Janet L. Stanford

The identification of recurrent founder variants in cancer predisposing genes may have important implications for implementing cost-effective targeted genetic screening strategies. In this study, we evaluated the prevalence and relative risk of the CHEK2 recurrent variant c.349A>G in a series of 462 Portuguese patients with early-onset and/or familial/hereditary prostate cancer (PrCa), as well as in the large multicentre PRACTICAL case–control study comprising 55,162 prostate cancer cases and 36,147 controls. Additionally, we investigated the potential shared ancestry of the carriers by performing identity-by-descent, haplotype and age estimation analyses using high-density SNP data from 70 variant carriers belonging to 11 different populations included in the PRACTICAL consortium. The CHEK2 missense variant c.349A>G was found significantly associated with an increased risk for PrCa (OR 1.9; 95% CI: 1.1–3.2). A shared haplotype flanking the variant in all carriers was identified, strongly suggesting a common founder of European origin. Additionally, using two independent statistical algorithms, implemented by DMLE+2.3 and ESTIAGE, we were able to estimate the age of the variant between 2300 and 3125 years. By extending the haplotype analysis to 14 additional carrier families, a shared core haplotype was revealed among all carriers matching the conserved region previously identified in the high-density SNP analysis. These findings are consistent with CHEK2 c.349A>G being a founder variant associated with increased PrCa risk, suggesting its potential usefulness for cost-effective targeted genetic screening in PrCa families.

Digital image analysis offers advantages over traditional pathologist visual scoring of immunohistochemistry, although few studies examining the correlation and reproducibility of these methods have been performed in prostate cancer. We evaluated the correlation between digital image analysis (continuous variable data) and pathologist visual scoring (quasi-continuous variable data), reproducibility of each method, and association of digital image analysis methods with outcomes using prostate cancer tissue microarrays (TMAs) stained for estrogen receptor-β2 (ERβ2). Prostate cancer TMAs were digitized and evaluated by pathologist visual scoring versus digital image analysis for ERβ2 staining within tumor epithelium. Two independent analysis runs were performed to evaluate reproducibility. Image analysis data were evaluated for associations with recurrence-free survival and disease specific survival following radical prostatectomy. We observed weak/moderate Spearman correlation between digital image analysis and pathologist visual scores of tumor nuclei (Analysis Run A: 0.42, Analysis Run B: 0.41), and moderate/strong correlation between digital image analysis and pathologist visual scores of tumor cytoplasm (Analysis Run A: 0.70, Analysis Run B: 0.69). For the reproducibility analysis, there was high Spearman correlation between pathologist visual scores generated for individual TMA spots across Analysis Runs A and B (Nuclei: 0.84, Cytoplasm: 0.83), and very high correlation between digital image analysis for individual TMA spots across Analysis Runs A and B (Nuclei: 0.99, Cytoplasm: 0.99). Further, ERβ2 staining was significantly associated with increased risk of prostate cancer-specific mortality (PCSM) when quantified by cytoplasmic digital image analysis (HR 2.16, 95 % CI 1.02–4.57, p = 0.045), nuclear image analysis (HR 2.67, 95 % CI 1.20–5.96, p = 0.016), and total malignant epithelial area analysis (HR 5.10, 95 % CI 1.70–15.34, p = 0.004). After adjusting for clinicopathologic factors, only total malignant epithelial area ERβ2 staining was significantly associated with PCSM (HR 4.08, 95 % CI 1.37–12.15, p = 0.012). Digital methods of immunohistochemical quantification are more reproducible than pathologist visual scoring in prostate cancer, suggesting that digital methods are preferable and especially warranted for studies involving large sample sizes.

