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

Benefit-Sharing by Design: A Call to Action for Human Genomics Research

The ethical standards for the responsible conduct of human research have come a long way; however, concerns surrounding equity remain in human genetics and genomics research. Addressing these concerns will help society realize the full potential of human genomics research. One outstanding concern is the fair and equitable sharing of benefits from research on human participants. Several international bodies have recognized that benefit-sharing can be an effective tool for ethical research conduct, but international laws, including the Convention on Biological Diversity and its Nagoya Protocol on Access and Benefit-Sharing, explicitly exclude human genetic and genomic resources. These agreements face significant challenges that must be considered and anticipated if similar principles are applied in human genomics research. We propose that benefit-sharing from human genomics research can be a bottom-up effort and embedded into the existing research process. We propose the development of a "benefit-sharing by design" framework to address concerns of fairness and equity in the use of human genomic resources and samples and to learn from the aspirations and decade of implementation of the Nagoya Protocol.

Patient-Derived Tumor Xenograft Study with CDK4/6 Inhibitor Plus AKT Inhibitor for the Management of Metastatic Castration-Resistant Prostate Cancer

Metastatic castration-resistant prostate cancer (mCRPC) is an aggressive malignancy with poor outcomes. To investigate novel therapeutic strategies, we characterized three new metastatic prostate cancer patient derived-tumor xenograft (PDTX) models and developed 3D spheroids from each to investigate molecular targeted therapy combinations including CDK4/6 inhibitors (CDK4/6i) with AKT inhibitors (ATKi). Metastatic prostate cancer tissue was collected and three PDTX models were established and characterized using whole-exome sequencing. PDTX 3D spheroids were developed from these three PDTXs to show resistance patterns and test novel molecular-targeted therapies. CDK4/6i's were combined with AKTi's to assess synergistic antitumor response to prove our hypothesis that blockade of AKT overcomes drug resistance to CDK4/6i. This combination was evaluated in PDTX three-dimensional (3D) spheroids and in vivo experiments with responses measured by tumor volumes, PSA, and Ga-68 PSMA-11 PET-CT imaging. We demonstrated CDK4/6i's with AKTi's possess synergistic antitumor activity in three mCRPC PDTX models. These models have multiple unique pathogenic and deleterious genomic alterations with resistance to single-agent CDK4/6i's. Despite this, combination therapy with AKTi's was able to overcome resistance mechanisms. The IHC and Western blot analysis confirmed on target effects, whereas tumor volume, serum PSA ELISA, and radionuclide imaging demonstrated response to therapy with statistically significant SUV differences seen with Ga-68 PSMA-11 PET-CT. These preclinical data demonstrating antitumor synergy by overcoming single-agent CDK 4/6i as well as AKTi drug resistance provide the rational for a clinical trial combining a CDK4/6i with an AKTi in patients with mCRPC whose tumor expresses wild-type retinoblastoma 1.

Prostate Cancer Among Black Men in Canada

Importance

Prostate cancer is a prevalent disease among men worldwide, exhibiting substantial heterogeneity in presentation and outcomes influenced by various factors, including race and ethnicity. Disparities in incidence, stage at diagnosis, and survival rates have been observed between Black men and those of other races and ethnicities.

Objective

To compare prostate cancer outcomes between Black men and men with other race (Asian, Hispanic, Indigenous, Middle Eastern, White, Multiracial, and Other) in a universal health care system, with race and ethnicity self-reported.

Design, Setting, and Participants

This was a prospective, observational cohort study of men diagnosed with prostate cancer between June 1, 2014, and August 28, 2023, who self-identified race and ethnicity. Participants included men who had been prospectively enrolled in the Alberta Prostate Cancer Research Initiative from the 2 major urology referral centers in Alberta (University of Alberta and University of Calgary). All men with prostate cancer enrolled in the initiative were included.

Exposure

Race and ethnicity.

Main Outcomes and Measures

The primary outcome was the stage and grade of prostate cancer at diagnosis. Further outcomes included age and prostate-specific antigen level at diagnosis, initial treatment modality, time from diagnosis to initial treatment, and prostate cancer-specific, metastasis-free, and overall survivals.

Results

A total of 6534 men were included; 177 (2.7%) were Black, and 6357 (97.3%) had another race or ethnicity. Men who identified as Black were diagnosed with prostate cancer at an earlier age (mean [SD], 62.0 [8.2] compared with 64.6 [7.7] years; P < .001) and had a lower Charlson Comorbidity Index rating (14% compared with 7% ≤ 1; P < .001) compared with men of other races. Men who identified as Black had similar prostate-specific antigen levels at diagnosis, TNM category (74% vs 74% with T1-T2; P = .83) and Gleason Grade Group (34% compared with 35% Gleason Grade Group 1; P = .63). Black men had similar rates of prostate cancer-specific (hazard ratio [HR], 1.10; 95% CI, 0.41-2.97; P = .85), metastasis-free (HR, 0.88; 95% CI, 0.42-1.46; P = .44), and overall (HR, 0.55; 95% CI, 0.25-1.24; P = .15) survival.

Conclusions and Relevance

The findings of this cohort study suggest that Black men, despite being diagnosed at a younger age, experience comparable prostate cancer outcomes compared with men of other races.

Plasma microRNA Signature as Companion Diagnostic for Abiraterone Acetate Treatment in Metastatic Castration-Resistant Prostate Cancer: A Pilot Study

Abiraterone acetate (AA) serves as a medication for managing persistent testosterone production in patients with metastatic castration-resistant prostate cancer (mCRPC). However, its efficacy varies among individuals; thus, the identification of biomarkers to predict and follow treatment response is required. In this pilot study, we explored the potential of circulating microRNAs (c-miRNAs) to stratify patients based on their responsiveness to AA. We conducted an analysis of plasma samples obtained from a cohort of 33 mCRPC patients before and after three, six, and nine months of AA treatment. Using miRNA RT-qPCR panels for candidate discovery and TaqMan RT-qPCR for validation, we identified promising miRNA signatures. Our investigation indicated that a signature based on miR-103a-3p and miR-378a-5p effectively discriminates between non-responder and responder patients, while also following the drug's efficacy over time. Additionally, through in silico analysis, we identified target genes and transcription factors of the two miRNAs, including PTEN and HOXB13, which are known to play roles in AA resistance in mCRPC. In summary, our study highlights two c-miRNAs as potential companion diagnostics of AA in mCRPC patients, offering novel insights for informed decision-making in the treatment of mCRPC.

Do Hispanic Puerto Rican men have worse outcomes after radical prostatectomy? Results from SEARCH

BACKGROUND

We previously reported that outcomes after radical prostatectomy (RP) were similar among non-Hispanic Black, non-Hispanic White, and Hispanic White Veterans Affairs (VA) patients. However, prostate cancer (PC) mortality in Puerto Rican Hispanics (PRH) may be higher than in other Hispanic groups. Data focused on PRH patients is sparse; thus, we tested the association between PR ethnicity and outcomes after RP.

METHODS

Analysis included men in SEARCH cohort who underwent RP (1988-2020, n = 8311). PRH patients (n = 642) were treated at the PR VA, and outcomes were compared to patients treated in the Continental US regardless of race. Logistic regression was used to test the associations between PRH and PC aggressiveness, adjusting for demographic and clinicopathological features. Multivariable Cox models were used to investigate PRH versus Continental differences in biochemical recurrence (BCR), metastases, castration-resistant PC (CRPC), and PC-specific mortality (PCSM).

RESULTS

Compared to Continental patients, PRH patients had lower adjusted odds of pathological grade group ≥2 (p < 0.001), lymph node metastasis (p < 0.001), and positive margins (p < 0.001). In contrast, PRH patients had higher odds of extracapsular extension (p < 0.001). In Cox models, PRH patients had a higher risk for BCR (HR = 1.27, p < 0.001), metastases (HR = 1.49, p = 0.014), CRPC (HR = 1.80, p = 0.001), and PCSM (HR = 1.74, p = 0.011). Further adjustment for extracapsular extension and other pathological variables strengthened these findings.

CONCLUSIONS

In an equal access setting, PRH RP patients generally had better pathological features, but despite this, they had significantly worse post-treatment outcomes than men from the Continental US, regardless of race. The reasons for the poorer prognosis among PRH men require further research.

Impact of modifiable lifestyle risk factors for prostate cancer prevention: a review of the literature

Introduction

Although prostate cancer (PCa) is one of the most common cancers among men, the impact of modifiable risk and protective factors is still being debated. This review aims to qualitatively summarize the most recent studies related to potential healthy lifestyle factors affecting the development of PCa.

Methods for data acquisition

The literature focusing on modifiable risk factors for prostate cancer was reviewed. Medline and Embase via the Ovid database were searched, and all relevant and inherent articles were analyzed. Non-eligible publications, such as review articles, editorials, comments, guidelines, or case reports, were excluded.

