSMA expression was positively correlated with genomic risk score and pathologic Gleason score (p&lt;0.0001), but LAT2-3 and ASCT2 were inversely correlated with genomic risk in primary tumors (p&lt;0.0001) and less expressed in GS 9-10 tumors (p&lt;0.0001). PSMA expression was associated with worse metastasis-free survival (MFS) (HR 1.45, p=0.001) and lymph node involvement (HR 2.14, p&lt;0.0001). Expression of LAT2, LAT3, ASCT2 expression was associated with better MFS (HR 0.85, 0.63, 0.74, p&lt;0.0001-0.04). After multivariable adjustment, PSMA expression remained independently prognostic of poorer MFS (HR 1.3, p=0.028). Luminal B subtype was notable for PSMA overexpression; Luminal A was enriched in ASCT2 and LAT2 (p&lt;0.0001). PSMA expression did not correlate with ERG fusion prostate cancers, but LAT2, ASCT1, and ASCT2 were overexpressed in ERG fusion negative tumors (p&lt;0.0001). Conclusions: PSMA expression is associated with more aggressive disease and poorer clinical outcomes than fluciclovine transporter genes in localized prostate cancer. Molecular subtypes of prostate cancer vary in PSMA and fluciclovine transporter gene expression.

Targeted next-generation sequencing for locally advanced prostate cancer in the Korean population.

PurposeThis study aimed to evaluate the feasibility of pan-cancer panel analysis for locally advanced prostate cancer in the Korean population.Materials and MethodsWe analyzed 20 patients with locally advanced prostate cancer who underwent radical prostatectomy. A pan-cancer panel (1.9 Mbp) developed by Seoul National University Hospital (SNUH), composed of 183 target genes, 23 fusion genes, and 45 drug target regions was used for this analysis. We compared the SNUH pan-cancer panel results with The Cancer Genome Atlas (TCGA) database to search for different mutations in the Korean population. Clinical data were analyzed with univariate and multivariate analysis, and p-values <0.05 were considered statistically significant. Kaplan–Meier curve and log-rank tests were performed to evaluate survival.ResultsThe average age of the patients and initial prostate-specific antigen values were 69.3±7.8 years and 66.3±16.9 ng/dL, respectively. Average sequencing depth was 574.5±304.1×. Ninety-nine genetic mutations and 5 fusions were detected. SPOP (25%), KMT2D (20%), and BRAF (15%) were frequently detected. ERG fusions were recurrently detected in 20% of the patients, with SLMAP and SETD4 as novel fusion partners. BRAF mutation was frequently detected in this study, but not in the TCGA database. Multivariate analysis showed BRAF mutation as an independent prognostic factor for biochemical recurrence (hazard ratio, 9.84; p=0.03).ConclusionsThe pan-cancer panel comprising genes related to prostate cancer is a useful tool for evaluating genetic alterations in locally advanced prostate cancers. Our results suggest that the BRAF mutation is associated with biochemical recurrence in the Korean population.

Loss of cytoplasmic survivin expression is an independent predictor of poor prognosis in radically operated prostate cancer patients.

Survivin is an inhibitor of apoptosis. Aberrant survivin expression occurs in malignant tumors and has often been linked to unfavorable patient outcome. Here we analyzed 12 432 prostate cancers by immunohistochemistry. Survivin immunostaining was regularly expressed at high levels in normal prostate epithelium but expression was often reduced in prostate cancers. Among 9492 evaluable prostate cancers, 9% expressed survivin strongly, 19% moderately, 28% weakly, and 44% lacked it. Loss of cytoplasmic survivin was seen in advanced tumor stage, higher Gleason score, preoperative PSA levels, and Ki‐67 labeling index, and associated with earlier PSA recurrence (P < .0001). Survivin loss was significantly more common in cancers carrying TMPRSS2:ERG fusions (61% survivin negative) than in ERG wild‐type cancers (32% survivin negative; P < .0001). Multivariate analysis revealed that reduced cytoplasmic survivin expression predicted poor prognosis independent from Gleason score, pT, pN, and serum PSA level. This was valid for ERG‐positive and ERG‐negative cancers. Survivin expression loss even retained its prognostic impact in 1020 PTEN deleted cancers, a group that is already characterized by dismal patient prognosis. In conclusion, reduced survivin expression is associated with more aggressive tumors and inferior prognosis in prostate cancer.