Background Aberrant DNA methylation may promote prostate carcinogenesis. We investigated epigenome‐wide DNA methylation profiles in prostate cancer (PCa) compared to adjacent benign tissue to identify differentially methylated CpG sites. Methods The study included paired PCa and adjacent benign tissue samples from 20 radical prostatectomy patients. Epigenetic profiling was done using the Infinium HumanMethylation450 BeadChip. Linear models that accounted for the paired study design and False Discovery Rate Q‐values were used to evaluate differential CpG methylation. mRNA expression levels of the genes with the most differentially methylated CpG sites were analyzed. Results In total, 2,040 differentially methylated CpG sites were identified in PCa versus adjacent benign tissue (Q‐value < 0.001), the majority of which were hypermethylated (n = 1,946; 95%). DNA methylation profiles accurately distinguished between PCa and benign tissue samples. Twenty‐seven top‐ranked hypermethylated CpGs had a mean methylation difference of at least 40% between tissue types, which included 25 CpGs in 17 genes. Furthermore, for 10 genes over 50% of promoter region CpGs were hypermethylated in PCa versus benign tissue. The top‐ranked differentially methylated genes included three genes that were associated with both promoter hypermethylation and reduced gene expression: SCGB3A1, HIF3A, and AOX1. Analysis of The Cancer Genome Atlas (TCGA) data provided confirmatory evidence for our findings. Conclusions This study of PCa versus adjacent benign tissue showed many differentially methylated CpGs and regions in and outside gene promoter regions, which may potentially be used for the development of future epigenetic‐based diagnostic tests or as therapeutic targets. Prostate 75:1941–1950, 2015.

The T2E gene fusion, formed by fusion of the transmembrane protease, serine 2, gene (TMPRSS2) with the erythroblast transformation-specific (ETS)-related gene (ERG), is found in approximately 50% of prostate cancers and may characterize distinct molecular subtypes of prostate cancer with different etiologies. We investigated the relationship between body mass index (BMI; weight (kg)/height (m)²) and prostate cancer risk by T2E status. Study participants were residents of King County, Washington, recruited for 2 population-based case-control studies conducted in 1993–1996 and 2002–2005. Tumor T2E status was determined for 563 prostate cancer patients who underwent radical prostatectomy. Information on weight, height, and covariables was obtained through in-person interviews. We performed polytomous logistic regression to calculate odds ratios and 95% confidence intervals for T2E-positive and -negative prostate cancer. Comparing the highest BMI quartile with the lowest, inverse associations were observed between recent (≥29.7 vs. T2E-positive prostate cancer. No significant associations were seen for men with T2E-negative tumors. This study provides evidence that obesity is specifically associated with reduced risk of developing androgen-responsive T2E fusion–positive tumors. The altered steroid hormone profile in obese men may contribute to this inverse association.

Germline genetic variants have been suggested as prognostic biomarkers for identifying patients at high risk for lethal prostate cancer (PCa). Validation studies have confirmed the association of several single nucleotide polymorphisms (SNPs) with fatal PCa, but whether these variants affect PCa‐specific mortality (PCSM) in patients with an inherited predisposition to PCa, based on familial history, is unknown. For this study, a cohort of 957 PCa patients from 270 hereditary prostate cancer families of European ancestry was genotyped for a panel of 22 PCSM‐associated SNPs. Death certificates were reviewed to confirm cause of death. Mixed‐effect Cox proportional hazards models were used to assess survival according to genotypes, accounting for relatedness and clinicopathological factors. Within this cohort, 98 PCa deaths were confirmed over an average follow‐up period of 12.7 years after diagnosis. Variant allele carriers for three SNPs had significantly altered risk for PCSM [rs635261 at RNASEL, hazard ratio (HR), 0.35, 95% CI, 0.18–0.66; p = 0.002; rs915927 in XRCC1, HR, 1.91, 95% CI, 1.21–3.02; p = 0.009; and rs2494750 at AKT1, HR, 0.45, 95% CI, 0.23–0.90; p = 0.016). These results confirm the association of genetic variation in three genes with PCa lethality in a cohort of men with an inherited susceptibility to the disease and provide validation evidence that germline SNPs provide prognostic information for PCa patients. Development of a panel of germline biomarkers with clinical utility for distinguishing patients at detection who have an increased risk for fatal PCa is warranted.

