The Association Between Vasectomy and Prostate Cancer: A Systematic Review and Meta-analysis

Vasectomy and risk of prostate cancer: A Mendelian randomization study and confounder analysis

BACKGROUND

Previous reports have shown a potential causal impact of vasectomy on prostate cancer (PCa). The objective of this study was to investigate the association between vasectomy and PCa, while evaluating the influence of confounding factors such as prostate-specific antigen (PSA) screening and body mass index (BMI).

METHODS

Mendelian randomization (MR) study using summary statistics from genome-wide associations of vasectomy (462,933 European ancestry), ever had PSA test (200,410 European ancestry), time since last PSA test (46,104 European ancestry), BMI (152,893 European males) and PCa (79,148 cases, 61,106 controls, European ancestry). This study was conducted using summary statistic data from large, previously described cohorts. Data analyses were conducted from November 2022 to June 2023.

RESULTS

Genetic liability to vasectomy was not associated with PCa (OR = 0.07, 95% CI: 2.95 ×  10-3 , 1.54, p = 0.09). Genetic liability to vasectomy was not associated with ever had PSA test (OR = 1.08, 95% CI: 0.49-2.39, p = 0.83) and time since last PSA test (OR = 2.49, 95% CI: 0.71-8.79, p = 0.16). After controlling for PSA test and BMI, there remains no causal relationship between vasectomy and PCa risk (OR = 5.56 ×  10-4 , 95% CI: 7.29 ×  10-8 , 4.24, p = 0.10). The reverse MR results showed a weak association between PCa and vasectomy patients (OR = 1.00, 95% CI: 1.0003-1.0033, p = 0.02).

CONCLUSION

Based on the available evidence from MR analysis, the current findings did not support vasectomy being a risk factor for PCa. Further work is required to provide additional confirmation and validation of the potential link.

2022 Update on Prostate Cancer Epidemiology and Risk Factors-A Systematic Review

CONTEXT

Prostate cancer (PCa) is one of the most common cancers worldwide. Understanding the epidemiology and risk factors of the disease is paramount to improve primary and secondary prevention strategies.

OBJECTIVE

To systematically review and summarize the current evidence on the descriptive epidemiology, large screening studies, diagnostic techniques, and risk factors of PCa.

EVIDENCE ACQUISITION

PCa incidence and mortality rates for 2020 were obtained from the GLOBOCAN database of the International Agency for Research on Cancer. A systematic search was performed in July 2022 using PubMed/MEDLINE and EMBASE biomedical databases. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and was registered in PROSPERO (CRD42022359728).

EVIDENCE SYNTHESIS

Globally, PCa is the second most common cancer, with the highest incidence in North and South America, Europe, Australia, and the Caribbean. Risk factors include age, family history, and genetic predisposition. Additional factors may include smoking, diet, physical activity, specific medications, and occupational factors. As PCa screening has become more accepted, newer approaches such as magnetic resonance imaging (MRI) and biomarkers have been implemented to identify patients who are likely to harbor significant tumors. Limitations of this review include the evidence being derived from meta-analyses of mostly retrospective studies.

CONCLUSIONS

PCa remains the second most common cancer among men worldwide. PCa screening is gaining acceptance and will likely reduce PCa mortality at the cost of overdiagnosis and overtreatment. Increasing use of MRI and biomarkers for the detection of PCa may mitigate some of the negative consequences of screening.

PATIENT SUMMARY

Prostate cancer (PCa) remains the second most common cancer among men, and screening for PCa is likely to increase in the future. Improved diagnostic techniques can help reduce the number of men who need to be diagnosed and treated to save one life. Avoidable risk factors for PCa may include factors such as smoking, diet, physical activity, specific medications, and certain occupations.

Vasectomy has No Impact on Future Lower Urinary Tract Symptoms Diagnoses: A Retrospective Cohort Claims Database Analysis

Purpose

The aim of this study was to assess whether there is an association between vasectomy and benign prostatic hyperplasia with associated lower urinary tract symptoms (BPH/LUTS) due to inflammatory etiology.

Materials and Methods

We assessed the incidence of BPH/LUTS in men who had undergone vasectomy in a matched cohort analysis using the TriNetX Research Network. We identified men aged 30 to 60 years who underwent vasectomy and had a follow-up visit within 6 months to 5 years after vasectomy from January 2010 through December 2022 and compared them with matched controls. Outcomes recorded include diagnoses of BPH (N40, N40.1), BPH-related medication prescriptions, and BPH-related procedures. We accounted for confounding variables through propensity score-matching for age; race; and history of comorbid medical conditions: hyperlipidemia (International Classification of Disease-10: E78), metabolic syndrome (E88.81), overweight or obesity (E66), testicular hypofunction (E29.1), hypertension (I10-I16), nicotine dependence (F17), and obstructive sleep apnea (G47.33).

