Interactive effect of TLR SNPs and exposure to sexually transmitted infections on prostate cancer risk in Jamaican men.

BACKGROUND: Prostate cancer (PC) risk increases with African ancestry and a history of sexually transmitted infections (STIs). Also, single-nucleotide polymorphisms (SNPs) in toll-like receptor (TLR) genes influence PC risk. This pilot study explores interactions between STIs and TLR-related SNPs in relation to PC risk among Jamaican men. METHODS: This case-control study evaluates two TLR related SNPs in 356 Jamaican men (194 controls and 162 cases) with or without history of STIs using stepwise penalized logistic regression in multivariable analyses. RESULTS: Age (odds ratio [OR] = 1.08; 95% confidence interval [CI]: 1.04-1>.12; p < .001) and IRF3_rs2304206 GG genotype (OR = 0.47; 95% CI: 0.29-0<.78; p = .003) modulated PC risk in people with history of STIs. In the population with no history of STIs, resulting interactions between risk factors did not survive correction for multiple hypothesis testing. CONCLUSION: Overall, an interaction between the IFR3_rs2304206 variant and a history of exposure to STIs leads to greater decrease of PC risk than the presence of polymorphic genotype alone. These findings are suggestive and require further validation. Identification of gene variants along with detection of lifestyle behaviors may contribute to identification of men at a greater risk of PC development in the population.

Exploring putative genetic determinants of inter-individual phenotypic heterogeneity in sickle cell disease: A cross-sectional Jamaican cohort-based study.

Patients with sickle cell disease (SCD) display puzzling inter-individual phenotypic heterogeneity, conceivably related to inherent differences in antioxidant protection, hemoglobin binding, bilirubin catabolism and methyl group handling. Therefore, we explored putative associations between clinically important phenotypic measures and functional polymorphisms within specific candidate genes encoding glutathione S-transferase, haptoglobin, uridine 5'-diphospho-glucuronosyltransferase 1A1, methyl tetrahydrofolate reductase, 5-methyltetrahydrofolate-homocysteine methyltransferase, and cystathionine beta-synthase. Two-hundred and thirty SCD participants (mean age 25.1 ±â€¯2.8) were recruited from Jamaica's Annual Sickle Cell Unit Cohort Review - two-hundred and five had homozygous hemoglobin SS (HbSS) disease, twenty-five had hemoglobin SC (HbSC) disease. Regression analyses revealed some novel genotype-phenotype associations. HbSC participants had significantly lower mean lactate dehydrogenase (p = 0.01) and glutathione (p < 0.001) values than HbSS participants. Glutathione S-transferase P1 (GSTP1) was significantly associated with mean corpuscular hemoglobin concentration using univariate (p = 0.044) and multivariable regression (p = 0.012). 5-methyltetrahydrofolate-homocysteine methyltransferase (MTR) was significantly associated with hemoglobin F % using univariate (p = 0.010) and multivariable regression (p = 0.009). In conclusion, this exploratory cross-sectional study generated novel, useable, and informative genotype-phenotype estimates of association, but larger studies are needed to determine whether these specific variants are related to inter-individual phenotypic variability in SCD.

A cross-sectional clinic-based study exploring whether variants within the glutathione S-transferase, haptoglobin and uridine 5'-diphospho-glucuronosyltransferase 1A1 genes are associated with interindividual phenotypic variation in sickle cell anaemia in Jamaica.

OBJECTIVES: To explore putative associations between specific variants in either the glutathione S-transferase (GST), haptoglobin (HP) or uridine 5'-diphospho-glucuronosyltransferase 1A1 (UGT1A1) genes and clinically important phenotypes in sickle cell anaemia (HbSS). METHODS: 371 HbSS participants were recruited from the Sickle Cell Clinic of the Sickle Cell Unit at the University of the West Indies, Kingston, Jamaica. Markers within four GST superfamily genes, the HP gene and the UGT1A1 gene were analysed using PCR-based assays. RESULTS: Multivariable regression revealed statistically significant associations between the GSTP1 Ile105Val heterozygote and HbA2 levels (P = .016), HbF percentage (P = .001), MCH concentration (P = .028) and reticulocyte count (P = .032), while the GSTM3 D/D homozygote was significantly associated with HbA2 levels (P = .032). The UGT1A1 (TA)6 /(TA)8 heterozygote showed statistically significant associations with HbA2 levels (P = .019), HbF percentage (P < .001), haemoglobin levels (P = .008), PCV values (P = .007) and RBC counts (P = .041). CONCLUSION: This exploratory cross-sectional study has generated novel and informative genotype-phenotype estimates of association, but larger studies are needed to determine whether these specific variants within the GST, UGT1A1 and HP genes are related to interindividual phenotypic variability in HbSS.

Effects of cholesterol, C-reactive protein, and interleukin-6 on prostate cancer risk in a population of African ancestry.

