Genetics of prostate cancer and its utility in treatment and screening.

Prostate cancer heritability is attributed to a combination of rare, moderate to highly penetrant genetic variants as well as commonly occurring variants conferring modest risks [single nucleotide polymorphisms (SNPs)]. Some of the former type of variants (e.g., BRCA2 mutations) predispose particularly to aggressive prostate cancer and confer poorer prognoses compared to men who do not carry mutations. Molecularly targeted treatments such as PARP inhibitors have improved outcomes in men carrying somatic and/or germline DNA repair gene mutations. Ongoing clinical trials are exploring other molecular targeted approaches based on prostate cancer somatic alterations. Genome wide association studies have identified >250 loci that associate with prostate cancer risk. Multi-ancestry analyses have identified shared as well as population specific risk SNPs. Prostate cancer risk SNPs can be used to estimate a polygenic risk score (PRS) to determine an individual's genetic risk of prostate cancer. The odds ratio of prostate cancer development in men whose PRS lies in the top 1% of the risk profile ranges from 9 to 11. Ongoing studies are investigating the utility of a prostate cancer PRS to target population screening to those at highest risk. With the advent of personalized medicine and development of DNA sequencing technologies, access to clinical genetic testing is increasing, and oncology guidelines from bodies such as NCCN and ESMO have been updated to provide criteria for germline testing of "at risk" healthy men as well as those with prostate cancer. Both germline and somatic prostate cancer research have significantly evolved in the past decade and will lead to further development of precision medicine approaches to prostate cancer treatment as well as potentially developing precision population screening models.

Runs of homozygosity and testicular cancer risk.

BACKGROUND: Testicular germ cell tumour (TGCT) is highly heritable but > 50% of the genetic risk remains unexplained. Epidemiological observation of greater relative risk to brothers of men with TGCT compared to sons has long alluded to recessively acting TGCT genetic susceptibility factors, but to date none have been reported. Runs of homozygosity (RoH) are a signature indicating underlying recessively acting alleles and have been associated with increased risk of other cancer types. OBJECTIVE: To examine whether RoH are associated with TGCT risk. METHODS: We performed a genome-wide RoH analysis using GWAS data from 3206 TGCT cases and 7422 controls uniformly genotyped using the OncoArray platform. RESULTS: Global measures of homozygosity were not significantly different between cases and controls, and the frequency of individual consensus RoH was not significantly different between cases and controls, after correction for multiple testing. RoH at three regions, 11p13-11p14.3, 5q14.1-5q22.3 and 13q14.11-13q.14.13, were, however, nominally statistically significant at p < 0.01. Intriguingly, RoH200 at 11p13-11p14.3 encompasses Wilms tumour 1 (WT1), a recognized cancer susceptibility gene with roles in sex determination and developmental transcriptional regulation, processes repeatedly implicated in TGCT aetiology. DISCUSSION AND CONCLUSION: Overall, our data do not support a major role in the risk of TGCT for recessively acting alleles acting through homozygosity, as measured by RoH in outbred populations of cases and controls.

Germline variants in IL4, MGMT and AKT1 are associated with prostate cancer-specific mortality: An analysis of 12,082 prostate cancer cases.

BACKGROUND: Prostate cancer (PCa) is a leading cause of mortality and genetic factors can influence tumour aggressiveness. Several germline variants have been associated with PCa-specific mortality (PCSM), but further replication evidence is needed. METHODS: Twenty-two previously identified PCSM-associated genetic variants were genotyped in seven PCa cohorts (12,082 patients; 1544 PCa deaths). For each cohort, Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals for risk of PCSM associated with each variant. Data were then combined using a meta-analysis approach. RESULTS: Fifteen SNPs were associated with PCSM in at least one of the seven cohorts. In the meta-analysis, after adjustment for clinicopathological factors, variants in the MGMT (rs2308327; HR 0.90; p-value = 3.5 × 10-2) and IL4 (rs2070874; HR 1.22; p-value = 1.1 × 10-3) genes were confirmed to be associated with risk of PCSM. In analyses limited to men diagnosed with local or regional stage disease, a variant in AKT1, rs2494750, was also confirmed to be associated with PCSM risk (HR 0.81; p-value = 3.6 × 10-2). CONCLUSIONS: This meta-analysis confirms the association of three genetic variants with risk of PCSM, providing further evidence that genetic background plays a role in PCa-specific survival. While these variants alone are not sufficient as prognostic biomarkers, these results may provide insights into the biological pathways modulating tumour aggressiveness.

