Hormones and prostate cancer: current perspectives and future directions

Vitamin D receptor polymorphism and prostate cancer prognosis

Background

Prostatic epithelial cells synthesize the active form of vitamin D (1,25-dihydroxyvitamin D₃), which participates in regulating prostate growth. Calcitriol, a synthetic form of vitamin D₃, exhibits antiproliferative and prodifferentiation activities in prostate cancer. The function of 1,25-dihydroxyvitamin D₃ is mediated by its binding to vitamin D receptor (VDR). VDR forms a heterodimer, typically with retinoid X receptor, to regulate vitamin D target genes. We evaluated the relationship between VDR polymorphism and clinical characteristics associated with prostate cancer risk and prognosis among Egyptian men.

Materials and methods

This case-control study included 2 groups of patients: group A, a control group of 50 subjects with benign prostate hyperplasia, and group B, 50 subjects newly diagnosed with prostate cancer. All participants performed complete blood count, liver and kidney function tests, prostate specific antigen measurement, histopathological analysis and immunohistochemistry for Dickkopf Homolog 3. Restriction fragment length polymorphism-polymerase chain reaction as performed to detect VDR polymorphism.

Results

Patients with prostate cancer and controls showed a significantly different CA genotype frequency (p = 0.007). Furthermore, prostate-specific antigen levels were significantly different in different genotypes in patients with prostate cancer (p < 0.001). Finally, T stage and the VDR ApaI C/A polymorphism were significantly associated (p < 0.041).

Conclusion

The VDR ApaI C/A polymorphism may be a diagnostic and prognostic marker for prostate cancer in Egyptian men.

Strength Training Modulates Prostate of Wistar Rats Submitted to High-Fat Diet

Our aim is to evaluate the effects of high-fat diet and strength training on ventral prostate health through investigations of rat prostate histology, endocrine modulation, and the expression of proliferative and apoptotic marker, including androgen receptors (AR), glucocorticoid receptors (GR), B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X protein (BAX), Fas cell surface death receptor (Fas/CD95/Apo-1), and Nuclear Factor Kappa-B (NF-κB). Eighty Wistar rats were into one of four subgroups: control (CT), strength training (ST), high-fat diet consumption (HF), and high-fat diet consumption with strength training (HFT). Animals then underwent strength training and/or high-fat diet consumption for 8 or 12 weeks, after which animals were euthanized and markers of prostatic health were evaluated histologically and through immunolabeling. Our results indicate that physical strength training reduced the expression of the prostate cell proliferation marker Bcl-2 while increasing expression of the pro-apoptotic marker BAX, as well as increasing expression of AR and GR relevant in the Bcl-2 pathway. We conclude that a high-fat diet can alter hormone receptor levels and cell-cycle protein expression, thereby modifying prostatic homeostasis, and that strength training was able to reduce prostate damage induced by high-fat diet consumption.

Association of finasteride with prostate cancer: A systematic review and meta-analysis

BACKGROUND

The Prostate Cancer Prevention Trial has shown a protective effect of finasteride on prostate cancer, but it also showed that finasteride can increase the risk of high-grade prostate cancer. Several studies have investigated the relationship between finasteride and prostate cancer, but these studies have shown inconsistent results.

ETHICS

The protocol was approved by the institutional review board of each study center. Written informed consent will be obtained from all patients before registration, in accordance with the Declaration of Helsinki.

METHODS

We performed a systematic literature review and meta-analysis to assess the association between finasteride and prostate cancer. Systematic literature searches were conducted using PubMed, EMBASE, Science Direct/Elsevier, MEDLINE, CNKI, and the Cochrane Library up to October 2018 to identify studies that involved the relationship between finasteride and prostate cancer. Meta-analysis was performed using Review Manager and Stata software. Combined ORs were identified with 95% confidence intervals (95% CI) in a random or fixed effects model.

RESULTS

Eight studies were identified, including 54,335 cases of patients that used finasteride and 9197 patients who served as placebo controls. Our results illustrate that there is a significant correlation between finasteride use and prostate cancer with combined ORs of 0.70 [0.51, 0.96]. A significant correlation between finasteride use and high-grade prostate cancer was also observed with combined ORs of 2.10 [1.85, 2.38].

CONCLUSIONS

This study confirms that finasteride significantly reduced the risk of prostate cancer; however, the malignant degree of prostate cancer was increased. Studies with larger sample sizes are needed to better clarify the correlation between finasteride use and prostate cancer.

Sulfiredoxin as a Potential Therapeutic Target for Advanced and Metastatic Prostate Cancer

The incidence of prostate cancer (PCa) is increasing, and it is currently the second most frequent cause of death by cancer in men. Despite advancements in cancer therapies, new therapeutic approaches are still needed for treatment-refractory advanced metastatic PCa. Cross-species analysis presents a robust strategy for the discovery of new potential therapeutic targets. This strategy involves the integration of genomic data from genetically engineered mouse models (GEMMs) and human PCa datasets. Considering the role of antioxidant pathways in tumor initiation and progression, we searched oxidative stress-related genes for a potential therapeutic target for PCa. First, we analyzed RNA-sequencing data from Pb-Cre4; Pten^f/f mice and discovered an increase in sulfiredoxin (Srxn1) mRNA expression in high-grade prostatic intraepithelial neoplasia (PIN), well-differentiated adenocarcinoma (medium-stage tumors), and poor-differentiated adenocarcinoma (advanced-stage prostate tumors). The increase of SRXN1 protein expression was confirmed by immunohistochemistry in mouse prostate tumor paraffin samples. Analyses of human databases and prostate tissue microarrays demonstrated that SRXN1 is overexpressed in a subset of high-grade prostate tumors and correlates with aggressive PCa with worse prognosis and decreased survival. Analyses in vitro showed that SRXN1 expression is also higher in most PCa cell lines compared to normal cell lines. Furthermore, siRNA-mediated downregulation of SRXN1 led to decreased viability of PCa cells LNCaP. In conclusion, we identified the antioxidant enzyme SRXN1 as a potential therapeutic target for PCa. Our results suggest that the use of specific SRXN1 inhibitors may be an effective strategy for the adjuvant treatment of castration-resistant PCa with SRXN1 overexpression.

Diagnostic significance of miR-21, miR-141, miR-18a and miR-221 as novel biomarkers in prostate cancer among Egyptian patients

Prostate cancer (PC) is considered as the fifth cause of cancer deaths worldwide. The exact etiopathogenesis is unclear; however, genetic predisposition, hormonal influencers, lifestyle and environmental factors act as major contributors. It has been found that several miRNAs may play a crucial role in cancer initiation and progression. Here, in this study, we evaluated the peripheral blood levels of miR-21, miR-141, miR-221 and miR-18a expression among 80 prostate cancer patients (50 localised and 30 metastatic) and 30 benign prostatic hyperplasia patients compared to 50 normal control subjects, using RT-PCR. Our results of analysis of miR-21, miR-141, miR-18a and miR-221 in the plasma of PC patients showed that miR-18a is a powerful discriminator of PC patients from healthy controls as it had the highest AUC (0.966; 95% CI, 0.937-1.000), while miR-221 provided better differentiation of metastatic from localised PC (sensitivity was 92.9% at 100% specificity), and when we combine miR-18a and miR-221 for differentiating patients with MPC, it will increase the sensitivity to 96.4% at a specificity of 100% (AUC, 0.997; 95% CI, 0.988-1.0) (p < .000). This current study recommends that analysis of these miRNAs might have clinical value in enhancing PSA testing.

