Ed Saunders

Multiple loci on 8q24 associated with prostate cancer susceptibility

Previous studies have identified multiple loci on 8q24 associated with prostate cancer risk. We performed a comprehensive analysis of SNP associations across 8q24 by genotyping tag SNPs in 5,504 prostate cancer cases and 5,834 controls. We confirmed associations at three previously reported loci and identified additional loci in two other linkage disequilibrium blocks (rs1006908: per-allele OR = 0.87, P = 7.9 × 10−8; rs620861: OR = 0.90, P = 4.8 × 10−8). Eight SNPs in five linkage disequilibrium blocks were independently associated with prostate cancer susceptibility.

Germline BRCA Mutations Are Associated With Higher Risk of Nodal Involvement, Distant Metastasis, and Poor Survival Outcomes in Prostate Cancer

PURPOSE To analyze the baseline clinicopathologic characteristics of prostate tumors with germline BRCA1 and BRCA2 (BRCA1/2) mutations and the prognostic value of those mutations on prostate cancer (PCa) outcomes. PATIENTS AND METHODS This study analyzed the tumor features and outcomes of 2,019 patients with PCa (18 BRCA1 carriers, 61 BRCA2 carriers, and 1,940 noncarriers). The Kaplan-Meier method and Cox regression analysis were used to evaluate the associations between BRCA1/2 status and other PCa prognostic factors with overall survival (OS), cause-specific OS (CSS), CSS in localized PCa (CSS_M0), metastasis-free survival (MFS), and CSS from metastasis (CSS_M1). RESULTS PCa with germline BRCA1/2 mutations were more frequently associated with Gleason ≥ 8 (P = .00003), T3/T4 stage (P = .003), nodal involvement (P = .00005), and metastases at diagnosis (P = .005) than PCa in noncarriers. CSS was significantly longer in noncarriers than in carriers (15.7 v 8.6 years, multivariable analyses [MVA] P = .015; hazard ratio [HR] = 1.8). For localized PCa, 5-year CSS and MFS were significantly higher in noncarriers (96% v 82%; MVA P = .01; HR = 2.6%; and 93% v 77%; MVA P = .009; HR = 2.7, respectively). Subgroup analyses confirmed the poor outcomes in BRCA2 patients, whereas the role of BRCA1 was not well defined due to the limited size and follow-up in this subgroup. CONCLUSION Our results confirm that BRCA1/2 mutations confer a more aggressive PCa phenotype with a higher probability of nodal involvement and distant metastasis. BRCA mutations are associated with poor survival outcomes and this should be considered for tailoring clinical management of these patients.

BRCA2 is a moderate penetrance gene contributing to young-onset prostate cancer: implications for genetic testing in prostate cancer patients

Background:A family history of prostate cancer (PrCa) is a strong risk factor for the disease, indicating that inherited factors are important in this disease. We previously estimated that about 2% of PrCa cases diagnosed ⩽55 years harbour a BRCA2 mutation and PrCa among BRCA2 carriers has been shown to be more aggressive, with poorer survival.Methods:To further evaluate the role of BRCA2 in PrCa predisposition, we screened 1864 men with PrCa aged between 36 and 88 years. We analysed the BRCA2 gene using a novel high-throughput multiplex fluorescence heteroduplex detection system developed for the ABI3130xl genetic analyzer.Results:We identified 19 protein-truncating mutations, 3 in-frame deletions and 69 missense variants of uncertain significance (UV) in our sample set. All the carriers of truncating mutations developed PrCa at ⩽65 years, with a prevalence of BRCA2 mutation of 1.20% for cases in this age group.Conclusion:Based on the estimated frequency of BRCA2 mutations in the United Kingdom we estimate that germline mutations in the BRCA2 gene confer an ∼8.6-fold increased risk of PrCa by age 65, corresponding to an absolute risk of ∼15% by age 65. These results suggest that routine testing of early onset PrCa cases for germline BRCA2 mutations will further help to refine the prevalence and risk associated with BRCA2 mutations and may be useful for guiding management options.

