Evaluating approaches for constructing polygenic risk scores for prostate cancer in men of African and European ancestry.

Genome-wide polygenic risk scores (GW-PRSs) have been reported to have better predictive ability than PRSs based on genome-wide significance thresholds across numerous traits. We compared the predictive ability of several GW-PRS approaches to a recently developed PRS of 269 established prostate cancer-risk variants from multi-ancestry GWASs and fine-mapping studies (PRS269). GW-PRS models were trained with a large and diverse prostate cancer GWAS of 107,247 cases and 127,006 controls that we previously used to develop the multi-ancestry PRS269. Resulting models were independently tested in 1,586 cases and 1,047 controls of African ancestry from the California Uganda Study and 8,046 cases and 191,825 controls of European ancestry from the UK Biobank and further validated in 13,643 cases and 210,214 controls of European ancestry and 6,353 cases and 53,362 controls of African ancestry from the Million Veteran Program. In the testing data, the best performing GW-PRS approach had AUCs of 0.656 (95% CI = 0.635-0.677) in African and 0.844 (95% CI = 0.840-0.848) in European ancestry men and corresponding prostate cancer ORs of 1.83 (95% CI = 1.67-2.00) and 2.19 (95% CI = 2.14-2.25), respectively, for each SD unit increase in the GW-PRS. Compared to the GW-PRS, in African and European ancestry men, the PRS269 had larger or similar AUCs (AUC = 0.679, 95% CI = 0.659-0.700 and AUC = 0.845, 95% CI = 0.841-0.849, respectively) and comparable prostate cancer ORs (OR = 2.05, 95% CI = 1.87-2.26 and OR = 2.21, 95% CI = 2.16-2.26, respectively). Findings were similar in the validation studies. This investigation suggests that current GW-PRS approaches may not improve the ability to predict prostate cancer risk compared to the PRS269 developed from multi-ancestry GWASs and fine-mapping.

SLCO1B3 and SLCO2B1 genotypes, androgen deprivation therapy, and prostate cancer outcomes: a prospective cohort study and meta-analysis.

Solute carrier organic anion (SLCO) transporters (OATP transporters) are involved in cellular uptake of drugs and hormones. Germline variants in SLCO1B3 and SLCO2B1 have been implicated in prostate cancer progression and therapy response, including to androgen deprivation and statin medications, but results have appeared heterogeneous. We conducted a cohort study of five single-nucleotide polymorphisms (SNPs) in SLCO1B3 and SLCO2B1 with prior evidence among 3208 men with prostate cancer who participated in the Health Professionals Follow-up Study or the Physicians' Health Study, following participants prospectively after diagnosis over 32 years (median, 14 years) for development of metastases and cancer-specific death (lethal disease, 382 events). Results were suggestive of, but not conclusive for, associations between some SNPs and lethal disease and differences by androgen deprivation and statin use. All candidate SNPs were associated with SLCO mRNA expression in tumor-adjacent prostate tissue. We also conducted a systematic review and harmonized estimates for a dose-response meta-analysis of all available data, including 9 further studies, for a total of 5598 patients and 1473 clinical events. The A allele of the exonic SNP rs12422149 (14% prevalence), which leads to lower cellular testosterone precursor uptake via SLCO2B1, was associated with lower rates of prostate cancer progression (hazard ratio per A allele, 0.80; 95% confidence interval, 0.69-0.93), with little heterogeneity between studies (I2, 0.27). Collectively, the totality of evidence suggests a strong association between inherited genetic variation in SLCO2B1 and prostate cancer prognosis, with potential clinical use in risk stratification related to androgen deprivation therapy.

Healthy dietary patterns and risk of prostate cancer in men at high genetic risk.

