Prostate cancer (PrCa) is the most common non-skin cancer diagnosed among males in developed countries and the second leading cause of cancer mortality, yet little is known regarding its etiology and factors that influence clinical outcome. Genome-wide association studies (GWAS) of PrCa have identified at least 30 distinct loci associated with small differences in risk. We conducted a GWAS in 2782 advanced PrCa cases (Gleason grade ≥ 8 or tumor stage C/D) and 4458 controls with 571 243 single nucleotide polymorphisms (SNPs). Based on in silico replication of 4679 SNPs (Stage 1, P < 0.02) in two published GWAS with 7358 PrCa cases and 6732 controls, we identified a new susceptibility locus associated with overall PrCa risk at 2q37.3 (rs2292884, P= 4.3 × 10−8). We also confirmed a locus suggested by an earlier GWAS at 12q13 (rs902774, P= 8.6 × 10−9). The estimated per-allele odds ratios for these loci (1.14 for rs2292884 and 1.17 for rs902774) did not differ between advanced and non-advanced PrCa (case-only test for heterogeneity P= 0.72 and P= 0.61, respectively). Further studies will be needed to assess whether these or other loci are differentially associated with PrCa subtypes.
There is a high and rising prevalence of prostate cancer (PRCA) within the male population of the United Kingdom. Although the relative risk of PRCA is higher in male BRCA2 and BRCA1 mutation carriers, the histological characteristics of this malignancy in these groups have not been clearly defined. We present the histopathological findings in the first UK series of BRCA1 and BRCA2 mutation carriers with PRCA. The archived histopathological tissue sections of 20 BRCA1/2 mutation carriers with PRCA were collected from histopathology laboratories in England, Ireland and Scotland. The cases were matched to a control group by age, stage and serum PSA level of PRCA cases diagnosed in the general population. Following histopathological evaluation and re-grading according to current conventional criteria, Gleason scores of PRCA developed by BRCA1/2 mutation carriers were identified to be significantly higher (Gleason scores 8, 9 or 10, P=0.012) than those in the control group. Since BRCA1/2 mutation carrier status is associated with more aggressive disease, it is a prognostic factor for PRCA outcome. Targeting screening to this population may detect disease at an earlier clinical stage which may therefore be beneficial.
prostate cancer; BRCA1 and BRCA2; prostate pathology
Background: The manganese superoxide dismutase (MnSOD) gene encodes an antioxidant enzyme (SOD2) that may protect cells from oxidative damage. The MnSOD allele with Val as amino acid 16 encodes a protein that has 30–40% lower activity compared with the MnSOD Ala variant, hence possibly increasing susceptibility to oxidative stress. On the other hand, some epidemiologic studies suggest that the Ala allele is associated with a higher risk of cancer, including prostate cancer. Methods: We conducted a nested case–control study in the Health Professionals Follow-up Study with 612 incident prostate cancer cases and 612 matched controls to investigate the role of the MnSOD gene Ala16Val polymorphism and its joint association with plasma carotenoid concentrations in relation to risk of total prostate cancer and aggressive prostate cancer (advanced stage or Gleason sum ≥7). Results: The allele frequencies in the controls were 49.8% for Ala and 50.2% for Val. No association was found between the MnSOD genotype and risk of total and aggressive prostate cancer. Furthermore, no statistically significant interaction was observed between the MnSOD genotype and any of the plasma carotenoids in relation to risk of total and aggressive prostate cancer. In analyses in which we combined data from plasma and dietary carotenoids and created a quintile score to reflect long-term carotenoid status, a 3-fold [95% confidence interval: 1.37–7.02] increased risk of aggressive prostate cancer was observed among men with the Ala/Ala genotype in the presence of low long-term lycopene status (P-value, test for interaction = 0.02) as compared with men with the Ala/Val+Val/Val genotypes with low long-term lycopene status. Conclusion: In this cohort of mainly white men, the MnSOD gene Ala16Val polymorphism was not associated with total or aggressive prostate cancer risk. However, men with the MnSOD Ala/Ala genotype who had low long-term lycopene status had a higher risk of aggressive prostate cancer compared with individuals with the other genotypes. These results are consistent with findings from earlier studies that reported when antioxidant status is low, the MnSOD Ala/Ala genotype may be associated with an increased risk of aggressive prostate cancer.
