Genetic and molecular differences in prostate carcinogenesis between African American and Caucasian American men

Regulation of SELENOF translation by eIF4a3: Possible role in prostate cancer progression

The levels of the SELENOF selenoprotein are dramatically reduced in prostate cancer compared to adjacent benign tissue and reducing SELENOF in prostate epithelial cells results in the acquisition of features of the transformed phenotype. It was hypothesized that the aberrant increase in the eiF4a3 translation factor, which has an established role in RNA splicing and the regulation of selenoprotein translation, contributes to the lower levels of SELENOF. Using the available databases, eIF4a3 messenger RNA (mRNA) levels are elevated in prostate cancer compared to normal tissue as is the hypomethylation of the corresponding gene. Using a prostate cancer tissue microarray, we established that eiF4a3 levels are higher in prostate cancer tissue. Ectopic expression of eIF4a3 in prostate cancer cells reduced SELENOF levels and attenuated the readthrough of the UGA codon using a specialized reporter construct designed to examine UGA decoding, with the opposite effects observed using eIF4a3 knock-down constructs. Direct binding of eIF4a3 to the regulatory regions of SELENOF mRNA was established with pull-down experiments. Lastly, we show that an eIF4a3 inhibitor, eIF4a3-IN-2, increases SELENOF levels, UGA readthrough, and reduces binding of eIF4a3 to the SELENOF mRNA 3'-UTR in exposed cells. These data establish eIF4a3 as a likely prostate cancer oncogene and a regulator of SELENOF translation.

Germline Genetic Variants Associated with Somatic TMPRSS2:ERG Fusion Status in Prostate Cancer: A Genome-Wide Association Study

BACKGROUND

The prostate cancer subtype defined by the presence of TMPRSS2:ERG has been shown to be molecularly and epidemiologically distinct. However, few studies have investigated germline genetic variants associating with TMPRSS2:ERG fusion status.

METHODS

We performed a genome-wide association study with 396 TMPRSS2:ERG(+) cases, 390 TMPRSS2:ERG(-) cases, and 2,386 cancer-free controls from the Physicians' Health Study (PHS), the Health Professionals Follow-up Study (HPFS), and a Seattle-based Fred Hutchinson (FH) Cancer Center Prostate Cancer Study. We applied logistic regression models to test the associations between ∼5 million SNPs with TMPRSS2:ERG fusion status accounting for population stratification.

RESULTS

We did not identify genome-wide significant variants comparing the TMPRSS2:ERG(+) to the TMPRSS2:ERG(-) prostate cancer cases in the meta-analysis. When comparing TMPRSS2:ERG(+) prostate cancer cases with controls without prostate cancer, 10 genome-wide significant SNPs on chromosome 17q24.3 were observed in the meta-analysis. When comparing TMPRSS2:ERG(-) prostate cancer cases with controls without prostate cancer, two SNPs on chromosome 8q24.21 in the meta-analysis reached genome-wide significance.

CONCLUSIONS

We observed SNPs at several known prostate cancer risk loci (17q24.3, 1q32.1, and 8q24.21) that were differentially and exclusively associated with the risk of developing prostate tumors either with or without the gene fusion.

IMPACT

Our findings suggest that tumors with the TMPRSS2:ERG fusion exhibit a different germline genetic etiology compared with fusion negative cases.

Obesity and prostate cancer - microenvironmental roles of adipose tissue

Obesity is known to have important roles in driving prostate cancer aggressiveness and increased mortality. Multiple mechanisms have been postulated for these clinical observations, including effects of diet and lifestyle, systemic changes in energy balance and hormonal regulation and activation of signalling by growth factors and cytokines and other components of the immune system. Over the past decade, research on obesity has shifted towards investigating the role of peri-prostatic white adipose tissue as an important source of locally produced factors that stimulate prostate cancer progression. Cells that comprise white adipose tissue, the adipocytes and their progenitor adipose stromal cells (ASCs), which proliferate to accommodate white adipose tissue expansion in obesity, have been identified as important drivers of obesity-associated cancer progression. Accumulating evidence suggests that adipocytes are a source of lipids that are used by adjacent prostate cancer cells. However, results of preclinical studies indicate that ASCs promote tumour growth by remodelling extracellular matrix and supporting neovascularization, contributing to the recruitment of immunosuppressive cells, and inducing epithelial-mesenchymal transition through paracrine signalling. Because epithelial-mesenchymal transition is associated with cancer chemotherapy resistance and metastasis, ASCs are considered to be potential targets of therapies that could be developed to suppress cancer aggressiveness in patients with obesity.

Racial disparity in the genomics of precision oncology of prostate cancer

BACKGROUND

Significant racial disparities in prostate cancer incidence and mortality have been reported between African American Men (AAM), who are at increased risk for prostate cancer, and European American Men (EAM). In most of the studies carried out on prostate cancer, this population is underrepresented. With the advancement of genome-wide association studies, several genetic predictor models of prostate cancer risk have been elaborated, as well as numerous studies that identify both germline and somatic mutations with clinical utility.

RECENT FINDINGS

Despite significant advances, the AAM population continues to be underrepresented in genomic studies, which can limit generalizability and potentially widen disparities. Here we outline racial disparities in currently available genomic applications that are used to estimate the risk of individuals developing prostate cancer and to identify personalized oncology treatment strategies. While the incidence and mortality of prostate cancer are different between AAM and EAM, samples from AAM remain to be unrepresented in different studies.

CONCLUSION

This disparity impacts the available genomic data on prostate cancer. As a result, the disparity can limit the predictive utility of the genomic applications and may lead to the widening of the existing disparities. More studies with substantially higher recruitment and engagement of African American patients are necessary to overcome this disparity.

Immunologic Assessment of Tumors from a Race-matched Military Cohort Identifies Mast Cell Depletion as a Marker of Prostate Cancer Progression

Elucidating the cellular immune components underlying aggressive prostate cancer, especially among African American (AA) men who are disproportionately affected by this disease compared with Caucasian American (CA) men, will support more inclusive precision medicine treatment strategies. We aimed to evaluate which immune-related genes and cell types are differentially expressed in AA tumors and how immunobiology impacts prostate cancer progression. We purified nucleic acid from tumor biopsies, obtained following radical prostatectomy, from 51 patients (AA = 26, CA = 25). Gene expression was measured using the NanoString platform from which we estimated immune cell abundances and assessed differences between groups based on clinicopathologic data. Product-limit estimates determined associations with biochemical recurrence (BCR)-free and metastasis-free survival. DVL2 and KLRC2 were significantly upregulated in CA tumors and were also associated with worse disease progression. No significant differences in immune cell abundances by race were observed. Highly significant reductions in abundances of mast cells versus tumor-infiltrating lymphocytes (TIL) were found in men with high-grade pathologies and in men who later developed metastases. Low ratios of mast cells versus TILs were associated with worse BCR-free survival and metastasis-free survival. Although estimated immune cell abundances were not different by race, we identified genes involved in metabolism and natural killer cell functions that were differentially expressed between AA and CA tumors. Among the entire cohort, depletion of mast cells within prostatectomy tumors was characteristic of advanced disease and susceptibility to disease progression.

Significance

Our findings demonstrate that there are immune-related genes and pathways that differ by race. Impaired intratumoral cellular immune composition, especially for TIL-normalized mast cells, may be vital in predicting and contributing to prostate cancer disease progression.

Recruiting African American Prostate Cancer Survivors for a Population-based Biobank Study

BACKGROUND

Prostate cancer affects African American men disproportionately compared with men of other racial/ethnic groups. To identify biological bases for this health disparity, we sought to create a state-wide biobank of African American prostate cancer survivors in Florida.

METHODS

African American men diagnosed with prostate cancer between 2013 and 2017 and living in Florida at diagnosis were identified through the State of Florida's cancer registry. Individuals were approached via mail and telephone, assessed for eligibility, and asked for informed consent. χ2 and t tests were conducted to identify differences between eligible and reachable individuals (i.e., had valid contact information) versus consented participants.

