Circadian genes and risk of prostate cancer in the prostate cancer prevention trial.

Circadian genes have been considered as a possible biological mechanism for the observed relationship between circadian rhythm disruptions and increased risk of hormone-related cancers. In the current study, we investigated the relationship between circadian gene variants and prostate cancer risk and whether reducing bioavailable testosterone modifies the circadian genes-prostate cancer relationship. We conducted a nested case-control study among Caucasian men in the Prostate Cancer Prevention Trial (PCPT), a randomized placebo-controlled clinical trial to assess if finasteride (an androgen bioactivation inhibitor) could prevent prostate cancer. We evaluated the associations between 240 circadian gene variations and prostate cancer risk among 1092 biopsy-confirmed prostate cancer cases and 1089 biopsy-negative controls in the study (642 cases and 667 controls from the placebo group; 450 cases and 422 controls from the finasteride group), stratified by treatment group. Among men in the finasteride group, there were suggestive associations between NPAS2 variants and total prostate cancer risk, with one SNP remaining statistically significant after Bonferroni correction (rs746924, odds ratio [OR] = 1.5, P = 9.6 × 10-5 ). However, we found little evidence of increased prostate cancer risk (overall or by low/high grade) associated with circadian gene variations in men of the placebo group, suggesting potential modification of genetic effects by treatment. We did not find strong evidence that circadian gene variants influenced prostate cancer risk in men who were not on finasteride treatment. There were suggestive associations between NPAS2 variants and prostate cancer risk among men using finasteride, which warrants further investigations.

Metabolomic profiles in breast cancer:a pilot case-control study in the breast cancer family registry.

BACKGROUND: Metabolomics is emerging as an important tool for detecting differences between diseased and non-diseased individuals. However, prospective studies are limited. METHODS: We examined the detectability, reliability, and distribution of metabolites measured in pre-diagnostic plasma samples in a pilot study of women enrolled in the Northern California site of the Breast Cancer Family Registry. The study included 45 cases diagnosed with breast cancer at least one year after the blood draw, and 45 controls. Controls were matched on age (within 5 years), family status, BRCA status, and menopausal status. Duplicate samples were included for reliability assessment. We used a liquid chromatography/gas chromatography mass spectrometer platform to measure metabolites. We calculated intraclass correlations (ICCs) among duplicate samples, and coefficients of variation (CVs) across metabolites. RESULTS: Of the 661 named metabolites detected, 338 (51%) were found in all samples, and 490 (74%) in more than 80% of samples. The median ICC between duplicates was 0.96 (25th - 75th percentile: 0.82-0.99). We observed a greater than 20% case-control difference in 24 metabolites (p < 0.05), although these associations were not significant after adjusting for multiple comparisons. CONCLUSIONS: These data show that assays are reproducible for many metabolites, there is a minimal laboratory variation for the same sample, and a large between-person variation. Despite small sample size, differences between cases and controls in some metabolites suggest that a well-powered large-scale study is likely to detect biological meaningful differences to provide a better understanding of breast cancer etiology.

A genome-wide association study of prostate cancer in West African men.

Age-adjusted mortality rates for prostate cancer are higher for African-American men compared with those of European ancestry. Recent data suggest that West African men also have elevated risk for prostate cancer relative to European men. Genetic susceptibility to prostate cancer could account for part of this difference. We conducted a genome-wide association study (GWAS) of prostate cancer in West African men in the Ghana Prostate Study. Association testing was performed using multivariable logistic regression adjusted for age and genetic ancestry for 474 prostate cancer cases and 458 population-based controls on the Illumina HumanOmni-5 Quad BeadChip. The most promising association was at 10p14 within an intron of a long non-coding RNA (lncRNA RP11-543F8.2) 360 kb centromeric of GATA3 (p = 1.29E-7). In sub-analyses, SNPs at 5q31.3 were associated with high Gleason score (≥7) cancers, the strongest of which was a missense SNP in PCDHA1 (rs34575154, p = 3.66E-8), and SNPs at Xq28 (rs985081, p = 8.66E-9) and 6q21 (rs2185710, p = 5.95E-8) were associated with low Gleason score (<7) cancers. We sought to validate our findings in silico in the African Ancestry Prostate Cancer GWAS Consortium, but only one SNP, at 10p14, replicated at p < 0.05. Of the 90 prostate cancer loci reported from studies of men of European, Asian or African-American ancestry, we were able to test 81 in the Ghana Prostate Study, and 10 of these replicated at p < 0.05. Further genetic studies of prostate cancer in West African men are needed to confirm our promising susceptibility loci.