Cigarette smoke contains carcinogenic aromatic and heterocyclic amines that are metabolized by N-acetyltransferase (NAT). These carcinogens also produce reactive oxygen species that are metabolized by manganese superoxide dismutase (MnSOD). The association between prostate cancer (PCA) and the polymorphism of MnSOD and NAT, and cigarette smoking was investigated.
Materials and Methods
DNA samples from 187 PCA patients and 175 age-matched controls were genotyped for MnSOD, NAT1 and NAT2 by PCR restriction fragment length polymorphism analysis and DNA sequencing.
MnSOD AA genotype, as compared to MnSOD VV and VA, was associated with PCA (odds ratio, 1.65; 95% confidence interval, 1.03–2.66]. There was no association of PCA with NAT or smoking. Results of exploratory analyses of the data suggest that the association of PCA and MnSOD exists only in the subpopulation of rapid NAT1 genotypes and smokers.
The present study demonstrates the association of PCA and MnSOD. Oxidative stress and cigarette smoking may play an important role in the carcinogenesis of the prostate in those who have MnSOD AA and rapid NAT1 genotypes.
Prostate cancer; prostate-specific antigen; manganese superoxide dismutase; N-acetyltransferase; smoking; polymorphism
Genome-wide association studies (GWAS) have identified multiple common genetic variants associated with an increased risk of prostate cancer (PrCa), but these explain less than one-third of the heritability. To identify further susceptibility alleles, we conducted a meta-analysis of four GWAS including 5953 cases of aggressive PrCa and 11 463 controls (men without PrCa). We computed association tests for approximately 2.6 million SNPs and followed up the most significant SNPs by genotyping 49 121 samples in 29 studies through the international PRACTICAL and BPC3 consortia. We not only confirmed the association of a PrCa susceptibility locus, rs11672691 on chromosome 19, but also showed an association with aggressive PrCa [odds ratio = 1.12 (95% confidence interval 1.03–1.21), P = 1.4 × 10−8]. This report describes a genetic variant which is associated with aggressive PrCa, which is a type of PrCa associated with a poorer prognosis.
Associations between single nucleotide polymorphisms (SNPs) at 5p15 and multiple cancer types have been reported. We have previously shown evidence for a strong association between prostate cancer (PrCa) risk and rs2242652 at 5p15, intronic in the telomerase reverse transcriptase (TERT) gene that encodes TERT. To comprehensively evaluate the association between genetic variation across this region and PrCa, we performed a fine-mapping analysis by genotyping 134 SNPs using a custom Illumina iSelect array or Sequenom MassArray iPlex, followed by imputation of 1094 SNPs in 22 301 PrCa cases and 22 320 controls in The PRACTICAL consortium. Multiple stepwise logistic regression analysis identified four signals in the promoter or intronic regions of TERT that independently associated with PrCa risk. Gene expression analysis of normal prostate tissue showed evidence that SNPs within one of these regions also associated with TERT expression, providing a potential mechanism for predisposition to disease.
Genome-wide association studies (GWAS) have identified multiple SNPs associated with prostate cancer (PrCa). Population isolates may have different sets of risk alleles for PrCa constituting unique population and individual risk profiles.
To test this hypothesis, associations between 31 GWAS SNPs of PrCa were examined among 979 PrCa cases and 1,251 controls of Ashkenazic descent using logistic regression. We also investigated risks by age at diagnosis, pathological features of PrCa, and family history of cancer. Moreover, we examined associations between cumulative number of risk alleles and PrCa and assessed the utility of risk alleles in PrCa risk prediction by comparing the area under the curve (AUC) for different logistic models.
Of the 31 genotyped SNPs, 8 were associated with PrCa at p≤0.002 (corrected p-value threshold) with odds ratios (ORs) ranging from 1.22 to 1.42 per risk allele. Four SNPs were associated with aggressive PrCa, while three other SNPs showed potential interactions for PrCa by family history of PrCa (rs8102476; 19q13), lung cancer (rs17021918; 4q22), and breast cancer (rs10896449; 11q13). Men in the highest vs. lowest quartile of cumulative number of risk alleles had ORs of 3.70 (95% CI 2.76–4.97); 3.76 (95% CI 2.57–5.50), and 5.20 (95% CI 2.94–9.19) for overall PrCa, aggressive cancer and younger age at diagnosis, respectively. The addition of cumulative risk alleles to the model containing age at diagnosis and family history of PrCa yielded a slightly higher AUC (0.69 vs. 0.64).