RESULTS

Of the 5,960 eligible and reachable individuals, 3,904 were eligible and contacted at least once, and 578 consented [overall consent rate = 10% (578/5,960); adjusted consent rate = 15% (578/3,904)]. Statistically significant (Ps < 0.05) but small differences in demographic and clinical variables were observed. Consented participants were less likely to be older than 64 (35% vs. 41%) and less likely to have received radiotherapy (36% vs. 41%) and hormone therapy (16% vs. 21%), but more likely to have regional prostate cancer (13% vs. 11%) and have undergone surgery (44% vs. 39%). Consented participants did not differ from reachable individuals on other demographic and clinical factors (Ps > 0.05).

CONCLUSIONS

Recruiting African American prostate cancer survivors to biobanking research through a cancer registry is feasible. However, the consent rate was low, and existing challenges limit consent and participation.

IMPACT

Strategies for overcoming barriers to informed consent and increasing participation in biospecimen research are needed to address cancer disparities.

Identification of novel biomarkers differentially expressed between African-American and Caucasian-American prostate cancer patients

Prostate cancer (PCa) incidence and mortality rate vary among racial and ethnic groups with the highest occurrence in African American (AA) men who have mortality rates twice that of Caucasians (CA). In this study, we focused on differential expression of proteins in AA prostate cancer compared to CA using Protein Pathway Array Analysis (PPAA), in order to identify protein biomarkers associated with PCa racial disparity. Fresh frozen prostate samples (n=90) obtained from radical prostatectomy specimens with PCa, including 25 AA tumor, 21 AA benign, 23 CA tumor, 21 CA benign samples were analyzed. A total of 286 proteins and phosphoproteins were assessed using PPAA. By PPAA analysis, 33 proteins were found to be significantly differentially expressed in tumor tissue (n=48, including both CA and AA) in comparison to benign tissue (n=42). We further compared protein expression levels between AA and CA tumor groups and found that 3 proteins were differentially expressed (P<0.05 and q<5%). Aurora was found to be significantly increased in AA tumors, while Cyclin D1 and HNF-3a proteins were downregulated in AA tumors. Predicted risk score was significantly different between AA and CA ethnic groups using logistic regression analysis. In conclusion, we identified Aurora, Cyclin D1 and HNF-3a proteins as being differentially expressed between AA and CA in PCa tissue. Our study suggests that these proteins might be involved in different pathways that lead to aggressive PCa behavior in AA patients, potentially serving as biomarkers for the PCa racial disparity.

Role of Precision Oncology in Type II Endometrial and Prostate Cancers in the African Population: Global Cancer Genomics Disparities

Precision oncology can be defined as molecular profiling of tumors to identify targetable alterations. Emerging research reports the high mortality rates associated with type II endometrial cancer in black women and with prostate cancer in men of African ancestry. The lack of adequate genetic reference information from the African genome is one of the major obstacles in exploring the benefits of precision oncology in the African context. Whilst external factors such as the geography, environment, health-care access and socio-economic status may contribute greatly towards the disparities observed in type II endometrial and prostate cancers in black populations compared to Caucasians, the contribution of African ancestry to the contribution of genetics to the etiology of these cancers cannot be ignored. Non-coding RNAs (ncRNAs) continue to emerge as important regulators of gene expression and the key molecular pathways involved in tumorigenesis. Particular attention is focused on activated/repressed genes and associated pathways, while the redundant pathways (pathways that have the same outcome or activate the same downstream effectors) are often ignored. However, comprehensive evidence to understand the relationship between type II endometrial cancer, prostate cancer and African ancestry remains poorly understood. The sub-Saharan African (SSA) region has both the highest incidence and mortality of both type II endometrial and prostate cancers. Understanding how the entire transcriptomic landscape of these two reproductive cancers is regulated by ncRNAs in an African cohort may help elucidate the relationship between race and pathological disparities of these two diseases. This review focuses on global disparities in medicine, PCa and ECa. The role of precision oncology in PCa and ECa in the African population will also be discussed.

Expression of Endogenous Retroviral RNA in Prostate Tumors has Prognostic Value and Shows Differences among Americans of African Versus European/Middle Eastern Ancestry

Simple Summary

Endogenous retroviruses (ERVs) are viral sequences that have been incorporated into the human genome over millions of years via integrations in germ-line cells. In this study, we investigated whether the expression of ERVs was associated with two different aspects of prostate cancer (PCa). First, Black American men have a higher incidence and poorer outcome of PCa compared to White men. We identified differences in ERV expression among prostate tumors between men of primarily African versus primarily European or Middle Eastern ancestry, which may be associated with differences in the mechanism of cancer progression in patients of these distinct ancestries. Second, we determined whether ERV expression might be correlated with the progression of disease, regardless of ancestry. We identified the ERV expression signatures that correlated with biochemical relapse among PCa patients of all ancestries, indicating that ERVs may be useful for identifying cancer patients at greatest risk of progression. The utility of ERV expression for studying cancer progression may extend to other cancers.

Abstract

Endogenous retroviruses (ERVs) are abundant, repetitive elements dispersed across the human genome and are implicated in various diseases. We investigated two potential roles for ERVs in prostate cancer (PCa). First, the PCa of Black Americans (BA) is diagnosed at an earlier median age and at a more advanced stage than the PCa of White Americans (WA). We used publicly available RNA-seq data from tumor-enriched samples of 27 BA and 65 WA PCa patients in order to identify 12 differentially expressed ERVs (p_adj < 0.1) and used a tissue microarray of the PCa cores from an independent set of BA and WA patients to validate the differential protein expression of one of these ERVs, ERV3-1 (p = 2.829 × 10⁻⁷). Second, we used 57 PCa tumors from patients of all ancestries from one hospital as a training set to identify the ERVs associated with time to biochemical relapse. A 29-ERV prognostic panel was then tested and validated on 35 separate PCa tumors from patients obtained in two different hospitals with a dramatic increase in prognostic power relative to clinical parameters alone (p = 7.4 × 10⁻¹¹). In summary, ERV RNA expression differences in the prostate tumors of patients of different ancestries may be associated with dissimilarities in the mechanism of cancer progression. In addition, the correlation of expression of certain ERVs in prostate tumors with the risk of biochemical relapse indicates a possible role for ERV expression in cancer progression.

A deep imputation and inference framework for estimating personalized and race-specific causal effects of genomic alterations on PSA

Prostate Specific Antigen (PSA) level in the serum is one of the most widely used markers in monitoring prostate cancer (PCa) progression, treatment response, and disease relapse. Although significant efforts have been taken to analyze various socioeconomic and cultural factors that contribute to the racial disparities in PCa, limited research has been performed to quantitatively understand how and to what extent molecular alterations may impact differential PSA levels present at varied tumor status between African-American and European-American men. Moreover, missing values among patients add another layer of difficulty in precisely inferring their outcomes. In light of these issues, we propose a data-driven, deep learning-based imputation and inference framework (DIIF). DIIF seamlessly encapsulates two modules: an imputation module driven by a regularized deep autoencoder for imputing critical missing information and an inference module in which two deep variational autoencoders are coupled with a graphical inference model to quantify the personalized and race-specific causal effects. Large-scale empirical studies on the independent sub-cohorts of The Cancer Genome Atlas (TCGA) PCa patients demonstrate the effectiveness of DIIF. We further found that somatic mutations in TP53, ATM, PTEN, FOXA1, and PIK3CA are statistically significant genomic factors that may explain the racial disparities in different PCa features characterized by PSA.

The Impact of African Ancestry on Prostate Cancer Disparities in the Era of Precision Medicine

Prostate cancer disproportionately affects men of African ancestry at nearly twice the rate of men of European ancestry despite the advancement of treatment strategies and prevention. In this review, we discuss the underlying causes of these disparities including genetics, environmental/behavioral, and social determinants of health while highlighting the implications and challenges that contribute to the stark underrepresentation of men of African ancestry in clinical trials and genetic research studies. Reducing prostate cancer disparities through the development of personalized medicine approaches based on genetics will require a holistic understanding of the complex interplay of non-genetic factors that disproportionately exacerbate the observed disparity between men of African and European ancestries.

