Meta-analysis of measures of sexual activity and prostate cancer

Health-Related and Psychosocial Factors Associated with Prostate Cancer Stage at Diagnosis among Males Participating in Alberta's Tomorrow Project

Prostate cancer (PCa) stage at diagnosis is an important predictor of cancer prognosis. In Canada, over one-quarter of males are diagnosed with advanced-stage PCa. Studies have identified several factors associated with PCa stage at diagnosis; however, evidence from Canada is limited. This study aimed to examine associations between sociodemographic characteristics, health history, health practices, and psychosocial factors and PCa stage at diagnosis among males participating in Alberta's Tomorrow Project (ATP), a prospective cohort in Alberta, Canada. The study included males aged 35-69 years who developed PCa until January 2018. Factors associated with PCa stage at diagnosis were examined using partial proportional odds (PPO) ordinal regression models. A total of 410 males were diagnosed with PCa over the study period. A higher number of lifetime prostate-specific antigen tests were associated with earlier-stage PCa (OR 0.91, p = 0.02, 95% CI 0.83-0.99), while higher abdominal circumference (OR 1.02, p = 0.05, 95% CI 1.00-1.03), lower social support (OR 2.34, p < 0.01, 95% CI 1.31-4.17), and having children (OR 2.67, p < 0.01, 95% CI 1.38-5.16) were associated with later-stage disease. This study identified factors previously found in the literature as well as novel factors associated with PCa stage at diagnosis, which can help inform targets for cancer prevention programs to improve PCa prognosis.

Viruses, bacteria and parasites: infection of the male genital tract and fertility

BACKGROUND

Infertility affects one couple out of six worldwide. Male infertilty can result from congenital or acquired factors, of which pathogens that reach the genital tract through sexual contact or blood dissemination. The impact of major viral, bacterial and parasitic infections on the male genital tract and fertility has been summarized.

RESULTS AND CONCLUSIONS

A systematic review of articles published in the Google Scholar and PubMed databases was conducted. It turns out that viruses, as well as bacteria and parasites are major inducers of male genital tract infections and ensuing infertility through damage to the organs and subsequent loss of function and/or through direct damage to the sperm cells. Moreover, not only male infertility results from such infections but these can also be transmitted to women and even to the offspring, thus highlighting the need to efficiently detect, treat and prevent them.

Detection of high-risk Human Papillomavirus in prostate cancer from a UK based population

Human papillomavirus (HPV) infection is one of the sexually transmitted diseases which have been implicated in the etiology of multiple cancers. To date, several studies have been conducted to evaluate the incidence of high-risk (HR) HPV in prostate cancer (PCa) which have generated widely conflicting data. Hence, this leaves a lack of awareness on the causal role of persistent HPV infection in the development of PCa. Although this has been investigated in a handful of countries, to the best of our knowledge, no prior studies have been conducted in the UK. In this study, polymerase chain reaction (PCR) and Sanger sequencing were implemented to analyze a total of 49 fresh prostate specimens (35 benign and 14 malignant specimens) for the presence of viral DNA of 12 HR-HPV types. Data obtained confirmed the presence of HR-HPV in 32.7% of analyzed benign and malignant prostate tissues with HPV 35 being identified as the most frequent type. Moreover, HR-HPV positivity rate was found to be higher in abnormal prostate tissues (adenocarcinoma and benign with prostatitis) compared those with normal prostate condition. Using immunohistochemistry, we have confirmed the expression of HPV E7 protein in prostate tissues positive for HPV DNA. This observation, the first reported from a UK population, suggests that the presence of HPV in prostate tissue is likely to be a related factor in the progression of certain cases of prostate cancer.

Unlocking the mystery associated with infertility and prostate cancer: an update

Male-specific reproductive disorders and cancers have increased intensely in recent years, making them a significant public health problem. Prostate cancer (PC) is the most often diagnosed cancer in men and is one of the leading causes of cancer-related mortality. Both genetic and epigenetic modifications contribute to the development and progression of PC, even though the exact underlying processes causing this disease have yet to be identified. Male infertility is also a complex and poorly understood phenomenon believed to afflict a significant portion of the male population. Chromosomal abnormalities, compromised DNA repair systems, and Y chromosome alterations are just a few of the proposed explanations. It is becoming widely accepted that infertility shares a link with PC. Much of the link between infertility and PC is probably attributable to common genetic defects. This article provides an overview of PC and spermatogenic abnormalities. This study also investigates the link between male infertility and PC and uncovers the underlying reasons, risk factors, and biological mechanisms contributing to this association.

Neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios alone or combined with prostate-specific antigen for the diagnosis of prostate cancer and clinically significant prostate cancer

Objective

We evaluated whether the blood parameters before prostate biopsy can diagnose prostate cancer (PCa) and clinically significant PCa (Gleason score [GS] ≥7) in our hospital.

Methods

This study included patients with increased prostate-specific antigen (PSA) up to 20 ng/mL. The associations of neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) alone or with PSA with PCa and clinically significant PCa were analyzed.

Results

We included 365 patients, of whom 52.9% (193) had PCa including 66.8% (129) with GS of ≥7. PSA density (PSAD) and PSA had better the area under the curve (AUC) of 0.722 and 0.585, respectively with p=0.001 for detecting PCa compared with other blood parameters. PSA combined with PLR (PsPLR) and PSA with NLR (PsNLR) had better AUC of 0.608 and 0.610, respectively with p<0.05, for diagnosing GS≥7 population, compared with PSA, free/total PSA, NLR, PLR, and PsNPLR (PSA combined with NLR and PLR). NLR and PLR did not predict PCa on multivariate analysis. For GS≥7 cancer detection, in the multivariate analysis, separate models with PSA and NLR (Model 1: PsNLR+baseline parameters) or PSA and PLR (Moder 2: PsPLR+baseline parameters) were made. Baseline parameters comprised age, digital rectal exam-positive lesions, PSA density, free/total PSA, and magnetic resonance imaging. Model 2 containing PsPLR was statistically significant (odds ratio: 2.862, 95% confidence interval: 1.174-6.975, p=0.021) in finding aggressive PCa. The predictive accuracy of Model 2 was increased (AUC: 0.734, p<0.001) than that when only baseline parameters were used (AUC: 0.693, p<0.001).

Conclusion

NLR or PLR, either alone or combined with PSA, did not detect PCa. However, the combined use of PSA with PLR could find the differences between clinically significant and insignificant PCa in our retrospective study limited by the small number of samples.

Modifiable risk factors for prostate cancer in low- and lower-middle-income countries: a systematic review and meta-analysis

BACKGROUND

Most of the epidemiological data on prostate cancer risk factors come from high-income countries (HIC). Reducing exposure to prostate cancer modifiable risk factors may significantly lower PCa morbidity and mortality in LIC and MIC. The objective of this study was to summarize the evidence on modifiable risk factors (RFs) for PCa in LIC and lower-middle-income countries (LMIC).

METHODS

We conducted a systematic search on MEDLINE, EMBASE, and Global Health databases. We selected case-control and cohort studies from 2010 onwards that studied modifiable RFs for PCa in LIC and LMIC with a population of 30 million or more, as defined by the World Bank in January 2021. Risk of bias was assessed by the Ottawa-Newcastle tool. Individual study estimates were pooled when estimates were available for at least two studies.

RESULTS

5740 studies were initially identified; 16 studies met inclusion criteria. All were case-control studies except one retrospective cohort study. Higher fat intake was associated with a higher risk of PCa incidence with an odds ratio (OR) of 3.13 (95% CI 1.33-7.33). Higher vegetable intake (OR 0.48, 95% CI 0.24-0.97) and tea consumption (OR 0.51, 95% CI 0.32-0.83) were associated with a lower risk for PCa. There was no association between fruits, fish, and chicken consumption and risk of PCa. Alcohol consumption, smoking, red meat intake, and a BMI ≥ 25-30 kg/m² showed a trend towards an increased risk, although these were not statistically significant.

CONCLUSIONS

In LIC and LMIC, high fat intake was associated with higher risk of PCa while a diet rich in vegetables and tea intake was associated with a lower risk. Future prospective studies will be important to elucidate whether other modifiable risk factors for PCa specific to LIC and LMIC can be identified to inform impactful and cost-effective preventive strategies in these countries.

Bacteria-Mediated Oncogenesis and the Underlying Molecular Intricacies: What We Know So Far

Cancers are known to have multifactorial etiology. Certain bacteria and viruses are proven carcinogens. Lately, there has been in-depth research investigating carcinogenic capabilities of some bacteria. Reports indicate that chronic inflammation and harmful bacterial metabolites to be strong promoters of neoplasticity. Helicobacter pylori-induced gastric adenocarcinoma is the best illustration of the chronic inflammation paradigm of oncogenesis. Chronic inflammation, which produces excessive reactive oxygen species (ROS) is hypothesized to cause cancerous cell proliferation. Other possible bacteria-dependent mechanisms and virulence factors have also been suspected of playing a vital role in the bacteria-induced-cancer(s). Numerous attempts have been made to explore and establish the possible relationship between the two. With the growing concerns on anti-microbial resistance and over-dependence of mankind on antibiotics to treat bacterial infections, it must be deemed critical to understand and identify carcinogenic bacteria, to establish their role in causing cancer.