These data define a set of risk alleles associated with PrCa in men of Ashkenazic descent and indicate possible genetic differences for PrCa between populations of European and Ashkenazic ancestry. Use of genetic markers might provide an opportunity to identify men at highest risk for younger age of onset PrCa; however, their clinical utility in identifying men at highest risk for aggressive cancer remains limited.
Although prostate cancer (PrCa) is one of the most common cancers in men in Western countries, little is known about the inherited factors that influence PrCa risk. On the basis of the fact that BRIP1/FANCJ interacts with BRCA1 and functions as a regulator of DNA double-strand break repair pathways, and that germline mutations within the BRIP1/FANCJ gene predispose to breast cancer, we chose this gene as a candidate for mutation screening in familial and young-onset PrCa cases. We identified a truncating mutation, R798X, in the BRIP1/FANCJ gene in 4 out of 2714 UK PrCa cases enriched for familial (2 out of 641; 0.3%) and young-onset cases (2 out of 2073; 0.1%). On screening 2045 controls from the UK population, we found one R798X sequence alteration (0.05%; odds ratio 2.4 (95% CI 0.25–23.4)). In addition, using our data from a genome-wide association study, we analysed 25 SNPs in the genomic region of the BRIP1/FANCJ gene. Two SNPs showed evidence of association with familial and young-onset PrCa (rs6504074; Ptrend=0.04 and rs8076727; Ptrend=0.01). These results suggest that truncating mutations in BRIP1/FANCJ might confer an increased risk of PrCa and common SNPs might also contribute to the alteration of risk, but larger case–control series will be required to confirm or refute this association.
prostate cancer predisposition; FANCJ/BRIP1; deleterious mutation; SNPs
Prostate cancer (PrCA) is the most commonly diagnosed non-skin cancer among men. PrCA mortality in African-American (AA) men in South Carolina is ~50% higher than for AAs in the U.S as a whole. AA men also have low rates of participation in cancer research. This paper describes partnership development and recruitment efforts of a Community-Academic-Clinical research team for a PrCA education intervention with AA men and women that was designed to address the discordance between high rates of PrCA mortality and limited participation in cancer research. Guided by Vesey's framework on recruitment and retention of minority groups in research, recruitment strategies were selected and implemented following multiple brainstorming sessions with partners having established community relationships. Based on findings from these sessions culturally appropriate strategies are recommended for recruiting AA men and women for PrCA education research. Community-based research recruitment challenges and lessons learned are presented.
African-American men and women; Community-based participatory research; Research partnerships; Recruitment; Cancer communication; Multi-media
The HOXB13 gene has been implicated in prostate cancer (PrCa) susceptibility. We performed a high resolution fine-mapping analysis to comprehensively evaluate the association between common genetic variation across the HOXB genetic locus at 17q21 and PrCa risk. This involved genotyping 700 SNPs using a custom Illumina iSelect array (iCOGS) followed by imputation of 3195 SNPs in 20,440 PrCa cases and 21,469 controls in The PRACTICAL consortium. We identified a cluster of highly correlated common variants situated within or closely upstream of HOXB13 that were significantly associated with PrCa risk, described by rs117576373 (OR 1.30, P = 2.62×10−14). Additional genotyping, conditional regression and haplotype analyses indicated that the newly identified common variants tag a rare, partially correlated coding variant in the HOXB13 gene (G84E, rs138213197), which has been identified recently as a moderate penetrance PrCa susceptibility allele. The potential for GWAS associations detected through common SNPs to be driven by rare causal variants with higher relative risks has long been proposed; however, to our knowledge this is the first experimental evidence for this phenomenon of synthetic association contributing to cancer susceptibility.
Genome-wide association studies (GWAS) have identified numerous low penetrance disease susceptibility variants, yet few causal alleles have been unambiguously identified. The underlying causal variants are expected to be predominantly common; however synthetic associations with rare, higher penetrance variants have been hypothesised though not yet observed. Here, we report detection of a novel common, low penetrance prostate cancer association at the HOXB locus at ch17q and show that this signal can actually be attributed to a previously identified rare, moderate penetrance coding variant (G84E) in HOXB13. This study therefore provides the first experimental evidence for the existence of synthetic associations in cancer and shows that where GWAS signals arise through this phenomenon, risk predictions derived using the tag SNP would substantially underestimate the relative risk conferred and overestimate the number of carriers of the causal variant. Synthetic associations at GWAS signals could therefore account for a proportion of the missing heritability of complex diseases.