Prostate cancer has high heritability. Healthy lifestyle has been associated with lower lethal prostate cancer risk among men at increased genetic susceptibility, but the role of healthy dietary patterns remains unknown. We prospectively followed 10,269 genotyped men in the Health Professionals Follow-up Study (1993-2019). Genetic risk was quantified using an established polygenic risk score (PRS). Five dietary patterns were investigated: healthy eating index, Mediterranean, diabetes risk-reducing, hyperinsulinemic and inflammatory diet. Overall and lethal prostate cancer rates (metastatic disease/prostate cancer-specific death) were analyzed using multivariable Cox proportional hazards models. During 26 years of follow-up, 2133 overall and 253 lethal prostate cancer events were documented. In the highest PRS quartile, higher adherence to a diabetes risk-reducing diet was associated with lower rates of overall (top vs. bottom quintile HR [95% CI], 0.74 [0.58-0.94]) and lethal prostate cancer (0.43 [0.21-0.88]). A low insulinemic diet was associated with similar lower rates (overall, 0.76 [0.60-0.95]; lethal, 0.46 [0.23-0.94]). Other dietary patterns showed weaker, but similar associations. In the highest PRS quartile, men with healthy lifestyles based on body weight, physical activity, and low insulinemic diet had a substantially lower rate (0.26 [0.13-0.49]) of lethal prostate cancer compared with men with unhealthy lifestyles, translating to a lifetime risk of 3.4% (95% CI, 2.3%-5.0%) among those with healthy lifestyles and 9.5% (5.3%-16.7%) among those with unhealthy lifestyles. Our findings indicate that lifestyle modifications lowering insulin resistance and chronic hyperinsulinemia could be relevant in preventing aggressive prostate cancer among men genetically predisposed to prostate cancer.

Impact of Family History and Germline Genetic Risk Single Nucleotide Polymorphisms on Long-Term Outcomes of Favorable-Risk Prostate Cancer.

PURPOSE: Family history and germline genetic risk single nucleotide polymorphisms (SNPs) have been separately shown to stratify lifetime risk of prostate cancer. Here, we evaluate the combined prognostic value of family history of prostate and other related cancers and germline risk SNPs among patients with favorable-risk prostate cancer. MATERIALS AND METHODS: A total of 1367 participants from the prospective Health Professionals Follow-up Study diagnosed with low- or favorable intermediate-risk prostate cancer from 1986 to 2017 underwent genome-wide SNP genotyping. Multivariable Cox regression was used to estimate the association between family history, specific germline risk variants, and a 269 SNP polygenic risk score with prostate cancer‒specific death. RESULTS: Family history of prostate, breast, and/or pancreatic cancer was observed in 489 (36%) participants. With median follow-up from diagnosis of 14.9 years, participants with favorable-risk prostate cancer with a positive family history had a significantly higher risk of prostate cancer‒specific death (HR 1.95, 95% CI 1.15-3.32, P = .014) compared to those without any family history. The rs2735839 (19q13) risk allele was associated with prostate cancer‒specific death (HR 1.81 per risk allele, 95% CI 1.04-3.17, P = .037), whereas the polygenic risk score was not. Combined family history and rs2735839 risk allele were each associated with an additive risk of prostate cancer‒specific death (HR 1.78 per risk factor, 95% CI 1.25-2.53, P = .001). CONCLUSIONS: Family history of prostate, breast, or pancreatic cancer and/or a 19q13 germline risk allele are associated with an elevated risk of prostate cancer‒specific death among favorable-risk patients. These findings have implications for how family history and germline genetic risk SNPs should be factored into clinical decision-making around favorable-risk prostate cancer.

Effect of Dietary Choline Consumption on the Development of Urinary Urgency Incontinence in a Longitudinal Cohort of Women.

INTRODUCTION AND HYPOTHESIS: The objective of this study was to determine whether differences in the cumulative dietary intake of choline, is associated with the risk of developing urge urinary incontinence (UUI). METHODS: This was an analysis within the Nurses' Health Study (NHS) I and II. The main exposure was the cumulative daily intake for each choline-containing compound obtained from a detailed daily food frequency questionnaire. The primary outcome was UUI, defined as urine loss with a sudden feeling of bladder fullness or when a toilet is inaccessible, occurring >1/month. Cox proportional hazards regression models were used to calculate multivariate-adjusted relative risks and 95% confidence intervals (CIs) for the association between total choline and choline derivatives and risk of UUI. Fixed effects meta-analyses of results from NHSI and NHSII were performed for postmenopausal women only to obtain a pooled estimate of the impact of choline consumption on UUI. RESULTS: There were 33,273 participants in NHSI and 38,732 in NHSII who met all the criteria for inclusion in the analysis. The incidence of UUI was 9.41% (n=3,139) in NHSI and 4.25% (n=1,646) in NHSII. After adjusting for confounders choline was not found to be associated with UUI in postmenopausal women. However, in premenopausal women, relative to the lowest quartile, the highest quartile of consumption of total choline (aRR = 0.79, 95% CI: 0.64-0.99), free choline (aRR = 0.74, 95% CI: 0.58-0.94), and phosphocholine (aRR = 0.77, 95% CI: 0.61-0.96) were associated with a reduced risk of UUI. CONCLUSIONS: Increased dietary choline consumption was associated with a reduced risk of UUI among premenopausal women.