High prevalence of screen detected prostate cancer in West Africans: implications for racial disparity of prostate cancer.

PURPOSE: To our knowledge the reasons for the high rates of prostate cancer in black American men are unknown. Genetic and lifestyle factors have been implicated. Better understanding of prostate cancer rates in West African men would help clarify why black American men have such high rates since the groups share genetic ancestry and yet have different lifestyles and screening practices. To estimate the prostate cancer burden in West African men we performed a population based screening study with biopsy confirmation in Ghana. MATERIALS AND METHODS: We randomly selected 1,037 healthy men 50 to 74 years old from Accra, Ghana for prostate cancer screening with prostate specific antigen testing and digital rectal examination. Men with a positive screen result (positive digital rectal examination or prostate specific antigen greater than 2.5 ng/ml) underwent transrectal ultrasound guided biopsies. RESULTS: Of the 1,037 men 154 (14.9%) had a positive digital rectal examination and 272 (26.2%) had prostate specific antigen greater than 2.5 ng/ml, including 166 with prostate specific antigen greater than 4.0 ng/ml. A total of 352 men (33.9%) had a positive screen by prostate specific antigen or digital rectal examination and 307 (87%) underwent biopsy. Of these men 73 were confirmed to have prostate cancer, yielding a 7.0% screen detected prostate cancer prevalence (65 patients), including 5.8% with prostate specific antigen greater than 4.0 ng/ml. CONCLUSIONS: In this relatively unscreened population in Africa the screen detected prostate cancer prevalence is high, suggesting a possible role of genetics in prostate cancer etiology and the disparity in prostate cancer risk between black and white American men. Further studies are needed to confirm the high prostate cancer burden in African men and the role of genetics in prostate cancer etiology.

Prospective evaluation of serum sarcosine and risk of prostate cancer in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial.

Metabolomic profiling has identified, sarcosine, a derivative of the amino acid glycine, as an important metabolite involved in the etiology or natural history of prostate cancer. We examined the association between serum sarcosine levels and risk of prostate cancer in 1122 cases (813 non-aggressive and 309 aggressive) and 1112 controls in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Sarcosine was quantified using high-throughput liquid chromatography-mass spectrometry. A significantly increased risk of prostate cancer was observed with increasing levels of sarcosine (odds ratio [OR] for the highest quartile of exposure [Q4] versus the lowest quartile [Q1] = 1.30, 95% confidence interval [CI]: 1.02, 1.65; P-trend 0.03). When stratified by disease aggressiveness, we observed a stronger association for non-aggressive cases (OR for Q4 versus Q1 = 1.44, 95% CI: 1.11, 1.88; P-trend 0.006) but no association for aggressive prostate cancer (OR for Q4 versus Q1 = 1.03, 95% CI: 0.73, 1.47; P-trend 0.89). Although not statistically significant, temporal analyses showed a stronger association between sarcosine and prostate cancer for serum collected closer to diagnosis, suggesting that sarcosine may be an early biomarker of disease. Interestingly, the association between sarcosine and prostate cancer risk was stronger among men with diabetes (OR = 2.66, 95% CI: 1.04, 6.84) compared with those without reported diabetes (OR = 1.23, 95% CI: 0.95-1.59, P-interaction = 0.01). This study found that elevated levels of serum sarcosine are associated with an increased prostate cancer risk and evidence to suggest that sarcosine may be an early biomarker for this disease.

Variants in CCK and CCKAR genes to susceptibility to biliary tract cancers and stones: a population-based study in Shanghai, China.