The genetic basis of susceptibility to prostate cancer (PRCA) remains elusive. Mutations in BRCA2 have been associated with increased prostate cancer risk and account for around 2% of young onset (<56 years) prostate cancer cases. PALB2 is a recently identified breast cancer susceptibility gene whose protein is closely associated with BRCA2 and is essential for BRCA2 anchorage to nuclear structures. This functional relationship made PALB2 a candidate PRCA susceptibility gene.
We sequenced PALB2 in probands from 95 PRCA families, 77 of which had two or more cases of early onset PRCA (age at diagnosis <55 years), and the remaining 18 had one case of early onset PRCA and five or more total cases of PRCA.
Two previously unreported variants, K18R and V925L were identified, neither of which is in a known PALB2 functional domain and both of which are unlikely to be pathogenic. No truncating mutations were identified.
These results indicate that deleterious PALB2 mutations are unlikely to play a significant role in hereditary prostate cancer.
hereditary prostate cancer; PALB2; BRCA2
Associations between Metabolic Syndrome (MetS) components and prostate cancer development have not been studied comprehensively; results have been divergent. Using the National Cholesterol Education Program Adult Treatment panel III (NCEP) and International Diabetes Federation (IDF) definitions of the MetS we investigated such associations taking competing risks of death into consideration.
In the prospective Uppsala Longitudinal Study of Adult Men (ULSAM) of 2322 Caucasian men with 34 years of follow-up baseline MetS-measurements at age 50 were used. Cumulative incidence of prostate cancer and death with/without the MetS were calculated. Competing risk of dying was taken into account by calculating the conditional probability of prostate cancer with/without the MetS.
Two-hundred-and- thirty-seven prostate cancers were identified. Prostate cancer probability by age 80 with baseline MetS compared to without the MetS was non-significantly higher, 5.2 percent-units (CI -0.8%-11.3%, (NCEP), 2.7 percent-units (CI -2.7%-8.0%) (IDF), cumulative incidence proportions of death was significantly higher, 19.3 percent-units (CI 13.4%-25.3%) (NCEP), 15.3 percent-units (CI 9.5%-21.1%) (IDF) and conditional probability of prostate cancer considering death from other causes was significantly higher, 7.3 percent-units (CI 0.2%-14.5%) odds ratio(OR) of 1.64 (CI 1.03-2.23). (NCEP), and non-significantly higher 5.0 percent-units (CI -1.6%-11.6%) OR 1.43 (CI 0.89-1.90). (IDF).
The MetS by the NCEP definition is associated with prostate cancer taking the competing risk of early death from other causes into account.
The results further highlight the public health impact of the increasing prevalence of MetS, and the importance of considering competing risks when studying risk factors for cancer.
epidemiology; prostate cancer; metabolic syndrome; competing risk; risk factors
To investigate whether the inclusion of occult cancer in the control group can influence the association of prostate cancer and the polymorphism of manganese superoxide dismutase (MnSOD).
Prostate specimens and sera were obtained from 194 deceased men who did not have a history of prostate cancer. Eighteen-core biopsy specimens and whole-mount sections were evaluated histologically. The MnSOD genotype of the specimens was determined by polymerase chain reaction restriction fragment length polymorphism analysis.
Tumors were present in 57 of the prostates, and biopsy detected 33 (including 1 false-positive finding). It detected 17 (1 false-positive finding) and missed 14 tumors in the subgroup of 135 specimens with a prostatic-specific antigen <4 ng/mL. The MnSOD AA genotype was associated with prostate cancer found in the step-sectioned specimens vs the control group in whom the absence of occult prostate cancer had been verified. However, no association was found if the control group consisted of subjects with negative biopsy results from the overall group or the subgroup with a prostatic-specific antigen level of <4 ng/mL.
The MnSOD AA genotype was associated with prostate cancer in our study; however, contamination of occult prostate cancer in the control group reduced the power of analysis and might yield seemingly negative results. Epidemiologic studies should strive to include control groups with a verified absence of occult cancer.