Nuclear up regulation of the BRCA1-associated ubiquitinase BAP1 is associated with tumor aggressiveness in prostate cancers lacking the TMPRSS2:ERG fusion.

Loss of the putative tumor suppressor BAP1 is a candidate biomarker for adverse prognosis in many cancer types, but conversely for improved survival in others. Studies on the expression and prognostic role of BAP1 in prostate cancer are currently lacking. We used a tissue microarray of 17,747 individual prostate cancer samples linked with comprehensive pathological, clinical and molecular data and studied the immunohistochemical expression of BAP1. BAP1 expression was typically up regulated in cancers as compared to adjacent normal prostatic glands. In 15,857 cancers, BAP1 staining was weak in 3.3%, moderate in 41.6% and strong in 17.4%. Strong BAP1 staining was associated with advanced tumor stage (p<0.0001), high classical and quantitative Gleason grade (p<0.0001), lymph node metastasis (p<0.0001), a positive surgical margin (p=0.0019) and early biochemical recurrence (p<0.0001). BAP1 expression was linked to ERG-fusion type cancers, with strong BAP1 staining in 12% of ERG-negative, but 30% of ERG-positive cancers (p<0.0001). Subset analyses in 5,415 cancers with and 4,217 cancers without TMPRSS2:ERG fusion revealed that these associations with tumor phenotype and patient outcome were largely driven by the subset of ERG-negative tumors. Multivariate analysis revealed that the prognostic impact was independent of established prognostic features in ERG negative p<0.001) but not in ERG positive cancers. BAP1 expression was further linked to androgen receptor (AR) expression: Only 2% of AR-negative, but 33% of strongly AR expressing cancers had strong BAP1 expression (p<0.0001). In conclusion, this study shows that BAP1 up regulation is linked to prostate cancer progression and aggressiveness.

High-level expression of protein tyrosine phosphatase non-receptor 12 is a strong and independent predictor of poor prognosis in prostate cancer

BackgroundProtein tyrosine phosphatase non-receptor 12 (PTPN12) is ubiquitously tyrosine phosphatase with tumor suppressive properties.MethodsPTPN12 expression was analyzed by immunohistochemistry on a tissue microarray with 13,660 clinical prostate cancer specimens.ResultsPTPN12 staining was typically absent or weak in normal prostatic epithelium but seen in the majority of cancers, where staining was considered weak in 26.5%, moderate in 39.9%, and strong in 4.7%. High PTPN12 staining was associated with high pT category, high classical and quantitative Gleason grade, lymph node metastasis, positive surgical margin, high Ki67 labeling index and early prostate specific antigen recurrence (p < 0.0001 each). PTPN12 staining was seen in 86.4% of TMPRSS2:ERG fusion positive but in only 58.4% of ERG negative cancers. Subset analyses discovered that all associations with unfavorable phenotype and prognosis were markedly stronger in ERG positive than in ERG negative cancers but still retained in the latter group. Multivariate analyses revealed an independent prognostic impact of high PTPN12 expression in all cancers and in the ERG negative subgroup and to a lesser extent also in ERG positive cancers. Comparison with 12 previously analyzed chromosomal deletions revealed that high PTPN12 expression was significantly associated with 10 of 12 deletions in ERG negative and with 7 of 12 deletions in ERG positive cancers (p < 0.05 each) indicating that PTPN12 overexpression parallels increased genomic instability in prostate cancer.ConclusionsThese data identify PTPN12 as an independent prognostic marker in prostate cancer. PTPN12 analysis, either alone or in combination with other biomarkers might be of clinical utility in assessing prostate cancer aggressiveness.