BACKGROUND AND AIM: Altered motility of the gallbladder is associated with an increased risk of gallstones and can result in biliary tract cancers. Cholecystokinin (CCK) is an important modulator of gallbladder motility which functions by activating CCK type-A receptor (CCKAR). The aim of this study was to determine whether genetic variants in CCK and CCKAR are associated with the risk of biliary tract cancers and stones. METHODS: We investigated the associations between nine single nucleotide polymorphisms in CCK and CCKAR in a population-based case-control study, including 439 biliary tract cancer cases (253 gallbladder, 133 extrahepatic bile duct, and 53 ampulla of Vater cancer cases), 429 biliary stone cases, and 447 population controls in Shanghai, China. RESULTS: We found that women with the CCKAR rs1800855 AA genotype had an increased risk of gallbladder cancer (odds ratio = 2.37, 95% confidence interval (CI): 1.36-4.14) compared with subjects with the TT genotype, and remained significant after Bonferroni correction (P = 0.0056). Additionally, female carriers of the CCKAR haplotype C-T-C-T (rs2071011-rs915889-rs3822222-rs1800855) had a reduced risk of gallbladder cancer (odds ratio = 0.61, 95% confidence interval: 0.43-0.86) compared with those with the G-C-C-A haplotype; the association also remained significant after Bonferroni correction. CONCLUSIONS: These findings suggest that variants in the CCKAR gene may influence the risk of gallbladder cancer in women. Additional studies are needed to confirm our findings.

Replication and cumulative effects of GWAS-identified genetic variations for prostate cancer in Asians: a case-control study in the ChinaPCa consortium.

A recent genome-wide association study has identified five new genetic variants for prostate cancer susceptibility in a Japanese population, but it is unknown whether these newly identified variants are associated with prostate cancer risk in other populations, including Chinese men. We genotyped these five variants in a case-control study of 1524 patients diagnosed with prostate cancer and 2169 control subjects from the Chinese Consortium for Prostate Cancer Genetics (ChinaPCa). We found that three of the five genetic variants were associated with prostate cancer risk (P = 4.33 × 10(-8) for rs12653946 at 5p15, 4.43 × 10(-5) for rs339331 at 6q22 and 8.42 × 10(-4) for rs9600079 at 13q22, respectively). A cumulative effect was observed in a dose-dependent manner with increasing numbers of risk variant alleles (P(trend) = 2.58 × 10(-13)), and men with 5-6 risk alleles had a 2-fold higher risk of prostate cancer than men with 0-2 risk alleles (odds ratio = 2.26, 95% confidence interval = 1.78-2.87). Furthermore, rs339331 T allele was significantly associated with RFX6 and GPRC6A higher messenger RNA expression, compared with the C allele. However, none of the variants was associated with clinical stage, Gleason score or family history. These results provide further evidence that the risk loci identified in Japanese men also contribute to prostate cancer susceptibility in Chinese men.

The association between inflammation-related genes and serum androgen levels in men: the prostate, lung, colorectal, and ovarian study.

BACKGROUND: Androgens and inflammation have been implicated in the etiology of several cancers, including prostate cancer. Serum androgens have been shown to correlate with markers of inflammation and expression of inflammation-related genes. METHODS: In this report, we evaluated associations between 9,932 single nucleotide polymorphisms (SNPs) marking common genetic variants in 774 inflammation-related genes and four serum androgen levels (total testosterone [T], bioavailable T [BioT]; 5α-androstane-3α, 17ß-diol glucuronide [3αdiol G], and 4-androstene-3,17-dione [androstenedione]), in 560 healthy men (median age 64 years) drawn from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Baseline serum androgens were measured by radioimmunoassay. Genotypes were determined as part of the Cancer Genetic Markers of Susceptibility Study genome-wide scan. SNP-hormone associations were evaluated using linear regression of hormones adjusted for age. Gene-based P values were generated using an adaptive rank truncated product (ARTP) method. RESULTS: Suggestive associations were observed for two inflammation-related genes and circulating androgen levels (false discovery rate [FDR] q-value <0.1) in both SNP and gene-based tests. Specifically, T was associated with common variants in MMP2 and CD14, with the most significant SNPs being rs893226G > T in MMP2 and rs3822356T > C in CD14 (FDR q-value = 0.09 for both SNPs). Other genes implicated in either SNP or gene-based tests were IK with T and BioT, PRG2 with T, and TNFSF9 with androstenedione. CONCLUSION: These results suggest possible cross-talk between androgen levels and inflammation pathways, but larger studies are needed to confirm these findings and to further clarify the interrelationship between inflammation and androgens and their effects on cancer risk.

Predictive performance of prostate cancer risk in Chinese men using 33 reported prostate cancer risk-associated SNPs.