Prostate Cancer Screening Recommendations for General and Specific Populations in the Western Nations

There is a chaotic scenario that exists in the field of prostate cancer (PCa) screening. To balance goals, such as decreasing mortality, avoiding unnecessary procedures, and decreasing the cost of medical care, the pendulum seems to have swung to the side of more restricted screening. The decrease in PCa screening has led to a slowly creeping decline in the favourable outcomes that existed among patients with PCa. If a potential patient or a family member is trying to get clear guidance about PCa screening by searching the internet, they will end up confused by several recommendations from many organisations. It is even more challenging to obtain any clarity about PCa screening for special populations, such as those with a family history of PCa, those of African descent/African Americans, and the elderly. The advent of genomic medicine and precision medicine is an opportunity to identify those at a very high risk of developing aggressive PCa, so that PCa screening can be more actively undertaken among them. In this paper, the authors review the current recommendations by different entities and summarise emerging molecular markers that may help bring clarity to PCa screening. The authors predict that concrete, consensual guidelines will emerge in less than one decade. Meanwhile, this article suggests intermediary steps that will help save lives from PCa mortality, especially for under-represented populations. This paper is a catalyst to stimulate further discussion and serves as a guide to noncancer-specialists for the near future as precision medicine progresses to better understand risk–benefit and cost–benefit ratios in PCa screening.

Lack of Racial Survival Differences in Metastatic Prostate Cancer in National Cancer Data Base (NCDB): A Different Finding Compared to Non-metastatic Disease

Background: Inconsistent findings have been reported in the literature regarding racial differences in survival outcomes between African American and white patients with metastatic prostate cancer (mPCa). The current study utilized a national database to determine whether racial differences exist among the target population to address this inconsistency.

Methods: This study retrospectively reviewed prostate cancer (PCa) patient data (N = 1,319,225) from the National Cancer Database (NCDB). The data were divided into three groupings based on the metastatic status: (1) no metastasis (N = 318,291), (2) bone metastasis (N = 29,639), and (3) metastases to locations other than bone, such as brain, liver, or lung (N = 952). Survival probabilities of African American and white PCa patients with bone metastasis were examined through parametric proportional hazards Weibull models and Bayesian survival analysis. These results were compared to patients with no metastasis or other types of metastases.

Results: No statistically supported racial disparities were observed for African American and white men with bone metastasis (p = 0.885). Similarly, there were no racial disparities in survival for those men suffering from other metastases (liver, lung, or brain). However, racial disparities in survival were observed among the two racial groups with non-metastatic PCa (p < 0.001) or when metastasis status was not taken into account (p < 0.001). The Bayesian analysis corroborates the finding.

Conclusion: This research supports our previous findings and shows that there are no racial differences in survival outcomes between African American and white patients with mPCa. In contrast, racial disparities in the survival outcome continue to exist among non-metastatic PCa patients. Further research is warranted to explain this difference.

The Interaction between Dietary Selenium Intake and Genetics in Determining Cancer Risk and Outcome

There is considerable interest in the trace element selenium as a possible cancer chemopreventive dietary component, but supplementation trials have not indicated a clear benefit. Selenium is a critical component of selenium-containing proteins, or selenoproteins. Members of this protein family contain selenium in the form of selenocysteine. Selenocysteine is encoded by an in-frame UGA codon recognized as a selenocysteine codon by a regulatory element, the selenocysteine insertion sequence (SECIS), in the 3′-untranslated region of selenoprotein mRNAs. Epidemiological studies have implicated several selenoprotein genes in cancer risk or outcome based on associations between allelic variations and disease risk or mortality. These polymorphisms can be found in or near the SECIS or in the selenoprotein coding sequence. These variations both function to control protein synthesis and impact the efficiency of protein synthesis in response to the levels of available selenium. Thus, an individual’s genetic makeup and nutritional intake of selenium may interact to predispose them to acquiring cancer or affect cancer progression to lethality.

A 17-Gene Panel Genomic Prostate Score Has Similar Predictive Accuracy for Adverse Pathology at Radical Prostatectomy in African American and European American Men

OBJECTIVE

To validate the 17-gene Oncotype DX Genomic Prostate Score (GPS) as a predictor of adverse pathology (AP) in African American (AA) men and to assess the distribution of GPS in AA and European American (EA) men with localized prostate cancer.

METHODS

The study populations were derived from 2 multi-institutional observational studies. Between February 2009 and September 2014, AA and EA men who elected immediate radical prostatectomy after a ≥10-core transrectal ultrasound biopsy were included in the study. Logistic regressions, area under the receiver operating characteristics curves (AUC), calibration curves, and predictive values were used to compare the accuracy of GPS. AP was defined as primary Gleason grade 4, presence of any Gleason pattern 5, and/or non-organ-confined disease (≥pT3aN0M0) at radical prostatectomy.

RESULTS

Overall, 96 AA and 76 EA men were selected and 46 (26.7%) had AP. GPS result was a significant predictor of AP (odds ratio per 20 GPS units [OR/20 units] in AA: 4.58; 95% confidence interval (CI) 1.8-11.5, P = .001; and EA: 4.88; 95% CI 1.8-13.5, P = .002). On multivariate analysis, there was no significant interaction between GPS and race (P >.10). GPS remained significant in models adjusted for either National Comprehensive Cancer Network (NCCN) risk group or Cancer of the Prostate Risk Assessment (CAPRA) score. In race-stratified models, area under the receiver operating characteristics curves for GPS/20 units was 0.69 for AAs vs 0.74 for EAs (P = .79). The GPS distributions were not statistically different by race (all P >.05).

CONCLUSION

In this clinical validation study, the Oncotype DX GPS is an independent predictor of AP at prostatectomy in AA and EA men with similar predictive accuracy and distributions.

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.

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.

Selenoproteins of the Human Prostate: Unusual Properties and Role in Cancer Etiology

The prostate is an important organ for the maintenance of sperm health with prostate cancer being a common disease for which there is a critical need to distinguish indolent from aggressive disease. Several selenium-containing proteins have been implicated in prostate cancer risk or outcome due to either enzyme function, the reduced levels of these proteins being associated with cancer recurrence after prostatectomy or their corresponding genes containing single-nucleotide polymorphisms associated with increased risk. Moreover, experimental data obtained from the manipulation of either cultured cells or animal models have indicated that some of these proteins are contributing mechanistically to prostate cancer incidence or progression. Among these are selenocysteine-containing proteins selenoprotein P (SELENOP), glutathione peroxidase (GPX1), and selenoprotein 15 (SELENOF); and the selenium-associated protein selenium-binding protein 1 (SBP1). Genotyping of some of the genes for these proteins has identified functional single-nucleotide polymorphisms that are associated with prostate cancer risk and the direct quantification of these proteins in human prostate tissues has not only revealed associations to clinical outcomes but have also identified unique properties that are different from what is observed in other tissue types. The location of GPX1 in the nucleus and SELENOF in the plasma membrane of prostate epithelial cells indicates that these proteins may have functions in normal prostate tissue that are distinct from that of the other tissue types.

Development and initial psychometric evaluation of the computer-based prostate Cancer screening decision aid acceptance scale for African-American men

BACKGROUND

To reliably evaluate the acceptance and use of computer-based prostate cancer decision aids (CBDAs) for African-American men, culturally relevant measures are needed. This study describes the development and initial psychometric evaluation of the 24-item Computer-Based Prostate Cancer Screening Decision Aid Acceptance Scale among 357 African-American men.

METHODS

Exploratory factor analysis (EFA) with maximum likelihood estimation and polychoric correlations followed by Promax and Varimax rotations.

RESULTS

EFA yielded three factors: Technology Use Expectancy and Intention (16 items), Technology Use Anxiety (5 items), and Technology Use Self-Efficacy (3 items) with good to excellent internal consistency reliability at .95, .90, and .85, respectively. The standardized root mean square residual (0.035) indicated the factor structure explained most of the correlations.

CONCLUSIONS

Findings suggest the three-factor, 24-item Computer-Based Prostate Cancer Screening Decision Aid Acceptance Scale has utility in determining the acceptance and use of CBDAs among African-American men at risk for prostate cancer. Future research is needed to confirm this factor structure among socio-demographically diverse African-Americans.

Emerging genomic biomarkers for improving kidney, prostate, and bladder cancer health disparities outcomes

BACKGROUND

Recent advances in genomic and genetic technologies have facilitated better health outcomes for urologic cancer patients. Genomic and genetic heterogeneity may contribute to differences in tumor biology and urologic cancer burden across various populations.

OBJECTIVE

To examine how emerging genomic and genetic biomarkers, self-reported race, and ancestry-informative markers are associated with kidney, prostate, and bladder cancer outcomes.