Results

There was no significant difference in BPH diagnosis between postvasectomy men vs controls (0.84% vs 0.80%, RR: 0.95, 95% CI 0.86-1.05) or BPH/LUTS diagnosis (0.48% vs 0.44%, RR: 0.92, 95% CI 0.81-1.05) within 6 months to 5 years after vasectomy, respectively. No differences in BPH medication prescription (0.94% vs 0.84%) or rate of BPH procedures (0.022% vs 0.017%) were detected between the 2 groups.

Conclusions

This study suggests that vasectomy does not increase the risk of BPH development and/or LUTS worsening compared with the general population, providing assurance to both patients and health care providers who may consider vasectomy as a safe family planning option.

Vasectomy and Risk of Prostate Cancer: A Systematic Review and Meta-analysis

Context

Previous reports have shown an association between vasectomy and prostate cancer (PCa). However, there exist significant discrepancies between studies and systematic reviews due to a lack of strong causal association and residual confounding factors such as prostate-specific antigen (PSA) screening.

Objective

To assess the association between vasectomy and PCa, in both unadjusted and PSA screen-adjusted studies.

Evidence acquisition

We performed a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses. The PubMed, Scopus, and Web of Science databases were searched in January 2022 for studies that analyzed the association between vasectomy and PCa.

Evidence synthesis

A total of 37 studies including 16 931 805 patients met our inclusion criteria. A pooled analysis from all studies showed a significant association between vasectomy and any-grade PCa (odds ratio [OR] 1.23; 95% confidence interval [CI], 1.10–1.37; p < 0.001; I² = 96%), localized PCa (OR 1.08; 95% CI, 1.06–1.11; p < 0.00001; I² = 31%), or advanced PCa (OR 1.07; 95% CI, 1.02–1.13; p = 0.006; I² = 0%). The association with PCa remained significant when the analyses were restricted to studies with a low risk of bias (OR 1.06; 95% CI, 1.02–1.10; p = 0.02; I² = 48%) or cohort studies (OR 1.09; 95% CI, 1.04–1.13; p < 0.0001; I² = 64%). Among studies adjusted for PSA screening, the association with localized PCa (OR 1.06; 95% CI, 1.03–1.09; p < 0.001; I² = 0%) remained significant. Conversely, vasectomy was no longer associated with localized high-grade (p = 0.19), advanced (p = 0.22), and lethal (p = 0.42) PCa.

Conclusions

Our meta-analysis found an association between vasectomy and any, mainly localized, PCa. However, the effect estimates of the association were increasingly close to null when examining studies of robust design and high quality. On exploratory analyses including studies, which adjusted for PSA screening, the association for aggressive and/or advanced PCa diminished.

Patient summary

In this study, we found an association between vasectomy and the risk of developing localized prostate cancer without being able to determine whether the procedure leads to a higher prostate cancer incidence.

Epidemiology beyond its limits

In 1995, journalist Gary Taubes published an article in Science titled "Epidemiology faces its limits," which questioned the utility of nonrandomized epidemiologic research and has since been cited more than 1000 times. He highlighted numerous examples of research topics he viewed as having questionable merit. Studies have since accumulated for these associations. We systematically evaluated current evidence of 53 example associations discussed in the article. Approximately one-quarter of those presented as doubtful are now widely viewed as causal based on current evaluations of the public health consensus. They include associations between alcohol consumption and breast cancer, residential radon exposure and lung cancer, and the use of tanning devices and melanoma. This history should inform current debates about the reproducibility of epidemiologic research results.

Family history, obesity, urological factors and diabetic medications and their associations with risk of prostate cancer diagnosis in a large prospective study

Background

Prostate cancer (PC) aetiology is unclear. PC risk was examined in relation to several factors in a large population-based prospective study.

Methods

Male participants were from Sax Institute’s 45 and Up Study (Australia) recruited between 2006 and 2009. Questionnaire and linked administrative health data from the Centre for Health Record Linkage and Services Australia were used to identify incident PC, healthcare utilisations, Prostate Specific Antigen (PSA) testing reimbursements and dispensing of metformin and benign prostatic hyperplasia (BPH) prescriptions. Multivariable Cox and Joint Cox regression analyses were used to examine associations by cancer spread, adjusting for various confounders.