BACKGROUND: Genome-wide association studies (GWAS) have identified more than 30 single nucleotide polymorphisms (SNPs) that were reproducibly associated with prostate cancer (PCa) risk in populations of European descent. In aggregate, these variants have shown potential to predict risk for PCa in European men. However, their utility for PCa risk prediction in Chinese men is unknown. METHODS: We selected 33 PCa risk-related SNPs that were originally identified in populations of European descent. Genetic scores were estimated for subjects in a Chinese case-control study (1,108 cases and 1,525 controls) based on these SNPs. To assess the performance of the genetic score on its ability to predict risk for PCa, we calculated area under the curve (AUC) of the receiver operating characteristic (ROC) in combination with 10-fold cross-validation. RESULTS: The genetic score was significantly higher for cases than controls (P = 5.91 × 10(-20)), and was significantly associated with risk of PCa in a dose-dependent manner (P for trend: 4.78 × 10(-18)). The AUC of the genetic score was 0.604 for risk prediction of PCa in Chinese men. When ORs derived from this Chinese study population were used to calculate genetic score, the AUCs were 0.631 for all 33 SNPs and 0.617 when using only the 11 significant SNPs. CONCLUSION: Our results indicate that genetic variants related to PCa risk may be useful for risk prediction in Chinese men. Prospective studies are warranted to further evaluate these findings.

Inflammatory gene variants and the risk of biliary tract cancers and stones: a population-based study in China.

BACKGROUND: Genetic variants in inflammation-related genes have been associated with biliary stones and biliary tract cancers in previous studies. METHODS: To follow-up on these findings, we examined 35 single nucleotide polymorphism (SNPs) in 5 genes related to inflammation (IL8, NFKBIL, RNASEL, TNF, and VEGFA) in 456 participants with incident biliary tract cancer cases (262 gallbladder, 141 extrahepatic bile duct, 53 ampulla of Vater), 982 participants with biliary stones, and 860 healthy controls in a population-based case-control study in Shanghai, China. RESULTS: Suggestive associations were observed for SNPs in VEGFA with biliary stones, IL8 with gallbladder and ampulla of Vater cancers, and RNASEL with ampulla of Vater cancer (false discovery rate≤0.2). CONCLUSION: These findings provide additional support for the role of inflammation in biliary stones and biliary tract cancer risk and need further validation.

Cholesterol metabolism gene polymorphisms and the risk of biliary tract cancers and stones: a population-based case-control study in Shanghai, China.

Biliary tract cancers are rare but fatal malignancies, with increasing incidence in Shanghai, China. Gallstones, the primary risk factor for biliary tract cancer, typically result from oversaturation of cholesterol in bile. We examined the association of five variants in three lipid metabolism-related genes (CETP, ABCG8 and LRPAP1) and biliary tract cancers and stones in a population-based case-control study in Shanghai, China. We included 439 biliary tract cancer cases (253 gallbladder, 133 extrahepatic bile duct and 53 ampulla of Vater cancer cases), 429 biliary stone cases and 447 population controls. Carriers of the CG genotype of ABCG8 rs11887534 had higher risk of biliary stones [odds ratio (OR) = 2.3, 95% confidence interval (CI) 0.82-6.5), gallbladder cancer (OR = 4.3, 95% CI 1.7-10.4) and bile duct cancer (OR = 1.94, 95% CI 0.64-5.91), compared with carriers of the GG genotype. Analysis stratified by gender showed both male and female carriers of CG rs11887534 had higher risks of biliary stones and gallbladder cancer, although the association was statistically significant only for women and gallbladder cancer (OR = 6.3, 95% CI 1.86-22.3). Carriers of the ABCG8 haplotype C-C (rs4148217-rs11887534) had a 4.16-fold (95% CI 1.71-10.1) risk of gallbladder cancer compared with those carrying the C-G haplotype. Our findings suggest that ABCG8 rs11887534, identified as a gallstone risk single-nucleotide polymorphism by whole genome scan, is also associated with an increased risk of biliary tract cancer.

Human polymorphisms at long non-coding RNAs (lncRNAs) and association with prostate cancer risk.