Prostate cancer prevention with 5-alpha reductase inhibitors: concepts and controversies

PURPOSE OF REVIEW

We review the concepts surrounding prostate cancer prevention strategies with 5-alpha reductase inhibitors (5-ARIs) and the controversies associated with their use.

RECENT FINDINGS

Updated data have shown no increased risk of death from the diagnosis of higher risk cancer; however, 5-ARIs remain controversial and not approved for prostate cancer prevention.

SUMMARY

The main theme of the review identifies the success of reducing insignificant prostate cancer and the controversy with the increased association of higher risk prostate cancer by approximately 20%. The reduction was shown to be most significant reduction in low-grade prostate cancer. The initial concern about 5-ARI use was that it could potentially increase high-risk prostate cancer leading to higher mortality in those men. Higher mortality has not been seen in follow-up data; however, 5-ARIs continue to have a black box warning and are not approved for prostate cancer prevention.

Androgens modulate male-derived endothelial cell homeostasis using androgen receptor-dependent and receptor-independent mechanisms

BACKGROUND

Sex-related differences in the role of androgen have been reported in cardiovascular diseases and angiogenesis. Moreover, androgen receptor (AR) has been causally involved in the homeostasis of human prostate endothelial cells. However, levels of expression, functionality and biological role of AR in male- and female-derived human endothelial cells (ECs) remain poorly characterized. The objectives of this work were (1) to characterize the functional expression of AR in male- and female-derived human umbilical vein endothelial cell (HUVEC), and (2) to specifically analyze the biological effects of DHT, and the role of AR on these effects, in male-derived HUVECs (mHUVECs).

RESULTS

Immunohistochemical analyses of tissue microarrays from benign human tissues confirmed expression of AR in ECs from several androgen-regulated and non-androgen-regulated human organs. Functional expression of AR was validated in vitro in male- and female-derived HUVECs using quantitative RT-PCR, immunoblotting and AR-mediated transcriptional activity assays. Our results indicated that functional expression of AR in male- and female-derived HUVECs was heterogeneous, but not sex dependent. In parallel, we analyzed in depth the biological effects of DHT, and the role of AR on these effects, on proliferation, survival and tube formation capacity in mHUVECs. Our results indicated that DHT did not affect mHUVEC survival; however, DHT stimulated mHUVEC proliferation and suppressed mHUVEC tube formation capacity. While the effect of DHT on proliferation was mediated through AR, the effect of DHT on tube formation did not depend on the presence of a functional AR, but rather depended on the ability of mHUVECs to further metabolize DHT.

CONCLUSIONS

(1) Heterogeneous expression of AR in male- and female-derived HUVEC could define the presence of functionally different subpopulations of ECs that may be affected differentially by androgens, which could explain, at least in part, the pleiotropic effects of androgen on vascular biology, and (2) DHT, and metabolites of DHT, generally thought to represent progressively more hydrophilic products along the path to elimination, may have differential roles in modulating the biology of human ECs through AR-dependent and AR-independent mechanisms, respectively.

Long-term Consequences of Finasteride vs Placebo in the Prostate Cancer Prevention Trial

BACKGROUND

Finasteride has been found to reduce the risk of low-grade prostate cancer but to have no impact on overall survival. The long-term adverse and beneficial consequences of finasteride have not been examined.

METHODS

We used a linkage between data from the Prostate Cancer Prevention Trial (PCPT) and Medicare claims. Patients were examined by randomized study arm (finasteride vs placebo for 7 years) for long-term consequences of the intervention, including cardiac, endocrine, and sexual dysfunction, depression, diabetes, and benign prostatic hyperplasia (BPH)-related events. To examine time to events, we used cumulative incidence and Cox regression, adjusting for covariates. All statistical tests were two-sided.

RESULTS

A total of 13 935 of 18 880 participants (73.8%) in the PCPT were linked to Medicare claims, with median Medicare follow-up assessment time of 16 years from trial registration. There were no differences between finasteride and placebo participants with respect to important baseline factors or amount of Medicare follow-up assessment time. Finasteride patients had a 10% higher risk of new claims for depression (hazard ratio [HR] = 1.10, 95% confidence interval [CI] = 1.01 to 1.19, P = .04) and a 6% lower risk of procedures for BPH-related events (primarily lower urinary tract symptoms; HR = 0.94, 95% CI = 0.89 to 1.00, P = .03). No other differences were found in rates of long-term consequences of intervention in the two study arms.

CONCLUSIONS

Finasteride use is associated with reduced need for procedures for relief of BPH-related events and a modest increase in depression. Overall, there is little need to worry about long-term noncancer consequences of finasteride use in those who use it for treatment of symptomatic BPH, hair growth, or prevention of cancer.

Efficacy and safety of testosterone replacement therapy in men with hypogonadism: A meta-analysis study of placebo-controlled trials

The purpose of the present meta-analysis was to evaluate the efficacy and safety of testosterone replacement therapy in men with hypogonadism. A search was conducted for appropriate randomized controlled trials and the data from 16 trials were pooled. The intended primary outcome of the present study was to determine the efficacy and safety of testosterone replacement therapy. The current data demonstrated that scores for Aging Male Symptoms (AMS) were significantly reduced following testosterone replacement therapy, with a mean decrease in AMS score of 1.52 [95% confidence interval (CI), 0.72 to 2.32; P=0.0002]. Testosterone replacement therapy increased lean body mass [mean difference (MD), 1.22; 95% CI, 0.33 to 2.11; P=0.007], reduced fat mass in a non-significantly manner (MD, −0.85; 95% CI, −1.74 to 0.04; P=0.06) and significantly reduced total cholesterol (MD, −0.16; 95% CI, −0.29 to −0.03; P=0.01). No significant differences were identified in body weight (MD, 0.09; 95% CI, −1.13 to 1.31; P=0.89), body mass index (MD, 0.10; 95% CI, −0.62 to 0.82; P=0.78) or bone mineral density (MD, −0.01; 95% CI, −0.03 to 0.02; P=0.60). Average prostate volume increased (MD, 1.58; 95% CI, 0.6 to 2.56; P=0.002) following testosterone replacement therapy, but the levels of prostate-specific antigen (PSA) (MD, 0.10; 95% CI, −0.03 to 0.22; P=0.14) and the International Prostate Symptom Scores (MD, 0.01; 95% CI, −0.37 to 0.39; P=0.96) did not change. In conclusion, testosterone replacement therapy improves quality of life, increases lean body mass, significantly decreases total cholesterol, and is well-tolerated and safe for men with hypogonadism who are exhibiting PSA levels of <4 ng/ml.

Bringing GC-MS profiling of steroids into clinical applications

Abnormalities of steroid biosynthesis and excretion are responsible for the development and prevention of endocrine disorders, such as metabolic syndromes, cancers, and neurodegenerative diseases. Due to their biochemical roles in endocrine system, qualitative and quantitative analysis of steroid hormones in various biological specimens is needed to elucidate their altered expression. Mass spectrometry (MS)-based steroid profiling can reveal the states of metabolites in biological systems and provide comprehensive insights by allowing comparisons between metabolites present in cells, tissues, or organisms. In addition, the activities of many enzymes related to steroid metabolism often lead to hormonal imbalances that have serious consequences, and which are responsible for the progress of hormone-dependent diseases. In contrast to immunoaffinity-based enzyme assays, MS-based methods are more reproducible in quantification. In particular, high-resolution gas chromatographic (GC) separation of steroids with similar chemical structures can be achieved to provide rapid and reproducible results with excellent purification. GC-MS profiling therefore has been widely used for steroid analysis, and offers the basis for techniques that can be applied to large-scale clinical studies. Recent advances in analytical technologies combined with inter-disciplinary strategies, such as physiology and bioinformatics, will help in understanding the biochemical roles of steroid hormones. Therefore, comprehensive analytical protocols in steroid analysis for different research purposes may contribute to the elucidation of complex metabolic processes relevant to steroid function in many endocrine disorders, and in the identification of diagnostic biomarkers.