Effect of BRCA Mutations on Metastatic Relapse and Cause-specific Survival After Radical Treatment for Localised Prostate Cancer.

BACKGROUND Germline BRCA mutations are associated with worse prostate cancer (PCa) outcomes; however, the most appropriate management for mutation carriers has not yet been investigated. OBJECTIVE To evaluate the response of BRCA carriers to conventional treatments for localised PCa by analysing metastasis-free survival (MFS) and cause-specific survival (CSS) following radical prostatectomy (RP) or external-beam radiation therapy (RT). DESIGN, SETTING, AND PARTICIPANTS Tumour features and outcomes of 1302 patients with local/locally advanced PCa (including 67 BRCA mutation carriers) were analysed. RP was undergone by 535 patients (35 BRCA); 767 received RT (32 BRCA). Median follow-up was 64 mo. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Median survival and 3-, 5-, and 10-yr survival rates were estimated using the Kaplan-Meier method. Generated survival curves were compared using the log-rank test. Cox regression analyses were used to assess the prognostic value of BRCA mutations. RESULTS AND LIMITATIONS A total of 67 BRCA carriers and 1235 noncarriers were included. At 3, 5, and 10 yr after treatment, 97%, 94%, and 84% of noncarriers and 90%, 72%, and 50% of carriers were free from metastasis (p<0.001). The 3-, 5- and 10-yr CSS rates were significantly better in the noncarrier cohort (99%, 97%, and 85%, respectively) than in carriers (96%, 76%, and 61%, respectively; p<0.001). Multivariate analysis confirmed BRCA mutations as an independent prognostic factor for MFS (hazard ratio [HR]: 2.36; 95% confidence interval [CI], 1.38-4.03; p=0.002) and CSS (HR: 2.17; 95% CI, 1.16-4.07; p=0.016). CONCLUSIONS BRCA carriers had worse outcomes than noncarriers when conventionally treated for local/locally advanced PCa. PATIENT SUMMARY Prostate cancer patients with germline BRCA mutations had worse outcomes than noncarriers when conventionally treated with surgery or radiation therapy.

Telomere shortening in leucocyte subsets of long‐term survivors of allogeneic bone marrow transplantation

Recent studies have demonstrated excessive telomeric shortening in peripheral blood leucocytes of bone marrow transplant (BMT) recipients. This finding has raised concerns about accelerated haemopoietic ageing that might predispose to clonal disorders and late graft failure. We studied the peripheral blood neutrophils and T cells of 14 fully engrafted long‐term survivors of BMT.

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.

Effect of germ-line BRCA mutations in biochemical relapse and survival after treatment for localized prostate cancer.