Influence of Neighborhood Social and Natural Environment on Prostate Tumor Histology in a Cohort of Male Health Professionals.

Adverse neighborhood social and natural (green space) environments may contribute to the etiology of prostate cancer (CaP), but mechanisms are unclear. We examined associations between neighborhood environment and prostate intratumoral inflammation in 967 men diagnosed with CaP with available tissue samples from 1986-2009 in the Health Professionals Follow-up Study. Exposures were linked to work or residential addresses in 1988. We estimated indices of neighborhood socioeconomic status (nSES) and segregation (Index of Concentration at the Extremes (ICE)) using US Census tract-level data. Surrounding greenness was estimated using seasonal averaged Normalized Difference Vegetation Index (NDVI) data. Surgical tissue underwent pathological review for acute and chronic inflammation, corpora amylacea, and focal atrophic lesions. Adjusted odds ratios (aORs) for inflammation (ordinal) and focal atrophy (binary) were estimated using logistic regression. No associations were observed for acute or chronic inflammation. Each interquartile-range increase in NDVI within 1,230 m of the participant's work or home address (aOR = 0.74, 95% confidence interval (CI): 0.59, 0.93), in ICE-income (aOR = 0.79, 95% CI: 0.61, 1.04), and in ICE-race/income (aOR = 0.79, 95% CI: 0.63, 0.99) was associated with lower odds of postatrophic hyperplasia. Interquartile-range increases in nSES (aOR = 0.76, 95% CI: 0.57, 1.02) and ICE-race/income (aOR = 0.73, 95% CI: 0.54, 0.99) were associated with lower odds of tumor corpora amylacea. Histopathological inflammatory features of prostate tumors may be influenced by neighborhood.

Modifiable risk factors for subsequent lethal prostate cancer among men with an initially negative prostate biopsy.

BACKGROUND: Previously suggested modifiable risk factors for prostate cancer could have resulted from detection bias because diagnosis requires a biopsy. We investigated modifiable risk factors for a subsequent cancer diagnosis among men with an initially negative prostate biopsy. METHODS: In total, 10,396 participants of the Health Professionals Follow-up Study with an initial negative prostate biopsy after 1994 were followed for incident prostate cancer until 2017. Potential risk factors were based on previous studies in the general population. Outcomes included localised, advanced, and lethal prostate cancer. RESULTS: With 1851 prostate cancer cases (168 lethal) diagnosed over 23 years of follow-up, the 20-year risk of any prostate cancer diagnosis was 18.5% (95% CI: 17.7-19.3). Higher BMI and lower alcohol intake tended to be associated with lower rates of localised disease. Coffee, lycopene intake and statin use tended to be associated with lower rates of lethal prostate cancer. Results for other risk factors were less precise but compatible with and of similar direction as for men in the overall cohort. CONCLUSIONS: Risk factors for future prostate cancer among men with a negative biopsy were generally consistent with those for the general population, supporting their validity given reduced detection bias, and could be actionable, if confirmed.

A systematic review and in silico study of potential genetic markers implicated in cases of overactive bladder.