Results

Of 107,706 eligible men, 4257 developed incident PC up to end 2013. Risk of PC diagnosis increased with: PC family history (versus no family history of cancer; HR_adjusted = 1.36; 95% CI:1.21–1.52); father and brother(s) diagnosed with PC (versus cancer-free family history; HR_adjusted = 2.20; 95% CI:1.61–2.99); severe lower-urinary-tract symptoms (versus mild; HR_adjusted = 1.77; 95% CI:1.53–2.04) and vasectomy (versus none; HR_adjusted = 1.08; 95% CI:1.00–1.16). PC risk decreased with dispensed prescriptions (versus none) for BPH (HR_adjusted = 0.76; 95% CI:0.69–0.85) and metformin (HR_adjusted = 0.57; 95% CI:0.48–0.68). Advanced PC risk increased with vasectomy (HR_adjusted = 1.28; 95% CI:1.06–1.55) and being obese (versus normal weight; HR_adjusted = 1.31; 95% CI:1.01–1.69).

Conclusion

Vasectomy and obesity are associated with an increased risk of advanced PC. The reduced risk of localised and advanced PC associated with BPH, and diabetes prescriptions warrants investigation.

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.

Review of Vasectomy Complications and Safety Concerns

Vasectomy is a simple, safe, effective, and economical method used worldwide for long-term male contraception. As a surgical operation, it has short-term and long-term complications such as hematoma formation, infection, sterilization failure, sperm granulomas, short-term postoperative pain (nodal pain, scrotal pain, and ejaculation pain), and chronic pain syndrome. Whether it increases the risk of autoimmune disease, cardiovascular disease, testicular cancer, or prostate cancer is still controversial. Changes in plasma concentrations of luteinizing hormone, follicle-stimulating hormone, and testosterone after vasectomy have also been studied, as well as the relation between vasectomy and sexual function. Sperm quality decreases very slowly after vasectomy, and vasovasostomy and intracytoplasmic sperm injection could help a couple achieve a pregnancy if they change their minds at any point. We include a follow-up strategy and suggestions for follow-up care at the end of this review.

Semen sampling as a simple, noninvasive surrogate for prostate health screening

The detection rates for prostate cancer (pCa) by invasive biopsy are high, fully justifying its use in confirmatory testing. False-positive results of prior, relatively insensitive screening tests, however, can lead to expensive and often unnecessary surgery. Several reports have suggested the potential use of the ejaculate to screen for prostate conditions. Hitherto, the potential impact of sterilization on the diagnostic potential of seminal plasma screening has not been examined. Herein, we report cellular and molecular comparisons of semen samples obtained from normal (N = 5), vasectomized (N = 5) and prostate pathology patients (N = 4; confirmed by a biopsy) that were centrifuged over 60% PureSperm cushions. Non-penetrating cells were washed prior to immunocytochemistry with prostatic epithelial cell markers including PSMA, NKX3.1 and CD24. KRT18 was used to highlight epithelial cells in these samples. RNA sequencing was then used to identify differentially expressed small RNAs associated with vasectomy and prostate pathology. Specific gene transcripts were confirmed by RT-qPCR. PMSA⁺/KRT18⁺, CD24⁺/KRT18⁺ and NKX3.1/⁺KRT18⁺ cells were observed, albeit infrequently in most processed semen samples by indirect immunocytochemistry. Targeted RT-qPCR supported their enrichment, along with their putative designation as prostatic luminal cells. Small RNAs in seminal plasma were highly heterogeneous, with tRNAs and miRNAs being the dominant forms. Hsa-miR-143 and hsa-miR-199 were among the most prominent of the differentially expressed miRNAs upregulated in samples with prostate pathology but not vasectomy. The targets of these small RNAs illustrate biological processes involved among others in transcription regulation and collagen metabolism. Our outcomes strongly support an appraisal of selected biologically meaningful small RNAs of ejaculate semen for prostate health screening. A long-term goal would be a simple, routine, noninvasive test for monitoring prostate health, potentially among younger men.