RESULTS

Genomic and genetic alterations found in African American kidney cancer patients included distinct somatic mutations, somatic copy number alterations, chromosomal instability, germ-line risk alleles, and germ-line genetic variants. These changes correlated with improved risk prediction, prognosis, and survival; and a predicted decrease in response to targeted therapies. SNP risk alleles and ancestry-informative markers were associated with improved risk prediction in prostate cancer patients of both African and European descent. AKT activation suggest differential response to AKT-targeted therapies in African American, Asian American, and Tunisian bladder cancer patients. Both self-reported race and genetic ancestry predicted urologic cancer risk prediction.

CONCLUSION

Precision medicine approaches that integrate population-specific genomic and genetic information with other known urologic cancer-specific characteristics can improve outcomes and be leveraged to reduce cancer health disparities. Further investigations are necessary to identify novel genomic biomarkers with clinical utility.

Placing prostate cancer disparities within a psychosocial context: challenges and opportunities for future research

Black men are more likely to be diagnosed with prostate cancer compared with White men. Despite advances in prevention and treatment strategies, disparities in prostate cancer among Black men persist. While research on the causes of higher incidence and mortality is ongoing, there is limited evidence in the existing literature that clearly speaks to the potential psychological or social factors that may contribute to disparities in prostate cancer incidence. Given the lack of attention to this issue, we review scientific evidence of the ways in which social factors, including socioeconomic status and racial segregation, as well as psychological factors, like depression and anxiety, are related to subsequent prostate cancer risk, which could occur through behavioral and biological processes. Our objective is to illuminate psychosocial factors and their context, using a racial disparity lens, which suggests opportunities for future research on the determinants of prostate cancer. Ultimately, we aim to contribute to a robust research agenda for the development of new prostate cancer prevention measures to reduce racial disparities.

Ethnic differences in TGFβ-signaling pathway may contribute to prostate cancer health disparity

Epidemiological studies show that the incidence and mortality rates of prostate cancer (PCa) are significantly higher in African-American (AA) men when compared with Caucasian (CA) men in the United States. Transforming growth factor β (TGFβ) signaling pathway is linked to health disparities in AAs. Recent studies suggest a role of TGFβ3 in cancer metastases and its effect on the migratory and invasive behavior; however, its role in PCa in AA men has not been studied. We determined the circulating levels of TGFβ3 in AA and CA men diagnosed with PCa using ELISA. We analyzed serum samples from both AA and CA men diagnosed with and without PCa. We show that AA PCa patients had higher levels of TGFβ3 protein compared with AA controls and CA patients. In fact, TGFβ3 protein levels in serum were higher in AA men without PCa compared with the CA population, which may correlate with more aggressive disease seen in AA men. Studies on AA-derived PCa cell lines revealed that TGFβ3 protein levels were also higher in these cells compared with CA-derived PCa cell lines. Our studies also reveal that TGFβ does not inhibit cell proliferation in AA-derived PCa cell lines, but it does induce migration and invasion through activation of PI3K pathway. We suggest that increased TGFβ3 levels are responsible for development of aggressive PCa in AA patients as a consequence of development of resistance to inhibitory effects of TGFβ on cell proliferation and induction of invasive metastatic behavior.

Prostate Cancer Genomics: Recent Advances and the Prevailing Underrepresentation from Racial and Ethnic Minorities

Prostate cancer (CaP) is the most commonly diagnosed non-cutaneous cancer and the second leading cause of male cancer deaths in the United States. Among African American (AA) men, CaP is the most prevalent malignancy, with disproportionately higher incidence and mortality rates. Even after discounting the influence of socioeconomic factors, the effect of molecular and genetic factors on racial disparity of CaP is evident. Earlier studies on the molecular basis for CaP disparity have focused on the influence of heritable mutations and single-nucleotide polymorphisms (SNPs). Most CaP susceptibility alleles identified based on genome-wide association studies (GWAS) were common, low-penetrance variants. Germline CaP-associated mutations that are highly penetrant, such as those found in HOXB13 and BRCA2, are usually rare. More recently, genomic studies enabled by Next-Gen Sequencing (NGS) technologies have focused on the identification of somatic mutations that contribute to CaP tumorigenesis. These studies confirmed the high prevalence of ERG gene fusions and PTEN deletions among Caucasian Americans and identified novel somatic alterations in SPOP and FOXA1 genes in early stages of CaP. Individuals with African ancestry and other minorities are often underrepresented in these large-scale genomic studies, which are performed primarily using tumors from men of European ancestry. The insufficient number of specimens from AA men and other minority populations, together with the heterogeneity in the molecular etiology of CaP across populations, challenge the generalizability of findings from these projects. Efforts to close this gap by sequencing larger numbers of tumor specimens from more diverse populations, although still at an early stage, have discovered distinct genomic alterations. These research findings can have a direct impact on the diagnosis of CaP, the stratification of patients for treatment, and can help to address the disparity in incidence and mortality of CaP. This review examines the progress of understanding in CaP genetics and genomics and highlight the need to increase the representation from minority populations.

Correlations of SELENOF and SELENOP genotypes with serum selenium levels and prostate cancer

BACKGROUND

Selenium status is inversely associated with the incidence of prostate cancer. However, supplementation trials have not indicated a benefit of selenium supplementation in reducing cancer risk. Polymorphisms in the gene encoding selenoprotein 15 (SELENOF) are associated with cancer incidence/mortality and present disproportionately in African Americans. Relationships among the genotype of selenoproteins implicated in increased cancer risk, selenium status, and race with prostate cancer were investigated.

METHODS

Tissue microarrays were used to assess SELENOF levels and cellular location in prostatic tissue. Sera and DNA from participants of the Chicago-based Adiposity Study Cohort were used to quantify selenium levels and genotype frequencies of the genes for SELENOF and the selenium-carrier protein selenoprotein P (SELENOP). Logistic regression models for dichotomous patient outcomes and regression models for continuous outcome were employed to identify both clinical, genetic, and biochemical characteristics that are associated with these outcomes.

RESULTS

SELENOF is dramatically reduced in prostate cancer and lower in tumors derived from African American men as compared to tumors obtained from Caucasians. Differing frequency of SELENOF polymorphisms and lower selenium levels were observed in African Americans as compared to Caucasians. SELENOF genotypes were associated with higher histological tumor grade. A polymorphism in SELENOP was associated with recurrence and higher serum PSA.

CONCLUSIONS

These results indicate an interaction between selenium status and selenoprotein genotypes that may contribute to the disparity in prostate cancer incidence and outcome experienced by African Americans.

Prostate cancer health disparities: An immuno-biological perspective

Prostate cancer (PCa) is the most commonly diagnosed malignancy in males, and, in the United States, is the second leading cause of cancer-related death for men older than 40 years. There is a higher incidence of PCa for African Americans (AAs) than for European-Americans (EAs). Investigations related to the incidence of PCa-related health disparities for AAs suggest that there are differences in the genetic makeup of these populations. Other differences are environmentally induced (e.g., diet and lifestyle), and the exposures are different. Men who immigrate from Eastern to Western countries have a higher risk of PCa than men in their native countries. However, the number of immigrants developing PCa is still lower than that of men in Western countries, suggesting that genetic factors are involved in the development of PCa. Altered genetic polymorphisms are associated with PCa progression. Androgens and the androgen receptor (AR) are involved in the development and progression of PCa. For populations with diverse racial/ethnic backgrounds, differences in lifestyle, diet, and biology, including genetic mutations/polymorphisms and levels of androgens and AR, are risk factors for PCa. Here, we provide an immuno-biological perspective on PCa in relation to racial/ethnic disparities and identify factors associated with the disproportionate incidence of PCa and its clinical outcomes.

Molecular mechanisms involving prostate cancer racial disparity

Prostate cancer (PCa) is the second leading cause of cancer-related deaths in the United States. The African (AA) descent has greater incidence and mortality rates of PCa as compared to Caucasian (CA) men. While socioeconomic differences across racial groups contribute to disparity in PCa, increasing evidence points that genetic and molecular alterations play important roles in racial disparities associated with PCa. In this review, we focus on genetic and molecular influences that contribute to racial disparity between AA and CA men including: androgen and estrogen receptor signaling pathways, growth factors, apoptotic proteins, genetic, genomic and epigenetic alterations. Future translational studies will identify prognostic and predictive biomarkers for AA PCa and assist in the development of new targeted-therapies specifically for AA men with PCa.