PURPOSE: To investigate the association between serum cholesterol and prostate cancer and whether any effect may be mediated through inflammatory markers. METHODS: Data from a case-control study of 40-80 years old Jamaican male patients (229 cases; 252 controls) were used. Cases had incident histologically-confirmed prostate cancer and controls were men with normal digital rectal examination and prostate-specific antigen (PSA) < 4 µg/L or free: total PSA > 0.15 obtained from the same clinic. Total and HDL cholesterol, interleukin-6 (IL-6), and C-reactive protein (CRP) were measured from a non-fasting sample. Multivariable logistic regression models were used to evaluate the associations between these factors and prostate cancer, adjusting for age, body mass index, waist circumference, family history of prostate cancer, diabetes, hypertension, use of cholesterol-lowering drugs, and smoking. RESULTS: Total cholesterol [Mean (cases, 4.71 ± 1.07; controls, 4.64 ± 1.07 mmol/L)], CRP [median (cases, 2.11; controls, 2.09 µg/ml)], and IL-6: [median (cases, 3.34; controls, 3.24 pg/ml)] did not differ by PCA status. Higher total cholesterol was associated with an increased risk of low-grade disease after adjusting for potential confounders [multivariable-adjusted OR (95% CI): tertile 2: 3.32(1.66, 6.45), tertile 3: 2.14(1.07, 4.32)]. Total cholesterol was unrelated to overall prostate cancer or high-grade disease. There was no significant association between HDL cholesterol or any of the inflammatory markers with prostate cancer. CONCLUSIONS: Increasing total cholesterol but not inflammatory markers were associated with low-grade prostate cancer in Caribbean men.

Polymorphisms in CYP17 and CYP3A4 and prostate cancer in men of African descent.

BACKGROUND: A meta and pooled analysis of published and unpublished case-control studies was performed to evaluate the association of CYP17 (rs743572) and CYP3A4 (rs2740574) polymorphisms and prostate cancer (PCa) in men from the USA, Caribbean, and Africa. METHODS: Eight publications (seven studies) and two unpublished studies for CYP17 included 1,580 subjects (559 cases and 1,021 controls) and eleven publications and three unpublished studies for CYP3A4 included 3,400 subjects (1,429 cases and 1,971 controls). RESULTS: Overall, the CYP17 heterozygous and homozygous variants were not associated with PCa, but they confer a 60% increased risk of PCa in a sub-group analysis restricted to African-American men (T/C + C/C, OR: 1.6, 95% CI: 1.1-2.4). No associations were observed for CYP3A4, overall and in stratified analyses for African-Americans and Africans. The pooled analysis suggests that after adjusting for study, age, PSA, and family history of PCa, CYP17 was associated with PCa for men of African ancestry (Adjusted OR: 3.5, 95% CI: 1.2-10.0). CONCLUSIONS: Our findings suggest that genetic factors involved in the androgen pathway play a role in PCa risk among men of African ancestry.

Dietary patterns as predictors of prostate cancer in Jamaican men.

Studies of diet and prostate cancer have focused primarily on food and nutrients; however, dietary patterns examine the overall diet, particularly foods eaten in combination, and risk of disease. We evaluated the association of dietary patterns and prostate cancer and low- and high-grade subgroups in Jamaican men. In a case-control study, we enrolled 243 incident cases and 273 urology controls in Jamaican clinics, March 2005-July 2007. Dietary patterns were identified using principal component analysis. Four food patterns were identified: a "vegetable and legume" pattern, a "fast food" pattern, a "meat" pattern, and a "refined carbohydrate" pattern. Men in the highest tertile for the refined carbohydrate pattern, characterized by high intakes of rice, pasta, sugar sweetened beverages, and sweet baked foods were at increased risk of total prostate cancer [odds ratio (OR) = 2.02; 95% confidence interval (CI) = 1.05-3.87 (Ptrend = 0.029)] and low-grade disease [OR = 2.91; 95% CI = 1.18-7.13 (Ptrend = 0.019)] compared with men in the lowest tertile. The vegetable and legumes pattern (healthy), meat pattern, or fast food pattern were not associated with prostate cancer risk. These data suggest a carbohydrate dietary pattern high in refined carbohydrates may be a risk factor for prostate cancer in Jamaican men.

The impact of genetic variants in inflammatory-related genes on prostate cancer risk among men of African Descent: a case control study.

PURPOSE: Although case-control studies have evaluated the role of variant inflammatory-related loci in prostate cancer, their impact is virtually unknown among men of African descent. To address this, we evaluated the impact of inflammatory cytokine single nucleotide polymorphisms (SNPs) on prostate cancer risk for men of African descent. METHODS: Forty-four SNPs in inflammatory cytokine-associated genes were evaluated among 814 African-American and Jamaican men (279 prostate cancer cases and 535 controls) using Illumina's Golden gate genotyping system. Individual SNP effects were evaluated using logistic regression analysis. RESULTS: Four SNPs were modestly associated with prostate cancer after adjusting for age. In the total population, inheritance of the IL1R2 rs11886877 AA, IL8RB rs11574752 AA, TNF rs1800629 GA + AA, and TNF rs673 GA genotypes modestly increased prostate cancer risk by 1.45 to 11.7-fold relative to the referent genotype. Among U.S. men, age-adjusted dominant, recessive and additive genetic models for the IL1R2 rs11886877 locus were linked to an increase in prostate cancer susceptibility. However, these main effects did not persist after adjusting for multiple hypothesis testing. CONCLUSION: Our preliminary data does not strongly support the hypothesis that inflammatory-related sequence variants influence prostate cancer risk among men of African descent. However, further evaluation is needed to assess whether other variant inflammatory-related genes may contribute to prostate cancer risk and disease progression in larger and ethnically diverse multi-center studies.