Expression of 17β-hydroxysteroid dehydrogenase type 2 is associated with some clinicopathological features in gastric cancer

In most populations, gastric cancer (GC) incidence is higher in men than in women, which may suggest the role of sex steroid hormones in gastric cancerogenesis. Both, androgens and estrogens can be synthetised in peripherial tissues. This process is controlled by expression of steroidogenic enzymes. Therefore, we evaluate the 17β-hydroxysteroid dehydrogenase type 2 (HSD17B2) transcript and protein levels in gastric tumoral and nontumoral tissue. We also determined the association between HSD17B2 transcript and protein levels and some clinicopathological features in GC. We found significantly decreased levels of HSD17B2 transcript (P=0.00072) and protein (P=0.00017) in primary tumoral tissues of GC patients, as compared to nontumoral tissues. In patients above 60 years of age the amounts of HSD17B2 transcript (P=0.00044) and protein (P=0.00027) were significantly lower in tumoral than nontumoral tissues. Similarly, lower HSD17B2 levels, both in terms of the transcript and protein, were observed in tumoral tissues of male (P=0.013, P=0.0014), patients stomach (P=0.0062, P=0.045) and cardia (P=0.02, P=0.02) site of tumor, T3 (P=0.018, P=0.014) depth of invasion, N0 (P=0.017, P=0.045) lymph node metastasis, G3 (P=0.0027, P=0.014) malignancy grade. We also observed significantly reduced level of HSD17B2 transcript in tumoral tissue specimens of females (P=0.014), T4 depth of invasion (P=0.02), N3 lymph node metastasis (P=0.037) and G2 malignancy grade (P=0.045). Furthermore, diffuse GC histological types were associated with lower HSD17B2 protein level (P=0.024) than nontumoral tissues. We demonstrated that HSD17B2 transcript and protein levels are linked to some clinicopathological features in GC.

Multiple roles for UDP-glucuronosyltransferase (UGT)2B15 and UGT2B17 enzymes in androgen metabolism and prostate cancer evolution

In the prostate, approximately 50% of androgens are from adrenal steroids, mainly dehydroepiandrosterone (DHEA), its sulfate and androstenedione. These compounds are converted first into testosterone, and then into the active hormone dihydrotestosterone (DHT). After having activated the androgen receptor (AR), DHT is reduced into androstane-3α-DIOL (3α-DIOL) and androsterone (ADT), which are subsequently converted into 2 inactive and easily excretable metabolites: 3α-DIOL-17glucuronide (3α-DIOL-17G) and ADT-3glucuronide (ADT-3G). The formation of these last derivatives through the glucuronidation reaction involves 2 UDP-glucuronosyltransferase (UGT) enzymes, namely UGT2B15 and UGT2B17. The present review article aims at providing a comprehensive view of the physiological and pharmacological importance of these 2 enzymes for the control of androgen homeostasis. We will resume: (i) how UGT2B15 and UGT2B17 contribute to androgen elimination; (ii) how their glucuronidation capacity influences the androgen signaling pathway in prostate cells; (iii) how they contribute to the anti-proliferative properties of AR antagonists in prostate cancer cells; and (iv) how AR and its spliced variants regulate the UGT2B15 and/or UGT2B17 genes expression. Finally, whether the unexploited AR-UGT axis could serve as a prognostic maker or a pharmacological target for novel therapeutics in the treatment of prostate cancer is also discussed. This article is part of a special issue entitled 'Essential role of DHEA'.

Serum Testosterone, 17β-Estradiol and PSA Levels in Subjects with Prostate Disorders

Prostate carcinoma is the most frequently diagnosed malignancy and the second leading cause of death as a result of cancer in men in the US and other parts of the world. There are conflicting reports on the serum levels of testosterone and 17β-estradiol (E2) in benign prostatic hyperplasia (BPH) and prostate cancer. This study was designed to evaluate the serum concentrations of these hormones in patients with these disorders. Serum levels of prostate specific antigen (PSA), total testosterone and estradiol were determined in 228 subjects comprising of 116 subjects with BPH, 62 subjects with prostate cancer (CaP) and 50 age-matched apparently healthy controls, using ELISA methods. PSA levels were significantly elevated (p < 0.05) in BPH subjects than controls, while there was no significant difference (p > 0.05) in testosterone and estradiol levels of these subjects. PSA and estradiol levels were significantly higher (p < 0.05) in CaP subjects than in controls, while there was no observed significant difference (p > 0.05) in testosterone levels. CaP subjects had significantly raised PSA, testosterone, and estradiol levels than BPH subjects. The mean molar ratio of testosterone: E2 was lowest among CaP patients (134:1) and highest among controls (166:1). Significant positive correlation between PSA and 17β-estradiol was observed in prostate disorders (BPH and CaP patients: r = 0.347; p = 0.000). Significant negative correlations between testosterone and PSA were also observed among BPH patients (r = -0.221, p = 0.049) and control subjects (r = -0.490, p = 0.000). No significant correlation existed between testosterone and PSA in CaP patients (r = 0.051, p = 0.693). Correlations between age and estradiol in both BPH and CaP were not significant (p > 0.05). This study has shown that, there was a significant increase in serum estradiol in CaP subjects, while the testosterone levels in both BPH and CaP subjects were not different from those of controls.

The effect of testosterone replacement therapy on prostate cancer: a systematic review and meta-analysis

BACKGROUND

Testosterone replacement therapy (TRT) is a widely accepted form of treatment worldwide for aging men with late-onset hypogonadism syndrome. Urologists have been concerned about the possibility of TRT causing prostate cancer. The aim of this study was to assess the relationship between TRT and prostate cancer.

METHODS

A literature review was performed to identify all published, randomized controlled trials (RCTs) of testosterone treatment for hypogonadism. The search included the MEDLINE, Embase and the Cochrane Controlled Trials Register databases. Fixed-effect model was chosen for homogeneous studies; otherwise, a random-effect model was used. Inconsistency was quantified by using the I2 statistic, which tests the proportion of heterogeneity across studies.

RESULTS

Results of 22 RCTs involving a total of 2351 patients were analyzed. Eleven RCTs were short-term (<12 months) and 11 were long-term (12-36 months) comparisons of TRT with a placebo; TRT was administered transdermally, orally or by injection. Respective odds ratio (OR) and 95% confidence interval (CI) values for injection, transdermal administration and oral administration of short-term TRT were as follows: prostate cancer: 0.39 (0.06-2.45), 1.10 (0.26-4.65) and no oral; biopsy: 5.28 (0.24-113.87), 2.11 (0.32-13.73) and no oral; and prostate nodule: 1.01 (0.13-7.60), no injection and oral. Respective OR and 95% CI values for injection, transdermal administration and oral administration of long-term TRT were as follows: prostate cancer: 2.09 (0.18-24.73), 3.06 (0.12-76.70) and 0.19 (0.01-4.03); biopsy: 2.09 (0.18-24.73), 3.65 (0.88-15.20) and 0.97 (0.13-7.03); and prostate nodule: 3.13 (0.12-80.68), 1.00 (0.06-16.41) and 0.97 (0.13-7.03). Though for some routes of administration and some end points, the OR associated with testosterone administration were >1 indicating increased risk, none of these reached or even approached statistical significance (all P>0.10), which was consistent with the results of subgroup analyses and sensitivity analysis. Besides, sensitivity analysis indicated that short-term TRT was more likely to increase PSA levels than treatment with placebo (P<0.00001).