OBJECTIVE: The contribution of genetic factors to the presence of an overactive bladder is recognized. This study aimed to (1) assemble and synthesize available data from studies assessing differential gene expression in patients with overactive bladder vs controls without overactive bladder and (2) determine possible correlations and functional pathways between genes. DATA SOURCES: We searched PubMed, Ovid or Medline, and Wiley Cochrane Central Register of Controlled Trials databases between January 1, 2000, and December 15, 2021. STUDY ELIGIBILITY CRITERIA: Studies were included if gene expression was detected and quantified using molecular approaches performed on human bladder tissue specimens directly and excluded if the gene expression analysis was carried out from blood and urine specimens alone. METHODS: A systematic review was completed to identify publications that reported differently expressed gene candidates among patients with overactive bladder vs healthy individuals. Gene networking connections and pathway analysis were performed employing Metascape software, where inputs were identified from our systematic review of differentially expressed genes in overactive bladder. RESULTS: A total of 9 studies were included in the final analysis and 11 genes were identified as being up-regulated (purinergic receptor P2X 2 [P2RX2], smoothelin [SMTN], growth-associated protein 43 [GAP43], transient receptor potential cation channel subfamily M member 8 [TRPM8], cadherin 11 [CDH1], gap junction protein gamma 1 [GJC1], cholinergic receptor muscarinic 2 [CHRM2], cholinergic receptor muscarinic 3 [CHRM3], and transient receptor potential cation channel subfamily V member 4 [TRPV4]) or down-regulated (purinergic receptor P2X 2 [P2RX3] and purinergic receptor P2X 5 [P2RX5]) in patients with overactive bladder. Gene network analysis showed that genes are involved in chemical synaptic transmission, smooth muscle contraction, blood circulation, and response to temperature stimulus. Network analysis demonstrated a significant genetic interaction between TRPV4, TRPM8, P2RX3, and PR2X2 genes. CONCLUSION: Outcomes of this systematic review highlighted potential biomarkers for treatment efficacy and have laid the groundwork for developing future gene therapies for overactive bladder in clinical settings.

Circulating free testosterone and risk of aggressive prostate cancer: Prospective and Mendelian randomisation analyses in international consortia.

Previous studies had limited power to assess the associations of testosterone with aggressive disease as a primary endpoint. Further, the association of genetically predicted testosterone with aggressive disease is not known. We investigated the associations of calculated free and measured total testosterone and sex hormone-binding globulin (SHBG) with aggressive, overall and early-onset prostate cancer. In blood-based analyses, odds ratios (OR) and 95% confidence intervals (CI) for prostate cancer were estimated using conditional logistic regression from prospective analysis of biomarker concentrations in the Endogenous Hormones, Nutritional Biomarkers and Prostate Cancer Collaborative Group (up to 25 studies, 14 944 cases and 36 752 controls, including 1870 aggressive prostate cancers). In Mendelian randomisation (MR) analyses, using instruments identified using UK Biobank (up to 194 453 men) and outcome data from PRACTICAL (up to 79 148 cases and 61 106 controls, including 15 167 aggressive cancers), ORs were estimated using the inverse-variance weighted method. Free testosterone was associated with aggressive disease in MR analyses (OR per 1 SD = 1.23, 95% CI = 1.08-1.40). In blood-based analyses there was no association with aggressive disease overall, but there was heterogeneity by age at blood collection (OR for men aged <60 years 1.14, CI = 1.02-1.28; Phet  = .0003: inverse association for older ages). Associations for free testosterone were positive for overall prostate cancer (MR: 1.20, 1.08-1.34; blood-based: 1.03, 1.01-1.05) and early-onset prostate cancer (MR: 1.37, 1.09-1.73; blood-based: 1.08, 0.98-1.19). SHBG and total testosterone were inversely associated with overall prostate cancer in blood-based analyses, with null associations in MR analysis. Our results support free testosterone, rather than total testosterone, in the development of prostate cancer, including aggressive subgroups.

A polymorphism in the promoter of FRAS1 is a candidate SNP associated with metastatic prostate cancer.

