Prostate-specific antigen and 17-hydroxylase polymorphic genotypes in patients with prostate cancer and benign prostatic hyperplasia

Systematic review and meta-analysis of candidate gene association studies of benign prostate hyperplasia

BACKGROUND

Benign prostate hyperplasia (BPH) is the most common urological problem in elderly males. Recent studies have reported polymorphism in various metabolic genes in BPH. However, their association with the susceptibility of BPH is still inconsistent. Here, we systematically reviewed and performed a meta-analysis of CYP17, VDR, and ACE genes to determine their precise association with the risk of BPH.

METHODS

A comprehensive literature search for published studies on candidate gene associations involving vitamin D receptor (VDR), angiotensin-converting enzyme (ACE), and CYP17 genes with the risk of BPH was done up to April 2020 in PubMed, Scopus, Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar databases. Fixed/random effects models were used to estimate the odd's ratio (OR) and 95% confidence intervals (CIs). Begg's funnel plot was used to assess the potential for publication bias.

RESULTS

We found a total of 23 studies containing 3461 cases and 3833 controls for these gene polymorphisms. A significant association of ACE gene polymorphism was observed under the recessive (II vs. ID + DD) model for BPH susceptibility compared to control subjects (overall OR = 1.67, 95% CI = 1.03-2.73). Similar trends were observed for ACE gene polymorphism in Caucasian (OR = 6.18, 95% CI = 1.38-27.68) and Asian (OR = 1.42, 95% CI = 0.99-2.03) populations under study. No significant association was observed in VDR and CYP17 gene polymorphisms in any dominant or recessive models.

CONCLUSION

Significant OR demonstrated the implication of ACE gene polymorphism in the proliferation of prostate tissue, which in turn is associated with BPH susceptibility. However, prospective studies at large scale and sample size are needed to confirm the current findings.

Role of CYP17 rs743572 Polymorphism in Benign Prostatic Hyperplasia: A Multivariate Integrated Analysis

Objective: Many published studies have investigated the association between CYP17 rs743572 polymorphism and benign prostatic hyperplasia (BPH) susceptibility but have yielded inconsistent results. Hence, we performed this meta-analysis using the multivariate statistic method to address a more precise association.

Methods: Case-control or cohort studies with adequate genotype distribution or minor allele frequency (MAF) were identified by searching the PubMed, Embase, and Web of Science databases up to December, 2018. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to estimate the association between CYP17 rs743572 polymorphism and BPH susceptibility.

Results: Pooled MAFs of 13 studies were 37% in Caucasians and 56% in Orientals, respectively. Pooled results of 8 studies suggested that CYP17 rs743572 was not associated with the BPH susceptibility in the overall population (OR = 0.98, 95% CI: 0.80–1.20 for A2 vs. A1; OR = 0.99, 95% CI: 0.79–1.25 for A1/A2 vs. A1/A1; OR = 0.97, 95% CI: 0.62–1.53 for A2/A2 vs. A1/A1). Sensitivity analysis showed the results were robust. Subgroup analysis based on ethnicity suggested that, in Orientals, A2 allele carriers had a 28% lower risk of developing BPH compared with A1 allele carriers, and the risk of BPH is 47% lower in A2/A2 genotype carriers compared with A1/A1 genotype carriers. No significant association was observed in Caucasians.

Conclusion: In conclusion, our study indicates a negative association between CYP17 and BPH in Orientals. However, due to limited sample size, the conclusion should be interpreted with caution.

Genetic association between PSA-158G/A polymorphism and the susceptibility of benign prostatic hyperplasia: a meta-analysis

Inconsistency between reported findings on the association of prostate specific antigen (PSA) gene -158G/A polymorphism with benign prostatic hyperplasia (BPH) susceptibility need a meta-analysis to obtain a more accurate conclusion. A systematic search was conducted in electronic databases for the collection of eligible studies on PSA -158G/A polymorphism and BPH susceptibility. Pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were then calculated. 7 case-control studies with 758 cases and 752 controls were included into the present meta-analysis. The analysis results showed no significant relationship between PSA -158G/A polymorphism and BPH susceptibility in total analysis. Interestingly, after subgroup analyses based on ethnicity and source of control, the polymorphism reduced the susceptibility of BPH in Caucasian group (AA vs. GG: OR=0.47, 95% CI=0.25-0.89; allele A vs. allele G: OR=0.68, 95% CI=0.49-0.93), but it increased the disease susceptibility in Asian (AA vs. GG: OR=1.63, 95% CI=1.02-2.60; allele A vs. allele G: OR=1.37, 95% CI=1.03-1.83) and population-based (AA vs. GG: OR=2.39, 95% CI=1.07-5.38; allele A vs. allele G: OR=1.83, 95% CI=1.26-2.65) groups. PSA-158G/A polymorphism may be an inhibitor to the incidence of BPH in Caucasians, but it is likely to be a susceptible factor in Asians.