Up regulation of Rho-associated coiled-coil containing kinase1 (ROCK1) is associated with genetic instability and poor prognosis in prostate cancer.

Background and objectives: Overexpression of the cytoskeleton-modulating kinase ROCK1 has been associated with unfavorable outcome in many cancers, but its impact in prostate cancer is largely unknown.Results: A weak ROCK1 staining was found in >90% of normal, and cancerous prostate tissues, but was generally stronger in cancer cells as compared to adjacent normal glands. In cancer, ROCK1 staining was considered weak, moderate, and strong in 22%, 53%, and 18% of cases respectively. Higher ROCK1 expression levels were associated with tumor stage, and Gleason grade, positive nodal stage, positive surgical margin, accelerated cell proliferation and early PSA recurrence in multivariable analysis. ROCK1 up regulation was associated with androgen receptor (AR) expression, TMPRSS2:ERG fusion, genomic deletions of the PTEN tumor suppressor, as well as recurrent deletions at chromosomes 3p, 5q, 6q. Strong ROCK1 staining was found in 3% of AR-negative, but in 27% of strongly AR positive cancers, in 13% of ERG-negative but in 25% of ERG positive cancers, and in 12% of PTEN normal but in 26% of PTEN deleted cancers.Conclusions: This study identifies ROCK1 expression associated with prognosis in prostate cancer.Methods: We tested ROCK1 expression in 12 427 prostate cancer specimens and followed PSA recurrence after prostatectomy.

Detecting FLI1 Fusion by Immunohistochemistry (IHC) Stain in Prostatic Adenocarcinoma

Abstract Objectives The most common genetic alterations in prostate cancer are fusions of ERG and other members of the E26 transformation-specific (ETS) family of transcription factors, including ETV1, ETV4, and FLI1. Analyzing TCGA data, we found that similar to ERG fusion, FLI1 fusion-associated FLI1 mRNA level increases. ERG IHC stain has been a surrogate test for ERG fusion. Therefore, we hypothesize that FLI IHC stain could also be used to detect FLI1 fusion in prostate cancer. Methods In total, 111 primary prostate adenocarcinoma (&gt;10% by volume) cases from our institute were selected for tissue microarray (TMA) construction. The regular full section slides and TMA slides were subject to IHC stain of ERG and FLI1 (Santa Cruz, SC-113). The criteria for positive FLI1 are (1) nuclear staining; (2) only in tumor cells, not in nontumor cells; and (3) FLI1-positive cells should be negative for ERG IHC staining. Results For prostate TMA slides, ~50% of cases were positive for ERG; ~30% of cases were weakly positive for FLI1. However, all of the FLI1 weakly positive cases were positive for ERG as well possibly due to cross-reactivity between ERG and FLI1, which was demonstrated in other studies. Conclusion Overall, we conclude that the cross-reactivity between FL1 and ERG precluded the detection of FLI1 fusion in prostatic adenocarcinoma under current conditions. We are in the process of selecting some cases to detect FLI1 fusion by next-generation sequencing (NGS) and FISH.

Nuclear ELAC2 overexpression is associated with increased hazard for relapse after radical prostatectomy.

ELAC2 is a ubiquitously expressed enzyme potentially involved in tRNA processing and cell signaling pathways. Mutations of the ELAC2 gene have been found to confer increased prostate cancer susceptibility in families. ELAC2 protein expression was analyzed by immunohistochemistry in 9,262 patients and Kaplan-Meier curves of PSA recurrence-free survival were calculated in 8,513 patients treated with radical prostatectomy. Nuclear ELAC2 staining was observed in 60.8% of prostate cancers. It was weak in 26.3%, moderate in 26.6% and strong in 7.9%. Strong nuclear ELAC2 expression was associated with advanced tumor stage, nodal metastasis, higher Gleason grade, presence of TMPRSS2:ERG fusion, higher Ki67-labeling index and PTEN deletion. The difference in 1-, 5- and 10-year recurrence-free survival between strong and weak nuclear ELAC2 intensity is 7.2/13.8/17.6% in all cancers, 7.4/16.1/26.5% in the ERG negative subset, and 3.1/5.7/9.8% in the ERG positive subset. Regarding the univariate hazard ratio, PSA recurrence-free survival after prostatectomy for strong nuclear ELAC2 expression is 1.89 (1.64–2.10, p < 0.0001). It is independent of preoperative PSA-level, Gleason grade, pathological stage, surgical margin stage, and lymph node stage (multivariate hazard ratio 1.29 (1.11–1.49, p = 0.001). We conclude that nuclear ELAC2 expression is an independent prognostic marker for PSA recurrence-free survival after radical prostatectomy with a weak to moderate increase of the hazard ratio for biochemical relapse.