BACKGROUND: Inflammation and one of its mediators, NF-kappa B (NFκB), have been implicated in prostate cancer carcinogenesis. We assessed whether germline polymorphisms associated with NFκB are associated with the risk of developing lethal disease (metastases or death from prostate cancer). METHODS: Using a Bayesian approach leveraging NFκB biology with integration of publicly available datasets we used a previously defined genome-wide functional association network specific to NFκB and lethal prostate cancer. A dense-module-searching method identified modules enriched with significant genes from a genome-wide association study (GWAS) study in a discovery data set, Physicians' Health Study and Health Professionals Follow-up Study (PHS/HPFS). The top 48 candidate single nucleotide polymorphisms (SNPs) from the dense-module-searching method were then assessed in an independent prostate cancer cohort and the one SNP reproducibly associated with lethality was tested in a third cohort. Logistic regression models evaluated the association between each SNP and lethal prostate cancer. The candidate SNP was assessed for association with lethal prostate cancer in 6 of 28 studies in the prostate cancer association group to investigate cancer associated alterations in the genome (PRACTICAL) Consortium where there was some medical record review for death ascertainment which also had SNP data from the ONCOARRAY platform. All men self-identified as Caucasian. RESULTS: The rs1910301 SNP which was reproducibly associated with lethal disease was nominally associated with lethal disease (odds ratio [OR] = 1.40; p = .02) in the discovery cohort and the minor allele was also associated with lethal disease in two independent cohorts (OR = 1.35; p = .04 and OR = 1.35; p = .07). Fixed effects meta-analysis of all three cohorts found an association: OR = 1.37 (95% confidence interval [CI]: 1.15-1.62, p = .0003). This SNP is in the promoter region of FRAS1, a gene involved in epidermal-basement membrane adhesion and is present at a higher frequency in men with African ancestry. No association was found in the subset of studies from the PRACTICAL consortium studies which had a total of 106 deaths out total of 3263 patients and a median follow-up of 4.4 years. CONCLUSIONS: Through its connection with the NFκB pathway, a candidate SNP with a higher frequency in men of African ancestry without cancer was found to be associated with lethal prostate cancer across three well-annotated independent cohorts of Caucasian men.

Loss of LDAH associated with prostate cancer and hearing loss.

Great strides in gene discovery have been made using a multitude of methods to associate phenotypes with genetic variants, but there still remains a substantial gap between observed symptoms and identified genetic defects. Herein, we use the convergence of various genetic and genomic techniques to investigate the underpinnings of a constellation of phenotypes that include prostate cancer (PCa) and sensorineural hearing loss (SNHL) in a human subject. Through interrogation of the subject's de novo, germline, balanced chromosomal translocation, we first identify a correlation between his disorders and a poorly annotated gene known as lipid droplet associated hydrolase (LDAH). Using data repositories of both germline and somatic variants, we identify convergent genomic evidence that substantiates a correlation between loss of LDAH and PCa. This correlation is validated through both in vitro and in vivo models that show loss of LDAH results in increased risk of PCa and, to a lesser extent, SNHL. By leveraging convergent evidence in emerging genomic data, we hypothesize that loss of LDAH is involved in PCa and other phenotypes observed in support of a genotype-phenotype association in an n-of-one human subject.

Genetic Variant Associated With Survival of Patients With Stage II-III Colon Cancer.

BACKGROUND & AIMS: Many genetic variants have been associated with colorectal cancer risk, although few have been associated with survival times of patients. Identification of genetic variants associated with survival times might improve our understanding of disease progression and aid in outcome prediction. We performed a genome-wide association study to identify variants associated with colon cancer survival time. METHODS: We performed a post hoc analysis of data from NCCTG N0147 (Alliance), a randomized phase 3 trial of patients with resected stage III colon cancer, and from NSABP C-08 (NRG), a phase 3 trial that compared therapy regimens for patients with resected stage II or III colon cancer. Genotype analyses were performed on DNA from blood samples from 4974 patients. We used Cox proportional hazards regression to evaluate the association of each single nucleotide polymorphism with times of overall survival and disease-free survival, adjusting for age at diagnosis, sex, treatment group, and principal components of genetic ancestry. We performed the analysis for studies N0147 and C-08 separately, and results were combined in a fixed-effects meta-analysis. RESULTS: A locus on chromosome 7p15.2 was significantly associated with overall survival time (P ≤ 5x10-08). The most significant variant at this locus, rs76766811 (P = 1.6x10-08), is common among African Americans (minor allele frequency, approximately 18%) but rare in European Americans (minor allele frequency <0.1%). Within strata of self-reported ancestry, this variant was associated with times of overall survival and disease-free survival in only African Americans (hazard ratio for overall survival, 2.82; 95% CI, 1.88-4.23; P = 5.0x10-07 and hazard ratio for disease-free survival, 2.27; 95% CI, 1.62-3.18; P = 1.8x10-06). CONCLUSIONS: In an analysis of data from 2 trials of patients with stage II or III colon cancer, we identified rs76766811 as a potential prognostic variant in African American patients. This finding should be confirmed in additional study populations. ClinicalTrials.gov Identifiers: NCT00096278 (NSABP C-08) and NCT00079274 (NCCTG N0147).