GSEH: A Novel Approach to Select Prostate Cancer-Associated Genes Using Gene Expression Heterogeneity

When a gene shows varying levels of expression among normal people but similar levels in disease patients or shows similar levels of expression among normal people but different levels in disease patients, we can assume that the gene is associated with the disease. By utilizing this gene expression heterogeneity, we can obtain additional information that abets discovery of disease-associated genes. In this study, we used collaborative filtering to calculate the degree of gene expression heterogeneity between classes and then scored the genes on the basis of the degree of gene expression heterogeneity to find "differentially predicted" genes. Through the proposed method, we discovered more prostate cancer-associated genes than 10 comparable methods. The genes prioritized by the proposed method are potentially significant to biological processes of a disease and can provide insight into them.

Genetic variation: effect on prostate cancer

The crucial role of androgens in the development of prostate cancer is well established. The aim of this review is to examine the role of constitutional (germline) and tumor-specific (somatic) polymorphisms within important regulatory genes of prostate cancer. These include genes encoding enzymes of the androgen biosynthetic pathway, the androgen receptor gene, genes that encode proteins of the signal transduction pathways that may have a role in disease progression and survival, and genes involved in prostate cancer angiogenesis. Characterization of deregulated pathways critical to cancer cell growth have lead to the development of new treatments, including the CYP17 inhibitor abiraterone and clinical trials using novel drugs that are ongoing or recently completed [1]. The pharmacogenetics of the drugs used to treat prostate cancer will also be addressed. This review will define how germline polymorphisms are known affect a multitude of pathways, and therefore phenotypes, in prostate cancer etiology, progression, and treatment.

Quantitative assessment of the association between CYP17 rs743572 polymorphism and prostate cancer risk

Published data on the association between CYP17 rs743572 polymorphism and risk of PC showed inconclusive results. The aim of this study was to further estimate the pooled effect size of rs743572 polymorphism and PC progression via large-scale meta-analysis. We searched the case-control studies of rs743572 polymorphism and PC risk in PubMed, Embase, and Web of Science databases up to February 2014. Odds ratios (ORs) along with 95 % confidence intervals (CIs) were pooled by means of both fixed effects model and random effects model. A total of 38 publications consisting of 42 studies with 15,735 cases and 17,825 controls were included in this meta-analysis. Overall, no significant association was found between rs743572 polymorphism and PC risk. Stratified analyses by control source and sample size did not provide significant results. However, there was a borderline association in African population under A2A2 versus A1A2 + A1A1 genetic model (OR = 1.39, 95 % CI: 1.01-1.92, P = 0.975, I (2) = 0.0 %). Results from the current meta-analysis suggested that CYP17 rs743572 polymorphism might modify the risk of PC in the subjects of African decent.

Systematic review and meta-analysis of candidate gene association studies of lower urinary tract symptoms in men

Context

Although family studies have shown that male lower urinary tract symptoms (LUTS) are highly heritable, no systematic review exists of genetic polymorphisms tested for association with LUTS.

Objective

To systematically review and meta-analyze studies assessing candidate polymorphisms/genes tested for an association with LUTS, and to assess the strength, consistency, and potential for bias among pooled associations.

Evidence acquisition

A systematic search of the PubMed and HuGE databases as well as abstracts of major urologic meetings was performed through to January 2013. Case-control studies reporting genetic associations in men with LUTS were included. Reviewers independently and in duplicate screened titles, abstracts, and full texts to determine eligibility, abstracted data, and assessed the credibility of pooled associations according to the interim Venice criteria. Authors were contacted for clarifications if needed. Meta-analyses were performed for variants assessed in more than two studies.