There is a known inverse association between type 2 diabetes (T2D) and prostate cancer (PrCa) that is poorly understood. Genetic studies of the T2D-PrCa association may provide insight into the underlying mechanisms of this association. We evaluated associations in the Atherosclerosis Risk in Communities study between PrCa and nine T2D single nucleotide polymorphisms (SNPs) from genome-wide association (GWA) studies of T2D (in CDKAL1, CDKN2A/B, FTO, HHEX, IGF2BP2, KCNJ11, PPARG, SLC30A8, and TCF7L2) and four T2D SNPs from pre-GWA studies (in ADRB2, CAPN10, SLC2A2, and UCP2). From 1987–2000, there were 397 incident PrCa cases among 6,642 men aged 45–64 years at baseline. We used race-adjusted Cox proportional hazards models to estimate associations between PrCa and increasing number of T2D risk-raising alleles. PrCa was positively associated with the CAPN10 rs3792267 G allele (hazard ratio [HR]=1.20; 95% confidence interval [CI]=1.00, 1.44) and inversely associated with the SLC2A2 rs5400 Thr110 allele (HR=0.85; 95% CI=0.72, 1.00), the UCP2 rs660339 Val55 allele (HR=0.84; 95% CI=0.73, 0.97) and the IGF2BP2 rs4402960 T allele (HR=0.79; 95% CI=0.61, 1.02; blacks only). The TCF7L2 rs7903146 T allele was inversely associated with PrCa using a dominant genetic model (HR=0.79; 95% CI=0.65, 0.97). Further knowledge of T2D gene-PrCa mechanisms may improve understanding of PrCa etiology.
Diabetes Mellitus; Type 2; Genetics; Risk; Polymorphism; Single Nucleotide; Prostatic Neoplasms
A recent genome-wide association (GWA) study suggested seven new loci as associated with prostate cancer (PRCA) susceptibility. The strongest associated SNP in each region was identified (rs2660753, rs9364554, rs6465657, rs10993994, rs7931342, rs2735839, rs5945619). We studied these seven SNPs in a replication study consisting of 169 familial PRCA cases selected from Utah high-risk PRCA pedigrees and 805 controls. We performed subset analyses for aggressive and early onset PRCA. At a nominal significance level, two SNPs were found to be associated with PRCA: rs10993994 on chromosome 10q11 (odds ratio (OR) =1.42 [95% confidence interval (CI), 1.05–1.90], p=0.022); and rs5945619 on chromosome Xp11 (OR=1.54 [95% CI, 1.03–2.31], p=0.035). Restricting analysis to familial PRCA cases with aggressive disease yielded very similar risk estimates at both SNPs. However, subset analysis for familial, early onset disease indicated highly significant association evidence and substantially higher risk estimates for rs10993994 (OR=2.20 [95% CI, 1.48–3.27], p<0.0001). This result suggests that the higher risk estimates from the stage 1 cohort in the original study for rs10993994 may have been due to the early-onset and familial nature of the PRCA cases in that cohort. In conclusion, in a small case-control study of PRCA cases from Utah high-risk pedigrees, we have significantly replicated association of PRCA with rs10993994 (10q11) upon study-wide correction for multiple comparisons. We also nominally replicated the association of PRCA with rs5945619 (Xp11). In particular, it appears that the susceptibility locus at 10q11 maybe involved in familial, early onset disease.
Prostate Cancer; Genetic Risk
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.
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.
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.
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.