CONCLUSIONS

This meta-analysis shows that regardless of the administration method, TRT is the short-term safety and does not promote prostate cancer development or progression but long-term data are warranted with justifiable end points.

Possible relations between oxidative damage and apoptosis in benign prostate hyperplasia and prostate cancer patients

Cancer has been described as the twentieth century plague, and is a very common health problem. It has been reported that ROS and ROS products play a key role in cancer and that oxidative damage is effective in apoptosis initiation. In this study we aimed to evaluate the relationship between MDA (malondialdehyde), DNA damage (8-hydroxyguanine, 8-OH-dG), and caspase-3 in BHP and prostate cancer patients. Twenty male patients with prostate cancer and 20 male patients with benign prostate hyperplasia were included into this study. The MDA (nanomole), DNA damage (nanograms per millilitre), and caspase-3 (nanograms per millilitre) levels were measured in prostate cancer and benign prostate hyperplasia using Elisa kits (Millipore Corporation, Billerica, MA, USA). In the prostate cancer group, serum MDA (30.96 ± 9.25) and DNA damage (4.42 ± 0.36) levels were significantly raised (p < 0.05) when compared to the benign prostate hyperplasia group (24.05 ± 8.06, 3.99 ± 0.54). However, in the prostate cancer group, serum caspase-3 (2.36 ± 0.82) levels were statistically significantly lowered (p < 0.05) compared with the benign prostate hyperplasia group (3.15 ± 1.04). We observed that altered prooxidant, DNA damage levels may lead to an increase in oxidative damage and may consequently play an important role in prostate carcinogenesis. These findings indicate that, although the triggering of these changes is unknown, changes in the levels of MDA, DNA damage, and caspase-3 in the blood are related to prostatic carcinoma development. In addition, it would be appropriate to conduct new studies with a large number of patients at different stages.

Genome-wide association study of sex hormones, gonadotropins and sex hormone-binding protein in Chinese men

BACKGROUND

Sex hormones and gonadotropins exert a wide variety of effects in physiological and pathological processes. Accumulated evidence shows a strong heritable component of circulating concentrations of these hormones. Recently, several genome-wide association studies (GWASs) conducted in Caucasians have identified multiple loci that influence serum levels of sex hormones. However, the genetic determinants remain unknown in Chinese populations. In this study, we aimed to identify genetic variants associated with major sex hormones, gonadotropins, including testosterone, oestradiol, follicle-stimulating hormone (FSH), luteinising hormone (LH) and sex hormone binding globulin (SHBG) in a Chinese population.

METHODS

A two-stage GWAS was conducted in a total of 3495 healthy Chinese men (1999 subjects in the GWAS discovery stage and 1496 in the confirmation stage).

RESULTS

We identified a novel genetic region at 15q21.2 (rs2414095 in CYP19A1), which was significantly associated with oestradiol and FSH in the Chinese population at a genome-wide significant level (p=6.54×10(-31) and 1.59×10(-16), respectively). Another single nucleotide polymorphism in CYP19A1 gene was significantly associated with oestradiol level (rs2445762, p=7.75×10(-28)). In addition, we confirmed the previous GWAS-identified locus at 17p13.1 for testosterone (rs2075230, p=1.13×10(-8)) and SHBG level (rs2075230, p=4.75×10(-19)) in the Chinese population.

CONCLUSIONS

This study is the first GWAS investigation of genetic determinants of FSH and LH. The identification of novel susceptibility loci may provide more biological implications for the synthesis and metabolism of these hormones. More importantly, the confirmation of the genetic loci for testosterone and SHBG suggests common genetic components shared among different ethnicities.

Obesity and prostate cancer incidence and mortality: a systematic review of prospective cohort studies

BACKGROUND

There has been a large body of research on obesity and the risk of prostate cancer (PCa) that has been published recently. However, the epidemiological evidence for such an association has not been consistent. This may be attributed to the nature of case-control and retrospective studies, which generally are more prone to biases. Therefore, we conducted a systematic review of prospective cohort studies to assess the association between obesity and the risk of PCa incidence and death.

METHODS

A search of the PubMed database and references of published studies (from inception until March 2013) was conducted. Twenty-three eligible studies were identified and included in the systematic review.

RESULTS

The evidence from the prospective cohort studies linking obesity with PCa incidence has not been consistent. However, cumulative data is compelling for a strong positive association between obesity and fatal PCa.

CONCLUSIONS

Obesity is a significant diet-related risk factor for fatal PCa. Further well-constructed, large cohort studies on the potential association between obesity and PCa, as well as on underlying mechanisms, are needed.

Role of androgen and vitamin D receptors in endothelial cells from benign and malignant human prostate

Forty years ago, Judah Folkman (Folkman. N Engl J Med 285: 1182-1186, 1971) proposed that tumor growth might be controlled by limiting formation of new blood vessels (angiogenesis) needed to supply a growing tumor with oxygen and nutrients. To this end, numerous "antiangiogenic" agents have been developed and tested for therapeutic efficacy in cancer patients, including prostate cancer (CaP) patients, with limited success. Despite the lack of clinical efficacy of lead anti-angiogenic therapeutics in CaP patients, recent published evidence continues to support the idea that prostate tumor vasculature provides a reasonable target for development of new therapeutics. Particularly relevant to antiangiogenic therapies targeted to the prostate is the observation that specific hormones can affect the survival and vascular function of prostate endothelial cells within normal and malignant prostate tissues. Here, we review the evidence demonstrating that both androgen(s) and vitamin D significantly impact the growth and survival of endothelial cells residing within prostate cancer and that systemic changes in circulating androgen or vitamin D drastically affect blood flow and vascularity of prostate tissue. Furthermore, recent evidence will be discussed about the expression of the receptors for both androgen and vitamin D in prostate endothelial cells that argues for direct effects of these hormone-activated receptors on the biology of endothelial cells. Based on this literature, we propose that prostate tumor vasculature represents an unexplored target for modulation of tumor growth. A better understanding of androgen and vitamin D effects on prostate endothelial cells will support development of more effective angiogenesis-targeting therapeutics for CaP patients.

14-3-3ζ, a novel androgen-responsive gene, is upregulated in prostate cancer and promotes prostate cancer cell proliferation and survival

PURPOSE

Androgen receptor is an essential transcriptional factor that contributes to the development and progression of prostate cancer. In this study, we investigated the androgen regulation and functional analysis of 14-3-3ζ in prostate cancer.

EXPERIMENTAL DESIGN

Using chromatin immunoprecipitation (ChIP) combined with DNA microarray (ChIP-chip) analysis in LNCaP cells, we identified a functional androgen receptor-binding site in the downstream region of the 14-3-3ζ gene. Androgen regulation was examined by quantitative reverse transcription PCR and Western blot analysis. Prostate cancer cells stably expressing 14-3-3ζ and siRNA knockdown were used for functional analyses. We further examined 14-3-3ζ expression in clinical samples of prostate cancer by immunohistochemistry and quantitative reverse transcription PCR.