Long non-coding RNAs (lncRNAs), representing a large proportion of non-coding transcripts across the human genome, are evolutionally conserved and biologically functional. At least one-third of the phenotype-related loci identified by genome-wide association studies (GWAS) are mapped to non-coding intervals. However, the relationships between phenotype-related loci and lncRNAs are largely unknown. Utilizing the 1000 Genomes data, we compared single-nucleotide polymorphisms (SNPs) within the sequences of lncRNA and protein-coding genes as defined in the Ensembl database. We further annotated the phenotype-related SNPs reported by GWAS at lncRNA intervals. Because prostate cancer (PCa) risk-related loci were enriched in lncRNAs, we then performed meta-analysis of two existing GWAS for discovery and an additional sample set for replication, revealing PCa risk-related loci at lncRNA regions. The SNP density in regions of lncRNA was similar to that in protein-coding regions, but they were less polymorphic than surrounding regions. Among the 1998 phenotype-related SNPs identified by GWAS, 52 loci were located directly in lncRNA intervals with a 1.5-fold enrichment compared with the entire genome. More than a 5-fold enrichment was observed for eight PCa risk-related loci in lncRNA genes. We also identified a new PCa risk-related SNP rs3787016 in an lncRNA region at 19q13 (per allele odds ratio = 1.19; 95% confidence interval: 1.11-1.27) with P value of 7.22 × 10(-7). lncRNAs may be important for interpreting and mining GWAS data. However, the catalog of lncRNAs needs to be better characterized in order to fully evaluate the relationship of phenotype-related loci with lncRNAs.

Genome-wide copy-number variation analysis identifies common genetic variants at 20p13 associated with aggressiveness of prostate cancer.

The genetic determinants for aggressiveness of prostate cancer (PCa) are poorly understood. Copy-number variations (CNVs) are one of the major sources for genetic diversity and critically modulate cellular biology and human diseases. We hypothesized that CNVs may be associated with PCa aggressiveness. To test this hypothesis, we conducted a genome-wide common CNVs analysis in 448 aggressive and 500 nonaggressive PCa cases recruited from Johns Hopkins Hospital (JHH1) using Affymetrix 6.0 arrays. Suggestive associations were further confirmed using single-nucleotide polymorphisms (SNPs) that tagged the CNVs of interest in an additional 2895 aggressive and 3094 nonaggressive cases, including those from the remaining case subjects of the JHH study (JHH2), the NCI Cancer Genetic Markers of Susceptibility (CGEMS) Study, and the CAncer of the Prostate in Sweden (CAPS) Study. We found that CNP2454, a 32.3 kb deletion polymorphism at 20p13, was significantly associated with aggressiveness of PCa in JHH1 [odds ratio (OR) = 1.30, 95% confidence interval (CI): 1.01-1.68; P = 0.045]. The best-tagging SNP for CNP2454, rs2209313, was used to confirm this finding in both JHH1 (P = 0.045) and all confirmation study populations combined (P = 1.77 × 10(-3)). Pooled analysis using all 3353 aggressive and 3584 nonaggressive cases showed the T allele of rs2209313 was significantly associated with an increased risk of aggressive PCa (OR = 1.17, 95% CI: 1.07-1.27; P = 2.75 × 10(-4)). Our results indicate that genetic variations at 20p13 may be responsible for the progression of PCa.

Systematic confirmation study of reported prostate cancer risk-associated single nucleotide polymorphisms in Chinese men.

More than 30 prostate cancer (PCa) risk-associated loci have been identified in populations of European descent by genome-wide association studies. We hypothesized that a subset of these loci might be associated with PCa risk in Chinese men. To test this hypothesis, 33 single nucleotide polymorphisms (SNP), one each from the 33 independent PCa risk-associated loci reported in populations of European descent, were investigated for their associations with PCa risk in a case-control study of Chinese men (1108 cases and 1525 controls). We found that 11 of the 33 SNP were significantly associated with PCa risk in Chinese men (P < 0.05). The reported risk alleles were associated with increased risk for PCa, with allelic odds ratios ranging from 1.12 to 1.44. The most significant locus was located on 8q24 region 2 (rs16901979, P = 5.14 × 10(-9)) with a genome-wide significance (P < (-8) ), and three loci reached the Bonferroni correction significance level (P < 1.52 × 10(-3)), including 8q24 region 1 (rs1447295, P = 7.04 × 10(-6)), 8q24 region 5 (rs10086908, P = 9.24 × 10(-4)) and 8p21 (rs1512268, P = 9.39 × 10(-4)). Our results suggest that a subset of the PCa risk-associated SNP discovered by genome-wide association studies among men of European descent is also associated with PCa risk in Chinese men. This finding provides evidence of ethnic differences and similarity in genetic susceptibility to PCa. Genome-wide association studies in Chinese men are needed to identify Chinese-specific PCa risk-associated SNP.

Urinary estrogen metabolites and prostate cancer risk: a pilot study.