prostate cancer; BRCA2 gene; mutation screening; cancer risk
The manganese superoxide dismutase (MnSOD) ala16val polymorphism has been associated with various diseases including breast cancer. In the present study, we investigated levels of MnSOD protein, enzymatic activity and mRNA with respect to MnSOD genotype in several human breast carcinoma cell lines and in mouse embryonic fibroblasts (MEF), developed from the MnSOD knockout mouse, stably expressing human MnSOD-ala and MnSOD-val. In human breast cell lines, the MnSOD-ala allele was associated with increased levels of MnSOD protein and MnSOD protein per unit mRNA. In the MEF transformants, MnSOD activity correlated fairly well with MnSOD protein levels. MnSOD mRNA expression was significantly lower in MnSOD-ala versus MnSOD-val lines. MnSOD protein and activity levels were not related to MnSOD genotype in the transformed MEF, although, as observed in the human breast cell lines, the MEF human MnSOD-ala lines produced significantly more human MnSOD protein per unit mRNA than the human MnSOD-val lines. This suggests that there is more efficient production of MnSOD-ala protein compared to MnSOD-val protein. Examination of several indicators of reactive oxygen species levels, including superoxide and hydrogen peroxide, in wild type MEF and in MEF expressing similar elevated amounts of MnSOD-ala or val activity did not show differences related to the levels of MnSOD protein expression. In conclusion, in both human breast carcinoma cell lines and MEF cell lines stably transfected with human MnSOD, the MnSOD-ala allele was associated with increased production of MnSOD protein per unit mRNA indicating a possible imbalance in MnSOD protein production from the MnSOD-val mRNA.
MnSOD; breast cancer; oxidative stress; polymorphism
Genome-wide association studies (GWAS) have identified more than 30 prostate cancer (PrCa) susceptibility loci. One of these (rs2735839) is located close to a plausible candidate susceptibility gene, KLK3, which encodes prostate-specific antigen (PSA). PSA is widely used as a biomarker for PrCa detection and disease monitoring. To refine the association between PrCa and variants in this region, we used genotyping data from a two-stage GWAS using samples from the UK and Australia, and the Cancer Genetic Markers of Susceptibility (CGEMS) study. Genotypes were imputed for 197 and 312 single nucleotide polymorphisms (SNPs) from HapMap2 and the 1000 Genome Project, respectively. The most significant association with PrCa was with a previously unidentified SNP, rs17632542 (combined P = 3.9 × 10−22). This association was confirmed by direct genotyping in three stages of the UK/Australian GWAS, involving 10,405 cases and 10,681 controls (combined P = 1.9 × 10−34). rs17632542 is also shown to be associated with PSA levels and it is a non-synonymous coding SNP (Ile179Thr) in KLK3. Using molecular dynamic simulation, we showed evidence that this variant has the potential to introduce alterations in the protein or affect RNA splicing. We propose that rs17632542 may directly influence PrCa risk.
Electronic supplementary material
The online version of this article (doi:10.1007/s00439-011-0981-1) contains supplementary material, which is available to authorized users.
Selenium is a potential chemopreventive agent against prostate cancer, whose chemoprotective effects are possibly mediated through the antioxidative properties of selenoenzymes. Interrelations with other antioxidative agents and oxidative stressors, such as smoking, are poorly understood.
The aims were to investigate the association between serum selenium and prostate cancer risk and to examine interactions with other antioxidants and tobacco use.
A nested case-control study was performed within the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Serum selenium in prospectively collected samples was compared between 724 incident prostate cancer case subjects and 879 control subjects, frequency-matched for age, time since initial screen, and year of blood draw. The men were followed for up to 8 y.
Overall, serum selenium was not associated with prostate cancer risk (P for trend = 0.70); however, higher serum selenium was associated with lower risks in men reporting a high (more than the median: 28.0 IU/d) vitamin E intake [odds ratio (OR) for the highest compared with the lowest quartile of selenium: 0.58; 95% CI: 0.37, 0.91; P for trend = 0.05; P for interaction = 0.01] and in multivitamin users (OR for highest compared with the lowest quartile of selenium: 0.61; 95% CI: 0.36, 1.04; P for trend = 0.06; P for interaction = 0.05). Furthermore, among smokers, high serum selenium concentrations were related to reduced prostate cancer risk (OR for the highest compared with the lowest quartile of selenium: 0.65; 95% CI: 0.44, 0.97; P for trend = 0.09; P for interaction = 0.007).
Greater prediagnostic serum selenium concentrations were not associated with prostate cancer risk in this large cohort, although greater concentrations were associated with reduced prostate cancer risks in men who reported a high intake of vitamin E, in multivitamin users, and in smokers.
Selenium; prostate cancer; vitamin E; smoking; serum; nested case-control study
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.
We screened 913 cases aged 36–86 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.
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
1.02–9.6) translating to a 8.6% cumulative risk by age 65.