Synthesis of the evidence obtained from data analysis

This review confirms that there is strong evidence that being overweight or obese increases the risk of advanced prostate cancer (assessed by body mass index (BMI), waist circumference, and waist-hip ratio), particularly considering central adiposity and ethnicity as contributing factors. The possible contribution of smoking still seems not entirely clear, while alcohol seems to affect PCa prevention in patients taking 5α-reductase inhibitors (5-ARIs). Dietary fibers may have anti-inflammatory properties and improve insulin sensitivity by reducing IGF bioactivity. In particular, dietary fiber intake like insoluble and legume fibers may be inversely associated with prostate cancer risk. Also, hyperglycemia and hyperinsulinemia, with untreated diabetic fasting blood glucose levels, could be modifiable prostate cancer risk factors. In two studies, aspirin was associated with a lower risk of lethal PCa and overall mortality. Concerning the role of vitamins, despite conflicting and divergent results, serum retinol concentration seems to be associated with an increased risk of prostate cancer and high-grade prostate cancer. Some studies resulted in disagreement about the role of selenium and vitamin E. We found inconsistent and controversial findings about the association between vitamin D and prostate cancer risk.

Conclusion

Far from being conclusive evidence, our findings confirm some strong evidence already found in the previous literature and highlight the need to clarify the role of some risk factors whose role is not yet completely known. This effort would facilitate the cultural and social change that may allow the shift from the treatment of prostate cancer when diagnosed to the real efforts needed for systematic prevention.

DNA Damage Repair Pathways in Prostate Cancer: A Narrative Review of Molecular Mechanisms, Emerging Biomarkers and Therapeutic Targets in Precision Oncology

Prostate cancer (PCa) has a distinct molecular signature, including characteristic chromosomal translocations, gene deletions and defective DNA damage repair mechanisms. One crucial pathway involved is homologous recombination deficiency (HRD) and it is found in almost 20% of metastatic castrate-resistant PCa (mCRPC). Inherited/germline mutations are associated with a hereditary predisposition to early PCa development and aggressive behavior. BRCA2, ATM and CHECK2 are the most frequently HRD-mutated genes. BRCA2-mutated tumors have unfavorable clinical and pathological characteristics, such as intraductal carcinoma. PARP inhibitors, due to the induction of synthetic lethality, have been therapeutically approved for mCRPC with HRD alterations. Mutations are detected in metastatic tissue, while a liquid biopsy is utilized during follow-up, recognizing acquired resistance mechanisms. The mismatch repair (MMR) pathway is another DNA repair mechanism implicated in carcinogenesis, although only 5% of metastatic PCa is affected. It is associated with aggressive disease. PD-1 inhibitors have been used in MMR-deficient tumors; thus, the MMR status should be tested in all metastatic PCa cases. A surrogate marker of defective DNA repair mechanisms is the tumor mutational burden. PDL-1 expression and intratumoral lymphocytes have ambivalent predictive value. Few experimental molecules have been so far proposed as potential biomarkers. Future research may further elucidate the role of DNA damage pathways in PCa, revealing new therapeutic targets and predictive biomarkers.

The impact of killer cell immunoglobulin-like receptor (KIR) genes and human leukocyte antigen (HLA) class I ligands on predisposition or protection against prostate cancer

Natural killer (NK) cell development largely depends on killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen (HLA) class I ligands. In the current study, we investigated the role of KIR genes, HLA ligands, and KIR-HLA combinations in vulnerability or protection against prostate cancer (PC). To analyze the frequency of 16 KIR genes and 5 HLA ligands, polymerase chain reaction with sequence-specific primers (PCR-SSP) was conducted in 150 PC patients and 200 healthy controls (CNs). KIR2DL5 (p = 0.0346, OR = 0.606, CI = 0.3916-0.9336), KIR2DS5 (p = 0.0227, OR = 0.587, CI = 0.3793-0.9139), HLA-B Bw4^Thr80 (p = 0.0401, OR = 0.3552, CI = 0.1466-0.9059), HLA Bw4 (p = 0.0190, OR = 0.4744, CI = 0.2656-0.8521), and T4 gene cluster (including KIR2DS5-2DL5-3DS1-2DS1 genes) (p = 0.0194, OR = 0.5575, CI = 0.3449-0.8938) had a lower frequency in the PC patients compared to the control group. Moreover, a lower frequency of the genotypes contacting activating KIR (aKIR) > inhibitory KIR (iKIR) (p = 0.0298, OR = 0.5291, CI = 0.3056-0.9174) and iKIR + HLA < aKIR + HLA (p = 0.0183, OR = 0.2197, CI = 0.0672-0.7001) in PC patients compared to the CNs implies a protective role for aKIR genes. In the case of KIR-HLA interactions, we detected a significant association between KIR3DS1⁺ + HLA-A Bw4⁺ (p = 0.0113, OR = 0.5093, CI = 0.3124-0.8416) and KIR3DL1^- + HLA-A Bw4⁺ (p = 0.0306, OR = 0.1153, CI = 0.0106-0.6537) combinations and resistance to prostate cancer. In contrast, the presence of KIR3DL1 in the absence of HLA-A Bw4 (p = 0.0040, OR = 2.00, CI = 1.264-3.111), HLA Bw4 (p = 0.0296, OR = 2.066, CI = 1.094-3.906), and HLA-Bw4^Thr80 (p = 0.0071, OR = 2.505, CI = 1.319-4.703) genes probably predisposes to prostate cancer. Carrying the CxT4 genotype in PC patients was positively associated with lower tumor grades (Gleason score ≤ 6) (p = 0.0331, OR = 3.290, and CI = 1.181-8.395). Altogether, our data suggest a protective role for aKIRs, HLA-B Bw4^Thr80, and HLA Bw4 ligands as well as a predisposing role for certain KIR-HLA combinations in prostate cancer. The findings of this study offer new insight into the population's risk assessment for prostate cancer in men. Additionally, predicting immunotherapy response based on KIR-HLA combinations aids in implementing the most effective therapeutic approach in the early stages of the disease.

Long-Term Exposure to Nitrate and Trihalomethanes in Drinking Water and Prostate Cancer: A Multicase-Control Study in Spain (MCC-Spain)

BACKGROUND

Nitrate and trihalomethanes (THMs) in drinking water are widespread and are potential human carcinogens.

OBJECTIVE

We evaluated the association between drinking-water exposure to nitrate and THMs and prostate cancer.

METHODS

During the period 2008-2013, 697 hospital-based incident prostate cancer cases (97 aggressive tumors) and 927 population-based controls were recruited in Spain, providing information on residential histories and type of water consumed. Average nitrate and THMs levels in drinking water were linked with lifetime water consumption to calculate waterborne ingestion. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using mixed models with recruitment area as random effect. Effect modification by tumor grade (Gleason score), age, education, lifestyle, and dietary factors was explored.

RESULTS

Mean (±standard deviation) adult lifetime waterborne ingested nitrate (milligrams per day), brominated (Br)-THMs (micrograms per day), and chloroform (micrograms per day) were 11.5 (±9.0), 20.7 (±32.4), and 15.1 (±14.7) in controls. Waterborne ingested nitrate >13.8 vs. <5.5mg/d was associated with an OR of 1.74 (95% CI: 1.19, 2.54) overall, and 2.78 (95% CI: 1.23, 6.27) for tumors with Gleason scores ≥8. Associations were higher in the youngest and those with lower intakes of fiber, fruit/vegetables, and vitamin C. Waterborne ingested THMs were not associated with prostate cancer. Residential tap water levels of Br-THMs and chloroform showed, respectively, inverse and positive associations with prostate cancer.

CONCLUSIONS

Findings suggest long-term waterborne ingested nitrate could be a risk factor of prostate cancer, particularly for aggressive tumors. High intakes of fiber, fruit/vegetables and vitamin C may lower this risk. Association with residential levels but not ingested chloroform/Br-THM may suggest inhalation and dermal routes could be relevant for prostate cancer. https://doi.org/10.1289/EHP11391.

Few Randomized Controlled Trials in Spine Surgery in the United States Include Sociodemographic Patient Data: A Systematic Review

INTRODUCTION

The importance of sociodemographic factors such as race, education, and income on spine surgery outcomes has been well established, yet the representation of sociodemographic data within randomized controlled trials (RCTs) in spine literature remains undefined in the United States (U.S).

METHODS

Medical literature was reviewed within PubMed for RCTs with "spine" in the title or abstract published within the last 8 years (2014 to 2021) in seven major spine journals. This yielded 128 results, and after application of inclusion criteria (RCTs concerning adult spine pathologies conducted in the U.S), 54 RCTs remained for analysis. Each article's journal of publication, year of publication, and spinal pathology was recorded. Pathologies included cervical degeneration, thoracolumbar degeneration, adult deformity, cervical trauma, and thoracolumbar trauma. Sociodemographic variables collected were race, ethnicity, insurance status, income, work status, and education. The Fisher's exact test was used to compare inclusion of sociodemographic data by journal, year, and spinal pathology.