RESULTS

Androgen-dependent upregulation of 14-3-3ζ was validated at the mRNA and protein levels. The 14-3-3ζ gene is favorable for cancer-cell survival, as its ectopic expression in LNCaP cells contributes to cell proliferation and the acquired resistance to etoposide-induced apoptosis. 14-3-3ζ expression was associated with androgen receptor transcriptional activity and prostate-specific antigen (PSA) mRNA expression. Immunoprecipitation indicated that 14-3-3ζ was associated with androgen receptor in the nucleus. Clinicopathologic studies further support the relevance of 14-3-3ζ in prostate cancers, as its higher expression is associated with malignancy and lymph node metastasis.

CONCLUSIONS

14-3-3ζ is a novel androgen-responsive gene that activates proliferation, cell survival, and androgen receptor transcriptional activity. 14-3-3ζ may facilitate the progression of prostate cancer.

Validation of a sequential extraction and liquid chromatography-tandem mass spectrometric method for determination of dihydrotestosterone, androstanediol and androstanediol-glucuronide in prostate tissues

Androgens are key mediators of prostate development and function, a role that extends to the development of prostate diseases such as benign prostatic hyperplasia (BPH) and prostate cancer. In prostate, DHT is the major androgen and reduction and glucuronidation are the major metabolic pathways for DHT elimination. A streamlined method for quantitation of dihydrotestosterone (DHT), 5α-androstan-3α,17β-diol (3α-diol), and 3α-diol glucuronide (diol-gluc) was established and validated for use with archived prostate tissue specimens to facilitate examination of the roles of the underlying metabolism. This involved a sequential 70/30 hexane/ethyl acetate (hex/EtOAc) extraction of steroids, followed by an ethyl acetate extraction for diol-gluc. Derivatization of the hex/EtOAc fraction with2-fluoro-1-methylpyridinium p-toluene-4-sulfonate (FMP) was used to enhance sensitivity for hydroxyl steroids and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was utilized for analysis of both fractions. The method was validated with calibration standards followed by recovery assessment from spiked samples of BPH and normal prostate. Lower limits of quantitation (LLOQ) were 50 pg/g, 20 pg/g and 100 pg/g for DHT, 3α-diol and diol-gluc, respectively for extracts from 50mg equivalents of tissue. Prepared samples were stable for up to three weeks at 4 °C and 37 °C. The method provides excellent sensitivity and selectivity for determination of tissue levels of DHT, 3α-diol, and diol-gluc. Furthermore, this protocol can easily be extended to other hydroxyl steroids, is relatively straightforward to perform and is an effective tool for assessing steroid levels in archived clinical prostate samples.

A population-based nested case-control study in taiwan: use of 5α-reductase inhibitors did not decrease prostate cancer risk in patients with benign prostate hyperplasia

BACKGROUND

5α-Reductase inhibitors (5ARIs) are commonly used to treat benign prostate hyperplasia (BPH) by blocking the conversion of testosterone into the more potent dihydrotestosterone. This study explored a possible association between the use of the 5ARIs finasteride and dutasteride and the subsequent risk of prostate cancer or other cancers.

METHODS

We analyzed data from the Taiwanese National Health Insurance system. In a BPH cohort, we identified 1,489 patients with cancer and included them in our study group. For the control group, 3 patients without cancer were frequency matched with each BPH case for age, BPH diagnosis year, index year, and month. Information regarding past 5ARI use was obtained from the Taiwanese National Health Insurance Research Database (NHIRD). Multivariate logistic regression analysis was conducted, and odds ratio (OR) and 95% confidence interval (CI) were estimated.

RESULTS

Finasteride use marginally increased the incidence of prostate and overall cancer at a level of statistical significance (prostate cancer: OR = 1.90; 95% CI: 1.00-3.59; overall cancer: OR = 1.51; 95% CI: 1.00-2.28). Dutasteride use significantly increased kidney cancer risk (OR = 9.68, 95% CI: 1.17-80.0). Dosage analysis showed that lower doses of finasteride were associated with higher overall and prostate cancer risks. The major limitation is the lack of important data in the NHIRD, such as prostate cancer histologic grades, smoking habits, alcohol consumption, body mass index, socioeconomic status, and family history of cancer.

CONCLUSIONS

This population-based nested case-control study suggested that finasteride use may increase prostate and overall cancer risks for patients with BPH. The effects were more prominent for patients using lower doses of finasteride.

Steroid hormone receptors, matrix metalloproteinases, insulin-like growth factor, and dystroglycans interactions in prostatic diseases in the elderly men

OBJECTIVES

The aim of this study was to evaluate the reactivity of steroid hormone receptors (SHRs), dystroglycans (DGs), matrix metalloproteinases (MMPs), insulin-like growth factor receptor (IGFR-1), and laminin (Lam) in both prostatic stromal and epithelial compartments showing different diseases in elderly men.

METHODS

Sixty prostatic samples were obtained from 60- to 90-year-old patients (mean 63 years) with and without prostatic lesions from Hospital of the School of Medicine, State University of Campinas (UNICAMP). The Samples were divided into standard (no lesions); high grade prostatic intraepithelial neoplasia (HGPIN); prostatic cancer (PC); and benign prostatic hyperplasia (BPH) groups. The samples were submitted to immunohistochemistry and Western blotting analyses. Research Ethics Committee of the School of Medicine, University of Campinas/UNICAMP (number 0094.0.146.000-08).

RESULTS

The results showed increased IGFR-1 and MMPs protein levels in the PC and HGPIN groups. Decreased αDG and βDG protein levels were verified in the PC and HGPIN groups. Androgen receptor (AR) reactivity was similar among all groups. Estrogen receptor α (Erα) immunoreactivity was more intense in the epithelium in the PC and HGPIN groups. Estrogen receptor β (ERβ) immunoreactivity was weak in the epithelium of the HGPIN and PC groups.

CONCLUSIONS

To conclude, there was an association among IGFR-1, MMPs, and SHRs, indicating IGFR-1 as a target molecule in prostate therapy, considering the IGF proliferative properties. Also, the distinct SHRs reactivities in the lesions in both prostatic compartments indicated different paracrine signals and pointed out the importance of estrogenic pathways in the activation of these disorders.

Steroid profiles as potential biomarkers in patients with urogenital tract cancer for diagnostic investigations analyzed by liquid chromatography coupled to mass spectrometry

Large discrepancy remains for the hormone-responsible cancers with regards to the conditions generating the optimal opportunity for cancerogenesis. In the research, altered steroid profiles were observed in patients with urogenital tract cancer diseases, namely bladder, kidney, prostate and testis ones. The presented steroid profiles from 154 subjects, including 77 urogenital tract cancer patient and 77 healthy controls were determined by liquid chromatography coupled to mass spectrometry method. Because the original experimental data obtained as a result of analytical experiment in order to interpret them in better way required the appropriate pre-treatment, the data were standardized by scaling and centering. In order to determine which samples form a collection for a high-capacity predictive model, Kennard-Stone's algorithm was used. A principal component analysis of preprocessed data provided better consistency of the steroid profiles with health status of subjects than PCA profiles without data preprocessing and showed a tendency to separate clusters of cancer patients from healthy subjects. The discriminant analysis was also performed and the percent of correct classification of cancer patients and control group was calculated. Finally, detailed studies examined the role of steroid profiles measured in urine, and considered as potential biomarkers related to urogenital cancer and associated renal dysfunctions.