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.
prostate cancer; BRCA1 gene; mutation screening; cancer risk
PALB2 1592delT mutation is associated with increased breast cancer and suggestive prostate cancer (PRCA) risk in Finland. In this study we wanted to assess if any other PALB2 variants associate to increased PRCA risk and clinically describe patients with formerly found PALB2 1592delT mutation.
Finnish families with two or more PRCA cases (n = 178) and unselected cases (n = 285) with complete clinical data were initially screened for variants in the coding region and splice sites of PALB2. Potentially interesting variants were verified in additional set of unselected cases (n = 463).
From our clinically defined sample set we identified total of six variants in PALB2. No novel variants among Finnish PRCA cases were found. Clinical characteristics of the variant carriers, including the previously described family carrying PALB2 1592delT, revealed a trend towards aggressive disease, which also applied to a few non-familial cases. Hypersensitivity to mitomycin C (MMC) of lymphoblasts from individuals from the family with 1592delT revealed haploinsufficiency among carriers with altered genotype.
Though any of the detected PALB2 variants do not associate to PRCA in population level in Finland it cannot be ruled out that some of these variants contribute to cancer susceptibility at individual level.
MSMB, a gene coding for β-microseminoprotein, has been identified as a candidate susceptibility gene for prostate cancer (PrCa) in two genome-wide association studies (GWAS). SNP rs10993994 is 2 bp upstream of the transcription initiation site of MSMB and was identified as an associated PrCa risk variant. The MSMB protein is underexpressed in PrCa and it was previously proposed to be an independent marker for the recurrence of cancer after radical prostatectomy.
In this study, the coding region of this gene and 1500 bp upstream of the 5′UTR has been sequenced in germline DNA in 192 PrCa patients with family history. To evaluate the possible effects of these variants we used in silico analysis.
No deleterious mutations were identified, however, nine new sequence variants were found, most of these in the promoter and 5′UTR region. In silico analysis suggests that four of these SNPs are likely to have some effect on gene expression either by affecting ubiquitous or prostate-specific transcription factor (TF)-binding sites or modifying splicing efficiency.
We conclude that MSMB is unlikely to be a familial PrCa gene and propose that the high-risk alleles of the SNPs in the 5′UTR effect PrCa risk by modifying MSMB gene expression in response to hormones in a tissue-specific manner.
MSMB; prostate cancer; SNP; in silico; gene expression
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.
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.
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).
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.
familial prostate cancer; DNA repair gene mutations; next-generation sequencing; relative risk
Prostate cancer (PrCA) is the most commonly diagnosed non-skin cancer among men. African-American (AA) men in South Carolina have a PrCA death rate 150% higher than that of European-American (EA) men. This in-depth qualitative research explored AA men’s and women’s current practices, barriers, and recommended strategies for PrCA communication. A purposive sample of 43 AA men and 38 AA spouses/female relatives participated in focus groups (11 male groups; 11 female groups). A 19-item discussion guide was developed. Coding and analyses were driven by the data; recurrent themes within and across groups were examined. Findings revealed AA men and women agreed on key barriers to discussing PrCA; however, they had differing perspectives on which of these were most important. Findings indicate that including AA women in PrCA research and education is needed to address barriers preventing AA men from effectively communicating about PrCA risk and screening with family and healthcare providers.
focus groups; cancer screening; health communication; social support; decision making
This study investigated the influence of gene-gene and gene-environment interactions on the risk of developing asbestosis. The study comprised 262 cases with asbestosis and 265 controls with no asbestos-related disease previously studied for MnSOD, ECSOD, CAT, GSTT1, GSTM1, GSTP1, and iNOS polymorphisms. Data on cumulative asbestos and smoking were available for all subjects. To assess gene-gene and gene-environmental interactions, logistic regression was used. The associations between MnSOD Ala −9Val polymorphism and the risk of asbestosis and between iNOS genotypes and asbestosis were modified by CAT –262 C > T polymorphism (P = 0.038; P = 0.031). A strong interaction was found between GSTM1-null polymorphism and smoking (P = 0.007), iNOS (CCTTT)n polymorphism and smoking (P = 0.054), and between iNOS (CCTTT)n polymorphism and cumulative asbestos exposure (P = 0.037). The findings of this study suggest that the interactions between different genotypes, genotypes and smoking, and between genotypes and asbestos exposure have an important influence on the development of asbestosis and should be seriously considered in future research on occupational/environmental asbestos-related diseases.