RESULTS

Sociodemographic data were included in the results and in any section of 57.4% (31/54) of RCTs. RCTs reported work status in 25.9% (14/54) of results and 38.9% (21/54) of RCTs included work status in any section. Income was included in the results and mentioned in any section in 13.0% (7/54) of RCTs. Insurance status was in the results or any section of 9.3% (5/54) and 18.5% (10/54) of RCTs, respectively. There was no association with inclusion of sociodemographic data within the results of RCTs as a factor of journal (P = 0.337), year of publication (P = 0.286), or spinal pathology (P = 0.199).

DISCUSSION

Despite evidence of the importance of sociodemographic factors on the natural history and treatment outcomes of myriad spine pathologies, this study identifies a surprising absence of sociodemographic data within contemporary RCTs in spine surgery. Failure to include sociodemographic factors in RCTs potentially bias the generalizability of outcome data.

Biomarkers of Aggressive Prostate Cancer at Diagnosis

In the United States, prostate cancer (CaP) remains the second leading cause of cancer deaths in men. CaP is predominantly indolent at diagnosis, with a small fraction (25-30%) representing an aggressive subtype (Gleason score 7-10) that is prone to metastatic progression. This fact, coupled with the criticism surrounding the role of prostate specific antigen in prostate cancer screening, demonstrates the current need for a biomarker(s) that can identify clinically significant CaP and avoid unnecessary biopsy procedures and psychological implications of being diagnosed with low-risk prostate cancer. Although several diagnostic biomarkers are available to clinicians, very few comparative trials have been performed to assess the clinical effectiveness of these biomarkers. It is of note, however, that a majority of these clinical trials have been over-represented by men of Caucasian origin, despite the fact that African American men have a 1.7 times higher incidence and 2.1 times higher rate of mortality from prostate cancer. Biomarkers for CaP diagnosis based on the tissue of origin include urine-based gene expression assays (PCA3, Select MDx, ExoDx Prostate IntelliScore, Mi-Prostate Score, PCA3-PCGEM1 gene panel), blood-based protein biomarkers (4K, PHI), and tissue-based DNA biomarker (Confirm MDx). Another potential direction that has emerged to aid in the CaP diagnosis include multi-parametric magnetic resonance imaging (mpMRI) and bi-parametric magnetic resonance imaging (bpMRI), which in conjunction with clinically validated biomarkers may provide a better approach to predict clinically significant CaP at diagnosis. In this review, we discuss some of the adjunctive biomarker tests along with newer imaging modalities that are currently available to help clinicians decide which patients are at risk of having high-grade CaP on prostate biopsy with the emphasis on clinical utility of the tests across African American (AA) and Caucasian (CA) men.

Prostate Cancer Disparities and Management in Southern Africa: Insights into Practices, Norms and Values

Prostate cancer (PCa) is a leading cause of mortality in men of African origin. While men of African descent in high-income countries (HICs) demonstrate poor prognosis compared to their European counterparts, African men on the African continent, particularly Southern Africa have shown even higher PCa mortality rates. Extrinsic factors such as the socioeconomic status, education level, income level, geographic location and race contribute to PCa patient outcome. These are further deepened by the African norms which are highly esteemed and may have detrimental effects on PCa patients' health. Insights into African cultures and social constructs have been identified as key elements towards improving men's health care seeking behaviour which will in turn improve PCa patients' outcome. Compared to Southern Africa, the Eastern, Western and Central African regions have lower PCa incidence rates but higher mortality rates. The availability of cancer medical equipment has also been reported to be disproportionate in Africa, with most cancer resources in Northern and Southern Africa. Even within Southern Africa, cancer management resources are unevenly available where one country must access PCa specialised care in the neighbouring countries. While PCa seems to be better managed in HICs, steps towards effective PCa management are urgently needed in Africa, as this continent represents a significant portion of low-middle-income countries (LMICs). Replacing African men in Africa with African American men may not optimally resolve PCa challenges in Africa. Adopting western PCa management practices can be optimised by integrating improved core-African norms. The aim of this review is to discuss PCa disparities in Africa, deliberate on the significance of integrating African norms around masculinity and discuss challenges and opportunities towards effective PCa care in Africa, particularly in Southern Africa.

Racial disparities in Black men with prostate cancer: A literature review

Black men are disproportionately affected by prostate cancer (PCa), with earlier presentation, more aggressive disease, and higher mortality rates versus White men. Furthermore, Black men have less access to PCa treatment and experience longer delays between diagnosis and treatment. In this review, the authors discuss the factors contributing to racial disparities and present solutions to improve access to care and increase clinical trial participation among Black men with PCa. Racial disparities observed among Black men with PCa are multifaceted, evolving from institutional racism. Cultural factors include generalized mistrust of the health care system, poor physician-patient communication, lack of information on PCa and treatment options, fear of PCa diagnosis, and perceived societal stigma of the disease. In the United States, geographic trends in racial disparities have been observed. Economic factors, e.g., cost of care, recovery time, and cancer debt, play an important role in racial disparities observed in PCa treatment and outcomes. Racial diversity is often lacking in genomic and precision medicine studies. Black men are largely underrepresented in key phase 3 PCa trials and may be less willing to enroll in clinical trials due to lack of awareness, lack of diversity in clinical trial research teams, and bias of health care providers to recommend clinical research. The authors propose solutions to address these factors that include educating clinicians and institutions on the barriers Black men experience, increasing the diversity of health care providers and clinical research teams, and empowering Black men to be involved in their treatment, which are keys to creating equity for Black men with PCa. LAY SUMMARY: Prostate cancer negatively affects Black men more than men of other races. The history of segregation and mistreatment in the health care system may contribute to mistrust among Black men. Outcomes are worse for Black men because they are less likely to be screened or to receive treatment for prostate cancer. Black men also are unlikely to participate in clinical research, making it difficult for investigators to understand how Black men are affected by prostate cancer. Suggestions for addressing these differences include teaching physicians and nurses about the issues Black men experience getting treatment and improving how Black men get information on prostate cancer.

Review of prostate cancer genomic studies in Africa

Prostate cancer (PCa) is the second most commonly diagnosed in men worldwide and one of the most frequent cancers in men in Africa. The heterogeneity of this cancer fosters the need to identify potential genetic risk factors/biomarkers. Omics variations may significantly contribute to early diagnosis and personalized treatment. However, there are few genomic studies of this disease in African populations. This review sheds light on the status of genomics research on PCa in Africa and outlines the common variants identified thus far. The allele frequencies of the most significant SNPs in Afro-native, Afro-descendants, and European populations were compared. We advocate how these few but promising data will aid in understanding, better diagnosing, and precisely treating this cancer and the need for further collaborative research on the genomics of PCa in the African continent.

Whole-exome Sequencing of Nigerian Prostate Tumors from the Prostate Cancer Transatlantic Consortium (CaPTC) Reveals DNA Repair Genes Associated with African Ancestry

In this study, we used whole-exome sequencing of a cohort of 45 advanced-stage, treatment-naïve Nigerian (NG) primary prostate cancer tumors and 11 unmatched nontumor tissues to compare genomic mutations with African American (AA) and European American (EA) The Cancer Genome Atlas (TCGA) prostate cancer. NG samples were collected from six sites in central and southwest Nigeria. After whole-exome sequencing, samples were processed using GATK best practices. BRCA1 (100%), BARD1 (45%), BRCA2 (27%), and PMS2(18%) had germline alterations in at least two NG nontumor samples. Across 111 germline variants, the AA cohort reflected a pattern [BRCA1 (68%), BARD1 (34%), BRCA2 (28%), and PMS2 (16%)] similar to NG samples. Of the most frequently mutated genes, BRCA1 showed a statistically (P ≤ 0.05) higher germline mutation frequency in men of African ancestry (MAA) and increasing variant frequency with increased African ancestry. Disaggregating gene-level mutation frequencies by variants revealed both ancestry-linked and NG-specific germline variant patterns. Driven by rs799917 (T>C), BRCA1 showed an increasing mutation frequency as African ancestry increased. BRCA2_rs11571831 was present only in MAA, and BRCA2_rs766173 was elevated in NG men. A total of 133 somatic variants were present in 26 prostate cancer-associated genes within the NG tumor cohort. BRCA2 (27%), APC (20%), ATM (20%), BRCA1 (13%), DNAJC6 (13%), EGFR (13%), MAD1L1 (13%), MLH1 (11%), and PMS2 (11%) showed mutation frequencies >10%. Compared with TCGA cohorts, NG tumors showed statistically significant elevated frequencies of BRCA2, APC, and BRCA1. The NG cohort variant pattern shared similarities (cosign similarities ≥0.734) with Catalogue of Somatic Mutations in Cancer signatures 5 and 6, and mutated genes showed significant (q < 0.001) gene ontology (GO) and functional enrichment in mismatch repair and non-homologous repair deficiency pathways. Here, we showed that mutations in DNA damage response genes were higher in NG prostate cancer samples and that a portion of those mutations correlate with African ancestry. Moreover, we identified variants of unknown significance that may contribute to population-specific routes of tumorigenesis and treatment. These results present the most comprehensive characterization of the NG prostate cancer exome to date and highlight the need to increase diversity of study populations.