Predictive value of the monocyte-to-lymphocyte ratio in the diagnosis of prostate cancer

It has been reported that inflammation and immune system are related to prostate cancer. The neutrophil-to-lymphocyte ratio (NLR), as well as the platelet-to-lymphocyte ratio (PLR), have already been proposed as new indices to help diagnose prostate cancer (PCa). However, the monocyte-to-lymphocyte ratio (MLR) with regard to PCa has rarely been mentioned.To investigate the capability of the MLR to predict PCa.Patients who were pathologically diagnosed with PCa in our hospital and healthy control subjects who conformed to the inclusion criteria were enrolled. Patient data were recorded, including age, complete blood counts, blood biochemistry, and serum prostate-specific antigen (PSA) levels. The differences in these data between the groups were analyzed and the diagnostic value of the MLR was compared with PSA.Our study included a total of 100 patients with PCa and 103 healthy control subjects. Patients with PCa presented with a significantly higher NLR, MLR, and PLR compared to control subjects. However, the hemoglobin and lymphocyte levels were lower (P < .05) in PCa patients. The area under the curve (AUC) of PSA and ratio of free/total serum prostate-specific antigen were 0.899 (95% confidence interval [CI]: 0.857-0.942) and 0.872 (95% CI: 0.818-0.926), respectively, while the AUC of the MLR was 0.852 (95% CI: 0.798-0.906), which was higher than that of the NLR, PLR, and any other blood parameters. Additionally, the optimal cut-off value of the MLR for PCa was 0.264, with a specificity of 87.4% and a sensitivity of 72.0%. An evaluation of the diagnostic value of MLR + PSA gave an AUC of 0.936 (95% CI: 0.902-0.970). However, the AUC of MLR + PSA + f/tPSA was 0.996 (95% CI: 0.991-1.000). The diagnostic value of MLR + NLR + PSA gave an AUC of 0.945 (95% CI: 0.913-0.977), and the specificity is 0.971.PSA remains the most important diagnostic indicator. MLR combined with PSA and f/tPSA has the higher predictive value than PSA. It suggests that MLR may be another good predictive indicator of PCa. It can help reduce the clinical false positive rate.

Canary in the Coal Mine? Male Infertility as a Marker of Overall Health

Male factor infertility is a common problem. Evidence is emerging regarding the spectrum of systemic disease and illness harbored by infertile men who otherwise appear healthy. In this review, we present evidence that infertile men have poor overall health and increased morbidity and mortality, increased rates of both genitourinary and non-genitourinary malignancy, and greater risks of systemic disease. The review also highlights numerous genetic conditions associated with male infertility as well as emerging translational evidence of genitourinary birth defects and their impact on male infertility. Finally, parallels to the overall health of infertile women are presented. This review highlights the importance of a comprehensive health evaluation of men who present for an infertility assessment.

Inflammation as a Driver of Prostate Cancer Metastasis and Therapeutic Resistance

Simple Summary

Prostate cancer is the most common malignancy in men, with a high mortality rate when disease progresses to metastasis and therapeutic resistance. Evidence implicates inflammation as a driver of prostate cancer risk and has a significant impact on processes in the tumor microenvironment that facilitate progression to advanced therapeutically resistant disease. In this review, we discuss the sources of inflammation in the prostate, the functional contribution of the critical inflammatory effectors to prostate cancer initiation and metastatic progression, and the therapeutic challenges that they impose on treatment of advanced disease and overcoming therapeutic resistance. Full understanding of the role of inflammation in prostate cancer progression to advanced metastatic disease and tumor relapse will aid in the development of personalized predictive biomarkers and therapy to reduce the burden and mortality in prostate cancer patients.

Abstract

Prostate cancer is the most common malignancy among men, and progression to metastasis and the emergence of therapeutically resistant disease confers a high mortality rate. Growing evidence implicates inflammation as a driver of prostate cancer development and progression, resulting in increased cancer risk for prostate cancer. Population-based studies revealed that the use of antinflammatory drugs led to a 23% risk reduction prostate cancer occurrence, a negative association that was stronger in men who specifically used COX-2 inhibitors. Furthermore, patients that were taking aspirin had a 21% reduction in prostate cancer risk, and further, long-term users of daily low dose aspirin had a 29% prostate cancer risk reduction as compared to the controls. Environmental exposure to bacterial and viral infections, exposure to mutagenic agents, and genetic variations predispose the prostate gland to inflammation, with a coordinated elevated expression of inflammatory cytokines (IL-6, TGF-β). It is the dynamics within the tumor microenvironment that empower these cytokines to promote survival and growth of the primary tumor and facilitate disease progression by navigating the immunoregulatory network, phenotypic epithelial-mesenchymal transition (EMT), angiogenesis, anoikis resistance, and metastasis. In this review, we discuss the sources of inflammation in the prostate, the functional contribution of the critical inflammatory effectors to prostate cancer initiation and metastatic progression, and the therapeutic challenges that they impose on treatment of advanced disease and overcoming therapeutic resistance. Growing mechanistic evidence supports the significance of inflammation in localized prostate cancer, and the systemic impact of the process within the tumor microenvironment on disease progression to advanced therapeutically-resistant prostate cancer. Rigorous exploitation of the role of inflammation in prostate cancer progression to metastasis and therapeutic resistance will empower the development of precise biomarker signatures and effective targeted therapeutics to reduce the clinical burden and lethal disease in the future.

Racial differences in prostate cancer: does timing of puberty play a role?

The burden of prostate cancer has a remarkably disproportionate distribution across racial groups. For example, in the USA, African Americans are twice as likely as individuals of European ancestry to develop or die from prostate cancer, and have a more aggressive disease nature at diagnosis. In contrast, Asian American men have the lowest incidence and mortality rates of prostate cancer. That considerable racial disparities exist even in the subclinical stage of prostate cancer among young men in their 20–30s suggests that patterns of prostate carcinogenesis start to diverge even earlier, perhaps during puberty, when the prostate matures at its most rapid rate. Mendelian randomisation studies have provided strong population-based evidence supporting the hypothesis that earlier onset of puberty increases the risk of prostate cancer—particularly of high grade—and prostate cancer-specific mortality later in life, observations which correspond to the epidemiology of the disease in African Americans. Notably, African American boys initiate genital development ~1 year earlier and thus go through longer periods of pubertal maturation compared with European American boys. In this perspective, bringing together existing evidence, we point to puberty as a potential critical window of increased susceptibility to prostate carcinogenesis that could account for the marked prevailing racial differences in the burden of prostate cancer.

The relationship between chronic diseases and number of sexual partners: an exploratory analysis

BACKGROUND

We investigated sex-specific associations between lifetime number of sexual partners and several health outcomes in a large sample of older adults in England.

METHODS

We used cross-sectional data from 2537 men and 3185 women aged ≥50 years participating in the English Longitudinal Study of Ageing. Participants reported the number of sexual partners they had had in their lifetime. Outcomes were self-rated health and self-reported limiting long-standing illness, cancer, coronary heart disease, and stroke. We used logistic regression to analyse associations between lifetime number of sexual partners and health outcomes, adjusted for relevant sociodemographic and health-related covariates.

RESULTS

Having had 10 or more lifetime sexual partners was associated with higher odds of reporting a diagnosis of cancer than having had 0-1 sexual partners in men (OR 1.69, 95% CI 1.01 to 2.83) and women (OR 1.91, 95% CI 1.04 to 3.51), respectively. Women who had 10 or more lifetime sexual partners also had higher odds of reporting a limiting long-standing illness (OR 1.64, 95% CI 1.15 to 2.35). No other statistically significant associations were observed.

CONCLUSIONS

A higher lifetime number of sexual partners is associated with increased odds of reported cancer. Longitudinal research is required to establish causality. Understanding the predictive value of lifetime number of sexual partners as a behavioural risk factor may improve clinical assessment of cancer risk in older adults.

IL-6 produced by prostate epithelial cells stimulated with Trichomonas vaginalis promotes proliferation of prostate cancer cells by inducing M2 polarization of THP-1-derived macrophages

Trichomonas vaginalis (Tv), a protozoan parasite causing sexually-transmitted disease, has been detected in tissue of prostatitis, benign prostatic hyperplasia (BPH) and prostate cancer (PCa). IL-6, a mediator of chronic inflammation, induces the progression of prostate cancer, and influences the polarization of M2 macrophages, which are the main tumor-associated macrophages. We investigated whether IL-6 produced by human prostate epithelial cells stimulated with Tv induces the M2 polarization of THP-1-derived macrophages, which in turn promotes the progression of PCa. Conditioned medium was prepared from Tv-infected (TCM) and uninfected (CM) prostate epithelial cells (RWPE-1). Thereafter conditioned medium was prepared from macrophages after incubation with CM (M-CM) or TCM (M-TCM). RWPE-1 cells infected with Tv produced IL-6 and chemokines such as CCL2 and CXCL8. When human macrophages were treated with conditioned medium of RWPE-1 cells co-cultured with Tv (TCM), they became polarized to M2-like macrophages as indicated by the production of IL-10 and TGF-β, and the expression of CD36 and arginase-1, which are M2 macrophage markers. Moreover, proliferation of the M2-like macrophages was also increased by TCM. Blockade of IL-6 signaling with IL-6 receptor antibody and JAK inhibitor (Ruxolitinib) inhibited M2 polarization of THP-1-derived macrophages and proliferation of the macrophages. To assess the effect of crosstalk between macrophages and prostate epithelial cells inflamed by Tv infection on the growth of prostate cancer (PCa) cells, PC3, DU145 and LNCaP cells were treated with conditioned medium from THP-1-derived macrophages stimulated with TCM (M-TCM). Proliferation and migration of the PCa cells were significantly increased by the M-TCM. Our findings suggest that IL-6 produced in response to Tv infection of the prostate has an important effect on the tumor microenvironment by promoting progression of PCa cells following induction of M2 macrophage polarization.

