Sexual partners, sexually transmitted infections, and prostate cancer risk

The impact of obesity and sexual behavior on prostate cancer risk is mediated by testosterone levels: a mendelian randomization study and mediation analysis

Background

The relationship between obesity, sexual behavior, and prostate cancer (PCa) has been widely debated, contributing to a lack of understanding of its potential mechanisms and hindering the development of effective prevention measures.

Purpose

The aim of this study was to examine the causal effect of body mass index (BMI), age at first sexual intercourse (AFS), and bioavailable testosterone levels on PCa while also quantifying the potential roles of mediators.

Method

We conducted a Mendelian randomization (MR) study using summary statistics from genome-wide associations of BMI (152,893 European males), AFS (182,791 European males), bioavailable testosterone (184,205 European males), and PCa (79,148 cases, 61,106 controls, European ancestry). Inverse-variance weighted method, weighted median method, MR-Egger regression, Least Absolute Shrinkage and Selection Operator (LASSO), and outlier test were used for MR analyses. Reverse MR and mediation analysis were performed. Data analyses were conducted from December 2022 to July 2023.

Results

The results showed that genetic liability to BMI was protective of PCa (OR, 0.82; 95% CI: 0.74-0.91; P = 3.29 × 10-4). Genetic liability to later AFS (OR, 1.28; 95% CI: 1.08-1.53; P = 5.64 × 10-3) and higher bioavailable testosterone levels (OR = 1.11, 95% CI: 1.01-1.24, P = 0.04) were associated with an increased risk of PCa. All of these potential causal effects could only be forwarded and were not affected by prostate specific antigen (PSA) screening. After controlling for bioavailable testosterone levels, the causal impact of BMI and AFS on PCa was no longer significant. The mediation analysis suggested that the causal influence of AFS/BMI on PCa relied on bioavailable testosterone levels.

Conclusion

In conclusion, the difference between the univariable and multivariable MR results suggested that the causal influence of BMI and AFS on PCa relied on bioavailable testosterone levels. Further work is needed to identify other risk factors and to elucidate the specific mechanisms that underlie this causal pathway.

Sexually and non-sexually transmitted infections and the risk of prostate cancer: Results from the EPICAP study

INTRODUCTION

Prostate cancer (PCa) is by far the most common type of cancer among men in western countries. However, relatively little is known about its etiology despite the high morbidity and mortality. It has been suggested that chronic inflammation may be involved in prostate carcinogenesis. We investigated the role of sexually and non-sexually transmitted infections in prostate cancer risk with a specific interest in the aggressive types.

METHODS

We used data from epidemiological study of prostate cancer (EPICAP), a population-based case-control study. A total of 819 incident cases and 879 controls were interviewed face-to-face using a standardized questionnaire gathering information on known or suspected risk factors of prostate cancer and personal history of specific sexually and non-sexually transmitted infections: gonorrhea, syphilis, trichomonas, herpes, mononucleosis, Epstein-Barr virus, varicella-zoster, and dengue. Odds ratios (OR) and their 95% confidence interval were estimated using multivariate unconditional logistic regression.

RESULTS

There was no significant association between gonorrhea (OR: 0.90, 95% CI: 0.61-1.33), trichomonas (OR: 0.74, 95% CI: 0.27-2.07), genital herpes (OR: 0.69, 95% CI: 0.38-1.27), and the risk of prostate cancer. No association emerged for overall sexually transmitted bacterial and viral infections (OR 1.05, 95% CI: 0.86-1.29) and overall non-sexually transmitted viral infections (OR 1.11, 95% CI: 0.90-1.35) and the risk of prostate cancer.

CONCLUSION

Our results showed that sexually or non-sexually transmitted infections, either bacterial or viral, were not associated to prostate cancer. Therefore, further investigation is needed to help advance our understanding of the role of chronic inflammation in the etiology of prostate cancer, with a particular focus on its most aggressive types.

Impact of modifiable lifestyle risk factors for prostate cancer prevention: a review of the literature

Introduction

Although prostate cancer (PCa) is one of the most common cancers among men, the impact of modifiable risk and protective factors is still being debated. This review aims to qualitatively summarize the most recent studies related to potential healthy lifestyle factors affecting the development of PCa.

Methods for data acquisition

The literature focusing on modifiable risk factors for prostate cancer was reviewed. Medline and Embase via the Ovid database were searched, and all relevant and inherent articles were analyzed. Non-eligible publications, such as review articles, editorials, comments, guidelines, or case reports, were excluded.