Evidence synthesis

We identified 74 eligible studies containing data on 70 different genes. A total of 35 meta-analyses were performed with statistical significance in five (ACE, ELAC2, GSTM1, TERT, and VDR). The heterogeneity was high in three of these meta-analyses. The rs731236 variant of the vitamin D receptor had a protective effect for LUTS (odds ratio: 0.64; 95% confidence interval, 0.49–0.83) with moderate heterogeneity (I² = 27.2%). No evidence for publication bias was identified. Limitations include wide-ranging phenotype definitions for LUTS and limited power in most meta-analyses to detect smaller effect sizes.

Conclusions

Few putative genetic risk variants have been reliably replicated across populations. We found consistent evidence of a reduced risk of LUTS associated with the common rs731236 variant of the vitamin D receptor gene in our meta-analyses.

Patient summary

Combining the results from all previous studies of genetic variants that may cause urinary symptoms in men, we found significant variants in five genes. Only one, a variant of the vitamin D receptor, was consistently protective across different populations.

CYP17 T27C polymorphism and prostate cancer risk: a meta-analysis based on 31 studies

Objective

The cytochrome P450 17α-hydroxylase (CYP17) plays a vital role in androgen biosynthesis. A T-to-C polymorphism in the 5′ promoter region of CYP17 has been implicated as a risk factor for prostate cancer, but the results of individual studies are inconclusive or controversial. To derive a more precise estimation of the relationship, we performed an updated meta-analysis from 31 studies based on 27 publications.

Methods

A comprehensive search was conducted to examine all the eligible studies of CYP17 polymorphism and prostate cancer risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association.

Results

Overall, individuals with CC/CT genotype were not associated with prostate cancer risk (CC vs. TT: OR = 1.03, 95% CI = 0.86-1.24, P = 0.72, P_{heterogeneity} < 0.0001; CT vs. TT: OR = 0.99, 95% CI = 0.87-1.12, P = 0.88, P_{heterogeneity} = 0.0006). In the stratified analysis by ethnicity, there was a significantly increased risk of prostate cancer among individuals of African descent under the recessive model (OR = 1.56, 95% CI = 1.01-2.39, P = 0.04, P_{heterogeneity} = 0.65).

Conclusion

This meta-analysis suggested that CYP17 polymorphism might be associated with prostate cancer risk among individuals of African descent.

CYP17 gene polymorphisms and prostate cancer risk: a meta-analysis based on 38 independent studies

BACKGROUND

The results of recent published studies focusing on CYP17 polymorphisms in prostate cancer (PCa) susceptibility are often conflicting. We performed a meta-analysis based on 38 independent studies to evaluate the association.

METHODS

Data were collected from the following electronic databases: PubMed, Excerpta Medica Database, and Chinese Biomedical Literature Database, with the last report up to September 2010. Meta-analysis was conducted in a fixed/random effect model.

RESULTS

Thirty-eight independent studies including 34,782 cases and 38,626 controls on the association of CYP17 gene polymorphisms with PCa risk in different ethnic groups were identified. The meta-analysis was performed for five polymorphisms: rs743572 (A1/A2, 38 studies), rs6162 (C/T, 3 studies), rs619824 (C/A, 4 studies), rs2486758 (T/C, 4 studies), and rs10883782 (A/G, 4 studies). When all groups were pooled, we did not detect the association of rs743572 polymorphism with PCa risk. In the subgroup analysis, a significant association of rs743572 polymorphism and PCa was found in Black population (A2/A2 vs. A1/A1 + A2/A1: OR = 1.70, 95% CI = 1.08-2.69, P = 0.02), but not in Caucasian or Asian population. For other polymorphisms, we found that rs619824 polymorphism was associated with a significant decreased risk of PCa (A vs. C: OR = 0.95, 95% CI = 0.92-0.99, P = 0.01), and rs2486758 polymorphism was associated with a significant increased risk of PCa (C vs. T: OR = 1.07, 95% CI = 1.03-1.12, P = 0.002).

CONCLUSION

This meta-analysis suggests that rs743572 polymorphism is associated with PCa risk in Black population, but not in Caucasian or Asian population. Moreover, our study suggests that rs619824 and rs2486758 polymorphisms are associated with PCa risk.