In male, T. vaginalis infection have been proposed to involve in several prostate diseases such as prostatitis, benign prostatic hyperplasia and prostate cancer. However, studies for these mechanisms have been rare. We have previously reported that T. vaginalis induce the production of inflammatory cytokines in prostate cells. Among these cytokines, IL-6 have been reported to play an important role in M2 macrophage polarization, which lead to formation of tumor microenvironment in various cancers. Here we show that IL-6 produced by T. vaginalis infection in prostate epithelial cells induces M2 polarization of macrophages and these macrophages promote proliferation of prostate cancer cells. These findings suggest that T. vaginalis indirectly induces progression of prostate cancer by creating a tumor microenvironment through an inflammatory response.

An examination of the association between lifetime history of prostate and pancreatic cancer diagnosis and occupation in a population sample of Canadians

BACKGROUND

Occupation was assessed as possible risk factors for prostate (PCa) and pancreatic cancer in a large Canadian worker cohort.

METHODS

The Canadian Census Health and Environment Cohort (CanCHEC) was derived from linking the 1991 Canadian Census Cohort to the Canadian Cancer Database (1969-2010), Canadian Mortality Database (1991-2011), and Tax Summary Files (1981-2011). From the total sample of 1,931,110 persons, we identified and derived two samples of 28,610 men and 3,220 men and women with a past history of PCa and pancreatic cancer diagnoses, respectively. Cox proportional hazards models were used to estimate hazards ratios and 95% confidence intervals for occupation.

RESULTS

In Canadian men aged 24-64 years, the highest elevated risks of PCa were observed for library clerks (HR = 2.36, 95% CI:1.12-4.97), medical radiation technologists (HR = 1.66, 95% CI:1.04-2.65), telecommunications and line cable workers (HR = 1.62, 95% CI: 1.22-3.16) and commissioned police officers (HR = 1.54, 95% CI: 1.10-2.16. The highest elevated risk for pancreatic cancer were observed for commissioned police officers (HR = 4.34, 95% CI: 1.85-10.21), photographic and film processors (HR = 3.97, 95% CI:1.69-9.34), railway and motor transport labourers (HR = 3.94, 95% CI: 1.67-9.29), and computer engineers (HR = 3.82, 95%CI: 1.52-9.61).

CONCLUSION

These findings emphasize the need for further study of job-related exposures and the potential influence of non-occupational factors such as screening practices.

Inflammatory mediators of prostate epithelial cells stimulated with Trichomonas vaginalis promote proliferative and invasive properties of prostate cancer cells

BACKGROUND

Trichomonas vaginalis (Tv) is the most common sexually transmitted parasite. It is detected in prostatic tissue of benign prostatic hyperplasia, prostatitis, and prostate cancer (PCa) and has been suggested to cause chronic prostatitis. Moreover, up to 20% of all cancers worldwide are associated with chronic inflammation. Here, we investigated whether inflammatory mediators produced by normal human prostate epithelial cells (RWPE-1) stimulated with Tv could promote growth and invasiveness of PCa cells.

METHODS

Conditioned medium of RWPE-1 cells was prepared by stimulating them with Tv (trichomonad-conditioned medium [TCM]) and without Tv (conditioned medium [CM]). Promotion of PCa cells (PC3, DU145, and LNCaP) was assessed by wound healing, proliferation, and invasion assays.

RESULTS

We observed that the production of interleukin (IL)-1β, IL-6, CCL2, CXCL8, prostaglandin-E2 (PGE₂ ), and COX2 by RWPE-1 cells was increased by stimulating them with Tv. When PCa cells were incubated with TCM, their proliferation, invasion, and migration increased. Moreover, they showed increased epithelial-mesenchymal transition (EMT)-related markers by a reduction in epithelial markers and an increase in mesenchymal markers. In vivo, xenograft tumor tissues injected with TCM also showed increased expression of cyclin D1 and proliferating cell nuclear antigen, as well as induction of EMT. Receptors and signal molecules of PCa cells increased in response to exposure to TCM, and blocking receptors (CXCR1, CXCR2, C-C chemokine receptor 2, glycoprotein 130, EP2, and EP4) reduced the proliferation of PCa cells with decreased production of cytokines (CCL2, IL-6, and CXCL8) and PGE₂ , and expression of NF-κB and Snail1.

CONCLUSIONS

Our results suggest that Tv infection may be one of the factors creating the supportive microenvironment to promote proliferation and invasiveness of PCa cells.

IFNL4-ΔG is associated with prostate cancer among men at increased risk of sexually transmitted infections

Sexually transmitted infections can reach the prostate gland where their harmful effects are mediated by innate immunity, including interferons. Humans are polymorphic for the germline dinucleotide variant, rs368234815-TT/ΔG, in the IFNL4 gene encoding interferon λ4. Since the IFNL4-ΔG allele has been linked to impaired viral clearance, we hypothesized that potential exposure to sexually transmitted pathogens, as assessed by the number of lifetime sexual partners, may increase prostate cancer risk in an IFNL4-ΔG-dependent manner. Accordingly, we find that men with 10 or more sexual partners and at least one copy of IFNL4-ΔG have a significantly increased risk of prostate cancer while those with the same number of partners but lacking IFNL4-ΔG do not. Moreover, a test for effect modification shows a positive interaction between the number of lifetime partners and IFNL4-ΔG in the development of aggressive prostate cancer. Based on these findings, we conclude that a gene-environment interaction between IFNL4-ΔG and sexual activity may increase the risk of prostate cancer.

Going viral? Linking the etiology of human prostate cancer to the PCA3 long noncoding RNA and oncogenic viruses

The hypothesis is discussed that prostate cancer marker lncRNA PCA3 was introduced into the human genome by an oncogenic virus, and that viral infection‐related mechanisms might underlie its overexpression and prostate cancer initiation and/or progression.

Elevated Serum Cytokines and Trichomonas vaginalis Serology at Diagnosis Are Not Associated With Higher Gleason Grade or Lethal Prostate Cancer

BACKGROUND

Inflammation and infections have been associated with prostate cancer progression. We assessed whether elevated serum cytokines or T. vaginalis seropositivity at the time of diagnosis was associated with higher grade or lethal prostate cancer.

PATIENTS AND METHODS

Men with localized or metastatic prostate cancer were included in this study. Cytokine serum levels including interleukin (IL)-1α, IL-1β, IL-2, IL-6, IL-8, monocyte chemotactic protein 1 (CCL-2), tumor necrosis factor α, and growth-regulated oncogene α (CXCL-1) using a multiplex enzyme-linked immunosorbent assay and T. vaginalis serology were measured in blood samples at diagnosis.

RESULTS

A total of 324 patients were identified at time of localized disease and 118 at time of metastatic disease. Of the 189 patients with localized disease and clinical follow-up data (median, 73 months), 28 developed lethal disease. There was no association between circulating cytokine levels above median concentrations nor T. vaginalis seropositivity and risk of intermediate- to high-risk or lethal prostate cancer.

CONCLUSION

Higher levels of serum cytokine levels and T. vaginalis seropositivity at diagnosis are not associated with high-grade or lethal prostate cancer and do not aid risk stratification of localized prostate cancer.

Is there a relationship between phosphodiesterase type 5 inhibitors and biochemical recurrence after radical prostatectomy: a systematic review and meta-analysis

PURPOSE

Conduct a systematic review and meta-analysis of studies to evaluate the association between the use of PDE5I and biochemical recurrence (BCR) after radical prostatectomy (RP).

METHODS

We searched Embase (from 1996 to Feb 2018), PubMed (from 1996 to Feb 2018), and Cochrane library (from 1999 to Feb 2018), then manually searched the reference lists of key retrieved articles. Original studies that reported the risk of postoperative BCR for PDE5I users, as compared with non-PDE5I users, were included. Data including the characteristic of participants, the risk of BCR after RP and key criteria of study quality were collected. The pooled relative risks (RRs) were calculated with random-effects model.

RESULTS

A total of 5 cohort studies and 1 case-control study were conducted for data analysis (a total of 17752 participants). Only 1 cohort study reported adjusted RR greater than 1 (range for all derived RRs, 0.7-1.47). The meta-analysis revealed that the PDE5I users had no higher risk of BCR after RP (RR = 1.04, 95% confidence interval [CI], 0.79-1.36). Sensitivity analysis showed that the remaining pooled RR and 95% CI were not changed significantly by omitting each study. In addition, the 5-year BCR rate had no significant difference between PDE5I users and non-PDE5I users.