Significance

MAA have higher rates of prostate cancer incidence and mortality, however, are severely underrepresented in genomic studies. This is the first study utilizing whole-exome sequencing in NG men to identify West African ancestry-linked variant patterns that impact DNA damage repair pathways.

Immune mechanisms behind prostate cancer in men of African ancestry: A review

BACKGROUND

Men of African ancestry (AA) with prostate cancer suffer from worse outcomes. However, a recent analysis of patients treated with the dendritic cell vaccine sipuleucel-T for prostate cancer suggested that AA patients could have improved outcomes relative to whites.

METHODS

We conducted a focused literature review of Medline-indexed articles and clinical trials listed on clinicaltrials.gov.

RESULTS

We identify several studies pointing to enrichment of inflammatory cellular infiltrates and cytokine signaling among AA patients with prostate cancer. We outline potential genomic and transcriptomic alterations that may contribute to immunogenicity. Last, we investigate differences in host immunity and vaccine responsiveness that may be enhanced in AA patients.

CONCLUSIONS

AA patients with prostate cancer may be enriched for an immunogenic phenotype. Dedicated studies are needed to better understand the immune mechanisms that contribute to existing cancer disparities and test immune-based therapies in this population.

Driver gene detection through Bayesian network integration of mutation and expression profiles

MOTIVATION

The identification of mutated driver genes and the corresponding pathways is one of the primary goals in understanding tumorigenesis at the patient level. Integration of multi-dimensional genomic data from existing repositories, e.g., The Cancer Genome Atlas (TCGA), offers an effective way to tackle this issue. In this study, we aimed to leverage the complementary genomic information of individuals and create an integrative framework to identify cancer-related driver genes. Specifically, based on pinpointed differentially expressed genes, variants in somatic mutations and a gene interaction network, we proposed an unsupervised Bayesian network integration (BNI) method to detect driver genes and estimate the disease propagation at the patient and/or cohort levels. This new method first captures inherent structural information to construct a functional gene mutation network and then extracts the driver genes and their controlled downstream modules using the minimum cover subset method.

RESULTS

Using other credible sources (e.g. Cancer Gene Census and Network of Cancer Genes), we validated the driver genes predicted by the BNI method in three TCGA pan-cancer cohorts. The proposed method provides an effective approach to address tumor heterogeneity faced by personalized medicine. The pinpointed drivers warrant further wet laboratory validation.

AVAILABILITY AND IMPLEMENTATION

The supplementary tables and source code can be obtained from https://xavieruniversityoflouisiana.sharefile.com/d-se6df2c8d0ebe4800a3030311efddafe5.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Correlation of NTRK1 Downregulation with Low Levels of Tumor-Infiltrating Immune Cells and Poor Prognosis of Prostate Cancer Revealed by Gene Network Analysis

Prostate cancer (PCa) is a life-threatening heterogeneous malignancy of the urinary tract. Due to the incidence of prostate cancer and the crucial need to elucidate its molecular mechanisms, we searched for possible prognosis impactful genes in PCa using bioinformatics analysis. A script in R language was used for the identification of Differentially Expressed Genes (DEGs) from the GSE69223 dataset. The gene ontology (GO) of the DEGs and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were performed. A protein-protein interaction (PPI) network was constructed using the STRING online database to identify hub genes. GEPIA and UALCAN databases were utilized for survival analysis and expression validation, and 990 DEGs (316 upregulated and 674 downregulated) were identified. The GO analysis was enriched mainly in the "collagen-containing extracellular matrix", and the KEGG pathway analysis was enriched mainly in "focal adhesion". The downregulation of neurotrophic receptor tyrosine kinase 1 (NTRK1) was associated with a poor prognosis of PCa and had a significant positive correlation with infiltrating levels of immune cells. We acquired a collection of pathways related to primary PCa, and our findings invite the further exploration of NTRK1 as a biomarker for early diagnosis and prognosis, and as a future potential molecular therapeutic target for PCa.

Fusion Genes in Prostate Cancer: A Comparison in Men of African and European Descent

Simple Summary

Men of African origin have a 2–3 times greater chance of developing prostate cancer than those of European origin, and of patients that are diagnosed with the disease, men of African descent are 2 times more likely to die compared to white men. Men of African origin are still greatly underrepresented in genetic studies and clinical trials. This, unfortunately, means that new discoveries in cancer treatment are missing key information on the group with a greater chance of mortality. A fusion gene is a hybrid gene formed from two previously independent genes. Fusion genes have been found to be common in all main types of human cancer. The objective of this study was to increase our knowledge of fusion genes in prostate cancer using computational approaches and to compare fusion genes between men of African and European origin. This identified novel gene fusions unique to men of African origin and suggested that this group has a greater number of fusion genes.

Abstract

Prostate cancer is one of the most prevalent cancers worldwide, particularly affecting men living a western lifestyle and of African descent, suggesting risk factors that are genetic, environmental, and socioeconomic in nature. In the USA, African American (AA) men are disproportionately affected, on average suffering from a higher grade of the disease and at a younger age compared to men of European descent (EA). Fusion genes are chimeric products formed by the merging of two separate genes occurring as a result of chromosomal structural changes, for example, inversion or trans/cis-splicing of neighboring genes. They are known drivers of cancer and have been identified in 20% of cancers. Improvements in genomics technologies such as RNA-sequencing coupled with better algorithms for prediction of fusion genes has added to our knowledge of specific gene fusions in cancers. At present AA are underrepresented in genomic studies of prostate cancer. The primary goal of this study was to examine molecular differences in predicted fusion genes in a cohort of AA and EA men in the context of prostate cancer using computational approaches. RNA was purified from prostate tissue specimens obtained at surgery from subjects enrolled in the study. Fusion gene predictions were performed using four different fusion gene detection programs. This identified novel putative gene fusions unique to AA and suggested that the fusion gene burden was higher in AA compared to EA men.

Germline mutation landscape of DNA damage repair genes in African Americans with prostate cancer highlights potentially targetable RAD genes

In prostate cancer, emerging data highlight the role of DNA damage repair genes (DDRGs) in aggressive forms of the disease. However, DDRG mutations in African American men are not yet fully defined. Here, we profile germline mutations in all known DDRGs (N = 276) using whole genome sequences from blood DNA of a matched cohort of patients with primary prostate cancer comprising of 300 African American and 300 European Ancestry prostate cancer patients, to determine whether the mutation status can enhance patient stratification for specific targeted therapies. Here, we show that only 13 of the 46 DDRGs identified with pathogenic/likely pathogenic mutations are present in both African American and European ancestry patients. Importantly, RAD family genes (RAD51, RAD54L, RAD54B), which are potentially targetable, as well as PMS2 and BRCA1, are among the most frequently mutated DDRGs in African American, but not in European Ancestry patients.

Soluble Programmed Death-Ligand 1 (sPD-L1) is Elevated in Aggressive Prostate Cancer Disease Among African Men

Introduction

Programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1)-targeted immunotherapies have become a new mode of treatment for several tumours; however, there is limited evidence on the expression and prognostic value of PD-1/PD-L1 in prostate cancer, especially in African men.

Methods

Plasma concentrations of PD-L1/PD-1 were assessed using enzyme-linked immunosorbent assay in patients with prostate cancer and normal healthy controls at the Uganda Cancer Institute. The associations between plasma PD-L1/PD-1 concentration levels and serum prostate-specific antigen (PSA) levels, Gleason scores, age, and body mass index (BMI) were determined.

Results

We found significant differences in the median plasma concentrations of PD-L1 and PD-1 immune checkpoint molecules between prostate cancer cases and normal healthy controls of 0.285 vs 0.035 (p = 0.001) and 0.596 vs 0.355 (p = 0.017), respectively. We found no significant association between age, serum PSA levels, BMI and Gleason scores, and PD-1 among patients with prostate cancer and controls. However, elevated levels of PD-L1 were significantly associated with higher Gleason scores among patients with prostate cancer (p = 0.014).

Conclusions

Elevated PD-L1 levels were statistically significantly linked to high Gleason scores. These results may guide clinicians in assessing the prognosis of patients individually and selecting patients who will be suitable candidates for anti-PD-L1 immunotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40487-022-00184-6.