CYP17 gene polymorphism and prostate cancer susceptibility in a Tunisian population

Prostate cancer (PCa) formation has been reported to be associated with androgen. Two key steps in the sex steroid synthesis are mediated by the enzyme cytochrome P450c 17α which is encoded in the CYP17 gene. The A2 allele of the CYP17 gene has been thought to be associated with increased functional activity of this steroidogenic enzyme. Consequently, the A2 allele has been examined as a biomarker of individual susceptibility to hormone-related diseases among men. We prospectively assessed the association between the A2 allele of CYP17 and PCa risk among 125 cases and 125 controls in a case-control study. Our aim was to investigate whether a polymorphism of CYP17 gene could be used as a genetic marker for associating PCa. The result revealed a significant association between the CYP17 polymorphic genotypes and PCa. Therefore, CYP17 gene polymorphism is likely contributed to the pathogenesis of PCa but not to disease severity.

Association of polymorphisms in CYP19A1 and CYP3A4 genes with lower urinary tract symptoms, prostate volume, uroflow and PSA in a population-based sample

PURPOSE

The known importance of testosterone for the development of benign prostatic hyperplasia (BPH) prompted us to test the hypothesis whether polymorphisms of two genes (CYP19A1 and CYP3A4) involved in testosterone metabolism are associated with clinical BPH-parameters.

METHODS

A random sample of the population-based Herne lower urinary tract symptoms cohort was analysed. All these men underwent a detailed urological work-up. Two polymorphisms in the CYP19A1 gene [rs700518 in exon 4 (A57G); rs10046 at the 3'UTR(C268T)] and one in the 3'UTR of CYP3A4 [rs2740574 (A392G)] were determined by TaqMan assay from genomic DNA of peripheral blood. These polymorphisms were correlated to clinical and laboratory BPH-parameters.

RESULTS

A total of 392 men (65.4 ± 7.0 years; 52-79 years) were analysed. Mean International Prostate Symptom Score (IPSS; 7.5), Q (max) (15.4 ml/s), prostate volume (31 ml) and prostate specific antigen (PSA) (1.8 ng/ml) indicated a typical elderly population. Both polymorphisms in the CYP19A1 gene were not correlated to age, IPSS, Q (max), prostate volume and post-void residual volume. Serum PSA was higher in men carrying the heterozygous rs10046 genotype (2.0 ± 0.1 ng/ml) than in those with the CC-genotype (1.7 ± 0.2 ng/ml, P = 0.012). Men carrying one a mutated allele of the CYP3A4 gene had smaller prostates (27.0 ± 2.0 vs. 32 ± 0.8 ml, P = 0.02) and lower PSA levels (1.6 ± 0.3 vs. 1.9 ± 0.1 ng/ml).

CONCLUSIONS

The inconsistent associations observed herein and for other gene polymorphisms warrant further studies. In general, the data regarding the association of gene polymorphism to BPH-parameters suggest that this disease is caused by multiple rather than a single genetic variant. A rigorous patient selection based on anatomo-pathological and hormonal profile may possible reduce the number of confounders for future studies thus enabling a more detailed assessment of the association between genetic factors and BPH-parameters.

Is there evidence of a relationship between benign prostatic hyperplasia and prostate cancer? Findings of a literature review

CONTEXT

More than half the male population aged >50 yr have histologic evidence of benign prostatic hyperplasia (BPH), while prostate cancer (PCa) is among the most common male cancers according to recent registry data. Understanding the aetiologies of both conditions is crucial to reduce the resulting burden of mortality and morbidity.

OBJECTIVE

This review aims to examine the available data on the epidemiology, pathology, risk factors, and genetic markers involved in BPH and PCa; to discuss their clinical implications for management of both conditions; and to discuss their implications for PCa prevention. Our primary objective was to clarify the relationship between BPH and PCa by bringing together evidence from diverse areas of research.

EVIDENCE ACQUISITION

The primary source of data was PubMed, which was searched using Boolean strategies and by scanning lists of related articles. We also examined secondary sources from reference lists of retrieved articles and data presented at recent congresses.

EVIDENCE SYNTHESIS

Accumulating evidence suggests that BPH and PCa share important anatomic, pathologic, and genetic links in addition to the well-established epidemiologic association between these conditions. We also found data that suggest interactions between apparently diverse factors, such as dihydrotestosterone levels and inflammation. Recent publications support the hypothesis that both BPH and PCa are part of the metabolic syndrome, while inflammation is emerging as a major contributor to the development of both BPH and PCa. Although many of the findings are preliminary and require further research, they offer new insight into the mechanisms of disease underlying the development of BPH and PCa.

CONCLUSIONS

Available data suggest that epidemiologic and pathologic links exist between BPH and PCa. Evidence of links between the conditions and contributory factors may offer common preventative strategies for BPH and PCa and common therapeutic approaches to their management.