Androgen regulated HN1 leads proteosomal degradation of androgen receptor (AR) and negatively influences AR mediated transactivation in prostate cells

We recently reported that hematological and neurological expressed 1 (HN1) is a ubiquitously expressed, EGF-regulated gene. Expression of HN1 in prostate cell lines down-regulates PI3K-dependent Akt activation. Here, we investigate whether HN1 is regulated by androgens through the putative androgen response elements (AREs) found in its promoter. Knockdown of HN1 expression by siRNA silencing leads to an increase in Akt((S473)) phosphorylation, resulting in the translocation of androgen receptor (AR) to the nucleus; these effects can be abrogated by the non-specific Akt inhibitor LY294002 but not by the ERK inhibitor PD98059. Furthermore, HN1 overexpression correlates with an increase in ubiquitination-mediated degradation (a consequence of the decrease in S213/210 phosphorylation of AR), ultimately resulting in the down-regulation of AR-mediated expression of the KLK3, KLK4, NKX3.1 and STAMP2 genes. We also found that HN1 overexpression suppresses colony formation as well as R1881-mediated growth in LNCaP cells, while it has the opposite effect (increasing colony formation but not proliferation) in PC-3 and DU145 cells. Therefore, we suggest that HN1 maintains a balance between the androgen-regulated nuclear translocation of AR and steady-state Akt phosphorylation, predominantly in the absence of androgens. If so, the balance between cell growth and EGF- and AR-signaling must be tightly regulated by HN1. This work has important implications for prostate cancer research, as AR, EGFR and HN1 are known to be highly expressed in prostate adenocarcinomas.

The targets of curcumin

Curcumin (diferuloylmethane), an orange-yellow component of turmeric or curry powder, is a polyphenol natural product isolated from the rhizome of the plant Curcuma longa. For centuries, curcumin has been used in some medicinal preparation or used as a food-coloring agent. In recent years, extensive in vitro and in vivo studies suggested curcumin has anticancer, antiviral, antiarthritic, anti-amyloid, antioxidant, and anti-inflammatory properties. The underlying mechanisms of these effects are diverse and appear to involve the regulation of various molecular targets, including transcription factors (such as nuclear factor-kB), growth factors (such as vascular endothelial cell growth factor), inflammatory cytokines (such as tumor necrosis factor, interleukin 1 and interleukin 6), protein kinases (such as mammalian target of rapamycin, mitogen-activated protein kinases, and Akt) and other enzymes (such as cyclooxygenase 2 and 5 lipoxygenase). Thus, due to its efficacy and regulation of multiple targets, as well as its safety for human use, curcumin has received considerable interest as a potential therapeutic agent for the prevention and/or treatment of various malignant diseases, arthritis, allergies, Alzheimer's disease, and other inflammatory illnesses. This review summarizes various in vitro and in vivo pharmacological aspects of curcumin as well as the underlying action mechanisms. The recently identified molecular targets and signaling pathways modulated by curcumin are also discussed here.

PSA mass as a marker of prostate cancer progression after radical prostatectomy

Background

Obese patients with prostate cancer may have lower preoperative PSA concentration due to hemodilution. Lower PSA concentration may falsely affect assessing the risk of progression after radical prostatectomy (RP). The aim of this study was to determine preoperative PSA mass as the absolute amount of PSA protein secreted into circulation, and evaluation of its usefulness in prediction of biochemical recurrence after RP.

Material/Methods

177 patients after RP due to prostate cancer were included in the study. On the basis of formulas, PSA mass was calculated {PSA mass [μg] = (weight [kg])^0.425 × (height [cm])^0.72 × 0.007184 × 1.670 × PSA concentration [ng/ml]}. Patients were divided into 3 groups according to increasing values of PSA mass. The following features were assessed and compared between these groups (χ-square test): pathologic stage T3, nodal metastases, positive surgical margins, biochemical and local recurrence and the rate of death. Cancer-specific survival was assessed depending on PSA mass (Kaplan-Meier curves with log rank test). The usefulness of PSA mass in prediction of biochemical recurrence was compared with PSA concentration (logistic regression with ROC curves).

Results

Pathologic stage T3, nodal metastases, positive surgical margins and progression were more common in patients with higher levels of PSA mass (p<0.01). Cancer-specific survival was significantly shorter in patients with elevated values of PSA mass (p=0.02). Preoperative PSA mass was a more sensitive predictor of biochemical recurrence than was PSA concentration (p=0.04).

Conclusions

The preoperative PSA mass is a better predictor of biochemical recurrence after RP than PSA concentration.

Finasteride metabolism and pharmacogenetics: new approaches to personalized prevention of prostate cancer

Incidences of prostate cancer in most countries are increasing owing to better detection methods; however, prevention with the use of finasteride, a very effective steroid 5α-reductase type II inhibitor, has been met with mixed success. A wide interindividual variation in response exists and is thought to be due to heritable factors. This article summarizes the literature that attempts to elucidate the molecular mechanisms of finasteride in terms of its metabolism, excretion and interaction with endogenous steroid molecules. We describe previously reported genetic variations of steroid-metabolizing genes and their potential association with finasteride efficacy. Based on the literature, we outline directions of research that may contribute to understanding the interindividual variation in finasteride prevention and to the future development of personalized medicine.

Maximizing outcomes in genitourinary cancers across the treatment continuum

Key controversies concerning the management of genitourinary cancers across the treatment continua were discussed at the second annual Interactive Genitourinary Cancer Conference (IGUCC) held in February 2010 in Athens, Greece. Prostate cancer is the most common form of cancer among western men and prevention strategies are needed. Trials evaluating 5α-reductase inhibitors have reported beneficial and clinically meaningful results, but uptake remains low for primary prostate cancer prevention. Prostate cancer detection programmes are also important as curative treatments for advanced disease are unavailable. Two large landmark randomized controlled trials reported conflicting results concerning screening efficacy and uncovered high levels of over-diagnosis and potential over-treatment. Tailored management strategies after diagnosis are important and predictive markers that distinguish between aggressive and indolent tumours are needed. The majority of newly diagnosed cases of prostate cancer are clinically localized. Active surveillance of favourable risk patients may be beneficial in the intermediate term, while an integrated approach of multi-modality therapy in patients with adverse features is recommended. The benefits of new technologies such as high-intensity focused ultrasound (HIFU) and robotic prostatectomy have not been established in prospective randomized trials vs current standards of care. A multidisciplinary approach is essential to evolving the management of advanced prostate cancer into a chronic disease paradigm. Docetaxel plus prednisone is the standard first-line chemotherapy for patients with metastatic castration-resistant prostate cancer (mCRPC), but the optimal timing of chemotherapy initiation has not been addressed in randomized clinical trials. Retrospective analyses suggest that asymptomatic patients with adverse prognostic factors for survival may also benefit from receiving chemotherapy. Bladder cancer is a common malignancy and the most expensive cancer per patient. Non-muscle-invasive bladder cancer is a heterogenous disease that requires dynamic multidisciplinary management. Aggressive early intervention may be beneficial in some cases. Platinum-based therapies represent the first-line standard of care for advanced bladder cancer, but the maximum benefit may have been reached for conventional chemotherapies and new strategies are needed. Several ongoing clinical trials are assessing combination chemotherapy and targeted therapy.