A roadmap to increase diversity in genomic studies

Two decades ago, the sequence of the first human genome was published. Since then, advances in genome technologies have resulted in whole-genome sequencing and microarray-based genotyping of millions of human genomes. However, genetic and genomic studies are predominantly based on populations of European ancestry. As a result, the potential benefits of genomic research-including better understanding of disease etiology, early detection and diagnosis, rational drug design and improved clinical care-may elude the many underrepresented populations. Here, we describe factors that have contributed to the imbalance in representation of different populations and, leveraging our experiences in setting up genomic studies in diverse global populations, we propose a roadmap to enhancing inclusion and ensuring equal health benefits of genomics advances. Our Perspective highlights the importance of sincere, concerted global efforts toward genomic equity to ensure the benefits of genomic medicine are accessible to all.

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.

A glance at the emerging diagnostic biomarkers in the most prevalent genitourinary cancers

Genitourinary cancers comprise of a heterogenous group of cancers of which renal cell carcinoma, urothelial bladder carcinoma, and prostate adenocarcinoma are the most commonly encountered subtypes. A lot of research is ongoing using various strategies for exploration of novel biomarkers for genitourinary cancers. These biomarkers would not reduce the need for invasive diagnostic techniques but also could be used for early and accurate diagnosis to improve the clinical management required for the disease. Moreover, selecting the appropriate treatment regimen for the responsive patients based on these biomarkers would reduce the treatment toxicity as well as cost. Biomarkers identified using various advanced techniques like next generation sequencing and proteomics, which have been classified as immunological biomarkers, tissue-specific biomarkers and liquid biomarkers. Immunological biomarkers include markers of immunological pathways such as CTLA4, PD-1/PDl-1, tissue biomarkers include tissue specific molecules such as PSA antigen and liquid biomarkers include biomarkers detectable in urine, circulating cells etc.

The purpose of this review is to provide a brief introduction to the most prevalent genitourinary malignancies, including bladder, kidney, and prostate cancers along with a major focus on the novel diagnostic biomarkers and the importance of targeting them prior to genitourinary cancers treatment. Understanding these biomarkers and their potential in diagnosis of genitourinary cancer would not help in early and accurate diagnosis as mentioned above but may also lead towards a personalized approach for better diagnosis, prognosis and specified treatment approach for an individual.

Racial differences in prostate tumor microenvironment: implications for disparate clinical outcomes and potential opportunities

Disparities in cancer incidence and outcome are common among the racial and ethnical minorities in the United States and are of significant social and clinical concern. Prostate cancer is the most commonly diagnosed non-cutaneous malignancy in American men and exhibits substantial racial disparities with African American men bearing the highest burden in terms of incidence and mortality. A multitude of factors, including socioeconomic, behavioral, and access to healthcare, have been implicated as the underlying causes of such disparities. More recent data also suggest that there are inherent molecular and biological differences in prostate tumors of patients having distinct racial backgrounds. Tumor microenvironment has tremendous impact on the course of cancer progression and clinical outcome and may also contribute to the racial disparities observed in prostate cancer. Therefore, a better understanding of critical differences in the tumor microenvironment components may provide newer directions to study the biological causes of prostate cancer health disparities and may identify novel therapeutic targets. This review discusses the findings related to the tumor microenvironment differences between African American and Caucasian American prostate cancer patients and makes suggestion regarding their potential significance in prostate cancer disparities.

Prostate Cancer Racial Disparities: A Systematic Review by the Prostate Cancer Foundation Panel

CONTEXT

Prostate cancer (PCa) is a complex disease that disproportionately impacts Black men in the USA. The structural factors that drive heterogeneous outcomes for patients of differing backgrounds are probably the same ones that result in population-level disparities. The relative contribution of drivers along the PCa disease continuum is an active area of investigation and debate.

OBJECTIVE

To critically synthesize the available evidence on PCa disparities from a population-level perspective in comparison to data from "equal access and equal care settings" and to provide a consensus summary of the state of PCa disparities.

EVIDENCE ACQUISITION

A plenary panel on PCa disparities presented at the Prostate Cancer Foundation meeting on October 24, 2019 and ensuing discussions are reported here. We used a systematic literature review approach and the Preferred Reporting Items for Systematic Reviews and Meta-analyses to select the most relevant publications. A total of 3333 publications between 2011 and 2021 were retrieved, of which 52 were included in the review; an additional 13 articles on screening guidelines, seminal clinical trials, and statistical methodology were used in the evidence synthesis.

EVIDENCE SYNTHESIS

Race disparities in PCa are a result of a complex interaction between socioeconomic factors impacting access to care and ancestral/genetic factors that may influence tumor biology. Black men in the USA continue to have a nearly 1.8 times higher population-level mortality rate than White men. Failure to account for the race-specific incidence burden would continue to lead to residual disparity even after achieving relatively similar outcomes after primary treatment, resulting in a higher long-term mortality burden. Selection bias remains possible in PCa studies, which often rely on highly specific cohorts of Black men with higher use of health care resources that may not represent the average Black patient in the USA. Novel methods including mediation analysis and genetic ancestry rather than self-identified race can optimize analytical models investigating racial disparities and may lead to a better understanding of PCa genomic diversity and behavior.

CONCLUSIONS

Our findings emphasize the importance of racially diverse studies, including precision -omics, prevention, and targeted therapy initiatives, to elucidate mechanisms underlying racial differences in outcomes and response to therapy. We propose novel approaches for studying and addressing PCa disparities. Contemporary methods, particularly in the domain of mediation analysis, can promote scientific rigor in understanding these disparities.

PATIENT SUMMARY

Inaccurate data interpretation or lack of data altogether for Black men can impact policy and ultimately affect millions of individuals of African origin worldwide. Our review identifies a need to develop and prioritize a strategy for including Black and other men with prostate cancer in intervention studies and randomized clinical trials to halt the widening prostate cancer disparities.

Pentz R. Prostate Cancer: Community Education and Disparities in Diagnosis and Treatment

Prostate cancer remains the leading diagnosed cancer and the second leading cause of death among American men. Despite improvements in screening modalities, diagnostics, and treatment, disparities exist among Black men in this country. The primary objective of this systematic review is to describe the reported disparities in screening, diagnostics, and treatments as well as efforts to alleviate these disparities through community and educational outreach efforts. Critical review took place of retrospective, prospective, and socially descriptive data of English language publications in the PubMed database. Despite more advanced presentation, lower rates of screening and diagnostic procedures, and low rates of trial inclusion, subanalyses have shown that various modalities of therapy are quite effective in Black populations. Moreover, patients treated on prospective clinical trials and within equal-access care environments have shown similar outcomes regardless of race. Additional prospective studies and enhanced participation in screening, diagnostic and genetic testing, clinical trials, and community-based educational endeavors are important to ensure equitable progress in prostate cancer for all patients. IMPLICATIONS FOR PRACTICE: Notable progress has been made with therapeutic advances for prostate cancer, but racial disparities continue to exist. Differing rates in screening and utility in diagnostic procedures play a role in these disparities. Black patients often present with more advanced disease, higher prostate-specific antigen, and other adverse factors, but outcomes can be attenuated in trials or in equal-access care environments. Recent data have shown that multiple modalities of therapy are quite effective in Black populations. Novel and bold hypotheses to increase inclusion in clinical trial, enhance decentralized trial efforts, and enact successful models of patient navigation and community partnership are vital to ensure continued progress in prostate cancer disparities.

Hereditary Prostate Cancer: Genes Related, Target Therapy and Prevention

Prostate cancer (PCa) is globally the second most diagnosed cancer type and the most common cause of cancer-related deaths in men. Family history of PCa, hereditary breast and ovarian cancer (HBOC) and Lynch syndromes (LS), are among the most important risk factors compared to age, race, ethnicity and environmental factors for PCa development. Hereditary prostate cancer (HPCa) has the highest heritability of any major cancer in men. The proportion of PCa attributable to hereditary factors has been estimated in the range of 5–15%. To date, the genes more consistently associated to HPCa susceptibility include mismatch repair (MMR) genes (MLH1, MSH2, MSH6, and PMS2) and homologous recombination genes (BRCA1/2, ATM, PALB2, CHEK2). Additional genes are also recommended to be integrated into specific research, including HOXB13, BRP1 and NSB1. Importantly, BRCA1/BRCA2 and ATM mutated patients potentially benefit from Poly (ADP-ribose) polymerase PARP inhibitors, through a mechanism of synthetic lethality, causing selective tumor cell cytotoxicity in cell lines. Moreover, the detection of germline alterations in MMR genes has therapeutic implications, as it may help to predict immunotherapy benefits. Here, we discuss the current knowledge of the genetic basis for inherited predisposition to PCa, the potential target therapy, and the role of active surveillance as a management strategy for patients with low-risk PCa. Finally, the current PCa guideline recommendations are reviewed.