Synthesis of the evidence obtained from data analysis

This review confirms that there is strong evidence that being overweight or obese increases the risk of advanced prostate cancer (assessed by body mass index (BMI), waist circumference, and waist-hip ratio), particularly considering central adiposity and ethnicity as contributing factors. The possible contribution of smoking still seems not entirely clear, while alcohol seems to affect PCa prevention in patients taking 5α-reductase inhibitors (5-ARIs). Dietary fibers may have anti-inflammatory properties and improve insulin sensitivity by reducing IGF bioactivity. In particular, dietary fiber intake like insoluble and legume fibers may be inversely associated with prostate cancer risk. Also, hyperglycemia and hyperinsulinemia, with untreated diabetic fasting blood glucose levels, could be modifiable prostate cancer risk factors. In two studies, aspirin was associated with a lower risk of lethal PCa and overall mortality. Concerning the role of vitamins, despite conflicting and divergent results, serum retinol concentration seems to be associated with an increased risk of prostate cancer and high-grade prostate cancer. Some studies resulted in disagreement about the role of selenium and vitamin E. We found inconsistent and controversial findings about the association between vitamin D and prostate cancer risk.

Conclusion

Far from being conclusive evidence, our findings confirm some strong evidence already found in the previous literature and highlight the need to clarify the role of some risk factors whose role is not yet completely known. This effort would facilitate the cultural and social change that may allow the shift from the treatment of prostate cancer when diagnosed to the real efforts needed for systematic prevention.

Prostate Cancer in Sexual Minorities: Epidemiology, Screening and Diagnosis, Treatment, and Quality of Life

Prostate cancer has the highest incidence among all cancers in men. Sexual minorities, including gay and bisexual men, as well as transgender, were previously a "hidden population" that experienced prostate cancer. Although there continues to remain a paucity of data in this population, analyses from studies do not reveal whether this population is more likely to endure prostate cancer. Nonetheless, several qualitative and quantitative studies have established worse quality-of-life outcomes for sexual minorities following prostate cancer treatment. Increased awareness of this previously "hidden population" among healthcare workers, as well as more research, is warranted to gain further understanding on potential disparities faced by this growing population.

The Impact of Lifestyle on Prostate Cancer: A Road to the Discovery of New Biomarkers

Prostate cancer (PCa) is one of the most common cancers among men, and its incidence has been rising through the years. Several risk factors have been associated with this disease and unhealthy lifestyles and inflammation were appointed as major contributors for PCa development, progression, and severity. Despite the advantages associated with the currently used diagnostic tools [prostate-specific antigen(PSA) serum levels and digital rectal examination (DRE)], the development of effective approaches for PCa diagnosis is still necessary. Finding lifestyle-associated proteins that may predict the development of PCa seems to be a promising strategy to improve PCa diagnosis. In this context, several biomarkers have been identified, including circulating biomarkers (CRP, insulin, C-peptide, TNFα-R2, adiponectin, IL-6, total PSA, free PSA, and p2PSA), urine biomarkers (PCA3, guanidine, phenylacetylglycine, and glycine), proteins expressed in exosomes (afamin, vitamin D-binding protein, and filamin A), and miRNAs expressed in prostate tissue (miRNA-21, miRNA-101, and miRNA-182). In conclusion, exploring the impact of lifestyle and inflammation on PCa development and progression may open doors to the identification of new biomarkers. The discovery of new PCa diagnostic biomarkers should contribute to reduce overdiagnosis and overtreatment.

The Role of Microbial Factors in Prostate Cancer Development-An Up-to-Date Review

Up-to-date studies emphasize the role of human urinary and intestinal microbiome in maintaining urogenital health. Both microbial flora and sexually transmitted pathogens may affect metabolic or immune mechanisms and consequently promote or inhibit prostate carcinogenesis. Hereby, we review the most current evidence regarding the microbial factors and their link to prostate cancer. We conducted a literature search up to December 2020. The microbial impact on prostate cancer initiation and progression is complex. The proposed mechanisms of action include induction of chronic inflammatory microenvironment (Propionibacterium spp., sexually-transmitted pathogens) and direct dysregulation of cell cycle (Helicobacter pylori, Kaposi’s sarcoma-associated herpesvirus- KSHV, human papilloma virus 18- HPV18). Suppression of immune cell expression and downregulating immune-associated genes are also observed (Gardnerella vaginalis). Additionally, the impact of the gut microbiome proved relevant in promoting tumorigenesis (Bacteroides massiliensis). Nevertheless, certain microbes appear to possess anti-tumor properties (Listeria monocytogenes, Pseudomonas spp.), such as triggering a robust immune response and apoptotic cancer cell death. The role of microbial factors in prostate cancer development is an emerging field that merits further studies. In the future, translating microbial research into clinical action may prove helpful in predicting diagnosis and potential outcomes of the disease.