Down-Regulation of S100A8 is an Independent Predictor of PSA Recurrence in Prostate Cancer Treated by Radical Prostatectomy

Dysregulation of S100A8 is described in many different human tumor types, but its role in prostate cancer is unknown. To evaluate the clinical relevance of S100A8 expression in prostate cancer, a tissue microarray containing 13,665 tumors was analyzed by immunohistochemistry. Cytoplasmic S100A8 staining was compared to prostate cancer phenotype, patient prognosis and molecular features including TMPRSS2:ERG fusion status and deletions of PTEN, 3p, 5q and 6q. S100A8 immunostaining was typically seen in normal prostate tissue but lost in 60% of 9786 interpretable prostate cancers. In the remaining tumors, S100A8 was considered weak in 17.9%, moderate in 17.8% and strong in 5.4% of cases. Loss of S100A8 expression was linked to advanced tumor stage, high Gleason grade, positive nodal status, positive surgical margin and high preoperative PSA (P < .0001 each). In addition, loss of S100A8 expression was associated with TMPRSS2:ERG fusions (P < .0001), deletions of PTEN, 3p, and 6q (P < .005), and a high number of genomic deletions per tumor (P = .0009). Absence of S100A8 immunostaining was also linked to an elevated risk for early PSA recurrence (P < .0001). In a multivariate analysis limited to features that are preoperatively available, the prognostic impact of S100A8 expression (P < .0001) was independent of clinical stage, Gleason grade, and serum PSA level (P < .0001). Taken together, the results of our study demonstrate that complete loss of S100A8 expression is linked to adverse tumor features and predicts early biochemical recurrence in prostate cancer. S100A8 measurement, either alone or in combination might be of clinical utility in prostate cancers.

Abstract 2748: The role of TMPRSS2_ERG fusions in modulating tumor microenvironment in prostate cancer

Abstract The control region of TMPRSS2 fuses with ETS transcription factor family members, particularly ERG. This occurs in ~20-50% of human prostate cancers depending on the ethnicity. TMPRSS2-ERG (T2E) fusions, however, do not display a notable phenotype in genetically engineered mouse models (GEMM) recapitulating the fusion expression and T2E also has no prognostic significance in humans, despite its high incidence. Wnt signaling has been implicated in prostate cancer. Here, we report a discovery of a role for T2E fusion that impacts the prostate stroma in pre-clinical models. The composition of stromal cells within the microenvironment in T2E mice was studied by single cell RNAseq analysis. We identified stromal cell clusters in T2E mice that differed from wild type mice in the expression of Pdgfrβ, Pdgfrα and Col1a1. Interestingly, these clusters showed an increase of expression of Wnt receptors such as Lgr5 and Fzd7 as well as Wnt ligands such as Sfrp2, Wnt2 and Wnt6. T2E GEMMs also exhibited upregulation of the Wnt-secretion regulator porcupine (PORCN-Protein-serine O-palmitoleoyltransferase) in the stroma adjacent to the T2E-expression prostate epithelial cells. Furthermore, lineage-tracing with the Wnt reporter and epithelial stem cell marker Lgr5 showed that Wnt-active cells were increased in prostatic intraepithelial neoplasia (PIN) lesions in T2E;Pten+/- mice. Strikingly, Lgr5+ cells were also found in the prostate stroma surrounding these PINs. Since, TMPRSS2/ERG fusions represent an early event in prostate tumorigenesis, here we provide a mechanism whereby induction of Wnt signaling in the stroma by T2E-expressing prostate epithelial cells increases the stem cell compartments in both epithelial and stromal cells. These data suggest that aberrant ERG-expressing prostate epithelial cells activate upregulation of Wnt signaling in stromal cells, which provides a possible route for enhancing prostate carcinogenesis. Citation Format: Hubert Pakula, Caroline F. Ribeiro, Giuseppe N. Fanelli, Rory Kirchner, Sudeepa Syamala, Basudev Chowdhury, Giorgia Zadra, Paolo Chetta, Zhe Li, Massimo Loda. The role of TMPRSS2_ERG fusions in modulating tumor microenvironment in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2748.