Ambiguity in a masculine world: Being a BRCA1/2 mutation carrier and a man with prostate cancer.

OBJECTIVE: Increased risk of prostate cancer (PCa) is observed in men with BRCA1/BRCA2 mutations. Sex and gender are key determinants of health and disease although unequal care exists between the sexes. Stereotypical male attitudes are shown to lead to poor health outcomes. METHODS: Men with BRCA1/2 mutations and diagnosed with PCa were identified and invited to participate in a qualitative interview study. Data were analysed using a framework approach. "Masculinity theory" was used to report the impact of having both a BRCA1/2 mutation and PCa. RESULTS: Eleven of 15 eligible men were interviewed. The umbrella concept of "Ambiguity in a Masculine World" was evident. Men's responses often matched those of women in a genetic context. Men's BRCA experience was described, as "on the back burner" but "a bonus" enabling familial detection and early diagnosis of PCa. Embodiment of PCa took precedence as men revealed stereotypical "ideal" masculine responses such as stoicism and control while creating new "masculinities" when faced with the vicissitudes of having 2 gendered conditions. CONCLUSION: Health workers are urged to take a reflexive approach, void of masculine ideals, a belief in which obfuscates men's experience. Research is required regarding men's support needs in the name of equality of care.

Genetic predisposition to prostate cancer.

INTRODUCTION: Prostate cancer (PrCa) is the commonest non-cutaneous cancer in men in the UK. Epidemiological evidence as well as twin studies points towards a genetic component contributing to aetiology. SOURCES OF DATA: Key recently published literature. AREAS OF AGREEMENT: A family history of PrCa doubles the risk of disease development in first-degree relatives. Linkage and genetic sequencing studies identified rare moderate-high-risk gene loci, which predispose to PrCa development when altered by mutation. Genome-wide association studies have identified common single-nucleotide polypmorphisms (SNPs), which confer a cumulative risk of PrCa development with increasing number of risk alleles. There are emerging data that castrate-resistant disease is associated with mutations in DNA repair genes. AREAS OF CONTROVERSY: Linkage studies investigating possible high-risk loci leading to PrCa development identified possible loci on several chromosomes, but most have not been consistently replicated by subsequent studies. Germline SNPs related to prostate specific antigen (PSA) levels and to normal tissue radiosensitivity have also been identified though not all have been validated in subsequent studies. GROWING POINTS: Utilizing germline SNP profiles as well as identifying high-risk genetic variants could target screening to high-risk groups, avoiding the drawbacks of PSA screening. AREAS TIMELY FOR DEVELOPING RESEARCH: Incorporating genetics into PrCa screening is being investigated currently using both common SNP profiles and higher risk rare variants. Knowledge of germline genetic defects will allow the development of targeted screening programs, preventive strategies and the personalized treatment of PrCa.

High burden of copy number alterations and c-MYC amplification in prostate cancer from BRCA2 germline mutation carriers.