Genome-Wide Association Study for Urinary and Fecal Incontinence in Women.

PURPOSE: Urinary incontinence and fecal incontinence are common disorders in women that negatively impact quality of life. In addition to known health and lifestyle risk factors, genetics may have a role in continence. Identification of genetic variants associated with urinary incontinence and fecal incontinence could result in a better understanding of etiologic pathways, and new interventions and treatments. MATERIALS AND METHODS: We previously generated genome-wide single nucleotide polymorphism data from Nurses' Health Studies participants. The participants provided longitudinal urinary incontinence and fecal incontinence information via questionnaires. Cases of urinary incontinence (6,120) had at least weekly urinary incontinence reported on a majority of questionnaires (3 or 4 across 12 to 16 years) while controls (4,811) consistently had little to no urinary incontinence reported. We classified cases of urinary incontinence in women into stress (1,809), urgency (1,942) and mixed (2,036) subtypes. Cases of fecal incontinence (4,247) had at least monthly fecal incontinence reported on a majority of questionnaires while controls (11,634) consistently had no fecal incontinence reported. We performed a genome-wide association study for each incontinence outcome. RESULTS: We identified 8 single nucleotide polymorphisms significantly associated (p <5×10-8) with urinary incontinence located in 2 loci, chromosomes 8q23.3 and 1p32.2. There were no genome-wide significant findings for the urinary incontinence subtype analyses. However, the significant associations for overall urinary incontinence were stronger for the urgency and mixed subtypes than for stress. While no single nucleotide polymorphism reached genome-wide significance for fecal incontinence, 4 single nucleotide polymorphisms had p <10-6. CONCLUSIONS: Few studies have collected genetic data and detailed urinary incontinence and fecal incontinence information. This genome-wide association study provides initial evidence of genetic associations for urinary incontinence and merits further research to replicate our findings and identify additional risk variants.

Association of genetic variations of selenoprotein genes, plasma selenium levels, and prostate cancer aggressiveness at diagnosis.

BACKGROUND: Genetic variations in some of the selenoprotein genes, alone or together with an individual's selenium status, may influence risk or progression of prostate cancer. We investigated the impact of genetic variants of selenoproteins on plasma selenium levels and cancer aggressiveness at diagnosis in men with localized prostate cancer (PCa). METHODS: The study cohort comprised 722 patients seen at Dana-Farber Cancer Institute who had localized/locally advanced PCa (i.e., stage T3 or less, N0, and M0) from 1994 to 2001. Fifty-five tagging single nucleotide polymorphisms (SNPs) from six selenoprotein genes (TXNRD1, TXNRD2, SEP15, GPX3, SELENBP1, and SEPP1) were analyzed. Logistic regression is used to examine associations of genotypes and plasma selenium levels with risk of aggressive disease, defined as D'Amico intermediate/high risk categories. Step down permutation was applied to adjust for multiple comparisons. RESULTS: Three hundred and forty-eight patients (48%) had aggressive disease at diagnosis. Two SNPs were associated with cancer aggressiveness at diagnosis (unadjusted P = 0.017 and 0.018, respectively). The odds ratio for aggressive disease in patients carrying TXNRD2 rs1005873-AG/GG genotypes or SELENBP1 rs10788804-AG/AA genotypes was 1.54 (95% CI = 1.08, 2.20) and 1.45 (95% CI = 1.07, 1.98), respectively, compared to TXNRD2 rs1005873-AA or SELENBP1 rs10788804-GG carriers. Four SNPs in TXNRD2 (rs1005873, rs13054371, rs3788310, and rs9606174) and the rs230820 in SEPP1 were associated with plasma selenium levels (unadjusted P < 0.05). Permutation adjusted P-values were not statistically significant for all these comparisons at the cut-off point of 0.05. CONCLUSION: We identified polymorphisms in selenoproteins that may influence the plasma selenium levels and may be associated with the risk of presenting with aggressive PCa in men with localized or locally advanced PCa. These results should be validated in other independent datasets.