Impact of Sexual Activity on the Risk of Male Genital Tumors: A Systematic Review of the Literature

Most cancers are related to lifestyle and environmental risk factors, including smoking, alcohol consumption, dietary habits, and environment (occupational exposures). A growing interest in the association between sexual activity (SA) and the development of different types of tumors in both men and women has been recorded in recent years. The aim of the present systematic review is to describe and critically discuss the current evidence regarding the association between SA and male genital cancers (prostatic, penile, and testicular), and to analyze the different theories and biological mechanisms reported in the literature. A comprehensive bibliographic search in the MEDLINE, Scopus, and Web of Science databases was performed in July 2021. Papers in the English language without chronological restrictions were selected. Retrospective and prospective primary clinical studies, in addition to previous systematic reviews and meta-analyses, were included. A total of 19 studies, including 953,704 patients were selected. Case reports, conference abstracts, and editorial comments were excluded. Men with more than 20 sexual partners in their lifetime, and those reporting more than 21 ejaculations per month, reported a decreased risk of overall and less aggressive prostate cancer (PCa). About 40% of penile cancers (PCs) were HPV-associated, with HPV 16 being the dominant genotype. Data regarding the risk of HPV in circumcised patients are conflicting, although circumcision appears to have a protective role against PC. Viral infections and epididymo-orchitis are among the main sex-related risk factors studied for testicular cancer (TC); however, data in the literature are limited. Testicular trauma can allow the identification of pre-existing TC. SA is closely associated with the development of PC through high-risk HPV transmission; in this context, phimosis appears to be a favoring factor. Sexual behaviors appear to play a significant role in PCa pathogenesis, probably through inflammatory mechanisms; however, protective sexual habits have also been described. A direct correlation between SA and TC has not yet been proven, although infections remain the most studied sex-related factor.

Prostate cancer and sexual consequences among men who have sex with men

Prostate cancer and its treatment frequently lead to sexual side effects that negatively impact personal identity, sexual function, and intimate relationships. The sexual consequences of prostate cancer treatment on men who have sex with men (MSM) differ in some ways from what is observed in heterosexual men. This review summarizes literature from the past two decades exploring how MSM are affected by, and adapt to, prostate cancer treatment. The evidence on whether prostate cancer has a lower prevalence in MSM is unclear but lower screening rates are well-documented within this population. Prostate cancer treatment affects urinary, bowel, and sexual function in both MSM and heterosexual men. These changes may have different sexual and psychological ramifications in MSM when compared to heterosexual men. A common concern among MSM treated for prostate cancer is absence of support, both from the medical profession and in some cases from their own communities. Many MSM with prostate cancer have developed coping strategies and altered sexual practices to accommodate side effects. Lessons learned from this population may have relevance to sexual wellness in non-MSM prostate cancer survivors. Concise recommendations for caring for MSM with prostate cancer are provided.

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.

Prostate cancer in sexual minorities and the influence of HIV status

Prostate cancer is the second most common cause of cancer-related death in men in the USA, but the effect of prostate cancer diagnosis and treatment on men in a sexual minority group, including men who have sex with men and transgender women, is poorly understood. Efforts to study this population are complicated, as cancer registries do not routinely collect information on sexual orientation. As a result, epidemiological data regarding this population have come from small studies that have included disparate rates of prostate cancer screening, diagnosis and treatment. Qualitative studies indicate that prostate cancer is experienced differently by sexual minorities, with distinct health-care needs that arise owing to differences in sexual practices, social support systems and relationships with the medical community. Notably, sexual minorities have been reported to experience poorer health-related quality of life outcomes than heterosexual men, and tend to have less robust social support systems, experience increased psychological distress caused by sexual dysfunction (areas of which are unmeasured after treatment), experience isolation within the health-care system and express increased levels of dissatisfaction with treatment. The incidence of prostate cancer actually seems to be decreased in men from sexual minorities living with HIV, despite there being no differences in screening and treatment, with poor cancer-specific mortality. Although the literature on patients with prostate cancer in men from sexual minority groups has historically been sparse, peer-reviewed research in this area has grown considerably during the past decade and has become an important field of study.