BACKGROUND: Germline BRCA2 mutations are associated with poorer outcome prostate cancer (PCa) compared with sporadic tumours but this association remains to be characterised. In this study, we aim to assess if there is a signature set of copy number alterations (CNA) that could aid to the identification of BRCA2-mutated tumours and would assist us to understand their aggressive clinical behaviour. METHODS: High-resolution array comparative genomic hybridisation profiling of DNA from PCa and matched morphologically normal prostate samples from 9 BRCA2 germline mutation carriers and 16 non-carriers in combination with unsupervised analysis was used to define copy number features. RESULTS: PCa from BRCA2 germline mutation carriers (B2T) harbour significantly more CNA than non-carrier tumours (NCTs) (P = 14 × 10(-6)). A hundred and sixteen regions had a significantly different distribution with both false discovery rate (FDR) and P value <0.01, including CNA in the genomic region containing c-MYC that was present in 89% B2T versus 12.5% NCT (P = 3 × 10(-4)). Loss of heterozygosity (LOH) at the BRCA2 locus was observed in 67% of B2T. Elevated CNA are already present in 50% of the morphologically normal prostate tissue from BRCA2 carriers. CONCLUSION: The relative high amount of CNAs in morphologically normal prostate tissue of BRCA2 carriers implies a field effect and together with the observed LOH could be used as a marker of PCa risk in these men. Several features previously associated with poor PCa outcome have been found to be significantly more common in BRCA2-mutated PCa than in sporadic tumours and may help to explain their adverse prognosis and be of relevance for targeted therapies.

Management of patients with advanced prostate cancer: recommendations of the St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) 2015.

The first St Gallen Advanced Prostate Cancer Consensus Conference (APCCC) Expert Panel identified and reviewed the available evidence for the ten most important areas of controversy in advanced prostate cancer (APC) management. The successful registration of several drugs for castration-resistant prostate cancer and the recent studies of chemo-hormonal therapy in men with castration-naïve prostate cancer have led to considerable uncertainty as to the best treatment choices, sequence of treatment options and appropriate patient selection. Management recommendations based on expert opinion, and not based on a critical review of the available evidence, are presented. The various recommendations carried differing degrees of support, as reflected in the wording of the article text and in the detailed voting results recorded in supplementary Material, available at Annals of Oncology online. Detailed decisions on treatment as always will involve consideration of disease extent and location, prior treatments, host factors, patient preferences as well as logistical and economic constraints. Inclusion of men with APC in clinical trials should be encouraged.

Selective organ preservation with neo-adjuvant chemotherapy for the treatment of muscle invasive transitional cell carcinoma of the bladder.

BACKGROUND: Radiotherapy for muscle invasive bladder cancer (MIBC) aims to offer organ preservation without oncological compromise. Neo-adjuvant chemotherapy provides survival advantage; response may guide patient selection for bladder preservation and identify those most likely to have favourable result with radiotherapy. METHODS: Ninety-four successive patients with T2-T4aN0M0 bladder cancer treated between January 2000 and June 2011 were analysed at the Royal Marsden Hospital. Patients received platinum-based chemotherapy following transurethral resection of bladder tumour; repeat cystoscopy (± biopsy) was performed to guide subsequent management. Responders were treated with radiotherapy. Poor responders were recommended radical cystectomy. Progression-free survival (PFS), disease-specific survival (DSS) and overall survival (OS) were estimated using Kaplan-Meier method; univariate and multivariate analyses were performed using the Cox proportional hazard regression model. RESULTS: Response assessment was performed in 89 patients. Seventy-eight (88%) demonstrated response; 53 (60%) achieved complete response (CR); 74 responders had radiotherapy; 4 opted for cystectomy. Eleven (12%) demonstrated poor response, 10 received cystectomy. Median survival for CR was 90 months (95% CI 64.7, 115.9) compared with 16 months (95% CI 5.4, 27.4; P < 0.001) poor responders. On multivariate analysis, only response was associated with significantly improved PFS, OS and DSS. After a median follow-up of 39 months (range 4-127 months), 14 patients (16%) required salvage cystectomy (8 for non-muscle invasive disease, 5 for invasive recurrence, 1 for radiotherapy related toxicity). In all, 82% had an intact bladder at last follow-up after radiotherapy; 67% had an intact bladder at last follow-up or death. Our study is limited by its retrospective nature. CONCLUSIONS: Response to neo-adjuvant chemotherapy is a favourable prognostic indicator and can be used to select patients for radiotherapy allowing bladder preservation in >80% of the selected patients.

Prevalence of the HOXB13 G84E germline mutation in British men and correlation with prostate cancer risk, tumour characteristics and clinical outcomes.