[Familial prostate cancer and genetic predisposition]

BACKGROUND

Twenty percent of all prostate cancer patients have a positive family history (at least 1 first-degree relative with prostate cancer) and a part of these patients have a genetic predisposition.

OBJECTIVES

A literature search and analysis of studies investigating incidence, diagnosis, and clinical course of familial compared to sporadic prostate cancer as well as genetic predisposition was performed using PubMed and Embase.

RESULTS

Risk of prostate cancer depends on number, degree of relationship, and age of onset of affected men in the family. The incidence of familial prostate cancer is higher and the age of diagnosis lower compared to sporadic cases. The clinical course of the disease is comparable, but in individuals with a germline mutation, more intensive therapy is needed due to a more aggressive disease.

CONCLUSIONS

Crucial for risk assessment is a detailed family history, including creation of a pedigree with cancer family history if necessary. In high-risk families, genetic counselling and annual prostate-specific antigen (PSA) screening beginning at the age of 40 should be performed. Verification of a germline mutation requires more intensive therapy due to more aggressive disease.

Identification of Germline Genetic Variants that Increase Prostate Cancer Risk and Influence Development of Aggressive Disease

Prostate cancer (PrCa) is a heterogeneous disease, which presents in individual patients across a diverse phenotypic spectrum ranging from indolent to fatal forms. No robust biomarkers are currently available to enable routine screening for PrCa or to distinguish clinically significant forms, therefore late stage identification of advanced disease and overdiagnosis plus overtreatment of insignificant disease both remain areas of concern in healthcare provision. PrCa has a substantial heritable component, and technological advances since the completion of the Human Genome Project have facilitated improved identification of inherited genetic factors influencing susceptibility to development of the disease within families and populations. These genetic markers hold promise to enable improved understanding of the biological mechanisms underpinning PrCa development, facilitate genetically informed PrCa screening programmes and guide appropriate treatment provision. However, insight remains largely lacking regarding many aspects of their manifestation; especially in relation to genes associated with aggressive phenotypes, risk factors in non-European populations and appropriate approaches to enable accurate stratification of higher and lower risk individuals. This review discusses the methodology used in the elucidation of genetic loci, genes and individual causal variants responsible for modulating PrCa susceptibility; the current state of understanding of the allelic spectrum contributing to PrCa risk; and prospective future translational applications of these discoveries in the developing eras of genomics and personalised medicine.

Family history of prostate cancer and prostate tumor aggressiveness in black and non-black men;results from an equal access biopsy study

Purpose

To test for racial differences in associations between family history (FH) of prostate cancer (PC) and prostate cancer aggressiveness in a racially diverse equal access population undergoing prostate biopsy.

Subjects/patients and methods

We prospectively enrolled men undergoing prostate biopsy at the Durham Veterans Administration from 2007 to 2018 and assigned case or control status based on biopsy results. Race and FH of PC were self-reported on questionnaires. Logistic regression was used to test the association between FH and PC diagnosis overall and by tumor aggressiveness [high- (Grade Group 3–5) or low-grade (Grade Group 1–2) vs. no cancer], overall, and stratified by race. Models were adjusted for age and year of consent, race, PSA level, digital rectal exam findings, prostate volume, and previous (negative) biopsy receipt.

Results

Of 1,225 men, 323 had a FH of PC and 652 men were diagnosed with PC on biopsy. On multivariable analysis, FH was associated with increased odds of high-grade PC in black (OR 1.85, p = 0.041) and all men (OR 1.56, p = 0.057) and was unrelated to overall or low-grade PC diagnosis, overall, or stratified by race (all p ≥ 0.325). In sensitivity analyses among men without a previous biopsy, results were slightly more pronounced.

Conclusion

In this setting of equal access to care, positive FH of PC was associated with increased tumor aggressiveness in black men, but not non-black men undergoing prostate biopsy. Further research is required to tease apart the contribution of genetics from increased PC awareness potentially influencing screening and biopsy rates in men with FH.

Supplementary Information

The online version of this article (10.1007/s10552-020-01389-8) contains supplementary material, which is available to authorized users.

Whole-exome Sequencing of Prostate Cancer in Sardinian Identify Recurrent UDP-glucuronosyltransferase Amplifications

Globally, prostate cancer is the third most common cancer in the world, and the second most common cancer in men. However, rates for incidence and mortality vary considerably with race, ethnicity, and geography. Over 97 significantly mutated genes that have been identified in prostate cancer; however, a lack of genomic prostate cancer studies focusing on different racial and ethnic groups and racial mixing pose a serious challenge to universalize these findings. The Sardinian population is an isolated Mediterranean population that has a high frequency of centenarians and a much lower incidence of prostate cancer than found in males in mainland Europe. Here, we conducted a genomic prostate cancer study on a Sardinian cohort diagnosed with local prostate cancer. Our data reveals a low rate of ERG fusion in Sardinian prostate cancer. Interestingly, we identified a novel BTBD7-SLC2A5 fusion that occurred in 13% of the patients. We also found that the UGT2B4 on 4q13.2 was amplified in 20% of the Sardinian patients but rarely amplified in patients of other population. These observations underscore the importance of the inter-population molecular heterogeneity of prostate cancer. In addition, we examined the expression of UGT2B4 in 497 prostate cancer patients derived from The Cancer Genome Atlas database. We found that high expression of UGT2B4 was associated with low-grade prostate cancer and upregulation of UGT2B4 in tumors was associated with upregulation of metabolism pathways such as 'de novo' IMP biosynthetic process, glutamine and monocarboxylic acid metabolism. These data provide insight into clinical relevance and functional mechanism of UGT2B4. Further understanding functional mechanism of UGT2B4 amplification and BTBD7-SLC2A5 fusion will aid in developing drugs to benefit the prostate cancer patients.

Advancing global equity in cancer genomics - challenges and opportunities in Sub-Saharan Africa

Developments in genomics in the last decade has improved our understanding of the role of genetics in health and disease. One area where the impact of genomics is very noticeable is in oncology, specifically in terms of diagnosis and elucidating genetic predisposition to rare and common cancers. Sub-Saharan Africa (SSA) stands to benefit from cancer genomics, given recent spikes in the incidence of various types of cancers in the region. This mini review presents, from a health and science equity perspective, how genomics could shape cancer research and clinical care in SSA. We highlight some pan-African genomics and cancer initiatives that are facilitating cancer genomics research in SSA. We conclude with recommendations on how the ideals of equity may be advanced in cancer genomics initiatives in SSA.

Inflammation as a Driver of Prostate Cancer Metastasis and Therapeutic Resistance

Simple Summary

Prostate cancer is the most common malignancy in men, with a high mortality rate when disease progresses to metastasis and therapeutic resistance. Evidence implicates inflammation as a driver of prostate cancer risk and has a significant impact on processes in the tumor microenvironment that facilitate progression to advanced therapeutically resistant disease. In this review, we discuss the sources of inflammation in the prostate, the functional contribution of the critical inflammatory effectors to prostate cancer initiation and metastatic progression, and the therapeutic challenges that they impose on treatment of advanced disease and overcoming therapeutic resistance. Full understanding of the role of inflammation in prostate cancer progression to advanced metastatic disease and tumor relapse will aid in the development of personalized predictive biomarkers and therapy to reduce the burden and mortality in prostate cancer patients.

Abstract

Prostate cancer is the most common malignancy among men, and progression to metastasis and the emergence of therapeutically resistant disease confers a high mortality rate. Growing evidence implicates inflammation as a driver of prostate cancer development and progression, resulting in increased cancer risk for prostate cancer. Population-based studies revealed that the use of antinflammatory drugs led to a 23% risk reduction prostate cancer occurrence, a negative association that was stronger in men who specifically used COX-2 inhibitors. Furthermore, patients that were taking aspirin had a 21% reduction in prostate cancer risk, and further, long-term users of daily low dose aspirin had a 29% prostate cancer risk reduction as compared to the controls. Environmental exposure to bacterial and viral infections, exposure to mutagenic agents, and genetic variations predispose the prostate gland to inflammation, with a coordinated elevated expression of inflammatory cytokines (IL-6, TGF-β). It is the dynamics within the tumor microenvironment that empower these cytokines to promote survival and growth of the primary tumor and facilitate disease progression by navigating the immunoregulatory network, phenotypic epithelial-mesenchymal transition (EMT), angiogenesis, anoikis resistance, and metastasis. In this review, we discuss the sources of inflammation in the prostate, the functional contribution of the critical inflammatory effectors to prostate cancer initiation and metastatic progression, and the therapeutic challenges that they impose on treatment of advanced disease and overcoming therapeutic resistance. Growing mechanistic evidence supports the significance of inflammation in localized prostate cancer, and the systemic impact of the process within the tumor microenvironment on disease progression to advanced therapeutically-resistant prostate cancer. Rigorous exploitation of the role of inflammation in prostate cancer progression to metastasis and therapeutic resistance will empower the development of precise biomarker signatures and effective targeted therapeutics to reduce the clinical burden and lethal disease in the future.