Understanding Prostate Cancer in Gay, Bisexual, and Other Men Who Have Sex with Men and Transgender Women: A Review of the Literature

PURPOSE OF REVIEW

a)Prostate cancer in sexual and gender minorities is an emerging medical and public health concern. The purpose of this review is to summarize the state of the science on prostate cancer in gay, bisexual, and other men who have sex with men (GBM) and transgender women (TGW). We undertook a literature review of all publications on this topic through February 2017. With 88 unique papers (83) on prostate cancer in GBM and 5 case reports of prostate cancer in TGW), a small but robust literature has emerged.

RECENT FINDINGS

b)The first half of this review critiques the literature to date, identifying gaps in approaches to study. The second half summarizes the key findings in eleven areas. In light of this admittedly limited literature, GBM appear to be screened for prostate cancer less than other men, but they are diagnosed with prostate cancer at about the same rate.

SUMMARY

c)Compared to other men, GBM have poorer urinary, bowel, and overall quality-of-life outcomes but better sexual outcomes after treatment; all these findings need more research. Prostate cancer in TGW remains rare and under researched, as the literature is limited to single-case clinical reports.

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.

The microbiome in prostate inflammation and prostate cancer

BACKGROUND

The human microbiome may influence prostate cancer initiation and/or progression through both direct and indirect interactions. To date, the majority of studies have focused on direct interactions including the influence of prostate infections on prostate cancer risk and, more recently, on the composition of the urinary microbiome in relation to prostate cancer. Less well understood are indirect interactions of the microbiome with prostate cancer, such as the influence of the gastrointestinal or oral microbiota on pro- or anti-carcinogenic xenobiotic metabolism, and treatment response.

METHODS

We review the literature to date on direct and indirect interactions of the microbiome with prostate inflammation and prostate cancer.

RESULTS

Emerging studies indicate that the microbiome can influence prostate inflammation in relation to benign prostate conditions such as prostatitis/chronic pelvic pain syndrome and benign prostatic hyperplasia, as well as in prostate cancer. We provide evidence that the human microbiome present at multiple anatomic sites (urinary tract, gastrointestinal tract, oral cavity, etc.) may play an important role in prostate health and disease.

CONCLUSIONS

In health, the microbiome encourages homeostasis and helps educate the immune system. In dysbiosis, a systemic inflammatory state may be induced, predisposing remote anatomical sites to disease, including cancer. The microbiome's ability to affect systemic hormone levels may also be important, particularly in a disease such as prostate cancer that is dually affected by estrogen and androgen levels. Due to the complexity of the potential interconnectedness between prostate cancer and the microbiome, it is vital to further explore and understand the relationships that are involved.

Latest Evidence on the Impact of Smoking, Sports, and Sexual Activity as Modifiable Lifestyle Risk Factors for Prostate Cancer Incidence, Recurrence, and Progression: A Systematic Review of the Literature by the European Association of Urology Section of Oncological Urology (ESOU)

CONTEXT

Smoking, sexual activity, and physical activity (PA) are discussed as modifiable lifestyle factors associated with prostate cancer (PCa) development and progression.

OBJECTIVE

To evaluate the available evidence concerning the association of smoking, sexual activity, and sports and exercise on PCa risk, treatment outcome, progression, and cancer-specific mortality.

EVIDENCE ACQUISITION

A systematic review of studies published between 2007 and 2017 using MEDLINE (via PubMed), Cochrane Central Register of Controlled Trials, and Web of Science databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement criteria was conducted.

EVIDENCE SYNTHESIS

While data concerning the impact of smoking on PCa development remain conflicting, there is robust evidence that smoking is associated with aggressive tumor features and worse cancer-related outcome, which seems to be maintained for 10 yr after smoking cessation. Less convincing and limited evidence exists for the association of sexual activity with PCa risk. The findings related to PA and PCa support the inference that exercise might be a useful factor in the prevention of PCa and tumor progression, while it is not finally proved under which specific conditions PA might be protective against disease development.