Racial differences in the expression of inhibitors of apoptosis (IAP) proteins in extracellular vesicles (EV) from prostate cancer patients

African-American men with prostate cancer typically develop more aggressive tumors than men from other racial/ethnic groups, resulting in a disproportionately high mortality from this malignancy. This study evaluated differences in the expression of inhibitors of apoptosis proteins (IAPs), a known family of oncoproteins, in blood-derived exosomal vesicles (EV) between African-American and European-American men with prostate cancer. The ExoQuick^™ method was used to isolate EV from both plasma and sera of African-American (n = 41) and European-American (n = 31) men with prostate cancer, as well as from controls with no cancer diagnosis (n = 10). EV preparations were quantified by acetylcholinesterase activity assays, and assessed for their IAP content by Western blotting and densitometric analysis. Circulating levels of the IAP Survivin were evaluated by ELISA. We detected a significant increase in the levels of circulating Survivin in prostate cancer patients compared to controls (P<0.01), with the highest levels in African-American patients (P<0.01). African-American patients with prostate cancer also contained significantly higher amounts of EVs in their plasma (P<0.01) and sera (P<0.05) than European-American patients. In addition, EVs from African-American patients with prostate cancer contained significantly higher amounts of the IAPs Survivin (P<0.05), XIAP (P<0.001), and cIAP-2 (P<0.01) than EVs from European-American patients. There was no significant correlation between expression of IAPs and clinicopathological parameters in the two patient groups. Increased expression of IAPs in EVs from African-American patients with prostate cancer may influence tumor aggressiveness and contribute to the mortality disparity observed in this patient population. EVs could serve as reservoirs of novel biomarkers and therapeutic targets that may have clinical utility in reducing prostate cancer health disparities.

Ethnicity and ERG frequency in prostate cancer

Emerging observations emphasize a distinct biology of prostate cancer among men of different ethnicities and races, as demonstrated by remarkable differences in the frequency of ERG oncogenic activation, one of the most common and widely studied prostate cancer driver genes. Worldwide assessment of ERG alterations frequencies show consistent trends, with men of European ancestry having the highest rates of alteration and men of African or Asian ancestries having considerably lower alteration rates. However, data must be interpreted cautiously, owing to variations in assay platforms and specimen types, as well as ethnic and geographical classifications. Many opportunities and challenges remain in assessing cancer-associated molecular alterations at a global level, and these need to be addressed in order to realize the true potential of precision medicine for all cancer patients.

Inclusion of diverse populations in genomic research and health services: Genomix workshop report

Clinical genetic services and genomic research are rapidly developing but, historically, those with the greatest need are the least to benefit from these advances. This encompasses low-income communities, including those from ethnic minority and indigenous backgrounds. The "Genomix" workshop at the European Society of Human Genetics (ESHG) 2016 conference offered the opportunity to consider possible solutions for these disparities from the experiences of researchers and genetic healthcare practitioners working with underserved communities in the USA, UK and Australia. Evident from the workshop and corresponding literature is that a multi-faceted approach to engaging communities is essential. This needs to be complemented by redesigning healthcare systems that improves access and raises awareness of the needs of these communities. At a more strategic level, institutions involved in funding research, commissioning and redesigning genetic health services also need to be adequately represented by underserved populations with intrinsic mechanisms to disseminate good practice and monitor participation. Further, as genomic medicine is mainstreamed, educational programmes developed for clinicians should incorporate approaches to alleviate disparities in accessing genetic services and improving study participation.

Proteomic characterization of paired non-malignant and malignant African-American prostate epithelial cell lines distinguishes them by structural proteins

Background

While many factors may contribute to the higher prostate cancer incidence and mortality experienced by African-American men compared to their counterparts, the contribution of tumor biology is underexplored due to inadequate availability of African-American patient-derived cell lines and specimens. Here, we characterize the proteomes of non-malignant RC-77 N/E and malignant RC-77 T/E prostate epithelial cell lines previously established from prostate specimens from the same African-American patient with early stage primary prostate cancer.

Methods

In this comparative proteomic analysis of RC-77 N/E and RC-77 T/E cells, differentially expressed proteins were identified and analyzed for overrepresentation of PANTHER protein classes, Gene Ontology annotations, and pathways. The enrichment of gene sets and pathway significance were assessed using Gene Set Enrichment Analysis and Signaling Pathway Impact Analysis, respectively. The gene and protein expression data of age- and stage-matched prostate cancer specimens from The Cancer Genome Atlas were analyzed.

Results

Structural and cytoskeletal proteins were differentially expressed and statistically overrepresented between RC-77 N/E and RC-77 T/E cells. Beta-catenin, alpha-actinin-1, and filamin-A were upregulated in the tumorigenic RC-77 T/E cells, while integrin beta-1, integrin alpha-6, caveolin-1, laminin subunit gamma-2, and CD44 antigen were downregulated. The increased protein level of beta-catenin and the reduction of caveolin-1 protein level in the tumorigenic RC-77 T/E cells mirrored the upregulation of beta-catenin mRNA and downregulation of caveolin-1 mRNA in African-American prostate cancer specimens compared to non-malignant controls. After subtracting race-specific non-malignant RNA expression, beta-catenin and caveolin-1 mRNA expression levels were higher in African-American prostate cancer specimens than in Caucasian-American specimens. The “ECM-Receptor Interaction” and “Cell Adhesion Molecules”, and the “Tight Junction” and “Adherens Junction” pathways contained proteins are associated with RC-77 N/E and RC-77 T/E cells, respectively.

Conclusions

Our results suggest RC-77 T/E and RC-77 N/E cell lines can be distinguished by differentially expressed structural and cytoskeletal proteins, which appeared in several pathways across multiple analyses. Our results indicate that the expression of beta-catenin and caveolin-1 may be prostate cancer- and race-specific. Although the RC-77 cell model may not be representative of all African-American prostate cancer due to tumor heterogeneity, it is a unique resource for studying prostate cancer initiation and progression.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3462-7) contains supplementary material, which is available to authorized users.

Aspirin Use Reduces the Risk of Aggressive Prostate Cancer and Disease Recurrence in African-American Men

Background: Men of African descent experience a disproportionately high prostate cancer mortality. Intratumoral inflammation was found to be associated with aggressive prostate cancer. We and others have shown that prostate tumors in African-American (AA) patients harbor a distinct immune and inflammation signature when compared with European-American (EA) patients. These observations suggest that inflammation could be a driver of aggressive disease in men of African descent, leading to the hypothesis that an anti-inflammatory drug like aspirin could prevent disease progression.Methods: We examined the relationship between aspirin use and prostate cancer in the NCI-Maryland Prostate Cancer Case-Control Study consisting of 823 men with incident prostate cancer (422 AA and 401 EA) and 1,034 population-based men without the disease diagnosis (486 AA and 548 EA).Results: We observed a significant inverse association between regular aspirin use and prostate cancer among AA men. Stratification of AA patients by disease stage showed that daily and long-term (>3 years) aspirin use significantly decreased the risk of advanced disease [adjusted ORs for T3/T4 disease: 0.35, 95% confidence interval (CI), 0.17-0.73; and 0.22, 95% CI, 0.08-0.60, respectively], but not early-stage disease (T1/T2). Regular aspirin use also reduced disease recurrence in AA men.Conclusions: Regular aspirin use is associated with a decreased risk of advanced stage prostate cancer and increased disease-free survival in AA men.Impact: Regular aspirin use before and after a prostate cancer diagnosis may prevent the development of aggressive disease in AA men who are at risk of a lethal malignancy. Cancer Epidemiol Biomarkers Prev; 26(6); 845-53. ©2017 AACR.

Race Does Not Affect Tumor Control, Adverse Effects, or Quality of Life after Proton Therapy

Purpose

To compare 5-year biochemical control, toxicity, and patient-reported quality of life (QOL) outcomes for African American and White patients treated with proton therapy (PT) for prostate cancer.

