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

Ejaculation Frequency and Prostate Cancer Risk: A Narrative Review of Current Evidence

Prostate cancer, constituting a substantial portion of global cancer incidence and mortality, prompts a critical examination of potential modifiers, notably ejaculation frequency. This narrative review explores the complex relationship between ejaculation frequency and prostate cancer risk, addressing the paucity of consensus and the intricate interplay of factors. The evidence drawn from eleven studies with diverse methodologies reveals a complex understanding of this association. While some studies suggest an inverse correlation between ejaculation frequency and prostate cancer risk, signifying a potential protective effect, others present conflicting findings, necessitating a comprehensive exploration. Evidence synthesis underscores the importance of considering age, urinary health, and lifestyle factors in elucidating the ejaculation frequency-prostate cancer relationship. Notably, technological advancements, including machine learning models and genetic markers, enhance the precision of patient counselling and individualized care. In a clinical context, the findings emphasize the clinical relevance of incorporating sexual behavior into preventive strategies. Public health campaigns emerge as influential tools, breaking taboos, raising awareness, and empowering men to prioritize their well-being. The paradigm shift in prostate cancer understanding, fueled by technology and personalized medicine, holds promise for more accurate risk assessments. Liquid biopsies, multiparametric MRI, and considerations of the gut microbiome present avenues for tailored preventive strategies. However, methodological challenges and study variations necessitate further research, emphasizing consistency, exploring underlying mechanisms, and a life course perspective.

Ejaculation Frequency and Prostate Cancer: CAPLIFE Study

PURPOSE

To evaluate the association between ejaculation frequency (EF) during four stages of life and prostate cancer (PCa) according to tumor aggressiveness, PCa stage, and urinary symptomatology.

MATERIALS AND METHODS

A total of 456 incident PCa cases histologically confirmed, and 427 controls aged 40-80 years from the CAPLIFE study were analyzed. This study is a population-based case-control study carried out in the south of Spain. Average EF was measured for: (1) 20s, (2) 30s, (3) 40s, and (4) one year before the interview. EF was categorized into: (1) 0-3, (2) 4, and (3) >4 ejaculations/month. Sociodemographic, lifestyle, and medical information were also collected. To estimate the association between EF and PCa, adjusted ORs (aORs) and 95% CIs were calculated by logistic regression models.

RESULTS

A year before the interview, PCa cases ejaculated less frequently than the controls. An inverse association was observed between the EF a year before and PCa, aOR=1.64 (95% CI 1.03-2.61) for men with 4 ejaculations/month, and aOR=2.38 (95% CI 1.57-3.60) for men with 0-3 ejaculations/month, compared to men with >4. The association was higher for cases with ISUP 3-5 (aOR=2.76 [95% CI 1.34-5.67] for men with 0-3 ejaculations/month) or with a locally advanced-metastatic tumor (aOR=4.70 [95% CI 1.55-14.29]). Moreover, men with moderate urinary symptoms and 0-3 ejaculations/month had the highest risk, aOR=3.83 (95% CI 1.84-7.95).

CONCLUSIONS

A low EF could be associated with a higher risk of PCa, especially for cases with ISUP 3-5 or with a locally advanced-metastatic tumor.

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.

Association between vasectomy and risk of prostate cancer: a meta-analysis

BACKGROUND

The debate over the association between vasectomy and prostate cancer has been lasted about 40 years and there is no sign of stopping. In the present study, we aimed to evaluate whether vasectomy is associated with prostate cancer based on the most comprehensive and up-to-date evidence available.

METHODS

The PubMed, Cochrane Library, and EMBASE databases were systematically searched inception to March 14, 2021 without year or language restriction. Multivariable adjusted risk ratios (RRs) were used to assess each endpoint. Risk of bias was assessed using the Newcastle-Ottawa scale.

RESULTS

A total of 58 studies involving 16,989,237 participants fulfilled inclusion criteria. There was significant association of vasectomy with risk of any prostate cancer (risk ratio, 1.18, 95% CI, 1.07-1.31). Association between vasectomy and advanced prostate cancer (risk ratio, 1.06, 95% CI, 1.01-1.12), low-grade prostate cancer (risk ratio, 1.06, 95% CI, 1.02-1.10), and intermediate-grade prostate cancer (risk ratio, 1.12, 95% CI, 1.03-1.22) were significant. There was no significant association between vasectomy and prostate cancer-specific mortality (risk ratio, 1.01, 95% CI, 0.93-1.10).

CONCLUSIONS

This study found that vasectomy was associated with the risk of any prostate cancer and advanced prostate cancer. From the current evidence, patients should be fully informed of the risk of prostate cancer before vasectomy.

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.

Rare Germline Pathogenic Variants Identified by Multigene Panel Testing and the Risk of Aggressive Prostate Cancer

Simple Summary

Identifying which men at the time of prostate cancer diagnosis have, or will progress to, an aggressive fatal disease will allow clinicians to assist men in making better informed treatment decisions. This will not only be important for those men whose disease is likely to remain indolent and who are currently undergoing unnecessary treatment procedures, but also for those who may need to be targeted with immediate and potentially life-saving therapy. Our case-control study confirms that men who carry BRCA1, BRCA2 and ATM germline pathogenic variants are at increased risk of aggressive disease and provides risk estimates that will be used by clinicians to improve counselling.