Molecular tracing of prostate cancer lethality

Prostate cancer is diagnosed mostly in men over the age of 50 years, and has favorable 5-year survival rates due to early cancer detection and availability of curative surgical management. However, progression to metastasis and emergence of therapeutic resistance are responsible for the majority of prostate cancer mortalities. Recent advancement in sequencing technologies and computational capabilities have improved the ability to organize and analyze large data, thus enabling the identification of novel biomarkers for survival, metastatic progression and patient prognosis. Large-scale sequencing studies have also uncovered genetic and epigenetic signatures associated with prostate cancer molecular subtypes, supporting the development of personalized targeted-therapies. However, the current state of mainstream prostate cancer management does not take full advantage of the personalized diagnostic and treatment modalities available. This review focuses on interrogating biomarkers of prostate cancer progression, including gene signatures that correspond to the acquisition of tumor lethality and those of predictive and prognostic value in progression to advanced disease, and suggest how we can use our knowledge of biomarkers and molecular subtypes to improve patient treatment and survival outcomes.

The Impact of HMGB1 Polymorphisms on Prostate Cancer Progression and Clinicopathological Characteristics

Prostate cancer is one of the major cancers of the genitourinary tract. High-mobility group box 1 (HMGB1) was suggested as a promising therapeutic target for prostate cancer. In this study, we aim to elucidate the associations of HMGB1 single nucleotide polymorphisms (SNPs) with prostate cancer susceptibility and clinicopathological characteristics. The HMGB1 SNPs rs1412125, rs2249825, rs1045411, and rs1360485 in 579 prostate cancer patients and 579 cancer-free controls were analyzed with real-time polymerase chain reactions (real-time PCR). All of the data were evaluated with SAS statistical software. Our results showed that the HMGB1 rs1045411 T allele genotype was significantly associated with advanced pathologic T stage (odds ratio (OR) = 1.433, 95% confidence interval (CI) = 1.021–2.012; p = 0.037) and pathologic N1 stage (OR = 2.091, 95% CI = 1.160–3.767; p = 0.012), and the rs1360485 polymorphic CT + TT genotype was associated with pathologic Gleason grade group (4 + 5) (OR = 1.583, 95% CI = 1.017–2.462; p = 0.041), pathologic T stage (3 + 4) (OR = 1.482, 95% CI = 1.061–2.070; p = 0.021), and pathologic N1 stage (OR = 2.131, 95% CI = 1.178–3.852; p = 0.011) compared with their wild-type carriers. In conclusion, our results revealed that the HMGB1 SNPs were associated with the clinical status of prostate cancer. The HMGB1 SNPs may have the potential to predict prostate cancer disease progression.

Night Shift Work, Chronotype, Sleep Duration, and Prostate Cancer Risk: CAPLIFE Study

To analyze the association between prostate cancer (PCa) risk and night shift work, chronotype, and sleep duration in the context of a population-based case-control study of incident prostate cancer in Spain, a total of 465 PCa cases and 410 controls were analyzed. Selection criteria were: (i) age 40-80 years, and (ii) residence in the coverage area of the reference hospitals for ≥6 months before recruitment. Exposure variables were: (i) night shift work (permanent or rotating); (ii) chronotype: morning, neither, or evening (Munich ChronoType Questionnaire) and (iii) sleep duration according to the recommendations of the American National Sleep Foundation. PCa aggressiveness was determined according to the International Society of Urology Pathology classification. Adjusted odds ratios (aOR) and 95% confidence intervals (95% CI) were estimated using logistic regression models. Night shift work was associated with PCa, aOR = 1.47 (95% CI 1.02-2.11), especially for rotating night shifts, aOR = 1.73 (95% CI 1.09-2.75). The magnitude of the association between ever night work and PCa was higher in evening subjects with aOR = 3.14 (95% CI 0.91-10.76) than in morning chronotypes with an aOR = 1.25 (95% CI 0.78-2.00). Working night shifts, especially rotating night shifts, could increase PCa risk. This risk may be higher in people with an evening chronotype.

The diverse roles of SPOP in prostate cancer and kidney cancer

Multiple studies have confirmed that speckle-type pox virus and zinc finger (POZ) protein (SPOP) functions as a substrate adaptor of cullin 3-based E3 ligase and has a crucial role in various cellular processes via specific targeting of proteins for ubiquitination and subsequent proteasomal degradation. Dysregulation of SPOP-mediated proteolysis might be involved in the development and progression of human prostate and kidney cancers. In prostate cancer, SPOP seems to function as a tumour suppressor by targeting several proteins, including androgen receptor (AR), steroid receptor coactivator 3 (SRC3) and BRD4, for degradation, whereas it might function as an oncoprotein in kidney cancer, for example, by targeting phosphatase and tensin homologue (PTEN) for proteasomal degradation. In addition, nuclear SPOP targets AR for degradation and has a role as a tumour suppressor in prostate cancer; however, in kidney cancer, SPOP largely accumulates in the cytoplasm and fails to promote degradation of AR located in the nucleus, resulting in activation of AR-driven pathways and cancer progression. Owing to the context-dependent function of SPOP in human malignancies, further assessment of the molecular mechanisms involving SPOP in prostate and kidney cancers is needed to improve our understanding of its role in the development of these cancer types. Treatments that target SPOP might become therapeutic strategies in these malignancies in the future.

Compliance with the 2018 World Cancer Research Fund/American Institute for Cancer Research Cancer Prevention Recommendations and Prostate Cancer

The etiology of prostate cancer (PCa) remains largely unknown. Compliance with the 2018 World Cancer Research Fund/American Institute for Cancer Research (WCRC/AICR) cancer prevention recommendations and its relationship to PCa was evaluated. A total of 398 incident PCa cases and 302 controls were included. The selection criteria for both cases and controls were: (i) age between 40-80 years; and (ii) residence in the coverage area of the reference hospitals for 6 months or more prior to recruitment. A score to measure the compliance with the recommendations of 2018 WCRC/AICR criteria was built. The level of compliance was used as a continuous variable and categorized in terciles. The aggressiveness of PCa was determined according to the ISUP classification. Adjusted odds ratios (aOR) and their 95% confidence intervals (95% CI) were estimated using multivariable logistic regression models. A slight protective tendency was observed between the level of compliance with the preventive recommendations and PCa risk, aOR = 0.81 (95% CI 0.69-0.96) for the total cases of PCa. This association also was observed when the aggressiveness was considered. In addition, limiting consumption of "fast foods", sugar-sweetened drinks, and alcohol were independently associated with lower risk of PCa.

Pseudogene Associated Recurrent Gene Fusion in Prostate Cancer

We present the functional characterization of a pseudogene associated recurrent gene fusion in prostate cancer. The fusion gene KLK4-KLKP1 is formed by the fusion of the protein coding gene KLK4 with the noncoding pseudogene KLKP1. Screening of a cohort of 659 patients (380 Caucasian American; 250 African American, and 29 patients from other races) revealed that the KLK4-KLKP1 is expressed in about 32% of prostate cancer patients. Correlative analysis with other ETS gene fusions and SPINK1 revealed a concomitant expression pattern of KLK4-KLKP1 with ERG and a mutually exclusive expression pattern with SPINK1, ETV1, ETV4, and ETV5. Development of an antibody specific to KLK4-KLKP1 fusion protein confirmed the expression of the full-length KLK4-KLKP1 protein in prostate tissues. The in vitro and in vivo functional assays to study the oncogenic properties of KLK4-KLKP1 confirmed its role in cell proliferation, cell invasion, intravasation, and tumor formation. Presence of strong ERG and AR binding sites located at the fusion junction in KLK4-KLKP1 suggests that the fusion gene is regulated by ERG and AR. Correlative analysis of clinical data showed an association of KLK4-KLKP1 with lower preoperative PSA values and in young men (<50 years) with prostate cancer. Screening of patient urine samples showed that KLK4-KLKP1 can be detected noninvasively in urine. Taken together, we present KLK4-KLKP1 as a class of pseudogene associated fusion transcript in cancer with potential applications as a biomarker for routine screening of prostate cancer.

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.