Materials and Methods

We reviewed the medical records of 1,066 men with clinically localized prostate cancer. Patients were treated with definitive PT between 2006 and 2010. Patients received a median radiation dose of 78 Gy (RBE) with conventional fractionation (1.8- 2 Gy [RBE] per fraction). Sixty-eight (6.4%) men self-identified as African American and 998 (93.6%) self-identified as White. Five-year rates of biochemical control, grade 3 genitourinary and gastrointestinal toxicity, and patient-reported QOL are reported and compared between African American and White patients.

Results

Median biochemical follow-up was 5.0 years for both African American and White patients. Median follow-up for toxicity was 5.0 and 5.2 years, respectively. On multivariate analysis, race was not a significant predictor for 5-year freedom from biochemical failure (HR 0.8, p=0.55). No significant association was found between race and grade 3 genitourinary toxicity on multivariate analysis at 5 years (HR 2.5, p=0.10). Patient-reported QOL using median EPIC bowel, urinary incontinence, and irritative summaries scores were not significantly different between the groups. African Americans had higher median sexual summary scores at 2 years than White patients (75 vs. 54, p=0.01) but by 5+ years, the sexual summary scores were no longer significantly different (63 vs. 53, p=0.35).

Conclusion

With a median follow-up of 5 years, there were no racial disparities in biochemical control, grade 3 toxicity, or patient-reported QOL after PT for prostate cancer.

Autoantibodies against oncogenic ERG protein in prostate cancer: potential use in diagnosis and prognosis in a panel with C-MYC, AMACR and HERV-K Gag

Overdiagnosis and overtreatment of prostate cancer (CaP) is attributable to widespread reliance on PSA screening in the US. This has prompted us and others to search for improved biomarkers for CaP, to facilitate early detection and disease stratification. In this regard, autoantibodies (AAbs) against tumor antigens could serve as potential candidates for diagnosis and prognosis of CaP. Towards this, our goals were: i) To investigate whether AAbs against ERG oncoprotein (overexpressed in 25-50% of Caucasian American and African American CaP) are present in the sera of CaP patients; ii) To evaluate an AAb panel to enhance CaP detection. The results using an enzyme-linked immunosorbent assay (ELISA) showed that anti-ERG AAbs are present in a significantly higher proportion in the sera of CaP patients compared to healthy controls (p = 0.0001). Furthermore, a panel of AAbs against ERG, AMACR and human endogenous retrovirus-K Gag successfully differentiated CaP patient sera from healthy controls (AUC = 0.791). These results demonstrate for the first time that anti-ERG AAbs are present in the sera of CaP patients. In addition, the data also suggest that AAbs against ERG together with AMACR and HERV-K Gag may be a useful panel of biomarkers for diagnosis and prognosis of CaP.

miRNAs as drivers of TMPRSS2-ERG negative prostate tumors in African American men

African Americans (AAs) who have PCa typically have more aggressive disease and make up a disproportionate number of the disease deaths, relative to European Americans (EAs). TMPRSS2 translocations, a common event in EA patients, are exploited in diagnostic and prognostic settings, whereas they are diminished in frequency in AA men. Thus, these patients with TMPRSS2 fusion-negative disease represent an under-investigated patient group. We propose that epigenetic events are a significant and alternative driver of aggressive disease in fusion-negative PCa. To reveal epigenetically governed microRNAs (miRNAs) that are enriched in fusion-negative disease and associated with aggressive in AA PCa, we leveraged both our experimental evidence and publically available data. These analyses identified 18 miRNAs that are differentially altered in fusion-negative disease, associated with DNA CpG methylation, and implicated in aggressive and AA PCas. Understanding the relationships between miRNA expression, upstream epigenetic regulation by DNA methylation, and downstream regulation of mRNA targets in fusion negative disease is imperative to understanding the biological basis of the racial health disparity in PCa.

Racial disparities in prostate cancer: a molecular perspective

Prostate cancer incidence and mortality rates are remarkably higher in African-American men as compared to their European-Americans counterparts. Despite these recognitions, precise causes underlying such prevalent racial disparities remain poorly understood. Although socioeconomic factors could account for such differences up to a certain extent, it is now being increasingly realized that such disparity has a molecular basis. Indeed, several differences, including genetic polymorphism, gene mutations, epigenetic modifications, miRNAs alterations, etc., have been reported in malignant prostate tissues from patients of diverse racial backgrounds. Here, we attempt to provide a molecular perspective on prostate cancer racial disparities by gathering available information on these associated factors and discussing their potential significance in disproportionate incidence and clinical outcomes.

MNX1 Is Oncogenically Upregulated in African-American Prostate Cancer

Incidence and mortality rates for prostate cancer are higher in African-American (AA) men than in European-American (EA) men, but the biologic basis for this disparity is unclear. We carried out a detailed analysis of gene expression changes in prostate cancer compared with their matched benign tissues in a cohort of AA men and compared them with existing data from EA men. In this manner, we identified MNX1 as a novel oncogene upregulated to a relatively greater degree in prostate cancer from AA men. Androgen and AKT signaling play a central role in the pathogenesis of prostate cancer and we found that both of these signaling pathways increased MNX1 expression. MNX1 in turn upregulated lipid synthesis by stimulating expression of SREBP1 and fatty acid synthetase. Our results define MNX1 as a novel targetable oncogene increased in AA prostate cancer that is associated with aggressive disease. Cancer Res; 76(21); 6290-8. ©2016 AACR.

Epigenetic effects of prenatal estradiol-17β exposure on the reproductive system of pigs

There is growing evidence that early life exposure to endocrine disrupting chemicals might increase the risk for certain adult onset diseases, in particular reproductive health problems and hormone dependent cancers. Studies in rodents suggest that perinatal exposure to even low doses of estrogenic substances can cause adverse effects, including epigenetic reprogramming of the prostate and increased formation of precancerous lesions. We analyzed the effects of an in utero exposure to the strongest natural estrogen, estradiol-17β, in a pig model. Two different low and one high dose of estradiol-17β (0.05, 10 and 1000 μg/kg body weight/day) were orally applied to gilts during pregnancy and potential effects on the reproductive system of the offspring were analyzed. No significant effects on sperm vitality parameters and testes size were observed in adult boars. However, prenatal exposure to the high dose decreased absolute, but not relative weight of the testes in prepubertal piglets. RNA sequencing revealed significantly regulated genes of the prepubertal prostate, while testes and uteri were not affected. Notably, we found an increased prostate expression of CCDC80 and a decreased ADH1C expression in the low dose treatment groups. BGN and SPARC, two genes associated with prostate tumor progression, were as well more abundant in exposed animals. Strikingly, the gene body DNA methylation level of BGN was accordingly increased in the high dose group. Thus, while only prenatal exposure to a high dose of estrogen altered testes development and local DNA methylation of the prostate, even low dose exposure had significant effects on gene expression in the prostate of prepubertal piglet offspring. The relevance of these distinct, but subtle transcriptional changes following low dose treatment lacking a clear phenotype calls for further long-term investigations. An epigenetic reprogramming of the pig prostate due to prenatal estrogen cannot be neglected.

Proteomic Upregulation of Fatty Acid Synthase and Fatty Acid Binding Protein 5 and Identification of Cancer- and Race-Specific Pathway Associations in Human Prostate Cancer Tissues

Protein profiling studies of prostate cancer have been widely used to characterize molecular differences between diseased and non-diseased tissues. When combined with pathway analysis, profiling approaches are able to identify molecular mechanisms of prostate cancer, group patients by cancer subtype, and predict prognosis. This strategy can also be implemented to study prostate cancer in very specific populations, such as African Americans who have higher rates of prostate cancer incidence and mortality than other racial groups in the United States. In this study, age-, stage-, and Gleason score-matched prostate tumor specimen from African American and Caucasian American men, along with non-malignant adjacent prostate tissue from these same patients, were compared. Protein expression changes and altered pathway associations were identified in prostate cancer generally and in African American prostate cancer specifically. In comparing tumor to non-malignant samples, 45 proteins were significantly cancer-associated and 3 proteins were significantly downregulated in tumor samples. Notably, fatty acid synthase (FASN) and epidermal fatty acid-binding protein (FABP5) were upregulated in human prostate cancer tissues, consistent with their known functions in prostate cancer progression. Aldehyde dehydrogenase family 1 member A3 (ALDH1A3) was also upregulated in tumor samples. The Metastasis Associated Protein 3 (MTA3) pathway was significantly enriched in tumor samples compared to non-malignant samples. While the current experiment was unable to detect statistically significant differences in protein expression between African American and Caucasian American samples, differences in overrepresentation and pathway enrichment were found. Structural components (Cytoskeletal Proteins and Extracellular Matrix Protein protein classes, and Biological Adhesion Gene Ontology (GO) annotation) were overrepresented in African American but not Caucasian American tumors. Additionally, 5 pathways were enriched in African American prostate tumors: the Small Cell Lung Cancer, Platelet-Amyloid Precursor Protein, Agrin, Neuroactive Ligand-Receptor Interaction, and Intrinsic pathways. The protein components of these pathways were either basement membrane proteins or coagulation proteins.