Associations of whole-blood fatty acids and dietary intakes with prostate cancer in Jamaica.

OBJECTIVE: To investigate the association of whole-blood fatty acids and reported intakes of fats with risk of prostate cancer (PCa). DESIGN: Case-control study of 209 men 40-80 years old with newly diagnosed, histologically confirmed prostate cancer and 226 cancer-free men attending the same urology clinics. Whole-blood fatty acid composition (mol%) was measured by gas chromatography and diet assessed by food frequency questionnaire. RESULTS: High whole-blood oleic acid composition (tertile 3 vs. tertile 1: OR, 0.37; CI, 0.14-0.0.98) and moderate palmitic acid proportions (tertile 2: OR, 0.29; CI, 0.12-0.70) (tertile 3: OR, 0.53; CI, 0.19-1.54) were inversely related to risk of PCa, whereas men with high linolenic acid proportions were at increased likelihood of PCa (tertile 3 vs. tertile 1: OR, 2.06; 1.29-3.27). Blood myristic, stearic and palmitoleic acids were not associated with PCa. Higher intakes of dietary MUFA were inversely related to prostate cancer (tertile 3 vs. tertile 1: OR, 0.39; CI 0.16-0.92). The principal source of dietary MUFA was avocado intake. Dietary intakes of other fats were not associated with PCa. CONCLUSIONS: Whole-blood and dietary MUFA reduced the risk of prostate cancer. The association may be related to avocado intakes. High blood linolenic acid was directly related to prostate cancer. These associations warrant further investigation.

Multi-institutional prostate cancer study of genetic susceptibility in populations of African descent.

Prostate cancer disparities have been reported in men of African descent who show the highest incidence, mortality, compared with other ethnic groups. Few studies have explored the genetic and environmental factors for prostate cancer in men of African ancestry. The glutathione-S-transferases family conjugates carcinogens before their excretion and is expressed in prostate tissue. This study addressed the role of GSTM1 and GSTT1 deletions on prostate cancer risk in populations of African descent. This multi-institutional case-control study gathered data from the Genetic Susceptibility to Environmental Carcinogens (GSEC) database, the African-Caribbean Cancer Consortium (AC3) and Men of African Descent and Carcinoma of the Prostate Consortium (MADCaP). The analysis included 10 studies (1715 cases and 2363 controls), five in African-Americans, three in African-Caribbean and two in African men. Both the GSTM1 and the GSTT1 deletions showed significant inverse associations with prostate cancer [odds ratio (OR): 0.90, 95% confidence interval (CI) 0.83-0.97 and OR 0.88, 95% CI: 0.82-0.96, respectively]. The association was restricted to Caribbean and African populations. A significant positive association was observed between GSTM1 deletion and prostate cancer in smokers in African-American studies (OR: 1.28, 95% CI: 1.01-1.56), whereas a reduced risk was observed in never-smokers (OR: 0.66, 95% CI: 0.46-0.95). The risk of prostate cancer increased across quartiles of pack-years among subjects carrying the deletion of GSTM1 but not among subjects carrying a functional GSTM1. Gene-environment interaction between smoking and GSTM1 may be involved in the etiology of prostate cancer in populations of African descent.

Urinary phytoestrogens and risk of prostate cancer in Jamaican men.

We evaluated the relationship of spot urinary concentrations of phytoestrogens with total prostate cancer and tumor grade in a hospital-based case-control study in Jamaica. Urine samples were analyzed for genistein, daidzein, equol (isoflavones), and enterolactone (lignan) among newly diagnosed cases (n = 175) and controls (n = 194). Urinary concentrations of enterolactone (lignan) were higher among cases. There were no significant differences in median concentrations of isoflavone excretion. Compared with non-producers of equol (reference tertile), men who produced equol were at decreased risk of total prostate cancer (tertile 2: OR, 0.42; CI, 0.23-0.75) (tertile 3: OR, 0.48; CI, 0.26-0.87) (p (trend), 0.020) and high-grade disease (tertile 2: OR, 0.31; CI, 0.15-0.61) (tertile 3: OR, 0.29; CI, 0.13-0.60) (p (trend), 0.001). Higher concentrations of enterolactone were positively related to total prostate cancer (OR, 1.85; CI, 1.01-3.44; p (trend), 0.027) as well as high-grade disease (OR, 2.46; CI, 1.11-5.46; p (trend), 0.023). There were no associations between urinary excretion of genistein and daidzein with risk of prostate cancer. Producers of equol (isoflavone) may be at reduced risk of total- and high-grade prostate cancer whereas enterolactone may increase the likelihood of disease.