CONCLUSIONS

Smoking is associated with aggressive tumor features and worse cancer-related prognosis; as this negative impact seems to be maintained for 10yr after smoking cessation, urologists should advise men to quit smoking latest at PCa diagnosis to improve their prognosis. As several studies indicate a positive impact of exercise on tumor development, progression, and treatment outcome, it is certainly reasonable to advocate an active lifestyle. Least convincing evidence is available for the interaction of sexual activity and PCa, and well-conducted and longitudinal studies are clearly necessary to evaluate whether the suggested associations between PCa risk and sexual behavior are real or spurious.

PATIENT SUMMARY

In this systematic review, we looked at the impact of smoking, sexual activity, and sports and exercise on prostate cancer risk and outcome after treatment. While the evidence for sexual activity is not overall clear, we found that smoking might lead to more aggressive cancers and result in worse treatment outcome. Physical activity might prevent prostate cancer and improve cancer-related outcomes as well. Hence, it is certainly reasonable to advocate an active lifestyle and advise men to quit smoking.

Ejaculatory frequency and the risk of aggressive prostate cancer: Findings from a case-control study

OBJECTIVES

Recent literature reports inverse associations with ejaculator frequency and prostate cancer (PC). We sought to explore the relationship between ejaculatory frequency from ages 20 to 50 and subsequent development of aggressive PC.

MATERIAL AND METHODS

We conducted a case-control study sampling 2,141 men from private urology practices in Victoria, Australia. Cases were defined as men with high grade or high stage PC and controls being biopsy negative men. Ejaculation frequency recalled at age decades 20, 30, and 40 second was assessed by questionnaire. Unconditional multivariable logistic regression models were used to generate odds ratios (ORs).

RESULTS

An inverse association with ejaculatory frequency at age 30 to 39 was observed (OR per 5-unit increase per week = 0.83, 95% CI: 0.72-0.96) but not at ages 20 to 29 (OR = 1.01, 95% CI: 0.89-1.14) or ages 40 to 49 (OR = 0.95, 95% CI: 0.81-1.12). This result differed between men with new sexual partners after age 30 (OR = 0.77, P = 0.009) and those with no new partners (OR = 0.97, P = 0.8) though the test for a difference between these estimates was not significant (P = 0.11).

CONCLUSION

We found only weak evidence of an inverse association between ejaculatory frequency in the fourth decade of life and advanced PC, which was not significantly modified by number of new sexual partners. No relationship was found for ejaculatory frequency in the third and fifth decades of life.

Gonorrhea infection increases the risk of prostate cancer in Asian population: a nationwide population-based cohort study

This nationwide population-based retrospective cohort study evaluated the risk of developing prostate cancer among patients with gonorrhea. We identified cases of newly diagnosed gonorrhea in men between 2000 and 2010 from the Taiwan National Health Insurance Research Database. Each patient with gonorrhea was matched to four controls, based on age and index year. All subjects were followed up from the index date to December 31, 2010. The Cox proportional hazards regression model was used to assess the risk of prostate cancer. A total of 355 men were included in the study group, and 1,420 age-matched subjects without gonorrhea were included in the control group. After adjusting for age, comorbidities, urbanization level, hospital level, and monthly income, gonorrhea was significantly associated with an increased risk of prostate cancer (adjusted hazard ratio = 5.66, 95% confidence interval = 1.36-23.52). Men aged 45-70 years and those with lower monthly income were more strongly associated with prostate cancer in the study group than the control group. The higher risk for developing prostate cancer were also found in those without syphilis, without genital warts, without diabetes mellitus, without chronic obstructive pulmonary disease, without benign prostatic hypertrophy, without chronic prostatitis, and without alcoholism. The Kaplan-Meier analysis showed the risk of prostate cancer was significantly higher in the study group than in the control group. Gonorrhea may be involved in the development of prostate cancer. More intensive screening and prevention interventions for prostate cancer should be recommended in men with gonorrhea.

Evidence for Masturbation and Prostate Cancer Risk: Do We Have a Verdict?

INTRODUCTION

Prostate cancer (PCa) is one of the leading causes of cancer death in men and remains one of the most diagnosed malignancies worldwide. Ongoing public health efforts continue to promote protective factors, such as diet, physical activity, and other lifestyle modifications, against PCa development. Masturbation is a nearly universal safe sexual activity that transcends societal boundaries and geography yet continues to be met with stigma and controversy in contemporary society. Although previous studies have examined associations between sexual activity and PCa risk, anecdotal relations have been suggested regarding masturbation practice and PCa risk.

AIM

To provide a summary of the published literature and examine the contemporary evidence for relations between masturbation practice and PCa risk.