TMPRSS2-ERG gene fusion in Turkish patients with localized prostate cancer: results of radical prostatectomy specimens

OBJECTIVE

Our aim was to evaluate and determine the frequency of Transmembrane protease, serine 2 (TMPRSS2)-ERG fusion in Turkish patients with clinically localized prostate cancer by using immunohistochemistry and reveal its relationship with clinicopathologic variables.

MATERIAL AND METHODS

Radical prostatectomy specimens of 99 patients, who underwent radical retropubic prostatectomy for localized cancer, between January 2002 and December 2011 were analyzed in the study. To detect ERG fusions, monoclonal ERG antibodyclone ID: EPR3864 (Epitomics, San Diego, CA, USA) and monoclonal anti-ERG antibody (9FY) (BiocareMedical, LLC, USA) were used. The immunistochemical expression of ERG protein was assessed as positive or negative regardless of stain intensity. Patients' age, total and primary Gleason scores, PSA levels, prostate volumes, tumor volumes, tumor stages and perineural invasion status were analysed retrospectively. Total fusion rate and correlation between the variables and fusion were evaluated.

RESULTS

Mean age, prostate volume, tumor volume, PSA value of 99 patients were 62.02 years (±5.93), 50.02 cc (±20.67), 3.19 cc (±4.16), and 9.34 ng/mL (±3.37) respectively. TMPRSS2-ERG fusion was seen in 46 (46.5%) of 99 patients. When the variables analysed with independent samples t test to predict fusion (+) status, none of them was found to be statistically significant. When evaluated by logistic regression analysis for (+) or (-) status, only tumor stage was found to be statistically significantly correlated with fusion (p=0.049).

CONCLUSION

The incidence of TMPRSS-ERG fusion in patients with localised prostate cancer in our study with Turkish population was found as 46.5%. Only tumor stage correlated with TMPRSS2-ERG fusion.

Difference in Association of Obesity With Prostate Cancer Risk Between US African American and Non-Hispanic White Men in the Selenium and Vitamin E Cancer Prevention Trial (SELECT)

IMPORTANCE

African American men have the highest rates of prostate cancer incidence and mortality in the United States. Understanding underlying reasons for this disparity could identify preventive interventions important to African American men.

OBJECTIVE

To determine whether the association of obesity with prostate cancer risk differs between African American and non-Hispanic white men and whether obesity modifies the excess risk associated with African American race.

DESIGN, SETTING, AND PARTICIPANTS

Prospective study of 3398 African American and 22,673 non-Hispanic white men who participated in the Selenium and Vitamin E Cancer Prevention Trial (2001-2011) with present analyses completed in 2014.

MAIN OUTCOMES AND MEASURES

Total, low-grade (Gleason score <7), and high-grade (Gleason score ≥7) prostate cancer incidence.

RESULTS

With a median (interquartile range) follow-up of 5.6 (1.8) years, there were 270, 148, and 88 cases of total, low-, and high-grade prostate cancers among African American men and a corresponding 1453, 898, and 441 cases in non-Hispanic white men, respectively. Although not associated with risk among non-Hispanic white men, BMI was positively associated with an increase in risk among African American men (BMI, <25 vs ≥35: hazard ratio [HR], 1.49 [95% CI, 0.95, 2.34]; P for trend = .03). Consequently, the risk associated with African American race increased from 28% (HR, 1.28 [95% CI, 0.91-1.80]) among men with BMI less than 25 to 103% (HR, 2.03 [95% CI, 1.38-2.98]) among African American men with BMI at least 35 (P for trend = .03). Body mass index was inversely associated with low-grade prostate cancer risk within non-Hispanic white men (BMI, <25 vs ≥35: HR, 0.80 [95% CI, 0.58-1.09]; P for trend = .02) but positively associated with risk within African American men (BMI, <25 vs ≥35: HR, 2.22 [95% CI, 1.17-4.21]; P for trend = .05). Body mass index was positively associated with risk of high-grade prostate cancer in both non-Hispanic white men (BMI, <25 vs ≥35: HR, 1.33 [95% CI, 0.90-1.97]; P for trend = .01) and African American men, although the increase may be larger within African American men, albeit the racial interaction was not statistically significant (BMI, <25 vs ≥35: HR, 1.81 [95% CI, 0.79-4.11]; P for trend = .02).

CONCLUSIONS AND RELEVANCE

Obesity is more strongly associated with increased prostate cancer risk among African American than non-Hispanic white men and reducing obesity among African American men could reduce the racial disparity in cancer incidence. Additional research is needed to elucidate the mechanisms underlying the differential effects of obesity in African American and non-Hispanic white men.

Vitamin D and Immune Response: Implications for Prostate Cancer in African Americans

Prostate cancer (PCa) is the most common cancer among men in the U.S. African American (AA) men have a higher incidence and mortality rate compared to European American (EA) men, but the cause of PCa disparities is still unclear. Epidemiologic studies have shown that vitamin D deficiency is associated with advanced stage and higher tumor grade and mortality, while its association with overall PCa risk is inconsistent. Vitamin D deficiency is also more common in AAs than EAs, and the difference in serum vitamin D levels may help explain the PCa disparities. However, the role of vitamin D in aggressive PCa in AAs is not well explored. Studies demonstrated that the active form of vitamin D, 1,25-dihydroxyvitamin D, has anti-inflammatory effects by mediating immune-related gene expression in prostate tissue. Inflammation also plays an important role in PCa pathogenesis and progression, and expression of immune-related genes in PCa tissues differs significantly between AAs and EAs. Unfortunately, the evidence linking vitamin D and immune response in relation to PCa is still scarce. This relationship should be further explored at a genomic level in AA populations that are at high risk for vitamin D deficiency and fatal PCa.

Prostate cancer in men of African origin

Men of African origin are disproportionately affected by prostate cancer: prostate cancer incidence is highest among men of African origin in the USA, prostate cancer mortality is highest among men of African origin in the Caribbean, and tumour stage and grade at diagnosis are highest among men in sub-Saharan Africa. Socioeconomic, educational, cultural, and genetic factors, as well as variations in care delivery and treatment selection, contribute to this cancer disparity. Emerging data on single-nucleotide-polymorphism patterns, epigenetic changes, and variations in fusion-gene products among men of African origin add to the understanding of genetic differences underlying this disease. On the diagnosis of prostate cancer, when all treatment options are available, men of African origin are more likely to choose radiation therapy or to receive no definitive treatment than white men. Among men of African origin undergoing surgery, increased rates of biochemical recurrence have been identified. Understanding differences in the cancer-survivorship experience and quality-of-life outcomes among men of African origin are critical to appropriately counsel patients and improve cultural sensitivity. Efforts to curtail prostate cancer screening will likely affect men of African origin disproportionately and widen the racial disparity of disease.

FGFR1 Amplification Is Often Homogeneous and Strongly Linked to the Squamous Cell Carcinoma Subtype in Esophageal Carcinoma

Background and Aims

Amplification of the fibroblast growth factor receptor 1 (FGFR1) is believed to predict response to multi-kinase inhibitors targeting FGFR1. Esophageal cancer is an aggressive disease, for which novel targeted therapies are highly warranted.

Methods

This study was designed to investigate the prevalence and clinical significance of FGFR1 amplification in a tissue microarray containing 346 adenocarcinomas and 254 squamous cell carcinomas of the esophagus, using dual-labeling fluorescence in situ hybridization (FISH) analysis.