BACKGROUND: A rare recurrent missense variant in HOXB13 (rs138213197/G84E) was recently reported to be associated with hereditary prostate cancer. Population-based studies have established that, since the frequency of this single-nucleotide polymorphism (SNP) varies between geographic regions, the associated proportion of prostate cancer (PrCa) risk contribution is also highly variable by country. PATIENTS AND METHODS: This is the largest comprehensive case-control study assessing the prevalence of the HOXB13 G84E variant to date and is the first in the UK population. We genotyped 8652 men diagnosed with PrCa within the UK Genetic Prostate Cancer Study (UKGPCS) and 5252 healthy men from the UK ProtecT study. RESULTS: HOXB13 G84E was identified in 0.5% of the healthy controls and 1.5% of the PrCa cases, and it was associated with a 2.93-fold increased risk of PrCa [95% confidence interval (CI) 1.94-4.59; P = 6.27 × 10(-8)]. The risk was even higher among men with family history of PrCa [odds ratio (OR) = 4.53, 95% CI 2.86-7.34; P = 3.1 × 10(-8)] and in young-onset PrCa (diagnosed up to the age of 55 years; OR = 3.11, 95% CI 1.98-5.00; P = 6.1 × 10(-7)). There was no significant association between Gleason Score, presenting prostate specific antigen, tumour-node-metastasis (TNM) stage or NCCN risk group and carrier status. HOXB13 G84E was not associated with overall or cancer-specific survival. We found that the polygenic PrCa risk score (PR score), calculated using the 71 known single-nucleotide polymorphisms (SNPs) associated with PrCa and the HOXB13 G84E variant act multiplicatively on PrCa risk. Based on the estimated prevalence and risk, this rare variant explains ∼1% of the familial risk of PrCa in the UK population. CONCLUSIONS: The clinical importance of HOXB13 G84E in PrCa management has not been established. This variant was found to have no effect on prognostic implications but could be used for stratifying screening, by identifying men at high risk. CLINICAL TRIALS NUMBERS: Prostate Testing for Cancer and Treatment (ProtecT): NCT02044172. UK GENETIC PROSTATE CANCER STUDY: Epidemiology and Molecular Genetics Studies (UKGPCS): NCT01737242.

Spontaneous antibodies against Engrailed-2 (EN2) protein in patients with prostate cancer.

We reported the expression of the homeodomain-containing transcription factor Engrailed-2 (EN2) in prostate cancer and showed that the presence of EN2 protein in the urine was highly predictive of prostate cancer. This study aimed to determine whether patients with prostate cancer have EN2 autoantibodies, what the prevalence of these antibodies is and whether they are associated with disease stage. The spontaneous immunoglobulin (Ig)G immune response against EN2 and for comparison the tumour antigen New York Esophageal Squamous Cell Carcinoma 1 (NY-ESO-1), were tested by enzyme-linked immunosorbent assay (ELISA) in three different cohorts of prostate cancer patients as well as a group of men genetically predisposed to prostate cancer. Thirty-two of 353 (9·1%) of the SUN cohort representing all stages of prostate cancer demonstrated EN2 IgG responses, 12 of 107 patients (11·2%) in the advanced prostate cancer patients showed responses, while only four of 121 patients (3·3%) with castrate-resistant prostate cancer showed EN2 autoantibodies. No significant responses were found in the predisposed group. Anti-EN2 IgG responses were significantly higher in patients with prostate cancer compared to healthy control males and similarly prevalent to anti-NY-ESO-1 responses. While EN2 autoantibodies are not a useful diagnostic or monitoring tool, EN2 immunogenicity provides the rationale to pursue studies using EN2 as an immunotherapeutic target.

Frequent germline deleterious mutations in DNA repair genes in familial prostate cancer cases are associated with advanced disease.