METHODS

A survey of the current literature using seven academic electronic databases was conducted using search terms and key words associated with masturbation practice and PCa risk.

MAIN OUTCOME MEASURES

The practice of masturbation and its relation to PCa risk.

RESULTS

The literature search identified study samples (n = 16) published before October 2015. Sample inclusions varied by study type, sample size, and primary objective. Protective relations (n = 7) between ejaculation through masturbation and PCa risk were reported by 44% of the study sample. Age range emerged as a significant variable in the relation between masturbation and PCa.

CONCLUSION

Findings included relations among masturbation, ejaculation frequency, and age range as individual factors of PCa risk. No universally accepted themes were identified across the study sample. Throughout the sample, there was insufficient agreement in survey design and data reporting. Potential avenues for new research include frequency of ejaculation and age range as covarying factors that could lead to more definitive statements about masturbation practice and PCa risk.

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.

Countries with high circumcision prevalence have lower prostate cancer mortality

The present study determined the relationship of male circumcision (MC) prevalence with prostatic carcinoma mortality rate in the 85 countries globally for which data on each were available. MC prevalence in different countries were obtained from a WHO report and allocated to WHO categories of 81%–100%, 20%–80%, and 0%–19%. Prostatic carcinoma mortality data were from Globoscan, gross national income per capita as well as male life expectancy were from a World Bank report, and percentages of Jews and Muslims by country were from the Pew Research Institute and the North American Jewish Data Bank. Negative binomial regression was used to estimate prostatic carcinoma mortality rate ratios. Compared to countries with 81%–100% MC prevalence, prostatic carcinoma mortality rate was higher in those with MC prevalence of 0%–19% (adjusted OR [adjOR] =1.82; 95% CI 1.14, 2.91) and 20%–80% (adjOR = 1.80; 95% CI, 1.16, 2.78). Higher Muslim percentage (adjOR = 0.92 [95% CI 0.87, 0.98] for each 10% increase) and longer life expectancy (adjOR = 0.82 [95% CI 0.72, 0.93] for each 5 additional years) were associated with lower prostatic carcinoma mortality. Higher gross national income per capita (adjOR = 1.10 [95% CI 1.01, 1.20] for double this parameter) correlated with higher mortality. Compared with American countries, prostatic carcinoma mortality rate was similar in Eastern Mediterranean countries (adjOR = 1.02; 95% CI 0.58, 1.76), but was lower in European (adjOR = 0.60; 95% CI 0.50, 0.74) and Western Pacific countries (adjOR = 0.54, 95% CI 0.37, 0.78). Thus, prostate cancer mortality is significantly lower in countries in which MC prevalence exceeds 80%.

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.

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.

Medical management of benign prostatic hyperplasia: Results from a population-based study

INTRODUCTION

In men with bothersome lower urinary tract symptoms (LUTS), medical treatment usually represents the first line. We examined the patterns of medical management of benign prostatic hyperplasia (BPH) in the Montreal metropolitan area, within the context of a case control study focusing on incident prostate cancer.

METHODS

Cases were 1933 men with incident prostate cancer. Population controls included 1994 age-matched men. In-person interviews collected sociodemographic characteristics and medical history, including BPH diagnosis, its duration, and type of medical treatment received. Baseline characteristics were compared by the chi-square likelihood test for categorical variables and by the students t-test for continuously coded variables.

RESULTS

Overall, 1120 participants had history of BPH; of those 53.7% received medical treatment for BPH. Individuals with medically treated BPH, compared to individuals with medically untreated BPH, were older at index date [mean: 66.9 vs. 64.9 years, p<0.001)] and at diagnosis of BPH [mean: 62.3 vs. 60.3 years, p<0.001]. They also had a longer duration of BPH-history [mean: 4.7 vs. 4.0 years, p=0.02]. Regarding medical treatment, mono-therapy was more often used than combination therapy [87.6% vs. 12.4%, p<0.001]. Alpha-blockers (69.9%) were most commonly used as monotherapy, followed by 5alpha-reductase inhibitors (5ARIs) (26.6%). Alpha-blockers plus 5ARIs were the most common combination therapy (97.3%).

CONCLUSIONS

Despite evidence from randomized, controlled trials for better efficacy with use of combination therapy, monotherapy consisting of alpha-blockers or 5ARI, in that order, is most frequently used. Additionally, 5ARI use was more common than previously reported (27% vs. 15%).

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.

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.