Familial Risk and Heritability of Cancer Among Twins in Nordic Countries.

IMPORTANCE: Estimates of familial cancer risk from population-based studies are essential components of cancer risk prediction. OBJECTIVE: To estimate familial risk and heritability of cancer types in a large twin cohort. DESIGN, SETTING, AND PARTICIPANTS: Prospective study of 80,309 monozygotic and 123,382 same-sex dizygotic twin individuals (N = 203,691) within the population-based registers of Denmark, Finland, Norway, and Sweden. Twins were followed up a median of 32 years between 1943 and 2010. There were 50,990 individuals who died of any cause, and 3804 who emigrated and were lost to follow-up. EXPOSURES: Shared environmental and heritable risk factors among pairs of twins. MAIN OUTCOMES AND MEASURES: The main outcome was incident cancer. Time-to-event analyses were used to estimate familial risk (risk of cancer in an individual given a twin's development of cancer) and heritability (proportion of variance in cancer risk due to interindividual genetic differences) with follow-up via cancer registries. Statistical models adjusted for age and follow-up time, and accounted for censoring and competing risk of death. RESULTS: A total of 27,156 incident cancers were diagnosed in 23,980 individuals, translating to a cumulative incidence of 32%. Cancer was diagnosed in both twins among 1383 monozygotic (2766 individuals) and 1933 dizygotic (2866 individuals) pairs. Of these, 38% of monozygotic and 26% of dizygotic pairs were diagnosed with the same cancer type. There was an excess cancer risk in twins whose co-twin was diagnosed with cancer, with estimated cumulative risks that were an absolute 5% (95% CI, 4%-6%) higher in dizygotic (37%; 95% CI, 36%-38%) and an absolute 14% (95% CI, 12%-16%) higher in monozygotic twins (46%; 95% CI, 44%-48%) whose twin also developed cancer compared with the cumulative risk in the overall cohort (32%). For most cancer types, there were significant familial risks and the cumulative risks were higher in monozygotic than dizygotic twins. Heritability of cancer overall was 33% (95% CI, 30%-37%). Significant heritability was observed for the cancer types of skin melanoma (58%; 95% CI, 43%-73%), prostate (57%; 95% CI, 51%-63%), nonmelanoma skin (43%; 95% CI, 26%-59%), ovary (39%; 95% CI, 23%-55%), kidney (38%; 95% CI, 21%-55%), breast (31%; 95% CI, 11%-51%), and corpus uteri (27%; 95% CI, 11%-43%). CONCLUSIONS AND RELEVANCE: In this long-term follow-up study among Nordic twins, there was significant excess familial risk for cancer overall and for specific types of cancer, including prostate, melanoma, breast, ovary, and uterus. This information about hereditary risks of cancers may be helpful in patient education and cancer risk counseling.

Molecular differences in transition zone and peripheral zone prostate tumors.

Prostate tumors arise primarily in the peripheral zone (PZ) of the prostate, but 20-30% arise in the transition zone (TZ). Zone of origin may have prognostic value or reflect distinct molecular subtypes; however, it can be difficult to determine in practice. Using whole-genome gene expression, we built a signature of zone using normal tissue from five individuals and found that it successfully classified nine tumors of known zone. Hypothesizing that this signature captures tumor zone of origin, we assessed its relationship with clinical factors among 369 tumors of unknown zone from radical prostatectomies (RPs) and found that tumors that molecularly resembled TZ tumors showed lower mortality (P = 0.09) that was explained by lower Gleason scores (P = 0.009). We further applied the signature to an earlier study of 88 RP and 333 transurethral resection of the prostate (TURP) tumor samples, also of unknown zone, with gene expression on ~6000 genes. We had observed previously substantial expression differences between RP and TURP specimens, and hypothesized that this might be because RPs capture primarily PZ tumors, whereas TURPs capture more TZ tumors. Our signature distinguished these two groups, with an area under the receiver operating characteristic curve of 87% (P < 0.0001). Our findings that zonal differences in normal tissue persist in tumor tissue and that these differences are associated with Gleason score and sample type suggest that subtypes potentially resulting from different etiologic pathways might arise in these zones. Zone of origin may be important to consider in prostate tumor biomarker research.