Abstract 1568: Clinical implications of tmprss2-erg fusion and tumor location in prostate cancer

Abstract Introduction: There is limited data on the impact of race on tumor location and TMPRSS2-ERG (ERG) gene fusion status in Prostate Cancer (PCa). African American men (AAM) often lack the ERG fusion and are likely to experience poor outcomes. Nonetheless, the extent to which ERG status, race, and tumor location impacts PCa outcomes remains unclear. Methods: This multi-institutional study included a retrospective cohort of 495 AAM and 422 European American men (EAM) who received prostatectomy at Moffitt Cancer Center (MCC) and University of Pennsylvania Health system (UPHS). To assess the race-dependent variation in ERG protein expression and its association with tumor location and PCa pathology, ERG antibody staining on 4 micron sections of FFPE blocks were carried out on all samples. ERG expression was categorized as ERGpos and ERGneg by two pathologists. Additionally, the staining pattern of ERG was analyzed within ERGpos tumors. A review of anatomic location of the dominant tumor lesions was performed and analyzed using methods of categorical analysis and logistic regression. Alpha value of &amp;lt; 0.05 was considered as statistically significant. Results: In all samples, analysis of ERG immunohistochemistry (IHC) yielded 39.7% ERGpos and 60.6% ERGneg. Variability in histopathologic expression of ERG was significant between races with AAM being more likely to lack TMPRSS2-ERG fusion (ERGneg) compared to EAM, (62% vs 38%, p &amp;lt; 0.001). Lack of ERG fusion was also associated with anatomically distinct tumor location with 72.1% of anteriorly located tumors having ERGneg staining, while only 27.9% were ERGpos, (p &amp;lt; 0.001). Among ERGpos patients, AAM (65.2%) showed significant heterogeneous expression of ERG compared to EAM (31.8%). Furthermore, ERGneg status was associated with higher pretreatment PSA. In a multivariate logistic regression model adjusted for tumor location and race, ERGneg tumors were more likely to have Gleason Score 4+3=7 (Grade Group 3) or higher compared with ERGpos tumors, Odds ratio 2.07, 95% CI 1.20 - 3.56, p = 0.008. Conclusions: The absence of TMPRSS2-ERG fusion is associated with higher grade disease and is a strong predictor for anatomic tumor location within the prostate gland. The clinical implications of ERGneg tumors among AAM and its association with anteriorly located tumors can be vital in addressing disparities in PCa. Citation Format: Kosj Yamoah, Shivanshu Awasthi, Priti Lal, Arash O. Naghavi, Shelly Mahajan, Jong Y. Park, Rob Rounbehler, Travis Gerke, Anders Berglund, Julio PowSang, Jasreman Dhillon, Timothy R. Rebbeck. Clinical implications of tmprss2-erg fusion and tumor location in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1568.