BACKGROUND: The high incidence of and few identified risk factors for prostate cancer underscore the need to further evaluate markers of prostate carcinogenesis. The aim of this pilot study was to evaluate urinary estrogen metabolites as a biomarker of prostate cancer risk. METHODS: Using a liquid chromatography-tandem mass spectrometry method, urinary concentrations of 15 estrogen metabolites were determined in 77 prostate cancer cases, 77 healthy controls, and 37 subjects who had no evidence of prostate cancer after a prostate biopsy. RESULTS: We observed an inverse association between the urinary 16-ketoestradiol (16-KE2) and 17-epiestriol (17-epiE3)--metabolites with high estrogenic activity--and prostate cancer risk. Men in the lowest quartile of 16-KE2, had a 4.6-fold risk of prostate cancer (OR=4.62, 95% CI=1.34-15.99), compared with those in the highest quartile. CONCLUSIONS: We observed modest differences in estrogen metabolite concentrations between prostate cancer patients and subjects without cancer. Larger studies with both androgen and estrogen measurements are needed to confirm these results to clarify further whether estrogen metabolites are independent biomarkers for prostate cancer risk and whether androgen/estrogen imbalance influences prostate cancer risk.

A reproducible and high-throughput HPLC/MS method to separate sarcosine from α- and ß-alanine and to quantify sarcosine in human serum and urine.

While sarcosine was recently identified as a potential urine biomarker for prostate cancer, further studies have cast doubt on its utility to diagnose this condition. The inconsistent results may be due to the fact that alanine and sarcosine coelute on an HPLC reversed-phase column and the mass spectrometer cannot differentiate between the two isomers, since the same parent/product ions are generally used to measure them. In this study, we developed a high-throughput liquid chromatography-mass spectrometry (LC-MS) method that resolves sarcosine from alanine isomers, allowing its accurate quantification in human serum and urine. Assay reproducibility was determined using the coefficient of variation (CV) and intraclass correlation coefficient (ICC) in serum aliquots from 10 subjects and urine aliquots from 20 subjects across multiple analytic runs. Paired serum/urine samples from 42 subjects were used to evaluate sarcosine serum/urine correlation. Both urine and serum assays gave high sensitivity (limit of quantitation of 5 ng/mL) and reproducibility (serum assay, intra- and interassay CVs < 3% and ICCs > 99%; urine assay, intra-assay CV = 7.7% and ICC = 98.2% and interassay CV = 12.3% and ICC = 94.2%). In conclusion, this high-throughput LC-MS method is able to resolve sarcosine from α- and ß-alanine and is useful for quantifying sarcosine in serum and urine samples.

High prevalence of polyclonal hypergamma-globulinemia in adult males in Ghana, Africa.

Chronic antigenic stimulation is associated with hypergamma-globulinemia. Higher rates of hypergamma-globulinemia in tropical populations are maintained even with migration to temperate regions. We conducted a population-based screening study to assess the prevalence and risk factors for hypergamma-globulinemia in Ghana, Africa. 917 Ghanaian males (50-74 years) underwent in-person interviews and health examinations. Serum from all persons was analyzed by electrophoresis performed on agarose gel; serum with a discrete/localized band was subjected to immunofixation. 54 persons with monoclonal proteins were excluded and 17 samples were insufficient for analysis. Using logistic regression and Chi-square statistics we analyzed patterns of hypergamma-globulinemia. Among 846 study subjects, the median γ-globulin level was 1.86 g/dL. On the basis of a U.S. reference, 616 (73%) had hypergamma-globulinemia (>1.6 g/dL) and 178 (21%) had γ-globulin levels >2.17 gm/dl. On multivariate analyses, lower education status (P = 0.0013) and never smoking (P = 0.038) were associated with increased γ-globulin levels. Self-reported history of syphilis was associated with hypergamma-globulinemia. We conclude that three quarters of this population-based adult Ghanaian male sample had hypergamma-globulinemia with γ-globulin levels >1.6 g/dL. Future studies are needed to uncover genetic and environmental underpinnings of our finding, and to define the relationship between hypergamma-globulinemia, monoclonal gammopathy of undetermined significance (MGUS), and multiple myeloma.

Association of 17 prostate cancer susceptibility loci with prostate cancer risk in Chinese men.