CONCLUSIONS

Our meta-analysis indicated that PDE5I treatment in men following RP did not increase the risk of BCR. The results preliminarily suggested that the use of PDE5I for erectile dysfunction after RP was oncologically safe. Nevertheless, more large sample cohort studies are needed to validate this conclusion.

Sexual Activity and Risk of Prostate Cancer: A Dose-Response Meta-Analysis

INTRODUCTION

The role of sexual activity (SA) on prostate cancer (PCa) risk is still controversial.

AIM

To determine the associations among number of female sexual partners, age at first intercourse, ejaculation frequency (EF), and the risk of PCa.

METHODS

A systematic literature search on MEDLINE, Cochrane Central Register of Controlled Trials, and Web of Science based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted to identify the relevant studies published before April 2018. We calculated the summary odds ratio (OR) and 95% CI to determine the association between SA and PCa risk. A 2-stage dose-response meta-analysis was performed to explore the trend from the correlated log OR estimates.

MAIN OUTCOME MEASURES

Outcome measures included characteristics of included studies, associations among number of female sexual partners, age at first intercourse, as well as EF and PCa risk.

RESULTS

A total of 21 case-control studies and 1 cohort study with 55,490 participants (14,976 patients and 40,514 controls) were included in this meta-analysis. Linear and significant dose-response associations were found among number of female sexual partner as well as age at first intercourse and PCa risk, an increment of 10 female sexual partners associated with a 1.10-fold increase of PCa risk (OR 1.10, 95% CI 1.01-1.21), and the risk of PCa was decreased by 4% for every 5-year delay in age at first intercourse (OR 0.96, 95% CI 0.92-0.99). Although no linear association was observed between EF and the risk of PCa, moderate EF (2-4 times per week) was significantly associated with a lower risk of PCa (OR 0.91, 95% CI 0.87-0.96).

CLINICAL IMPLICATIONS

Modification of SA factors would appear to be a useful low-risk approach to decreasing the risk of PCa.

STRENGTHS & LIMITATIONS

This is the first dose-response meta-analysis performed to describe the association between SA and PCa risk. However, the direction of causality between SA and risk of PCa should be interpreted with caution because most included studies used case-control design.

CONCLUSION

Meta-analysis of the included studies indicated that men with fewer sexual partner numbers, older age at first intercourse, and moderate frequent ejaculation were associated with a significantly decreased risk of PCa. Jian Z, Ye D, Chen Y, et al. Sexual Activity and Risk of Prostate Cancer: A Dose-Response Meta-Analysis. J Sex Med 2018;15:1300-1309.

Polygamy, sexual behavior in a population under risk for prostate cancer diagnostic: an observational study from the Black Sea Region in Turkey

Aim:

Although prostate cancer (PCa) is the most common cancer type in men, a replaceable risk factor has not yet been established. In our study, we assessed the relationship between the number of sexual partners, age of first sexual experience and age of first masturbation and prostate cancer incidence.

Materials and Methods:

In Ordu University Department of Urology between January 2013 and September 2016, in PSA elevation and rectal examination, patients with prostate biopsy were evaluated due to nodule palpation in the prostate. At younger ages and at present, their first masturbation ages, first sexual debut ages, and total sexual partner numbers were recorded. The correlation between the obtained data and PCa frequency was evaluated.

Results:

The study included 146 patients with PCa identified on biopsy and 171 patients with benign biopsy results who answered the questions. 66.7% of the ones whose biopsy results were benign and 40.6% of cancer suspects had only one sexual partner. The median number of sexual partners was 1±4 (1-100) in the benign group and 2±6 (1-500) in the malignant group (p=0.039). There was a negative correlation between age of first sexual debut and number of partners (r: −0,479; p <0.001).

Conclusion:

In our study, it appears that there may be an association between the number of sexual partners and prostate cancer in the patient group with PSA level above 4ng/mL. Avoidance of sexual promiscuity or participation in protected sex may be beneficial to protect against prostate cancer.

Social determinants of prostate cancer in the Caribbean: a systematic review and meta-analysis

BACKGROUND

Prostate cancer remains the leading cause of cancer deaths among Caribbean men. However, little data exists on the influence of social factors on prostate cancer in the Caribbean setting. This article supports the 2011 Rio Political Declaration on addressing health inequalities by presenting a systematic review of evidence on the role of social determinants on prostate cancer in Caribbean men. It aims to determine the distribution, by known social determinants of health, of the frequency and adverse outcomes of prostate cancer among Caribbean populations.

METHODS

Observational studies reporting an association between a social determinant and prostate cancer frequency and outcomes were sought in MEDLINE, EMBASE, SciELO, CINAHL, CUMED, LILACS, and IBECS databases. Fourteen social determinants and 7 prostate cancer endpoints were chosen, providing 98 possible relationship groups exploring the role of social determinants on prostate cancer. Observational studies with > 50 participants conducted in Caribbean territories between 2004 and 2016 were eligible. The review was conducted according to STROBE and PRISMA guidelines. Random-effects meta-analyses were performed.

RESULTS

From 843 potentially relevant citations, 13 articles from 9 studies were included. From these included studies, 24 relationships were reported looking at 11 distinct relationship groups, leaving 90 relationship groups (92% of all relationship groups) unexplored. Study heterogeneity and risk of bias restricted results to a narrative synthesis in most instances. Meta-analyses showed more diagnosed prostate cancer among men with less formal education (n = 2 studies, OR 1.60, 95%CI 1.18-2.19) and among men who were married (n = 3 studies, OR 1.54, 95%CI 1.22-1.95).

CONCLUSIONS

This review highlights limited evidence for a higher occurrence of diagnosed prostate cancer among Caribbean men with lower levels of education and among men who are married. The role of social determinants on prostate cancer among Caribbean men remains poorly understood. Improvements in study quantity and quality, and reduced variability in outcomes and reporting are needed. This report represents the current evidence, and provides a roadmap to future research priorities for a better understanding of Caribbean prostate cancer inequalities.

Prostatitis, other genitourinary infections and prostate cancer risk: Influence of non-steroidal anti-inflammatory drugs? Results from the EPICAP study

Epidemiological studies have suggested that prostatitis may increase the risk of prostate cancer due to chronic inflammation. We studied the association between several genitourinary infections and the risk of prostate cancer based on data from the EPICAP study. EPICAP is a population-based case-control study conducted in the département of Hérault, France, between 2012 and 2014. A total of 819 incident cases and 879 controls have been face to face interviewed using a standardized questionnaire gathering information on known or suspected risk factors of prostate cancer, and personal history of genitourinary infections: prostatitis, urethritis, orchi-epididymitis, and acute pyelonephritis. Odds Ratios (OR) and their 95% confidence interval were estimated using multivariate unconditional logistic regression. Overall, 139 (18%) cases and 98 (12%) controls reported having at least one personal history of genitourinary infections (OR = 1.64 [1.23-2.20]). The risk increased with the number of infections (p-trend < 0.05). The association was specifically observed with personal history of chronic prostatitis and acute pyelonephritis (OR = 2.95 [1.26-6.92] and OR = 2.66 [1.29-5.51], respectively) and in men who did not use any non-steroidal anti-inflammatory drugs (OR = 2.00 [1.37-2.91]). Our results reinforce the hypothesis that chronic inflammation, generated by a personal history of genitourinary infections, may play a role in prostate carcinogenesis.

Spondyloarthritis, Acute Anterior Uveitis, and Fungi: Updating the Catterall-King Hypothesis

Spondyloarthritis is a common type of arthritis which affects mostly adults. It consists of idiopathic chronic inflammation of the spine, joints, eyes, skin, gut, and prostate. Inflammation is often asymptomatic, especially in the gut and prostate. The HLA-B*27 allele group, which presents intracellular peptides to CD8+ T cells, is by far the strongest risk factor for spondyloarthritis. The precise mechanisms and antigens remain unknown. In 1959, Catterall and King advanced a novel hypothesis explaining the etiology of spondyloarthritis: an as-yet-unrecognized sexually acquired microbe would be causing all spondyloarthritis types, including acute anterior uveitis. Recent studies suggest an unrecognized sexually acquired fungal infection may be involved in prostate cancer and perhaps multiple sclerosis. This warrants reanalyzing the Catterall-King hypothesis based on the current literature. In the last decade, many links between spondyloarthritis and fungal infections have been found. Antibodies against the fungal cell wall component mannan are elevated in spondyloarthritis. Functional polymorphisms in genes regulating the innate immune response against fungi have been associated with spondyloarthritis (CARD9 and IL23R). Psoriasis and inflammatory bowel disease, two common comorbidities of spondyloarthritis, are both strongly associated with fungi. Evidence reviewed here lends credence to the Catterall-King hypothesis and implicates a common fungal etiology in prostate cancer, benign prostatic hyperplasia, multiple sclerosis, psoriasis, inflammatory bowel disease, and spondyloarthritis. However, the evidence available at this time is insufficient to definitely confirm this hypothesis. Future studies investigating the microbiome in relation to these conditions should screen specimens for fungi in addition to bacteria. Future clinical studies of spondyloarthritis should consider antifungals which are effective in psoriasis and multiple sclerosis, such as dimethyl fumarate and nystatin.