29 Background: Biochemical relapse after local treatment for prostate cancer (PCa) indicates recurrent disease and is associated with shorter cause-specific survival (CSS). Germline BRCA mutations are associated with worse PrCa outcomes. In this study, we analyzed biochemical-progression free survival (bPFS) after conventional treatments for localized PCa in a cohort of BRCA patients from the UK. Currently, BRCA1/2 carriers are treated with the same protocols used for non-carriers. METHODS In this retrospective case-control study, each BRCA carrier (10 BRCA1 and 34 BRCA2) treated with radical prostatectomy (RP) or external beam radiotherapy (RT) was matched with 3 non-carriers (NC) by: age at diagnosis (±5 yrs), TNM stage, Gleason score, presenting PSA, local treatment (RT or RP), androgen-deprivation therapy (ADT) and year of treatment (±5yrs). All NC were screened for BRCA1 and BRCA2 mutations. Biochemical failure was reviewed according to ASTRO and NCCN criteria. The Kaplan-Meier method and a multivariate Cox regression model adjusted by matching factors were employed. RESULTS 176 patients (pts) were included. Median follow-up was 97 months (ms). Median age at diagnosis was 58.5 yrs (43-75). 80 pts received RT (16 BRCA2, 4 BRCA1, 60 NC) and 85% also received ADT≥6 ms. 96pts underwent RP (18 BRCA2, 6 BRCA1 and 72 NC). Following RT treatment, 5yrs-CSS was 96% in NC and 47% in BRCA carriers (p=2x10-5), whilst no difference was seen after RP (5yrs-CSS was 98.5% in NC vs 93.3% in BRCA). Five-years bFPFS after RT was 74% in NC and 24% in BRCA (p=0.002). No difference was observed in 5yrs-bPFS between BRCA carriers and NC treated with RP (52% vs 66% , p=0.346). The adjusted MVA (including tumour stage, local treatment, ADT and BRCA status) confirmed the independent prognostic value of BRCA status for bPFS and CSS. Among BRCA carriers, the independent risk was greater when the analysis was limited to BRCA2 pts . CONCLUSIONS Our results suggest that BRCA carriers have worse local disease control than NC when conventionally treated with RT. No differences in bPFS were observed in pts treated with RP after >8 yrs median follow-up. These results may have implications for tailoring clinical management in these patients.

Abstract 4606: Fine mapping of 64 prostate cancer GWAS regions identifies multiple novel association signals

Proceedings: AACR 106th Annual Meeting 2015; April 18-22, 2015; Philadelphia, PA Genome-wide association studies (GWAS) have identified 100 common prostate cancer (PrCa) susceptibility loci to date. We performed comprehensive fine-mapping of 64 GWAS regions using genotyping and imputation to a 1000 Genomes reference panel for 25,779 PrCa cases and 26,218 controls of European ancestry from the PRACTICAL Consortium and two UK GWAS studies. In order to identify independent variants associated to PrCa, SNPs significant at P ≤10-4 were included in a stepwise logistic regression (SLR). Where the initial SLR identified multiple independent SNPs in a region, we re-analysed the region conditioning on the top hit. The adjusted results were subsequently trimmed using a P-value cut-off of ≤10-5 and a second SLR performed to identify independently significant index SNPs. We observed a single independent signal at 39 regions, with a novel, more significantly associated index SNP at 35 of these. Amongst these, we confirmed association in the European population for 2 loci previously reported in Asian GWAS. At 16 regions there was evidence for multiple independent signals, 14 of these contain newly identified additional significant associations. Functional annotation using data from ENCODE filtered for PrCa cell lines showed enrichment for overlap with bio-features within the fine-mapped SNP set and eQTL analysis identified novel candidate genes regulated by SNPs discovered in this study. Furthermore, we observed a 7% (from 32%-to 39%) improvement in the estimated proportion of familial relative risk explained through these refined and newly identified genetic variants. This study demonstrates the utility of fine-mapping, in silico functional annotation and eQTL approaches to narrow down the number of candidate functional variants. In addition, since a greater proportion of GWAS loci contained multiple independent risk variants than previously appreciated; this may explain a proportion of the missing heritability of complex diseases. Citation Format: Zsofia Kote-Jarai, Ali Amin Al Olama, Tokhir Dadaev, Dennis Hazelett, Qiuyan Li, Daniel Leongamornlert, Ed Saunders, Matthew Feedman, David Conti, Douglas Easton, Gerhard Coetzee, Rosalind Eeles, The PRACTICAL Consortium. Fine mapping of 64 prostate cancer GWAS regions identifies multiple novel association signals. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4606. doi:10.1158/1538-7445.AM2015-4606

751OPREVALENCE OF HOXB13G84E GERMLINE MUTATION IN UK PROSTATE CANCER CASES; CORRELATION WITH TUMOUR CHARACTERISTICS AND OUTCOMES