Dysregulated Transcriptional Control in Prostate Cancer

Recent advances in whole-genome and transcriptome sequencing of prostate cancer at different stages indicate that a large number of mutations found in tumors are present in non-protein coding regions of the genome and lead to dysregulated gene expression. Single nucleotide variations and small mutations affecting the recruitment of transcription factor complexes to DNA regulatory elements are observed in an increasing number of cases. Genomic rearrangements may position coding regions under the novel control of regulatory elements, as exemplified by the TMPRSS2-ERG fusion and the amplified enhancer identified upstream of the androgen receptor (AR) gene. Super-enhancers are increasingly found to play important roles in aberrant oncogenic transcription. Several players involved in these processes are currently being evaluated as drug targets and may represent new vulnerabilities that can be exploited for prostate cancer treatment. They include factors involved in enhancer and super-enhancer function such as bromodomain proteins and cyclin-dependent kinases. In addition, non-coding RNAs with an important gene regulatory role are being explored. The rapid progress made in understanding the influence of the non-coding part of the genome and of transcription dysregulation in prostate cancer could pave the way for the identification of novel treatment paradigms for the benefit of patients.

RAD51 and XRCC3 Polymorphisms Are Associated with Increased Risk of Prostate Cancer

Genetic polymorphisms in DNA repair genes may affect DNA repair efficiency and may contribute to the risk of developing cancer. The aim of our study was to investigate single nucleotide polymorphisms (SNPs) in RAD51 (rs2619679, rs2928140, and rs5030789) and XRCC3 (rs1799796) involved in DNA double-strand break repair and their relationship to prostate cancer. The study group included 99 men diagnosed with prostate cancer and 205 cancer-free controls. SNP genotyping was performed using the PCR-RFLP method. A significant association was detected between RAD51 rs5030789 polymorphism and XRCC3 rs1799796 polymorphism and an increased risk of prostate cancer. Our results indicate that RAD51 and XRCC3 polymorphism may contribute to prostate cancer.

Essential role of JunD in cell proliferation is mediated via MYC signaling in prostate cancer cells

JunD, a member of the AP-1 family, is essential for cell proliferation in prostate cancer (PCa) cells. We recently demonstrated that JunD knock-down (KD) in PCa cells results in cell cycle arrest in G1-phase concomitant with a decrease in cyclin D1, Ki67, and c-MYC, but an increase in p21 levels. Furthermore, the over-expression of JunD significantly increased proliferation suggesting JunD regulation of genes required for cell cycle progression. Here, employing gene expression profiling, quantitative proteomics, and validation approaches, we demonstrate that JunD KD is associated with distinct gene and protein expression patterns. Comparative integrative analysis by Ingenuity Pathway Analysis (IPA) identified 1) cell cycle control/regulation as the top canonical pathway whose members exhibited a significant decrease in their expression following JunD KD including PRDX3, PEA15, KIF2C, and CDK2, and 2) JunD dependent genes are associated with cell proliferation, with MYC as the critical downstream regulator. Conversely, JunD over-expression induced the expression of the above genes including c-MYC. We conclude that JunD is a crucial regulator of cell cycle progression and inhibiting its target genes may be an effective approach to block prostate carcinogenesis.

Racial disparities, cancer and response to oxidative stress

At the intersection of genetics, biochemistry and behavioral sciences, there is a largely untapped opportunity to consider how ethnic and racial disparities contribute to individual sensitivity to reactive oxygen species and how these might influence susceptibility to various cancers and/or response to classical cancer treatment regimens that pervasively result in the formation of such chemical species. This chapter begins to explore these connections and builds a platform from which to consider how the disciplines can be strengthened further.

A Rich Array of Prostate Cancer Molecular Biomarkers: Opportunities and Challenges

Prostate cancer is the most prevalent non-skin cancer in men and is the leading cause of cancer-related death. Early detection of prostate cancer is largely determined by a widely used prostate specific antigen (PSA) blood test and biopsy is performed for definitive diagnosis. Prostate cancer is asymptomatic in the early stage of the disease, comprises of diverse clinico-pathologic and progression features, and is characterized by a large subset of the indolent cancer type. Therefore, it is critical to develop an individualized approach for early detection, disease stratification (indolent vs. aggressive), and prediction of treatment response for prostate cancer. There has been remarkable progress in prostate cancer biomarker discovery, largely through advancements in genomic technologies. A rich array of prostate cancer diagnostic and prognostic tests has emerged for serum (4K, phi), urine (Progensa, T2-ERG, ExoDx, SelectMDx), and tumor tissue (ConfirmMDx, Prolaris, Oncoytype DX, Decipher). The development of these assays has created new opportunities for improving prostate cancer diagnosis, prognosis, and treatment decisions. While opening exciting opportunities, these developments also pose unique challenges in terms of selecting and incorporating these assays into the continuum of prostate cancer patient care.

JAK3 Variant, Immune Signatures, DNA Methylation, and Social Determinants Linked to Survival Racial Disparities in Head and Neck Cancer Patients

To inform novel personalized medicine approaches for race and socioeconomic disparities in head and neck cancer, we examined germline and somatic mutations, immune signatures, and epigenetic alterations linked to neighborhood determinants of health in Black and non-Latino White (NLW) patients with head and neck cancer. Cox proportional hazards revealed that Black patients with squamous cell carcinoma of head and neck (HNSCC) with PAX5 (P = 0.06) and PAX1 (P = 0.017) promoter methylation had worse survival than NLW patients, after controlling for education, zipcode, and tumor-node-metastasis stage (n = 118). We also found that promoter methylation of PAX1 and PAX5 (n = 78), was correlated with neighborhood characteristics at the zip-code level (P < 0.05). Analyses also showed differences in the frequency of TP53 mutations (n = 32) and tumor-infiltrating lymphocyte (TIL) counts (n = 24), and the presence of a specific C → A germline mutation in JAK3, chr19:17954215 (protein P132T), in Black patients with HNSCC (n = 73; P < 0.05), when compared with NLW (n = 37) patients. TIL counts are associated (P = 0.035) with long-term (>5 years), when compared with short-term survival (<2 years). We show bio-social determinants of health associated with survival in Black patients with HNSCC, which together with racial differences shown in germline mutations, somatic mutations, and TIL counts, suggests that contextual factors may significantly inform precision oncology services for diverse populations.

Androgen receptor splice variant-7 expression emerges with castration resistance in prostate cancer

BACKGROUND

Liquid biopsies have demonstrated that the constitutively active androgen receptor splice variant-7 (AR-V7) associates with reduced response and overall survival from endocrine therapies in castration-resistant prostate cancer (CRPC). However, these studies provide little information pertaining to AR-V7 expression in prostate cancer (PC) tissue.

METHODS

Following generation and validation of a potentially novel AR-V7 antibody for IHC, AR-V7 protein expression was determined for 358 primary prostate samples and 293 metastatic biopsies. Associations with disease progression, full-length androgen receptor (AR-FL) expression, response to therapy, and gene expression were determined.

RESULTS

We demonstrated that AR-V7 protein is rarely expressed (<1%) in primary PC but is frequently detected (75% of cases) following androgen deprivation therapy, with further significant (P = 0.020) increase in expression following abiraterone acetate or enzalutamide therapy. In CRPC, AR-V7 expression is predominantly (94% of cases) nuclear and correlates with AR-FL expression (P ≤ 0.001) and AR copy number (P = 0.026). However, dissociation of expression was observed, suggesting that mRNA splicing remains crucial for AR-V7 generation. AR-V7 expression was heterogeneous between different metastases from a patient, although AR-V7 expression was similar within a metastasis. Moreover, AR-V7 expression correlated with a unique 59-gene signature in CRPC, including HOXB13, a critical coregulator of AR-V7 function. Finally, AR-V7-negative disease associated with better prostate-specific antigen (PSA) responses (100% vs. 54%, P = 0.03) and overall survival (74.3 vs. 25.2 months, hazard ratio 0.23 [0.07-0.79], P = 0.02) from endocrine therapies (pre-chemotherapy).

CONCLUSION

This study provides impetus to develop therapies that abrogate AR-V7 signaling to improve our understanding of AR-V7 biology and to confirm the clinical significance of AR-V7.

FUNDING

Work at the University of Washington and in the Plymate and Nelson laboratories is supported by the Department of Defense Prostate Cancer Research Program (W81XWH-14-2-0183, W81XWH-12-PCRP-TIA, W81XWH-15-1-0430, and W81XWH-13-2-0070), the Pacific Northwest Prostate Cancer SPORE (P50CA97186), the Institute for Prostate Cancer Research, the Veterans Affairs Research Program, the NIH/National Cancer Institute (P01CA163227), and the Prostate Cancer Foundation. Work in the de Bono laboratory was supported by funding from the Movember Foundation/Prostate Cancer UK (CEO13-2-002), the US Department of Defense (W81XWH-13-2-0093), the Prostate Cancer Foundation (20131017 and 20131017-1), Stand Up To Cancer (SU2C-AACR-DT0712), Cancer Research UK (CRM108X-A25144), and the UK Department of Health through an Experimental Cancer Medicine Centre grant (ECMC-CRM064X).