Alzheimer's disease is associated with prostate cancer: a population-based study

Alzheimer’s disease and cancer are increasingly prevalent with advancing age. However, the association between Alzheimer’s disease and prostate cancer remains unclear. The aim of this study was to examine the relationship between prior Alzheimer’s disease and subsequent prostate cancer using a population-based dataset in Taiwan. Data for this study were sourced from the Taiwan Longitudinal Health Insurance Database 2005. This case-control study included 2101 prostate cancer patients as cases and 6303 matched controls. We used conditional logistic regression analyses to calculate the odds ratio (OR) and corresponding 95% confidence interval (CI) for Alzheimer’s disease between prostate cancer patients and controls. We found that of the 8404 sampled patients, 128 (1.5%) had been diagnosed with Alzheimer’s disease prior to the index date. A Chi-squared test showed that there was a significant difference in the prevalences of prior Alzheimer’s disease between prostate cancer patients and controls (2.1% vs. 1.3%, p < 0.001). The conditional logistic regression analysis showed that the OR of prior Alzheimer’s disease for prostate cancer patients was 1.53 (95% CI: 1.06∼2.21) compared to controls. Furthermore, the OR of prior Alzheimer’s disease for prostate cancer patients was 1.52 (95% CI: 1.04∼2.22) compared to controls after adjusting for hypertension, diabetes, coronary heart disease, hyperlipidemia, obesity, prostatitis, gonorrhea or chlamydia infection, testitis or epididymitis, and alcohol abuse/alcohol dependency syndrome. This study revealed an association between prior Alzheimer’s disease and prostate cancer. We suggest that clinicians be alert to the increased risk of prostate cancer when caring for elderly individuals with Alzheimer’s disease.

The Role of Fungi in the Etiology of Multiple Sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disorder of the central nervous system. Infectious triggers of MS are being actively investigated. Substantial evidence supports the involvement of the Epstein-Barr virus (EBV), though other viruses, bacteria, protists, and fungi are also being considered. Many links between fungi and diseases involving chronic inflammation have been found recently. Evidence linking MS and fungi is reviewed here. The HLA-DRB1*15 allele group is the most important genetic risk factor of MS, and is a risk factor in several other conditions linked to fungal infections. Many biomarkers of MS are consistent with fungal infections, such as IL-17, chitotriosidase, and antibodies against fungi. Dimethyl fumarate (DMF), first used as an industrial fungicide, was recently repurposed to reduce MS symptoms. Its mechanisms of action in MS have not been firmly established. The low risk of MS during childhood and its moderate association with herpes simplex virus type 2 suggest genital exposure to microbes (including fungi) should be investigated as a possible trigger. Molecular and epidemiological evidence support a role for infections such as EBV in MS. Though fungal infections have not been widely studied in MS, many lines of evidence are consistent with a fungal etiology. Future microbiome and serological studies should consider fungi as a possible risk factor for MS, and future clinical studies should consider the effect of fungicides other than DMF on MS symptoms.

Role of antibodies to human papillomavirus 16 in prostate cancer: A seroscreening by peptide microarray

Evidence is accumulating in estimating the potential role of human papillomavirus infection in prostate carcinogenesis. However, the results remain inconclusive. We measured the serostatus of antibodies to one of the high-risk human papillomaviruses, human papillomavirus 16, with a newly developed peptide microarray. Serum samples were collected from 75 untreated prostate cancer patients, along with 80 control subjects. We identified 12 peptides with significant differences in prostate cancer samples from all 241 peptides derived from human papillomavirus 16. Our results showed human papillomavirus 16 infection in 64.0% of prostate cancer serum samples, which is significantly different compared with the controls ( p < 0.01) because only 17.5% of the control serum was considered seropositive. The area under the receiver operator characteristic curve was 0.793 (95% confidence interval 0.721-0.864), indicating that the new microarray technique may have diagnostic value. The results showed an association between serological evidence for human papillomavirus 16 infection and risk of prostate cancer. The different serostatus of antibodies in the two subgroups indicated that human papillomavirus 16 infection might occur and play a potential role of progression in a minority of prostate cancer.

Chemopreventive Strategies for Inflammation-Related Carcinogenesis: Current Status and Future Direction

A sustained and chronically-inflamed environment is characterized by the presence of heterogeneous inflammatory cellular components, including neutrophils, macrophages, lymphocytes and fibroblasts. These infiltrated cells produce growth stimulating mediators (inflammatory cytokines and growth factors), chemotactic factors (chemokines) and genotoxic substances (reactive oxygen species and nitrogen oxide) and induce DNA damage and methylation. Therefore, chronic inflammation serves as an intrinsic niche for carcinogenesis and tumor progression. In this article, we summarize the up-to-date findings regarding definitive/possible causes and mechanisms of inflammation-related carcinogenesis derived from experimental and clinical studies. We also propose 10 strategies, as well as candidate agents for the prevention of inflammation-related carcinogenesis.

Erectile dysfunction and the risk of prostate cancer

Background

Prostate cancer (PCa) is the most commonly diagnosed malignancy and the third leading cause of cancer death among men in developed countries. Because some risk factors are common between erectile dysfunction (ED) and PCa, we investigated the association between ED and subsequent PCa.

Methods

This nationwide population-based cohort study used data from the Taiwan National Health Insurance Research Database for the period 2000–2010. We identified patients newly diagnosed with ED by using codes from the International Classification of Diseases, Ninth Revision, Clinical Modification.

Results

In total, 5858 and 23432 patients were enrolled in the ED and non-ED cohorts, respectively. After adjustment for age, sex, and comorbidities, the overall incidence densities of PCa were significantly higher in the ED cohort than in the non-ED cohort, with an adjusted hazard ratio (aHR) of 1.19. The age-specific relative risk of PCa was significantly higher for all age groups in the ED cohort than in the non-ED cohort. Compared with patients without ED, those with organic ED had a 1.27-fold higher risk of PCa.

Conclusion

ED is a harbinger of PCa in some men. Physicians should consider the possibility of occult PCa in patients with ED regardless of age and comorbidities.

Adult body size, sexual history and adolescent sexual development, may predict risk of developing prostate cancer: Results from the New South Wales Lifestyle and Evaluation of Risk Study (CLEAR)

Prostate cancer (PC) is the most common non-cutaneous cancer in men worldwide. The relationships between PC and possible risk factors for PC cases (n = 1,181) and male controls (n = 875) from the New South Wales (NSW) Cancer, Lifestyle and Evaluation of Risk Study (CLEAR) were examined in this study. The associations between PC risk and paternal history of PC, body mass index (BMI), medical conditions, sexual behaviour, balding pattern and puberty, after adjusting for age, income, region of birth, place of residence, and PSA testing, were examined. Adjusted risk of PC was higher for men with a paternal history of PC (OR = 2.31; 95%CI: 1.70-3.14), personal history of prostatitis (OR = 2.30; 95%CI: 1.44-3.70), benign prostatic hyperplasia (OR = 2.29; 95%CI: 1.79-2.93), being overweight (vs. normal; OR = 1.24; 95%CI: 0.99-1.55) or obese (vs. normal; OR = 1.44; 95%CI: 1.09-1.89), having reported more than seven sexual partners in a lifetime (vs. < 3 partners; OR = 2.00; 95%CI: 1.49-2.68), and having reported more than 5 orgasms a month prior to PC diagnosis (vs. ≤3 orgasms; OR = 1.59; 95%CI: 1.18-2.15). PC risk was lower for men whose timing of puberty was later than their peers (vs. same as peers; OR = 0.75; 95%CI: 0.59-0.97), and a smaller risk reduction of was observed in men whose timing of puberty was earlier than their peers (vs. same as peers; OR = 0.85; 95%CI: 0.61-1.17). No associations were found between PC risk and vertex balding, erectile function, acne, circumcision, vasectomy, asthma or diabetes. These results support a role for adult body size, sexual activity, and adolescent sexual development in PC development.

The association between sexual function and prostate cancer risk in US veterans

Sexual dysfunction and prostate cancer are common among older men. Few studies explored the association between these two illnesses. We examined whether sexual function is associated with prostate cancer risk among older men. Among 448 men undergoing prostate biopsy at the Durham Veterans Affairs Hospital, sexual function was ascertained from the Expanded Prostate Cancer Index Composite sexual assessment. We tested the link between sexual function and prostate cancer risk adjusting for multiple demographic and clinical characteristics using logistic regression. Multinomial logistic regression was used to test the associations with risk of low-grade (Gleason ≤6) and high-grade (Gleason ≥7 or ≥4 + 3) disease versus no cancer. Of 448 men, 209 (47%) had a positive biopsy; these men were less likely to be white (43% vs 55%, P = 0.013), had higher prostate-specific antigen (PSA) (6.0 vs 5.4 ng ml⁻¹, P < 0.001), but with lower mean sexual function score (47 vs 54, P = 0.007). There was no difference in age, BMI, pack years smoked, history of heart disease and/or diabetes. After adjusting for baseline differences, sexual function was linked with a decreased risk of overall prostate cancer risk (OR: 0.91 per 10-point change in sexual function, P = 0.004) and high-grade disease whether defined as Gleason ≥7 (OR: 0.86, P = 0.001) or ≥4 + 3 (OR: 0.85, P = 0.009). Sexual function was unrelated to low-grade prostate cancer (OR: 0.94, P = 0.13). Thus, among men undergoing prostate biopsy, higher sexual function was associated with a decreased risk of overall and high-grade prostate cancer. Confirmatory studies are needed.