BACKGROUND: Prostate cancer (PrCa) is one of the most common diseases to affect men worldwide and among the leading causes of cancer-related death. The purpose of this study was to use second-generation sequencing technology to assess the frequency of deleterious mutations in 22 tumour suppressor genes in familial PrCa and estimate the relative risk of PrCa if these genes are mutated. METHODS: Germline DNA samples from 191 men with 3 or more cases of PrCa in their family were sequenced for 22 tumour suppressor genes using Agilent target enrichment and Illumina technology. Analysis for genetic variation was carried out by using a pipeline consisting of BWA, Genome Analysis Toolkit (GATK) and ANNOVAR. Clinical features were correlated with mutation status using standard statistical tests. Modified segregation analysis was used to determine the relative risk of PrCa conferred by the putative loss-of-function (LoF) mutations identified. RESULTS: We discovered 14 putative LoF mutations in 191 samples (7.3%) and these mutations were more frequently associated with nodal involvement, metastasis or T4 tumour stage (P=0.00164). Segregation analysis of probands with European ancestry estimated that LoF mutations in any of the studied genes confer a relative risk of PrCa of 1.94 (95% CI: 1.56-2.42). CONCLUSIONS: These findings show that LoF mutations in DNA repair pathway genes predispose to familial PrCa and advanced disease and therefore warrants further investigation. The clinical utility of these findings will become increasingly important as targeted screening and therapies become more widespread.

Randomised pilot study of dose escalation using conformal radiotherapy in prostate cancer: long-term follow-up.

BACKGROUND: Radical three-dimensional conformal radiotherapy (CFRT) with initial androgen suppression (AS) is a standard management for localised prostate cancer (PC). This pilot study evaluated the role of dose escalation and appropriate target volume margin. Here, we report long-term follow-up. METHODS: Eligible patients had T1b-T3b N0 M0 PC. After neoadjuvant AS, they were randomised to CFRT, giving (a) 64 Gy with either a 1.0- or 1.5-cm margin and (b) ±10 Gy boost to the prostate alone. RESULTS: One hundred and twenty-six men were randomised and treated. Median follow-up was 13.7 years. The median age was 66.6 years at randomisation. Median presenting prostate-specific antigen (PSA) was 14 ng ml(-1). Sixty-four out of 126 patients developed PSA failure. Forty-nine out of 126 patients restarted AS, 34 out of 126 developed metastases and 28 out of 126 developed castrate-resistant prostate cancer (CRPC). Fifty-one out of 126 patients died; 19 out of 51 died of PC. Median overall survival (OS) was 14.4 years. Although escalated dose results were favourable, no statistically significant differences were seen between the randomised groups; PSA control (hazard ratio (HR): 0.77 (95% confidence interval (CI): 0.47-1.26)), development of CRPC (HR: 0.81 (95% CI: 0.40-1.65)), PC-specific survival (HR: 0.59 (95% CI:0.23-1.49)) and OS (HR: 0.81 (95% CI: 0.47-1.40)). There was no evidence of a difference in PSA control according to margin size (HR: 1.01 (95% CI: 0.61-1.66)). INTERPRETATION: Long-term follow-up of this small pilot study is compatible with a benefit from dose escalation, but confirmation from larger trials is required. There was no obvious detriment using the smaller radiotherapy margin.

Stratified cancer screening: the practicalities of implementation.

BACKGROUND: Improving understanding of the genetic basis of disease susceptibility enables us to estimate individuals' risk of developing cancer and offer them disease prevention, including screening, stratified to reflect that risk. Little attention has so far been given to the implementation of stratified screening. This article reviews the issues that would arise in delivering such tailored approaches to prevention in practice. RESULTS: Issues analysed include the organisational context within which implementation of stratified prevention would occur, how the offer of screening would be made, making sure consent is adequately informed, how individuals' risk would be assessed, the age at which risk estimation should occur, and the potential use of genetic data for other purposes. The review also considers how management might differ depending on individuals' risk, how their results would be communicated and their follow-up arranged, and the different issues raised by modification of an existing screening programme, such as that for breast cancer, and the establishment of a new one, for example for prostate cancer. CONCLUSION: Stratified screening based on genetic testing is a radically new approach to prevention. Various organisational issues would need to be considered before it could be introduced, and a number of questions require further research.

Reproductive decision-making in young female carriers of a BRCA mutation.