Androgen deprivation induces rapid involution and recovery of human prostate vasculature

The response of the prostate tissue microenvironment to androgen deprivation (AD) represents a critical component in the treatment of benign prostatic hyperplasia and prostate cancer (CaP). Primary xenografts of human benign and CaP tissue transplanted to immunocompromized SCID mice were used to characterize the response of the prostate vasculature during the initial 14 days of AD. Microvessel density and vascular lumen diameter in the prostate xenografts decreased rapidly after AD, reached a nadir on days 2-4, and recovered between days 4 and 14. The number of apoptotic endothelial cells peaked on day 2 after AD and decreased to precastration levels over days 4-7. Leakage of vascular contents in the interstitial space was apparent between days 1 and 3 after AD; however, the vascular permeability barrier reestablished between days 7 and 14. Expression of vascular endothelial growth factor (VEGF)-A, VEGF receptor-2, and basic fibroblast growth factor protein increased in endothelial cells between days 2 and 4 after AD, which preceded vascular recovery and appeared to be a direct and specific response of the endothelial cells to AD. Lack of comparable upregulation of these genes in primary cultures of human prostate endothelial cells in response to AD suggests a role for paracrine signaling mediated through stromal or epithelial cells. VEGF-A expression by prostate endothelial cells appears to represent a key facilitator of the vascular rebound in human prostate tissue induced by removal of circulating testicular androgens.

Association of obesity with prostate cancer: a case-control study within the population-based PSA testing phase of the ProtecT study

Background:

Obesity has been inconsistently linked to prostate cancer, mainly with mortality rather than incidence. Few large-scale studies exist assessing obesity in relation to prostate-specific antigen (PSA)-detected prostate cancer.

Methods:

We used cases and stratum-matched controls from the population-based PSA-testing phase of the Prostate testing for cancer and Treatment study to examine the hypothesis that obesity as measured by body mass index (BMI), waist circumference and waist-to-hip ratio (WHR) is associated with increased prostate cancer risk, and with higher tumour stage and grade. In all, 2167 eligible cases and 11 638 randomly selected eligible controls with PSA values were recruited between 2001 and 2008. A maximum of 960 cases and 4156 controls had measurement data, and also complete data on age and family history, and were included in the final analysis. BMI was categorised as <25.0, 25.0–29.9, ⩾30.0 in kg m⁻².

Results:

Following adjustment for age and family history of prostate cancer, we found little evidence that BMI was associated with total prostate cancer (odds ratio (OR): 0.83, 95% confidence interval (CI): 0.67, 1.03; highest vs lowest tertile; P-trend 0.1). A weak inverse association was evident for low-grade (OR: 0.76, 95% CI: 0.59, 0.97; highest vs lowest tertile; P-trend 0.045) prostate cancer. We found no association of either waist circumference (OR: 0.94, 95% CI: 0.80, 1.12; highest vs lowest tertile) or waist-to-hip ratio (WHR; OR: 0.93, 95% CI: 0.77, 1.11; highest vs lowest tertile) with total prostate cancer, and in analyses stratified by disease stage (all P-trend>0.35) or grade (all P-trend>0.16).

Conclusion:

General adiposity, as measured by BMI, was associated with a decreased risk of low-grade PSA-detected prostate cancer. However, effects were small and the confidence intervals had limits very close to one. Abdominal obesity (as measured by WHR/waist circumference) was not associated with PSA-detected prostate cancer.

A nutrient approach to prostate cancer prevention: The Selenium and Vitamin E Cancer Prevention Trial (SELECT)

The Selenium and Vitamin E Cancer Prevention Trial (SELECT) randomized 35,533 healthy men, >55 yr old (>50 yr if African American), with normal digital rectal exams and prostate specific antigens <4 ng/ml to 1) 200 μg/day l-selenomethionine, 2) 400 IU/day all-rac-alpha-tocopheryl acetate (vitamin E), 3) both supplements, or 4) placebo for 7 to 12 yr. The hypotheses underlying SELECT, that selenium and vitamin E individually and together decrease prostate cancer incidence, derived from epidemiologic and laboratory evidence and significant secondary endpoints in the Nutritional Prevention of Cancer (selenium) and Alpha-Tocopherol Beta-Carotene (vitamin E) trials. In SELECT, prostate cancer incidence did not differ among the 4 arms: hazard ratios [99% confidence intervals (CIs)] for prostate cancer were 1.13 (99% CI = 0.95-1.35, P = 0.06; n = 473) for vitamin E, 1.04 (99% CI = 0.87-1.24, P = 0.62; n = 432) for selenium, and 1.05 (99% CI = 0.88-1.25, P = 0.52; n = 437) for selenium + vitamin E vs. 1.00 (n = 416) for placebo. Statistically nonsignificant increased risks of prostate cancer with vitamin E alone [relative risk (RR) = 1.13, P = 0.06) and newly diagnosed Type 2 diabetes mellitus with selenium alone (RR = 1.07, P = 0.16) were observed. SELECT data show that neither selenium nor vitamin E, alone or together, in the doses and formulations used, prevented prostate cancer in this heterogeneous population of healthy men.

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.

Is a decreased serum testosterone level a risk factor for prostate cancer? A cohort study of korean men

Purpose

To investigate patients who had transrectal ultrasonography (TRUS)-guided prostate biopsy to define the role of the serum testosterone level in predicting prostate cancer risk and its association with a high Gleason score.

Materials and Methods

A total of 568 patients who underwent prostate biopsy were entered in this study. We divided the patients into two groups according to serum testosterone level (median level, 3.85 ng/ml): the high-testosterone group (n=285) and the low-testosterone group (n=283). Multivariate regression analysis was used to define the effect of age, prostate volume, serum prostate-specific antigen (PSA) level and PSA density, and serum testosterone level on the risk of prostate cancer and a high Gleason score.

Results

Baseline characteristics did not differ significantly between the two groups. Compared with the high-testosterone group, the low-testosterone group had a significantly higher prostate cancer incidence (38.9% vs. 29.5%, p=0.018). Factors associated with an increased risk of prostate cancer were increased age (odds ratio [OR]=1.08, 95% confidence interval [CI]=1.25-3.16, p=0.001), a high serum PSA level (OR=3.35, 95% CI=2.63-4.25, p=0.001), a low prostate volume (OR=0.183, 95% CI=0.11-0.30, p=0.001), and a low serum testosterone level (OR=1.99, 95% CI=1.25-3.16, p=0.001). Among these, only the serum PSA level was a strong predictor of high-grade prostate cancer (Gleason score ≥7) (OR=2.19, 95% CI=1.57-2.95, p=0.001).

Conclusions

Patients with lower levels of serum testosterone had a higher risk of prostate cancer than did patients with high serum testosterone. Even though a lower serum testosterone level was a predictor of prostate cancer risk, it was not associated with an increased risk of high-grade prostate cancer.

Association of SRD5A2 Variants and Serum Androstane-3α,17β-Diol Glucuronide Concentration in Chinese Elderly Men

BACKGROUND

Results of recent studies have demonstrated that genetic variants of the enzyme steroid 5α reductase type II (SRD5A2) are associated with serum concentrations of major androgen metabolites such as conjugates of androstane-3α,17β-diol-glucuronide (3α-diol-G). However, this association was not consistently found among different ethnic groups. Thus, we aimed to determine whether the association with SRD5A2 genetic variations exists in a cohort of healthy Chinese elderly men, by examining 2 metabolite conjugates: androstane-3α,l7β-diol-3-glucuronide (3α-diol-3G) and androstane-3α,17β-diol-17-glucuronide (3α-diol-17G).

METHODS

We used GC-MS and LC-MS to measure serum sex steroid concentrations, including testosterone and dihydrotestosterone, and 3α-diol-3G and 3α-diol-17G in 1182 Chinese elderly men age 65 and older. Genotyping of the 3 SRD5A2 tagSNPs [rs3731586, rs12470143, and rs523349 (V89L)] was performed by using melting-temperature–shift allele-specific PCR.