Epidemiology of Prostate Cancer

Prostate cancer is the most common malignancy among males worldwide, and is the second leading cause of cancer death among men in United States. According to GLOBOCAN (2012), an estimated 1.1 million new cases and 307,000 deaths were reported in 2012. The reasons for the increase of this disease are not known, but increasing life expectancy and modified diagnostic techniques have been suggested as causes. The established risk factors for this disease are advancing age, race, positive family history of prostate cancer and western diet (use of fat items). Several other risk factors, such as obesity, physical activity, sexual activity, smoking and occupation have been also associated with prostate cancer risk, but their roles in prostate cancer etiology remain uncertain. This mini-review aims to provide risk factors, disease knowledge, prevalence and awareness about prostate cancer.

Pubertal development and prostate cancer risk: Mendelian randomization study in a population-based cohort

BACKGROUND

Epidemiological studies have observed a positive association between an earlier age at sexual development and prostate cancer, but markers of sexual maturation in boys are imprecise and observational estimates are likely to suffer from a degree of uncontrolled confounding. To obtain causal estimates, we examined the role of pubertal development in prostate cancer using genetic polymorphisms associated with Tanner stage in adolescent boys in a Mendelian randomization (MR) approach.

METHODS

We derived a weighted genetic risk score for pubertal development, combining 13 SNPs associated with male Tanner stage. A higher score indicated a later puberty onset. We examined the association of this score with prostate cancer risk, stage and grade in the UK-based ProtecT case-control study (n = 2,927), and used the PRACTICAL consortium (n = 43,737) as a replication sample.

RESULTS

In ProtecT, the puberty genetic score was inversely associated with prostate cancer grade (odds ratio (OR) of high- vs. low-grade cancer, per tertile of the score: 0.76; 95 % CI, 0.64-0.89). In an instrumental variable estimation of the causal OR, later physical development in adolescence (equivalent to a difference of one Tanner stage between pubertal boys of the same age) was associated with a 77 % (95 % CI, 43-91 %) reduced odds of high Gleason prostate cancer. In PRACTICAL, the puberty genetic score was associated with prostate cancer stage (OR of advanced vs. localized cancer, per tertile: 0.95; 95 % CI, 0.91-1.00) and prostate cancer-specific mortality (hazard ratio amongst cases, per tertile: 0.94; 95 % CI, 0.90-0.98), but not with disease grade.

CONCLUSIONS

Older age at sexual maturation is causally linked to a reduced risk of later prostate cancer, especially aggressive disease.

Ejaculation Frequency and Risk of Prostate Cancer: Updated Results with an Additional Decade of Follow-up

BACKGROUND

Evidence suggests that ejaculation frequency may be inversely related to the risk of prostate cancer (PCa), a disease for which few modifiable risk factors have been identified.

OBJECTIVE

To incorporate an additional 10 yr of follow-up into an original analysis and to comprehensively evaluate the association between ejaculation frequency and PCa, accounting for screening, clinically relevant disease subgroups, and the impact of mortality from other causes.

DESIGN, SETTING, AND PARTICIPANTS

A prospective cohort study of participants in the Health Professionals Follow-up Study utilizing self-reported data on average monthly ejaculation frequency. The study includes 31925 men who answered questions on ejaculation frequency on a 1992 questionnaire and followed through to 2010. The average monthly ejaculation frequency was assessed at three time points: age 20-29 yr, age 40-49 yr, and the year before questionnaire distribution.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Incidence of total PCa and clinically relevant disease subgroups. Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS AND LIMITATIONS

During 480831 person-years, 3839 men were diagnosed with PCa. Ejaculation frequency at age 40-49 yr was positively associated with age-standardized body mass index, physical activity, divorce, history of sexually transmitted infections, and consumption of total calories and alcohol. Prostate-specific antigen (PSA) test utilization by 2008, number of PSA tests, and frequency of prostate biopsy were similar across frequency categories. In multivariable analyses, the hazard ratio for PCa incidence for ≥21 compared to 4-7 ejaculations per month was 0.81 (95% confidence interval [CI] 0.72-0.92; p<0.0001 for trend) for frequency at age 20-29 yr and 0.78 (95% CI 0.69-0.89; p<0.0001 for trend) for frequency at age 40-49 yr. Associations were driven by low-risk disease, were similar when restricted to a PSA-screened cohort, and were unlikely to be explained by competing causes of death.

CONCLUSIONS

These findings provide additional evidence of a beneficial role of more frequent ejaculation throughout adult life in the etiology of PCa, particularly for low-risk disease.

PATIENT SUMMARY

We evaluated whether ejaculation frequency throughout adulthood is related to prostate cancer risk in a large US-based study. We found that men reporting higher compared to lower ejaculatory frequency in adulthood were less likely to be subsequently diagnosed with prostate cancer.

Reduced risk of prostate cancer in childless men as compared to fathers: a systematic review and meta-analysis

The previously reported association between fatherhood status and prostate cancer risk was controversial. We carried out the present meta-analysis of all relevant studies to summarize evidence on this association. A comprehensive literature search of studies was performed in PubMed, Web of Science, and the Chinese National Knowledge Infrastructure (CNKI) databases, covering all the papers published from their inception to September 2015. The combined risk estimates with 95% confidence intervals (CIs) were calculated using a random effects model. Heterogeneity and publication bias were also evaluated. A total of 11 studies were finally included in this meta-analysis. We found a significantly reduced risk of prostate cancer associated with being childless (OR 0.91, 95% CI 0.87–0.96). There was statistically significant heterogeneity across the studies (P < 0.001, I² = 88.2%). In summary, this meta-analysis supports that being fatherless is associated with a lower risk of prostate cancer. Because of the substantial heterogeneity and residual confounding, using other study designs to further explore this association and the underling mechanism is warranted.

History of gonorrhea and prostate cancer in a population-based case-control study in Mexico

We evaluated the association between a history of sexually transmitted diseases (STDs) and the risk for prostate cancer (PC) among Mexican males.

METHODS

PC incident cases (n=402) that were identified at six public hospitals in Mexico City were matched by age (±5 years) with 805 population controls with no history of PC. By face-to-face interview, we obtained information about sexual history, previous STDs, sociodemographic characteristics, and familial history of PC. An unconditional logistic regression model was used to estimate the risk for PC.

RESULTS

A total of 16.6% of men reported having had at least one previous STD, and the most frequently reported STD was gonorrhea (10.5%). After adjusting by PC familial history, the history of STD was associated with a two-fold greater risk of PC: odds ratio (OR)=2.67; 95% confidence interval (95% CI=1.91-3.73). When each STD was evaluated separately, only gonorrhea was associated with a significant increase in PC risk (OR=3.04; 95% CI=1.99-4.64). These associations were similar when we stratified by low-risk PC (Gleason <7) and high-risk PC (Gleason ≥7).

CONCLUSION

These results confirm that STDs, and particularly gonorrhea, may play an etiological role in PC among Mexican males, which is consistent with a previous report from a multiethnic cohort.

An epidemiological analysis of potential associations between C-reactive protein, inflammation, and prostate cancer in the male US population using the 2009-2010 National Health and Nutrition Examination Survey (NHANES) data

Prostate cancer is the second leading cause of cancer-related deaths in US males, yet much remains to be learned about the role of inflammation in its etiology. We hypothesized that preexisting exposure to chronic inflammatory conditions caused by infectious agents or inflammatory diseases increase the risk of prostate cancer. Using the 2009-2010 National Health and Nutrition Examination Survey, we examined the relationships between demographic variables, inflammation, infection, circulating plasma C-reactive protein (CRP), and the risk of occurrence of prostate cancer in US men over 18 years of age. Using IBM SPSS, we performed bivariate and logistic regression analyses using high CRP values as the dependent variable and five study covariates including prostate cancer status. From 2009-2010, an estimated 5,448,373 men reported having prostate cancer of which the majority were Caucasian (70.1%) and were aged 40 years and older (62.7%). Bivariate analyses demonstrated that high CRP was not associated with an increased risk of prostate cancer. Greater odds of having prostate cancer were revealed for men that had inflammation related to disease (OR = 1.029, CI 1.029-1.029) and those who were not taking drugs to control inflammation (OR = 1.330, CI 1.324-1.336). Men who did not have inflammation resulting from non-infectious diseases had greater odds of not having prostate cancer (OR = 1.031, CI 1.030-1.031). Logistic regression analysis yielded that men with the highest CRP values had greater odds of having higher household incomes and lower odds of having received higher education, being aged 40 years or older, being of a race or ethnicity different from other, and of having prostate cancer. Our results show that chronic inflammation of multiple etiologies is a risk factor for prostate cancer and that CRP is not associated with this increased risk. Further research is needed to elucidate the complex interactions between inflammation and prostate cancer.