The independent prognostic impact of the GATA2 pioneering factor is restricted to ERG-negative prostate cancer

GATA2 is a pioneering transcription factor governing androgen receptor expression and signaling in prostate cells. To understand the prognostic potential of GATA2 assessment in prostate cancer, we analyzed nuclear GATA2 expression on an annotated tissue microarray with 12,427 prostate cancer samples. Normal prostate glands were negative to weakly positive. GATA2 staining was found in almost all prostate cancers (95%). Strong GATA2 staining was linked to advanced tumor stage, high classical and quantitative Gleason grade (p < 0.0001 each), positive nodal stage (p = 0.0116), and early biochemical recurrence (p < 0.0001). GATA2 was linked to ERG-fusion-type cancers, with strong GATA2 staining in 29% of ERG-negative and 53% of ERG-positive cancers (p < 0.0001). Separate calculations in 3854 cancers with and 4768 cancers without TMPRSS2:ERG fusion revealed that these associations with tumor phenotype and patient outcome were largely driven by the subset of ERG-negative tumors. GATA2 expression was further linked to androgen receptor expression: Only 8% of androgen receptor-negative, but 56% of strongly androgen receptor expressing cancers had strong GATA2 expression (p < 0.0001). In conclusion, the results of our study demonstrate that increasing GATA2 levels are linked to prostate cancer progression and aggressiveness. The prognostic value of GATA2 is remarkable in ERG-negative cancers. However, the upregulation of GATA2 in ERG-positive cancers makes it unsuitable as a prognostic marker in this patient subset.

Transcriptomic and Clinical Characterization of Neuropeptide Y Expression in Localized and Metastatic Prostate Cancer: Identification of Novel Prostate Cancer Subtype with Clinical Implications

BackgroundTumor microenvironment and its interaction with neuroendocrine modulators contribute to prostate carcinogenesis and progression. ObjectiveWe sought to define the transcriptomic and clinical implications of neuropeptide Y (NPY) expression in prostate cancer progression. Design, setting, and participantsGenome-wide expression profiling of three localized prostate cancer (total n=18818) and five metastatic castrate-resistant prostate cancer (mCRPC; total n=495) cohorts was used to characterize NPY expression. All men underwent radical prostatectomy (RP) for localized prostate cancer. Outcome measurements and statistical analysisPatients were grouped into those with low NPY and high NPY based on NPY expression. Associations between these groups and histological, genomic, and clinical outcomes including progression-free survival (PFS) and metastases-free survival (MFS) were examined. Combining ERG-fusion status with NPY expression, four groups were defined (lowNPY/ERG+, lowNPY/ERG−, highNPY/ERG+, and highNPY/ERG−). Cox proportional hazards modeled the time to distant metastasis after RP. Genomic risk scores for metastasis were calculated for prospective samples, based on a 22-gene signature. Results and limitationsAcross cancers, NPY showed the highest expression in prostate cancer in The Cancer Genome Atlas (TCGA) PAN-Cancer cohort (n=9483, p<0.0001). In 17967 prospective samples, low NPY expression was associated with aggressive grade group 5 disease and a higher genomic risk (p<0.0001). In the retrospective (n=355) and TCGA (n=497) cohorts, low NPY was associated with shorter MFS and PFS, respectively (p=0.001 for both). In mCRPC cohorts, low NPY was associated with neuroendocrine development (p<0.01). NPY was highly correlated to ERG; thus, we defined four groups based on NPY expression and ERG fusion. The lowNPY/ERG+ subtype was associated with the highest genomic risk for metastasis (p<0.0001) and the highest rate of metastasis compared with all other subtypes (hazard ratio [HR]: 2.2 [1.22–4.03], p=0.008), while the highNPY/ERG− subtype was associated with the lowest genomic risk for metastasis (p<0.0001) and the lowest rate of metastasis (HR: 0.53 [0.35–0.81], p=0.003). ConclusionsLow NPY expression is associated with adverse genomic features and clinical correlates and outcomes. The lowNPY/ERG+ subtype was associated with the highest risk of developing metastasis. Prognostic subgrouping and tailored treatments by NPY expression and ERG fusion status warrant further study. Patient summaryThe low neuropeptide Y prostate cancer subtype appears to be aggressive with a high risk of developing metastasis.