Background: One challenge in prostate cancer is distinguishing indolent from aggressive disease at diagnosis. DNA promoter hypermethylation is a frequent epigenetic event in prostate cancer, but few studies of DNA methylation in relation to features of more aggressive tumors or prostate cancer recurrence have been completed. Methods: We used the Infinium HumanMethylation450 BeadChip to assess DNA methylation in tumor tissue from 407 patients with clinically localized prostate cancer who underwent radical prostatectomy. Recurrence status was determined by follow-up patient surveys, medical record review, and linkage with the Surveillance, Epidemiology, and End Results (SEER) registry. The methylation status of 14 genes for which promoter hypermethylation was previously correlated with advanced disease or biochemical recurrence was evaluated. Average methylation level for promoter region CpGs in patients who recurred compared with those with no evidence of recurrence was analyzed. For two genes with differential methylation, time to recurrence was examined. Results: During an average follow-up of 11.7 years, 104 (26%) patients recurred. Significant promoter hypermethylation in at least 50% of CpG sites in two genes, ABHD9 and HOXD3, was found in tumors from patients who recurred compared with those without recurrence. Evidence was strongest for HOXD3 (lowest P = 9.46 × 10⁻⁶), with higher average methylation across promoter region CpGs associated with reduced recurrence-free survival (P = 2 × 10⁻⁴). DNA methylation profiles did not differ by recurrence status for the other genes. Conclusions: These results validate the association between promoter hypermethylation of ADHB9 and HOXD3 and prostate cancer recurrence. Impact: Tumor DNA methylation profiling may help to distinguish patients with prostate cancer at higher risk for disease recurrence. Cancer Epidemiol Biomarkers Prev; 23(7); 1331–9. ©2014 AACR.

Background: Rare, inherited mutations account for 5% to 10% of all prostate cancer cases. However, to date, few causative mutations have been identified. Methods: To identify rare mutations for prostate cancer, we conducted whole-exome sequencing (WES) in multiple kindreds (n = 91) from 19 hereditary prostate cancer (HPC) families characterized by aggressive or early-onset phenotypes. Candidate variants (n = 130) identified through family- and bioinformatics-based filtering of WES data were then genotyped in an independent set of 270 HPC families (n = 819 prostate cancer cases; n = 496 unaffected relatives) for replication. Two variants with supportive evidence were subsequently genotyped in a population-based case–control study (n = 1,155 incident prostate cancer cases; n = 1,060 age-matched controls) for further confirmation. All participants were men of European ancestry. Results: The strongest evidence was for two germline missense variants in the butyrophilin-like 2 (BTNL2) gene (rs41441651, p.Asp336Asn and rs28362675, p.Gly454Cys) that segregated with affection status in two of the WES families. In the independent set of 270 HPC families, 1.5% (rs41441651; P = 0.0032) and 1.2% (rs28362675; P = 0.0070) of affected men, but no unaffected men, carried a variant. Both variants were associated with elevated prostate cancer risk in the population-based study (rs41441651: OR, 2.7; 95% CI, 1.27–5.87; P = 0.010; rs28362675: OR, 2.5; 95% CI, 1.16–5.46; P = 0.019). Conclusions: Results indicate that rare BTNL2 variants play a role in susceptibility to both familial and sporadic prostate cancer. Impact: Results implicate BTNL2 as a novel prostate cancer susceptibility gene. Cancer Epidemiol Biomarkers Prev; 22(9); 1520–8. ©2013 AACR.

BACKGROUND: Recently, a genetic variant (rs10993994) in the MSMB gene associated with prostate cancer (PCa) risk was shown to correlate with reduced prostate secretory protein of 94 amino acids (PSP94) levels. Although the biological activity of PSP94 is unclear, one of its hypothesized functions is to protect prostatic cells from pathogens. Number of sexual partners and a history of sexually transmitted infections (STIs) have been positively associated with PCa risk, and these associations may be related to pathogen‐induced chronic prostatic inflammation. Based on these observations, we investigated whether MSMB genotype modifies the PCa‐sexual history association.METHODS: We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for the association between number of sexual partners and PCa by fitting logistic regression models, stratified by MSMB genotype, and adjusted for age, family history of PCa, and PCa screening history among 1,239 incident cases and 1,232 controls.RESULTS: Compared with 1–4 female sexual partners, men with ≥15 such partners who carried the variant T allele of rs10993994 were at increased risk for PCa (OR = 1.32; 95% CI, 1.03–1.71); no association was observed in men with the CC genotype (OR = 1.03; 95% CI, 0.73–1.46; P = 0.05 for interaction). Similar estimates were observed for total sexual partners (any T allele OR = 1.37; 95% CI, 1.07–1.77; CC genotype OR = 1.11; 95% CI, 0.79–1.55; P = 0.06 for interaction).CONCLUSIONS: The rs10993994 genotype in the MSMB gene modifies the association between number of sexual partners and PCa risk. These findings support a hypothesized biological mechanism whereby prostatic infection/inflammation may enhance risk of PCa. Prostate 73:1803–1809, 2013.

Bioactive compounds found in coffee and tea may delay the progression of prostate cancer.