Association of male circumcision with risk of prostate cancer: a meta-analysis

BACKGROUND

Although early reports have suggested an association between circumcision and prostate cancer (PCa) development, results of subsequent epidemiological studies have been conflicting. Here we examine published articles that explore this association.

METHODS

We searched MEDLINE through PubMed and Embase for articles reporting on the association between PCa and circumcision, and performed a meta-analysis of qualifying studies.

RESULTS

On the basis of seven reports of case-control studies published from 1971 to 2014, overall findings showed nonsignificant reduced risk (odds ratio (OR) 0.88, P=0.19) of PCa in circumcised men compared with uncircumcised men, obtained under heterogeneous conditions (I(2)=65%). Heterogeneity and nonsignificance were erased when the overall effect was subjected to outlier treatment and three studies omitted (OR 0.90, P=0.04, I(2)=0%). Furthermore, subgroup analysis showed significantly reduced risks in the following subgroups: (i) post-PSA testing publications (OR 0.88, P=0.01), (ii) population-based studies (OR 0.84, P=0.05), (iii) studies that collected data by personal interview (OR 0.83, P=0.03) and (iv) studies in black race (OR 0.59, P=0.02). The strengths of these summary effects lie in the robustness revealed by sensitivity analysis.

CONCLUSIONS

Stability of the reduced risks observed in key subgroups suggests that the protective feature of circumcision status against PCa is best seen in the context of the post-PSA testing and population-based studies as well as in the black race subgroup.

Gonorrhea and Prostate Cancer Incidence: An Updated Meta-Analysis of 21 Epidemiologic Studies

BACKGROUND

The association between gonorrhea and prostate cancer risk has been investigated widely, but the results remain inconsistent and contradictory. We conducted an updated meta-analysis to obtain a more precise estimate of this association.

MATERIAL AND METHODS

PubMed, EMBASE, and the Cochrane Library were searched for papers up to June 2014 to identify eligible studies. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the influence of gonorrhea on prostate cancer risk.

RESULTS

Twenty-one observational studies (19 case-control and 2 cohort) were eligible, comprising 9965 prostate cancer patients and 118 765 participants. Pooled results indicated that gonorrhea was significantly associated with increased incidence of prostate cancer (OR 1.31, 95% CI 1.14-1.52). The association between gonorrhea and prostate cancer was stronger in African American males (OR 1.32, 95% CI 1.06-1.65) than in Whites (OR 1.05, 95% CI 0.90-1.21).

CONCLUSIONS

Our findings suggest that gonorrhea is associated with an increased risk of prostate cancer, especially among African American males. These results warrant further well-designed, large-scale cohort studies to draw definitive conclusions.

Prostatitis, other genitourinary infections and prostate cancer: results from a population-based case-control study

PURPOSE

We relied on a population-based case-control study (PROtEuS) to examine a potential association between the presence of histologically confirmed prostate cancer (PCa) and history of genitourinary infections, e.g., prostatitis, urethritis, orchitis and epididymitis.

PATIENTS AND METHODS

Cases were 1933 men with incident PCa, diagnosed across Montreal hospitals between 2005 and 2009. Population controls were 1994 men from the same residential area and age distribution. In-person interviews collected information about socio-demographic characteristics, lifestyle and medical history, e.g., self-reported history of several genitourinary infections, as well as on PCa screening. Logistic regression analyses tested overall and grade-specific associations, including subgroup analyses with frequent PSA testing.

RESULTS

After multivariable adjustment, prostatitis was associated with an increased risk of any PCa (OR 1.81 [1.44-2.27]), but not urethritis (OR 1.05 [0.84-1.30]), orchitis (OR 1.28 [0.92-1.78]) or epididymitis (OR 0.98 [0.57-1.68]). The association between prostatitis and PCa was more pronounced for low-grade PCa (Gleason ≤ 6: OR 2.11 [1.61-2.77]; Gleason ≥ 7: OR 1.59 [1.22-2.07]). Adjusting for frequency of physician visits, PSA testing frequency or restricting analyses to frequently screened subjects did not affect these results.

CONCLUSION

Prostatitis was associated with an increased probability for detecting PCa even after adjustment for frequency of PSA testing and physician visits, but not urethritis, orchitis or epididymitis. These considerations may be helpful in clinical risk stratification of individuals in whom the risk of PCa is pertinent.

Red cell distribution width as a predictor of prostate cancer progression

BACKGROUND

The aims of this study were to investigate the utility of red blood cell distribution width (RDW) as a simple and readily available marker in prostate cancer, as well as to evaluate RDW as a predictor of progression in prostate cancer patients.

MATERIALS AND METHODS

We evaluated 62 newly diagnosed prostate cancer patients who underwent transrectal ultrasound (TRUS)-guided biopsy and 62 healthy controls of mean age 64 (range, 45-75) years at the Urology Clinic of Bozok University Hospital. Data collection was performed using our laboratory information system database to retrieve findings regarding RDW, hemoglobin, prostate- specific antigen (PSA), and age. The RDW values were compared between the healthy control group and prostate cancer patients. A high risk of progression as defined as a Gleason score (GS) >6, total number of cores positive for cancer >33%, each core containing >50% cancer cells, and a prostate-specific antigen (PSA) level >10 ng/ mL. Patients were classified according to risk of progression, as well as divided into subgroups according to the RDW quartile.

RESULTS

The mean RDW value of prostate cancer patients was 14.6, compared with 13.7 in the healthy control group (p=0.001). A higher RDW was associated with an increased risk of progression, whereas a lower RDW value was correlated with a low risk of progression.

CONCLUSIONS

RDW is an easily derived measure that might, in combination with other markers, help predict prostate cancer risk and progression. We suggest that RDW may be used in combination with other parameters in the assessment of prostate cancer.

Polymorphisms of an innate immune gene, toll-like receptor 4, and aggressive prostate cancer risk: a systematic review and meta-analysis

BACKGROUND

Toll-like receptor 4 (TLR4) is one of the best known TLR members expressed on the surface of several leukocytes and tissue cells and has a key function in detecting pathogen and danger-associated molecular patterns. The role of TLR4 in the pathophysiology of several age-related diseases is also well recognized, such as prostate cancer (PCa). TLR4 polymorphisms have been related to PCa risk, but the relationship between TLR4 genotypes and aggressive PCa risk has not been evaluated by any systematic reviews.

METHODS

We performed a systematic review and meta-analysis of candidate-gene and genome-wide association studies analyzing this relationship and included only white population. Considering appropriate criteria, only nine studies were analyzed in the meta-analysis, including 3,937 aggressive PCa and 7,382 controls.

RESULTS

Using random effects model, no significant association was found in the ten TLR4 SNPs reported by at least four included studies under any inheritance model (rs2737191, rs1927914, rs10759932, rs1927911, rs11536879, rs2149356, rs4986790, rs11536889, rs7873784, and rs1554973). Pooled estimates from another ten TLR4 SNPs reported by three studies also showed no significant association (rs10759930, rs10116253, rs11536869, rs5030717, rs4986791, rs11536897, rs1927906, rs913930, rs1927905, and rs7045953). Meta-regression revealed that study type was not a significant source of between-study heterogeneity.

CONCLUSIONS

TLR4 polymorphisms were not significantly associated with the risk of aggressive PCa.

Fathering of dizygotic twins and risk of prostate cancer: nationwide, population-based case-control study

BACKGROUND

An association between male fertility and risk of prostate cancer has been suggested, possibly through lower androgen levels in subfertile men. We evaluated male fertility in relation to risk of prostate cancer by assessing the frequency of fathering of dizygotic twins, a marker of high fertility, among cases of prostate cancer and controls.

METHODS

We performed a case-control study in Prostate Cancer data Base Sweden (PCBaSe), a nationwide, population-based cohort. PCBaSe was linked to the Swedish twin register for information on zygosity for same-sex twins and to other nationwide health care registers and demographic databases for information on socioeconomic factors, comorbidity, and tumor characteristics for 96 301 prostate cancer cases and 378 583 matched controls. To account for the influence of in vitro fertilization on dizygotic twinning, analyses were restricted to men who had fathered children before 1991, when in vitro fertilization was still uncommon in Sweden.

RESULTS

1 112 cases and 4 538 controls had fathered dizygotic twins. Men with dizygotic twins had no increased risk of prostate cancer compared to fathers of singletons; neither for total prostate cancer odds ratio (OR) 0.95(95% CI 0.89-1.02), nor for any risk category, OR 0.97 (95% CI 0.84-1.12) for low-risk disease, and OR 1.04 (95% CI 0.90-1.22) for metastatic disease.

CONCLUSION

The lack of association between fathering of dizygotic twins and prostate cancer risk give no support for an association between male fertility and prostate cancer risk.

Sexual partners, sexually transmitted infections, and prostate cancer risk

BACKGROUND

The etiology of prostate cancer (PCa) is poorly understood. Sexual activity and sexually transmitted infections (STIs) are among factors under scrutiny, with controversial findings to date.

METHODS

We examined the association between the number and gender of sexual partners, STIs and PCa risk in the context of PROtEuS, a population-based case-control study set amongst the mainly French-speaking population in Montreal, Canada. The study included 1590 histologically-confirmed PCa cases diagnosed in a Montreal French hospital between 2005 and 2009, and 1618 population controls ascertained from the French electoral list, Montreal residents, frequency-matched to cases by age. In-person interviews elicited information on sociodemographic, lifestyle and environmental factors. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) between sexually related factors and PCa risk, adjusting for age, ancestry, family history of PCa, and PCa screening history.