RESULTS

The well-described SRD5A2 missense variant rs523349 (V89L) was modestly associated with the 3α-diol-17G concentration (P = 0.040). On the other hand, SNP rs12470143 was found to be significantly correlated with 3α-diol-3G concentration (P = 0.021). Results of haplotype analysis suggested that the presence of an A-C-G haplotype leads to an increased 3α-diol-3G concentration, a finding consistent with results of single SNP analysis.

CONCLUSIONS

The genetic variation of SRD5A2 is associated with circulating 3α-diol-3G and 3α-diol-17G concentrations in Chinese elderly men. In addition, we showed that SRD5A2 haplotypic association, rather than a single SNP alone, might be a better predictor of the 3α-diol-G concentration. Thus, the effect of either the haplotype itself or of other ungenotyped SNPs in linkage disequilibrium with the haplotype is responsible for the interindividual variation of 3α-diol-G.

Coumaphos exposure and incident cancer among male participants in the Agricultural Health Study (AHS)

BACKGROUND

Coumaphos is an organophosphate livestock insecticide. Previous research in the Agricultural Health Study (AHS) cohort observed a positive association between coumaphos and prostate cancer in men with a family history of prostate cancer.

OBJECTIVES

This study was performed to determine the association between coumaphos and other major cancer sites and to explore the consistency of the association with prostate cancer early (1993-1999) and later (2000-2005) in AHS follow-up.

METHODS

This study included 47,822 male licensed pesticide applicators. Incident cases were ascertained by linkage to state cancer registries, and exposure data were collected by enrollment questionnaire. Poisson regression was used to estimate rate ratio (RR) and 95% confidence interval (CI) of cancer for coumaphos exposure controlling for potentially confounding variables.

RESULTS

Approximately 8% of applicators reported use of coumaphos; 8.5% reported a family history of prostate cancer. Cumulative exposure to coumaphos was not associated with cancer risk overall or with any major cancer site including prostate. In men with a family history of prostate cancer, we observed a positive association between ever use of coumaphos and prostate cancer in both early (RR = 2.07; 95% CI, 1.19-3.62, p-interaction = 0.005) and later (RR = 1.46; 95% CI, 0.89-2.40; p-interaction = 0.11) periods of follow-up. Across all years, this association was statistically significant (RR = 1.65; 95% CI, 1.13-2.38; p-interaction = 0.004).

CONCLUSION

Coumaphos was not associated with any cancer evaluated here. In men with a family history of disease, there was evidence of an association between coumaphos and prostate cancer, possibly due to genetic susceptibility; however, other explanations, including chance, are plausible.

Association between serum sex hormone levels and prostate cancer: effect of prostate cancer on serum testosterone levels

Androgens are essential for prostatic growth and development, but also play a significant role in the pathogenesis of prostate disease. The traditional view that higher testosterone levels represent a risk factor for prostate cancer (PCa) appears to have little evidentiary support. Some studies have described a relationship between lower testosterone levels and more advanced disease. Serum androgen levels, within a broad range, are thus suggested to show no association with PCa risk, whereas low rather than high serum testosterone levels have been found to be associated with advanced or high-grade disease at the time of PCa diagnosis. Dihydrotestosterone, the principal prostatic androgen, is transformed from testosterone by type 1 and type 2 5alpha-reductase, and therapeutic benefits may thus be potentially achieved through the inhibition of 5alpha-reductase.

Disorders related with ageing in the gerbil female prostate (Skene's paraurethral glands)

The female organs, which are regulated by steroid hormones, are targets of studies especially those related to senescence. However, although the female prostate is an organ influenced by hormones and susceptible to lesions, there is still little information about its histopathology. Thus, given the morphophysiological similarity between the prostate in women and female gerbils, the present study aimed to identify the spontaneous histopathological changes in this rodent to provide contributions to the understanding of lesions that also affect the human female prostate. The structural, ultrastructural, immunohistochemical, morphometric-stereological and serological aspects, as well as the quantification of the incidence, multiplicity and percentage of acini affected by different lesions were analyzed. Benign prostate lesions including hyperplasia, prostatitis, microcalculi and calculi; preneoplastic lesions like dysplasias; premalignant lesions, such as high grade prostatic intraepithelial neoplasia as well as malignant ones, specifically adenocarcinoma, were identified in the adult gland, but they were intensified during senescence, which is possibly due to the imbalance among steroid hormone levels. Although clinical attention focuses on other urogenital organs, the real condition of the histopathological injuries in the human female prostate should be considered. A serious preventive work regarding the female prostate could be applied in the gynaecological context in order to monitor the gland and avoid possible disturbances to women's health and consequently provide better quality of life.

Diet, physical activity and energy balance and their impact on breast and prostate cancers

Obesity, physical activity status and circulating levels of sex steroid hormones and growth factor proteins are intrinsically linked to energy balance. Epidemiological studies have previously reported associations between these factors and the risk of hormone-related cancers such as prostate and breast cancer in men and postmenopausal women. An increasing number of intervention studies in 'at-risk' populations and cancer survivors are now investigating the effects of lifestyle interventions that promote negative energy balance on circulating levels of sex hormones and growth factor proteins as surrogate markers of cancer risk. Evidence from these studies suggests that lifestyle interventions can improve insulin sensitivity, alter the balance of circulating sex steroid hormones and insulin-like growth factor (IGF) axis proteins (including IGF-1 and the IGF binding proteins 1 and 3) and change the functioning of immune cells in peripheral blood. Such changes could influence the risk of developing hormone-related cancers, as well as having the potential to improve disease-free survival in patients recovering from cancer treatment. However, despite promising results, the methodological quality of most intervention studies has been limited due to small subject numbers, lack of adequate control groups or non-randomised designs and the absence of long-term follow-up measures. More intervention studies with randomised controlled designs, higher numbers of subjects and longer-term follow-up measures are needed to establish which combination of specific dietary and physical activity interventions work best for reducing risk in 'at-risk' populations and survivors, optimal dose-response relationships and the magnitude of change in surrogate markers of cancer risk that is required to induce a protective effect.

The protective effect of diabetes mellitus against prostate cancer: role of sex hormones

BACKGROUND

Diabetes mellitus (DM) has been associated with decreased risk of prostate cancer (PC) in several reports. Hormonal environment of diabetic patients is believed to be an important contributing factor in this regard.

METHODS

Using data from a multi-center case-control study in Iran, base line testosterone, sex hormone binding globulin (SHBG), estradiol, and albumin levels as well as thorough demographic and medical characteristics of 194 newly diagnosed prostate cancer patients were determined. There were 317 ethnicity-matched men with no cancer as controls as well. Data was analyzed for hormones of interest in DM patients regarding their cancer status.

RESULTS

Of 511 enrolled patients, twenty-one cases and 63 controls were diagnosed as DM. Patients with DM were significantly less likely to have PC (OR: 0.44, P = 0.003). Time since DM diagnosis was also inversely correlated with the risk of cancer (P trend < 0.0001). Control patients had significantly higher testosterone, estradiol, and testosterone/SHBG ratio (P < 0.05). As time since DM diagnosis increased by quartiles, testosterone significantly increased (P trend < 0.05). The risk of PC also significantly declined (P trend < 0.0001) following an initial remarkable increase early after DM diagnosis. After including the hormones in the logistic regression model, there was a weak, yet significant inverse association of testosterone/SHBG and DM duration with the risk of PC.

CONCLUSIONS

Based on our results DM duration is inversely correlated with the risk of prostate cancer. Our results do not support the hypothesis that sex hormones, including testosterone, play a major role in the protective effect of DM against PC.