BACKGROUND: Several genome-wide association studies (GWAS) in populations of European descent have identified more than a dozen common genetic variants that are associated with prostate cancer risk. METHODS: To determine whether these variants are also associated with prostate cancer risk in the Chinese population, we evaluated 17 prostate cancer susceptibility loci in a population-based case-control study from Shanghai, including 288 prostate cancer cases and 155 population controls. RESULTS: After adjustment for age, two of the 17 loci were significantly associated with prostate cancer risk, while the other 15 loci were suggestively associated with prostate cancer risk in this population. The strongest associations were found for chromosome 8q24 Region 2 (rs1016343: OR = 2.07, 95% CI: 1.35-3.20, P = 9.4 x 10(-4)) and 8q24 Region 1 (rs10090154: OR = 2.07, 95% CI: 1.31-3.28, P = 0.002); additional single nucleotide polymorphisms (SNPs) assessed in these two 8q24 regions were also significant (OR(Region2) = 1.92-2.05, P = 9.4 x 10(-4) to 0.003, and OR(Region1) = 1.77-1.81, P = 0.01 for all SNPs). CONCLUSIONS: Our study shows that multiple prostate cancer risk loci identified in European populations by GWAS are also associated with prostate cancer risk in Chinese men, a low-risk population with mostly clinically relevant cancers. Larger studies in Chinese and Asian populations are needed to confirm these findings and the role of these risk loci in prostate cancer etiology in Asian men.

Maternal diet and risk of childhood acute lymphoblastic leukemia.

OBJECTIVE: Intrauterine environmental factors, including maternal diet, may play an etiologic role in acute lymphoblastic leukemia (ALL), a common childhood cancer. Expanding on previous findings from phase 1 of the Northern California Childhood Leukemia Study (NCCLS), a population-based case-control study, we sought to further elucidate and replicate the relationships between maternal diet and ALL risk. METHODS: We matched 282 case-control sets of children (205 pairs and 77 triplets) from phases 1 and 2 of the NCCLS on sex, date of birth, mother's race, Hispanic racial/ethnic status, and county of residence at birth. We used an interviewer-administered food frequency questionnaire to obtain information on maternal dietary intake in the 12 months prior to pregnancy. RESULTS: Risk of ALL was inversely associated with maternal consumption of vegetable (adjusted odds ratio [AOR] = 0.65, 95% confidence interval [CI] 0.50, 0.84); protein sources (AOR = 0.55, 95% CI 0.32, 0.96); fruit (AOR = 0.81, 95% CI 0.65, 1.00); and legume food groups (AOR = 0.75, 95% CI 0.59, 0.95). The risk reduction was strongest for consumption of the protein sources and vegetable food groups, independent of the child's diet up to age 2 years, and consistent across phases 1 and 2 of data collection for vegetable consumption. CONCLUSIONS: These data suggest that it may be prudent for women to consume a diet rich in vegetables and adequate in protein prior to and during pregnancy as a possible means of reducing childhood ALL risk in their offspring.

Polymorphic variants in PTGS2 and prostate cancer risk: results from two large nested case-control studies.

Chronic inflammation has been hypothesized to increase prostate cancer risk. Prostaglandin-endoperoxide synthase 2 (PTGS2) encodes the proinflammatory cyclooxygenase 2 enzyme believed to be the rate-limiting step in the synthesis of prostaglandins, important mediators of inflammation. We investigated associations between PTGS2 polymorphisms and prostate cancer risk among 2321 prostate cancer cases and 2560 controls in two large case-control studies nested within the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial and the Cancer Prevention Study II Nutrition Cohort. Five single nucleotide polymorphisms (SNPs) (rs5277, rs20432, rs4648276, rs5275 and rs689470) were examined in SNP and haplotype analyses (five SNPs in PLCO and four SNPs in the Nutrition Cohort). In PLCO, the Ex10 +837 T>C marker (rs5275) was initially associated with prostate cancer risk (P-trend = 0.02) but became non-significant after adjustment for multiple comparisons (P = 0.08); this SNP showed no association with prostate cancer risk in the Nutrition Cohort (P-trend = 0.54) or in an analysis pooling the two cohorts (P-trend = 0.20). No other SNP was associated with prostate cancer risk in PLCO or the Nutrition Cohort individually or combined. Haplotype analyses suggested an association between PTGS2 variants in PLCO alone (global P = 0.007), but not in the Nutrition Cohort (global P = 0.78) or pooled analysis (global P = 0.18). In conclusion, despite the potential importance of inflammation in prostate carcinogenesis, results from our large study of five PTGS2 SNPs does not support a strong association between PTGS2 variants and prostate cancer risk in non-Hispanic white men.