RESULTS

Subjects with more than 20 sexual partners in their lifetime had a decreased risk of PCa (OR 0.78, 95% CI 0.61-1.00) as did subjects who specifically had more than 20 female sexual partners (OR 0.72, 95% CI 0.56-0.94). By contrast, having had several male sexual partners appeared to confer some excess in risk of PCa. No association emerged for history of STIs and PCa but STIs prevalence was low.

CONCLUSION

Our findings are in support of a role for the number of sexual partners in PCa development. The gender of sexual partners should be taken into account in future studies investigating this association.

Detection of human papillomavirus (HPV) DNA prevalence and p53 codon 72 (Arg72Pro) polymorphism in prostate cancer in a Greek group of patients

Prostate cancer is the most common neoplasm found in males and the second most frequent cause of cancer-related mortality in males in Greece. Among other pathogens, the detection frequency of human papillomavirus (HPV) has been found to be significantly increased in tumor tissues among patients with sexually transmitted diseases (STDs), depending on the geographical distribution of each population studied. The present study focused on the detection of HPV and the distribution of Arg72Pro p53 polymorphism in a cohort of healthy individuals, as well as prostate cancer patients. We investigated the presence of HPV in 50 paraffin-embedded prostate cancer tissues, as well as in 30 physiological tissue samples from healthy individuals by real-time PCR. Furthermore, the same group of patients was also screened for the presence of the Arg72Pro polymorphism of the p53 gene, a p53 polymorphism related to HPV. Out of the 30 control samples, only 1 was found positive for HPV (3.33 %). On the contrary, HPV DNA was detected in 8 out of the total 50 samples (16 %) in the prostate cancer samples. The distribution of the three genotypes, Arg/Arg, Arg/Pro, and Pro/Pro, was 69.6, 21.7, and 8.7 % in the cancer patients and 75.0, 17.86, and 7.14 % in healthy controls, respectively. No statistically significant association was observed between the HPV presence and the age, stage, p53 polymorphism status at codon 72, or PSA. The increased prevalence of HPV detected in the prostate cancer tissues is in agreement with that reported in previous studies, further supporting the association of HPV infection and prostate cancer.

The same and not the same: heterogeneous functional activation of prostate tumor cells by TLR ligation

Background

Many types of tumors are organized in a hierarchy of heterogeneous cell populations with different molecular signature. Such heterogeneity may be associated with different responsiveness to microenvironment stimuli. In the present study, the effects of lipopolysaccharide (LPS) and lipoteichoic acid (LTA), as well-known mediators of inflammation, on cancerous behavior of three prostate tumor cells, LNCaP, PC3 and DU145, were investigated.

Methods

Expression of TLR1-10, CD14 and MyD88 transcripts was investigated by RT-PCR. Protein expression of TLR2 and 4 was scrutinized by flow cytometry, immunofluorescent staining and Western blotting. Experiments were set up to assess the effects of LPS and LTA at different concentrations and times on cell proliferation, extracellular matrix invasion, adhesion and cytokine production.

Results

We showed that prostate cancer cell lines differentially express TLR1-10, MyD88 and CD14 transcripts. DU145 failed to express TLR4 gene. Positively-identified TLR2 protein in all prostate cancer cells and TLR4 protein in PC3 and LNCaP by Western blotting was not accompanied by cell surface expression, as judged by flow cytometry. Immunofluorescent staining clearly demonstrated predominantly perinuclear localization of TLR2 and TLR4. LTA activation of all prostate cancer cells significantly increased cell proliferation. Regardless of lacking TLR4, DU145 cells proliferated in response to LPS treatment. While LPS caused increased invasiveness of LNCaP, invasive capacity of PC3 was significantly reduced after LPS or LTA stimulation. Stimulation of all prostate tumor cells with LTA was associated with increased cell adhesion and IL-8 production. IL-6 production, however, was differentially regulated by LPS stimulation in prostate tumor cells.

Conclusion

The data shows that cancer cells originated from the same histologically origin exhibit heterogeneous response to the same TLR ligand. Therefore, a thorough and comprehensive judgment on how and to what extent a particular cancer is affected by TLR agonist could not be inferred by studying an individual cell line.

Epigallocatechin-3-gallate suppresses proinflammatory cytokines and chemokines induced by Toll-like receptor 9 agonists in prostate cancer cells

Chronic inflammation of the prostate contributes to the increased risk of prostate cancer. Microbial pathogens in the prostate cause inflammation that leads to prostatitis and proliferative inflammatory atrophy frequently associated with the development of prostate cancer. Bacterial lipopolysaccharides and DNA mediate immune responses by engaging Toll-like receptor (TLR) 4 and 9, respectively. Synthetic oligodeoxynucleotides containing CpG motifs (CpG-ODN) mimic bacterial DNA and signal through TLR9 to initiate innate immune responses. Here, we show that stimulation of DU145, PC3, or LnCap prostate cancer cells by the TLR9 agonists, CpG-ODN, induces mRNA expression of IL-6, IL-8, CXCL1, IP-10, CCL5, and TGFβ. In addition, activity of matrix metalloproteinase (MMP)-9 and -2 and cell migration increased on CpG-ODN treatment. Induction of cytokines and chemokines was mediated by NF-κB activation and translocation to the nucleus. Treatment with epigallocatechin-3-gallate (EGCG), the major constituent of green tea, prior to CpG-ODN stimulation, inhibits cytokine and chemokine gene induction, activity of MMP-9 and -2, and cell migration. EGCG treatment sequesters the p65 subunit of transcription factor NF-κB in the cytoplasm and inhibits transcriptional activity of the NF-κB-driven promoter in response to CpG-ODN. Our results suggest that the ability of the TLR9 agonists, CpG-ODN, to induce cytokines, chemokines, and MMP activity, as well as suppression by EGCG are independent of the androgen receptor and p53 status of the cells. EGCG may provide protective effects against inflammation in the prostate and benefit prostate cancer treatment.

Prostate cancer in young men: an important clinical entity

Prostate cancer is considered a disease of older men (aged >65 years), but today over 10% of new diagnoses in the USA occur in young men aged ≤55 years. Early-onset prostate cancer, that is prostate cancer diagnosed at age ≤55 years, differs from prostate cancer diagnosed at an older age in several ways. Firstly, among men with high-grade and advanced-stage prostate cancer, those diagnosed at a young age have a higher cause-specific mortality than men diagnosed at an older age, except those over age 80 years. This finding suggests that important biological differences exist between early-onset prostate cancer and late-onset disease. Secondly, early-onset prostate cancer has a strong genetic component, which indicates that young men with prostate cancer could benefit from evaluation of genetic risk. Furthermore, although the majority of men with early-onset prostate cancer are diagnosed with low-risk disease, the extended life expectancy of these patients exposes them to long-term effects of treatment-related morbidities and to long-term risk of disease progression leading to death from prostate cancer. For these reasons, patients with early-onset prostate cancer pose unique challenges, as well as opportunities, for both research and clinical communities. Current data suggest that early-onset prostate cancer is a distinct phenotype-from both an aetiological and clinical perspective-that deserves further attention.

Circumcision and prostate cancer: a population-based case-control study in Montréal, Canada

Objectives

To investigate the possible association between circumcision and prostate cancer risk, to examine whether age at circumcision influences prostate cancer risk, and to determine whether race modifies the circumcision–prostate cancer relationship.

Subjects and Methods

PROtEuS (Prostate Cancer and Environment Study), a population-based case-control study set amongst the mainly French-speaking population in Montréal, Canada, was used to address study objectives. The study included 1590 pathologically confirmed prostate cancer cases diagnosed in a Montréal French hospital between 2005 and 2009, and 1618 population controls ascertained from the French electoral list, frequency-matched to cases by age. In-person interviews elicited information on sociodemographic, lifestyle and environmental factors. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) between circumcision, age at circumcision and prostate cancer risk, adjusting for age, ancestry, family history of prostate cancer, prostate cancer screening history, education, and history of sexually transmitted infections.

Results

Circumcised men had a slightly lower risk, albeit not statistically significant, of developing prostate cancer than uncircumcised men (OR 0.89, 95% CI 0.76–1.04). Circumcision was found to be protective in men circumcised aged ≥36 years (OR 0.55, 95% CI 0.30–0.98). A weaker protective effect was seen among men circumcised within 1 year of birth (OR 0.86, 95% CI 0.72–1.04). The strongest protective effect of circumcision was recorded in Black men (OR 0.40, 95% CI 0.19–0.86, P-value for interaction 0.02) but no association was found with other ancestral groups.

Conclusion

Our findings provide novel evidence for a protective effect of circumcision against prostate cancer development, especially in those circumcised aged ≥36 years; although circumcision before the age of 1 year may also confer protection. Circumcision appeared to be protective only among Black men, a group that has the highest rate of disease. Further research into the differences in effect of circumcision on prostate cancer risk by ancestry is warranted, as is the influence of age at circumcision.