Abstract

While gene panel sequencing is becoming widely used for cancer risk prediction, its clinical utility with respect to predicting aggressive prostate cancer (PrCa) is limited by our current understanding of the genetic risk factors associated with predisposition to this potentially lethal disease phenotype. This study included 837 men diagnosed with aggressive PrCa and 7261 controls (unaffected men and men who did not meet criteria for aggressive PrCa). Rare germline pathogenic variants (including likely pathogenic variants) were identified by targeted sequencing of 26 known or putative cancer predisposition genes. We found that 85 (10%) men with aggressive PrCa and 265 (4%) controls carried a pathogenic variant (p < 0.0001). Aggressive PrCa odds ratios (ORs) were estimated using unconditional logistic regression. Increased risk of aggressive PrCa (OR (95% confidence interval)) was identified for pathogenic variants in BRCA2 (5.8 (2.7–12.4)), BRCA1 (5.5 (1.8–16.6)), and ATM (3.8 (1.6–9.1)). Our study provides further evidence that rare germline pathogenic variants in these genes are associated with increased risk of this aggressive, clinically relevant subset of PrCa. These rare genetic variants could be incorporated into risk prediction models to improve their precision to identify men at highest risk of aggressive prostate cancer and be used to identify men with newly diagnosed prostate cancer who require urgent treatment.

Trends in Sexual Activity and Associations With All-Cause and Cause-Specific Mortality Among US Adults

BACKGROUND

Sexual activity can be referred to as a health behavior and may also act as an indicator of health status.

AIM

To evaluate temporal trends in sexual activity and to examine associations of sexual activity with all-cause and cause-specific mortality risk.

METHODS

We examined the trends and prevalence of sexual activity and association of sexual activity with all-cause and cause-specific mortality in a nationally representative sample using data from the US National Health and Nutrition Examination Survey from 2005 to 2016 and the National Health and Nutrition Examination Survey 2005-2014 Linked Mortality File (through December 31, 2015).

OUTCOMES

All-cause, cardiovascular disease, and cancer mortality.

RESULTS

A total of 15,269 US adults (mean age, 39.1 years [standard error, 0.18 years]) were included in the trend analysis. In the 2015-2016 cycle, while 71.7% (95% CI, 67.7-75.7%) US adults aged 20-59 years engaged in sexual activity ≥ 12 times/year (monthly), only 36.1% (95% CI, 31.6-40.7%) of them engaged in sexual activity ≥ 52 times/year (weekly). Since the 2005-2006 cycle, the estimated prevalence of sexual activity, ≥52 times/year and ≥12 times/year, were both stable over time among overall and each age group (all P for trend >0.1). During a median follow-up of 5.7 years (range, 1-11 years) and 71,960 person-years of observation, among 12,598 participants with eligible information on mortality status, 228 deaths occurred, including 29 associated with cardiovascular disease and 62 associated with cancer. Overall, participants with higher sexual activity frequency were at a lower risk of all-cause death in a dose-response manner (P for trend = 0.020) during the follow-up period. In addition, the multivariable-adjusted hazard ratios for all-cause mortality, CVD mortality, cancer mortality, and other cause mortality among participants who had sex ≥52 times/year compared with those having sex 0-1 time/year were 0.51 (95% CI, 0.34 to 0.76), 0.79 (95% CI, 0.19 to 3.21), 0.31 (95% CI, 0.11 to 0.84), and 0.52 (95% CI, 0.28 to 0.96), respectively.

CLINICAL IMPLICATIONS

Sexual activity appears to be a health indicator of all-cause and cancer mortality in US middle-aged adults.

STRENGTHS & LIMITATIONS

Clear strengths of the present study include the large representative sample of the noninstitutionalized US population as well as the identification of precise estimates in relation to sexual activity and mortality. However, because of the observational nature of the study design, causality could not be determined.

CONCLUSIONS

Sexual activity was found to be associated with a lower risk of mortality from all cause and cancer. Cao C, Yang L, Xu T, et al. Trends in Sexual Activity and Associations With All-Cause and Cause-Specific Mortality Among US Adults. J Sex Med 2020;17:1903-1913.

Rare germline genetic variants and risk of aggressive prostate cancer

Few genetic risk factors have been demonstrated to be specifically associated with aggressive prostate cancer (PrCa). Here, we report a case-case study of PrCa comparing the prevalence of germline pathogenic/likely pathogenic (P/LP) genetic variants in 787 men with aggressive disease and 769 with nonaggressive disease. Overall, we observed P/LP variants in 11.4% of men with aggressive PrCa and 9.8% of men with nonaggressive PrCa (two-tailed Fisher's exact tests, P = .28). The proportion of BRCA2 and ATM P/LP variant carriers in men with aggressive PrCa exceeded that observed in men with nonaggressive PrCa; 18/787 carriers (2.3%) and 4/769 carriers (0.5%), P = .004, and 14/787 carriers (0.02%) and 5/769 carriers (0.01%), P = .06, respectively. Our findings contribute to the extensive international effort to interpret the genetic variation identified in genes included on gene-panel tests, for which there is currently an insufficient evidence-base for clinical translation in the context of PrCa risk.

Epidemiology of Prostate Cancer

Prostate cancer is the second most frequent cancer diagnosis made in men and the fifth leading cause of death worldwide. Prostate cancer may be asymptomatic at the early stage and often has an indolent course that may require only active surveillance. Based on GLOBOCAN 2018 estimates, 1,276,106 new cases of prostate cancer were reported worldwide in 2018, with higher prevalence in the developed countries. Differences in the incidence rates worldwide reflect differences in the use of diagnostic testing. Prostate cancer incidence and mortality rates are strongly related to the age with the highest incidence being seen in elderly men (> 65 years of age). African-American men have the highest incidence rates and more aggressive type of prostate cancer compared to White men. There is no evidence yet on how to prevent prostate cancer; however, it is possible to lower the risk by limiting high-fat foods, increasing the intake of vegetables and fruits and performing more exercise. Screening is highly recommended at age 45 for men with familial history and African-American men. Up-to-date statistics on prostate cancer occurrence and outcomes along with a better understanding of the etiology and causative risk factors are essential for the primary prevention of this disease.

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.