ABSTRACT Aim: A rare recurrent missense variant in HOXB13 rs 138213197 is associated with hereditary prostate cancer (PrCa). The frequency of this variant varies between different geographic regions. We performed a case-control study in the UK population to assess the prevalence of this variant and its implications on PrCa risk and tumour characteristics. Methods: We screened 8652 white Caucasian men from 3 UKGPCS (United Kingdom Prostate Cancer Genetic) studies and 5252 population based controls from the ProtecT study. Germline blood DNA was genotyped for G84E (rs13821397) using a custom made TaqMan assay. 2 duplicate samples and 4 positive and 4 negative controls were included on each 384 well plate.Concordance for the control samples was >99%. Results: HOXB13 rs138213197 was identified in 0.5% of healthy controls and in 1.6% of PrCa cases. The Odds Ratio (OR) was 2.93 for increased risk of developing prostate cancer and the association was stronger for cases with family history with an OR = 4.53 and young onset PrCa (diagnosed under the age of 55) with an OR = 3.1. Multivariate analysis showed no association with Gleason score, presenting PSA, TNM stage or NCCN risk score. The biochemical relapse rate was not higher for carriers. We found no evidence of interaction between this rare variant and a Polygenic Risk Score (PRS) based on common variants consisting of 71 single nucleotide polymorphisms (SNPs). As a result men with the mutation in the highest quintile of the PRS have a 5-fold higher PrCa risk compared to those in the third quintile. Conclusions: HOXB13G84E is a highly penetrant, rare genetic predisposition variant linked with young onset and familial PrCa. No assocation with an aggressive phenotype was found. The clinical application of this finding in genetic PrCa screening modelling is still unclear. Based on the estimated incidence this variant accounts for approxiately 1% of the familial PrCa risk in the UK population. Disclosure: All authors have declared no conflicts of interest.

Abstract 2612: The PROFILE study; Germline genetic profiling: Correlation with targeted prostate cancer screening and treatment

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Introduction: Men with a first degree relative with prostate cancer (PC) have twice the general population risk. This risk is greater amongst young cases and amongst men with more affected relatives. Genome Wide Association studies have identified a number of common single nucleotide polymorphisms (SNPs) that confer small but cumulatively substantial risks of PC. These findings open the possibility for exploring the use of SNPs in PC risk stratification for targeted screening. Objectives: PROFILE has been developed as a pilot study; the primary aim is to determine the acceptability and feasibility of targeted PC screening using prostatic biopsy in men with a family history and its association with specific genetic profiles. The secondary aims are to: (1) determine PC risk related SNPs signatures in men with a family history; (2) study the correlation between specific PC risk related SNP signatures and prostate biopsy (PB) outcomes; (3) estimate the sensitivity and specificity of PSA screening and the optimal PSA threshold for PB in men with a family history of PC; (4) to assess the value of Diffusion Weighted Magnetic Resonance Imaging (DW-MRI) as a PC screening tool in men with a family history of PC. Method: Eligible men were aged 40-69 years with i) first degree relative (FDR) with PC 1 year ago were offered a DW-MRI prior to biopsy. Blood DNA from each participant was analysed for a panel of 39 SNPs associated with increased risk of PC using iPLEX Sequenom technology. The results were fed back to participants and an associated psycho-social study has collected data on cancer worry, anxiety and depression and illness perceptions. We aim to enrol 100 men Results: 70 men had been recruited by 1st November 2011. 45 PB have been performed, finding 10 (22.2%) PC, 5 (11.1%) ASAP and 2 (4.4%) high grade PIN. The results of SNP profiling, risk prediction modelling and clinical parameters will be presented alongside the outcome of the baseline psychosocial measures Conclusions: Our preliminary results indicate that PB as a means of PC screening is feasible and acceptable in men with a family history of the disease. The incidence of PC and ASAP in this group of men is higher than expected in the general population. No adverse psychosocial variables were noted. These results support the development of a larger national study. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2612. doi:1538-7445.AM2012-2612