Results

FGFR1 amplification, defined as a ratio of FGFR1:centromere 8 copy numbers ≥ 2.0, was more frequently seen in squamous cell carcinoma (8.9% of 202 interpretable cases) than in adenocarcinoma (1.6% of 308; p<0.0001). There was no association between FGFR1 amplification and tumor phenotype or clinical outcome. To study potential heterogeneity of FGFR1 amplification, all available tumor blocks from 23 FGFR1 amplified tumors were analyzed on conventional large sections. This analysis revealed complete homogeneity of FGFR1 amplification in 20 (86.9%) primary tumors and in all available lymph node metastases. Remarkably, FGFR1 amplification was also seen in dysplasia adjacent to tumor in 6 of 9 patients with FGFR1 amplified primary cancers.

Conclusions

In conclusion, FGFR1 amplification occurs in a relevant subgroup of carcinomas of the esophagus and may play a particular role for development of squamous cell cancers. The high homogeneity of FGFR1 amplification suggests that patients with FGFR1 amplified esophageal cancers may particularly benefit from anti-FGFR1 therapies and prompt for clinical studies in this tumor type.

A novel genomic alteration of LSAMP associates with aggressive prostate cancer in African American men

Evaluation of cancer genomes in global context is of great interest in light of changing ethnic distribution of the world population. We focused our study on men of African ancestry because of their disproportionately higher rate of prostate cancer (CaP) incidence and mortality. We present a systematic whole genome analyses, revealing alterations that differentiate African American (AA) and Caucasian American (CA) CaP genomes. We discovered a recurrent deletion on chromosome 3q13.31 centering on the LSAMP locus that was prevalent in tumors from AA men (cumulative analyses of 435 patients: whole genome sequence, 14; FISH evaluations, 101; and SNP array, 320 patients). Notably, carriers of this deletion experienced more rapid disease progression. In contrast, PTEN and ERG common driver alterations in CaP were significantly lower in AA prostate tumors compared to prostate tumors from CA. Moreover, the frequency of inter-chromosomal rearrangements was significantly higher in AA than CA tumors. These findings reveal differentially distributed somatic mutations in CaP across ancestral groups, which have implications for precision medicine strategies.

Impact of aspirin on clinical outcomes for African American men with prostate cancer undergoing radiation

AIMS AND BACKGROUND

Preclinical and clinical studies have suggested that aspirin (ASA) may exhibit antineoplastic activity. Particularly in prostate cancer, several reports have suggested that ASA plays a role in improved outcomes. Therefore, we studied the role of ASA in a uniquely African American population, which is known to harbor more aggressive and biologically different disease compared to the general population.

METHODS

We identified 289 African American men with prostate cancer who were treated with definitive radiation therapy to a dose of ≥7560 cGy. The median follow-up was 76 months. Kaplan-Meier analysis was used to analyze biochemical failure-free survival (bFFS), distant progression-free survival (DMPFS), and prostate cancer-specific survival (PCSS). Multivariate Cox regression was used to analyze the impact of covariates on all endpoints.

RESULTS

There were 147 men who were ASA+ and 142 who were ASA-. The 7-year bFFS was 80.9% for ASA+ men and 70.3% for ASA- men (p = 0.03). On multivariate analysis, ASA use was associated with a significant reduction in biochemical recurrences (hazard ratio [HR] 0.56, 95% confidence interval [CI] 0.34-0.93, p = 0.03). The 7-year DMPFS was 98.4% for ASA+ and 91.8% for ASA- men (p = 0.04). On multivariate analysis, ASA use was associated with a decreased risk of distant metastases (HR 0.23, 95% CI 0.06-0.91, p = 0.04). The 7-year PCSS was 99.3% for ASA+ and 96.9% for ASA- men (p = 0.07).

CONCLUSIONS

In this study, ASA use was associated with improved biochemical outcomes and reduced distant metastases. This indicates that ASA appears to play an important antineoplastic role in African American men.

Weaker ERG expression in patients with ERG-positive prostate cancer is associated with advanced disease and weaker androgen receptor expression: An Indian outlook

INTRODUCTION

Gene fusion between TMPRSS2 and ERG has a causal role in prostate cancer initiation. However, studies evaluating its role clinically have shown conflicting results. We investigated simultaneously multiple aspects of ERG, namely, "presence" and "strength" of ERG expression and "correlation" of ERG with other common clinicopathological parameters.

MATERIALS AND METHODS

From January 2012 to November 2013, the status of ERG, androgen receptor (AR), and p53 was prospectively determined by immunohistochemistry unselectively in all types of specimens positive for prostate cancer. "Strength" of expression was measured in terms of "intensity" as well as "percentage positivity," with each parameter given a score from 0 to 3 based on fixed protocol, which was tested for interrater variability as well as test-retest reliability. Data were collected for age, Gleason score, prostate specific antigen levels, presence of perineural invasion and lymphovascular invasion, high-grade prostatic intraepithelial neoplasia, and cancer stage.

RESULTS

In total, 100 specimens were analyzed, and overall 51 patients had ERG-positive immunostaining. ERG-positive tumors had lower presence of high-grade prostatic intraepithelial neoplasia and p53 positivity, with no significant difference in prostate specific antigen levels, Gleason scores, and presence of lymphovascular invasion. Moreover, 54 patients had complete stage information, and the absolute number of patients with ERG positivity increased with increasing clinical stage. Among these, 30 patients were ERG positive, and ERG score had strong positive correlation with AR expression (Spearman correlation coefficient 0.677). However, median ERG scores showed a significant decline (consistent across percentage positivity and intensity) in patients with stage 4 disease, and score ≤ 2 had 88.2% specificity in identifying patient with stage 4 disease. Cohen׳s κ = 0.81, whereas intraclass correlation coefficient was 0.95, indicating substantial agreement and near-perfect reproducibility of scoring scheme for immunohistochemistry.

CONCLUSION

ERG-positive tumors increase in proportion with increasing stage of disease, but strength of ERG expression in ERG-positive patients shows a significant decline, or "loss," in patients with stage 4 disease. This may have potential therapeutic implications as ERG expression score showed strong positive correlation with AR expression score.

Cancer-specific mortality of Asian Americans diagnosed with cancer: a nationwide population-based assessment

BACKGROUND

Racial disparities in cancer survival outcomes have been primarily attributed to underlying biologic mechanisms and the quality of cancer care received. Because prior literature shows little difference exists in the socioeconomic status of non-Hispanic whites and Asian Americans, any difference in cancer survival is less likely to be attributable to inequalities of care. We sought to examine differences in cancer-specific survival between whites and Asian Americans.

METHODS

The Surveillance, Epidemiology, and End Results Program was used to identify patients with lung (n = 130 852 [16.9%]), breast (n = 313 977 [40.4%]), prostate (n = 166 529 [21.4%]), or colorectal (n = 165 140 [21.3%]) cancer (the three leading causes of cancer-related mortality within each sex) diagnosed between 1991 and 2007. Fine and Gray's competing risks regression compared the cancer-specific mortality (CSM) of eight Asian American groups (Chinese, Filipino, Hawaiian/Pacific Islander, Japanese, Korean, other Asian, South Asian [Indian/Pakistani], and Vietnamese) to non-Hispanic white patients. All P values were two-sided.

RESULTS

In competing risks regression, the receipt of definitive treatment was an independent predictor of CSM (hazard ratio [HR] = 0.37, 95% confidence interval [CI] = 0.35 to 0.40; HR = 0.55, 95% CI = 0.53 to 0.58; HR = 0.61, 95% CI = 0.60 to 0.62; and HR = 0.27, 95% CI = 0.25 to 0.29) for prostate, breast, lung, and colorectal cancers respectively, all P < .001). In adjusted analyses, most Asian subgroups (except Hawaiians and Koreans) had lower CSM relative to white patients, with hazard ratios ranging from 0.54 (95% CI = 0.38 to 0.78) to 0.88 (95% CI = 0.84 to 0.93) for Japanese patients with prostate and Chinese patients with lung cancer, respectively.

CONCLUSIONS

Despite adjustment for potential confounders, including the receipt of definitive treatment and tumor characteristics, most Asian subgroups had better CSM than non-Hispanic white patients. These findings suggest that underlying genetic/biological differences, along with potential cultural variations, may impact survival in Asian American cancer patients.