Calcium intake, polymorphisms of the calcium-sensing receptor, and recurrent/aggressive prostate cancer.

PURPOSE: To assess whether calcium intake and common genetic variants of the calcium-sensing receptor (CASR) are associated with either aggressive prostate cancer (PCa) or disease recurrence after prostatectomy. METHODS: Calcium intake at diagnosis was assessed, and 65 common single-nucleotide polymorphisms (SNPs) in CASR were genotyped in 886 prostatectomy patients. We investigated the association between calcium intake and CASR variants with both PCa recurrence and aggressiveness (defined as Gleason score ≥4 + 3, stage ≥pT3, or nodal-positive disease). RESULTS: A total of 285 men had aggressive disease and 91 experienced recurrence. A U-shaped relationship between calcium intake and both disease recurrence and aggressiveness was observed. Compared to the middle quintile, the HR for disease recurrence was 3.07 (95% CI 1.41-6.69) for the lowest quintile and 3.21 (95% CI 1.47-7.00) and 2.97 (95% CI 1.37-6.45) for the two upper quintiles, respectively. Compared to the middle quintile, the OR for aggressive disease was 1.80 (95% CI 1.11-2.91) for the lowest quintile and 1.75 (95% CI 1.08-2.85) for the highest quintile of calcium intake. The main effects of CASR variants were not associated with PCa recurrence or aggressiveness. In the subgroup of patients with moderate calcium intake, 31 SNPs in four distinct blocks of high linkage disequilibrium were associated with PCa recurrence. CONCLUSIONS: We observed a protective effect of moderate calcium intake for PCa aggressiveness and recurrence. While CASR variants were not associated with these outcomes in the entire cohort, they may be associated with disease recurrence in men with moderate calcium intakes.

Transferability of tag SNPs in genetic association studies in multiple populations.

A general question for linkage disequilibrium-based association studies is how power to detect an association is compromised when tag SNPs are chosen from data in one population sample and then deployed in another sample. Specifically, it is important to know how well tags picked from the HapMap DNA samples capture the variation in other samples. To address this, we collected dense data uniformly across the four HapMap population samples and eleven other population samples. We picked tag SNPs using genotype data we collected in the HapMap samples and then evaluated the effective coverage of these tags in comparison to the entire set of common variants observed in the other samples. We simulated case-control association studies in the non-HapMap samples under a disease model of modest risk, and we observed little loss in power. These results demonstrate that the HapMap DNA samples can be used to select tags for genome-wide association studies in many samples around the world.

Genetic variation across C-reactive protein and risk of prostate cancer.

BACKGROUND: Inflammation has been hypothesized to play an important etiological role in the initiation or progression of prostate cancer. Circulating levels of the systemic inflammation marker C-reactive protein (CRP) have been associated with increased risk of prostate cancer. We investigated the role of genetic variation in CRP and prostate cancer, under the hypothesis that variants may alter risk of disease. METHODS: We undertook a case-control study nested within the prospective Physicians' Health Study among 1,286 men with incident prostate cancer and 1,264 controls. Four single-nucleotide polymorphisms (SNPs) were selected to capture the common genetic variation across CRP (r(2) > 0.8). We used unconditional logistic regression to assess the association between each SNP and risk of prostate cancer. Linear regression models explored associations between each genotype and plasma CRP levels. RESULTS: None of the CRP SNPs were associated with prostate cancer overall. Individuals with one copy of the minor allele (C) in rs1800947 had an increased risk of high-grade prostate cancer (OR: 1.7; 95% CI: 1.1-2.8), and significantly lower mean CRP levels (P-value <0.001), however, we found no significant association with lethal disease. Mean CRP levels were significantly elevated in men with one or two copies of the minor allele in rs3093075 and rs1417939, but these were unrelated to prostate cancer risk. CONCLUSION: Our findings suggest that SNPs in the CRP gene are not associated with risk of overall or lethal prostate cancer. Polymorphisms in CRP rs1800947 may be associated with higher grade disease, but our results require replication in other cohorts.