STUDY QUESTION: How do young women, who were identified as carrying a BRCA gene mutation before they had children, approach reproductive decision-making and what are their attitudes towards reproductive genetic testing? SUMMARY ANSWER: Reproductive decision-making within the context of cancer risk is complex and influenced by personal experiences of cancer. Younger women were not concerned with reproductive decision-making at the time of their genetic test; however, the impact on subsequent reproductive decision-making was considerable and left them with unanticipated dilemmas, such as having children who would be at risk of inheriting cancer predisposition, timing risk-reducing surgery and changing perceptions of responsibility. WHAT IS KNOWN ALREADY: Individuals carrying gene mutations predisposing to hereditary breast/ovarian cancer have concerns about passing on the gene mutation to children. STUDY DESIGN, SIZE, DURATION: Qualitative methodology and thematic analysis. PARTICIPANTS/MATERIALS, SETTING, METHODS: Data were collected through semi-structured interviews with 25 women aged 18-45 who had received a positive result for a BRCA1 or BRCA2 gene mutation while childless. MAIN RESULTS AND THE ROLE OF CHANCE: Analysis revealed four central themes: (i) the impact of cancer on reproductive decision-making; (ii) motivation for genetic testing; (iii) risk management and timing of planning children; and (iv) optimism for future medical advancements. LIMITATIONS, REASONS FOR CAUTION: This study explores the views of female BRCA carriers. Further research should explore the views of couples, men, and include samples with greater ethnic and social diversity. WIDER IMPLICATIONS OF THE FINDINGS: This evidence highlights the need for reproductive decision-making to be addressed at the time of pretest genetic counselling. More information should be provided on reproductive options as well as counselling/support to guide women's reproductive decision-making and prenatal testing options at the time they undertake genetic testing. STUDY FUNDING/COMPETING INTEREST(S): This research was supported by Cancer Research UK (Number C1226 A7920) and NIHR support to the Biomedical Research Centre at The Institute of Cancer Research and RMH. The authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: Not applicable.

Beyond prostate-specific antigen - future biomarkers for the early detection and management of prostate cancer.

Prostate-specific antigen is currently commonly used as a screening biomarker for prostate cancer, but it has limitations in both sensitivity and specificity. The development of novel biomarkers for early cancer detection has the potential to improve survival, reduce unnecessary investigations and benefit the health economy. Here we review the use and limitations of prostate-specific antigen and its subtypes, urinary biomarkers including PCA3, alpha-methylacyl-CoA racemase, the TMPRSS2-ERG fusion gene and microseminoprotein-beta, and other novel markers in both serum and urine. Many of these biomarkers are at early stages of development and require evaluation in prospective trials to determine their potential usefulness in clinical practice. Genetic profiling may allow for the targeting of high-risk populations for screening and may offer the opportunity to combine biomarker results with genotype to aid risk assessment.

Germline BRCA1 mutations increase prostate cancer risk.

BACKGROUND: Prostate cancer (PrCa) is one of the most common cancers affecting men but its aetiology is poorly understood. Family history of PrCa, particularly at a young age, is a strong risk factor. There have been previous reports of increased PrCa risk in male BRCA1 mutation carriers in female breast cancer families, but there is a controversy as to whether this risk is substantiated. We sought to evaluate the role of germline BRCA1 mutations in PrCa predisposition by performing a candidate gene study in a large UK population sample set. METHODS: We screened 913 cases aged 36­86 years for germline BRCA1 mutation, with the study enriched for cases with an early age of onset. We analysed the entire coding region of the BRCA1 gene using Sanger sequencing. Multiplex ligation-dependent probe amplification was also used to assess the frequency of large rearrangements in 460 cases. RESULTS: We identified 4 deleterious mutations and 45 unclassified variants (UV). The frequency of deleterious BRCA1 mutation in this study is 0.45%; three of the mutation carriers were affected at age 65 years and one developed PrCa at 69 years. Using previously estimated population carrier frequencies, deleterious BRCA1 mutations confer a relative risk of PrCa of ~3.75-fold, (95% confidence interval 1.02­9.6) translating to a 8.6% cumulative risk by age 65. CONCLUSION: This study shows evidence for an increased risk of PrCa in men who harbour germline mutations in BRCA1. This could have a significant impact on possible screening strategies and targeted treatments.