Vasectomy and prostate cancer risk: a meta-analysis of prospective studies

Epidemiological cohort studies investigating the association between vasectomy and prostate cancer risk have yielded inconsistent results. The aim of the present meta-analysis is to update the evidence on the association between vasectomy and prostate cancer. A comprehensively literature search of relevant studies was performed in December 2019 using PubMed. A DerSimonian and Laird random-effects model was used to calculate the summary relative risk (RR) and its 95% confidence interval (CI). A total of 15 eligible cohort studies (16 data sets) with more than four million of participants were eventually included in this meta-analysis. There was a statistically significant higher risk of prostate cancer among men who underwent vasectomy (RR: 1.09, 95% CI: 1.04-1.13) with obvious heterogeneity among included studies (P < 0.001, I2 = 64.2%). Vasectomy was also associated with the risk of advanced prostate cancer (RR: 1.07, 95% CI: 1.02-1.13), which is less likely to be affected from detection bias. In conclusion, findings from this meta-analysis of prospective studies indicate that vasectomy may be positively associated with the risk of prostate cancer. Further large prospective studies with long follow-up are warranted to verify the findings from this meta-analysis. In addition, the potential underlying molecular mechanism needed further exploration with in vitro and animal studies.

The effects of metabolic surgery on microvascular complications in obese patients with type 2 diabetes: a meta-analysis

BACKGROUND

Metabolic surgery is a standard treatment for obesity with type 2 diabetes (T2D), although the effects of metabolic surgery on the incidence rate of microvascular complications remain controversial.

OBJECTIVES

We aimed to evaluate the effect of metabolic surgery versus nonsurgical treatments on the incidence rate of microvascular complications in obesity with T2D.

SETTING

A meta-analysis of published studies.

METHODS

We searched PubMed, Web of Science, and the Cochrane Library to identify clinical studies assessing the effect of metabolic surgery on the incidence rate of microvascular diabetic complications compared with that of nonsurgical treatments. We extracted the primary outcomes, including the incidence rate of microvascular complications after metabolic surgery.

RESULTS

A total of 32,756 participants from 12 studies were identified. Metabolic surgery reduced the incidence rate of microvascular complications (odds ratios [OR], .34; 95% confidence intervals [CI], .30-.39; P < .001) compared with that of nonsurgical treatments in obesity with T2D. Moreover, metabolic surgery also reduced the incidence of diabetic nephropathy (OR, .39; 95% CI, .30-.50; P < .001), diabetic retinopathy (OR, .52; 95% CI, .42-.65; P < .001) and diabetic neuropathy (OR, .27; 95% CI, .22-.34; P < .001) compared with nonsurgical treatments in obesity with T2D.

CONCLUSION

Metabolic surgery was superior to nonsurgical treatments in reducing the incidence of microvascular complications in obesity with T2D. Prospective studies, preferably randomized controlled trials, with evaluations of different types of metabolic surgery are warranted to provide guidelines for treatment preferences in obesity with T2D.

Impact of Vasectomy on the Development and Progression of Prostate Cancer: Preclinical Evidence

Some observational studies have implied a link between vasectomy and an elevated risk of prostate cancer. We investigated the impact of vasectomy on prostate cancer outgrowth, mainly using preclinical models. Neoplastic changes in the prostate were compared in transgenic TRAMP mice that underwent vasectomy vs. sham surgery performed at 4 weeks of age. One of the molecules identified by DNA microarray (i.e., ZKSCAN3) was then assessed in radical prostatectomy specimens and human prostate cancer lines. At 24 weeks, gross tumor (p = 0.089) and poorly differentiated adenocarcinoma (p = 0.036) occurred more often in vasectomized mice. Vasectomy significantly induced ZKSCAN3 expression in prostate tissues from C57BL/6 mice and prostate cancers from TRAMP mice. Immunohistochemistry showed increased ZKSCAN3 expression in adenocarcinoma vs. prostatic intraepithelial neoplasia (PIN), PIN vs. non-neoplastic prostate, Grade Group ≥3 vs. ≤2 tumors, pT3 vs. pT2 tumors, pN1 vs. pN0 tumors, and prostate cancer from patients with a history of vasectomy. Additionally, strong (2+/3+) ZKSCAN3 expression (p = 0.002), as an independent prognosticator, or vasectomy (p = 0.072) was associated with the risk of tumor recurrence. In prostate cancer lines, ZKSCAN3 silencing resulted in significant decreases in cell proliferation/migration/invasion. These findings suggest that there might be an association between vasectomy and the development and progression of prostate cancer, with up-regulation of ZKSCAN3 expression as a potential underlying mechanism.

Epidemiology, Staging and Management of Prostate Cancer

Prostate cancer is the second most common and fifth most aggressive neoplasm among men worldwide. It is particularly incident in high human development index (HDI) nations, with an estimated one in seven men in the US receiving a prostate cancer diagnosis in their lifetime. A rapid rise and then fall in prostate cancer incidence in the US and Europe corresponded to the implementation of widespread prostate specific antigen (PSA) testing in 1986 and then subsequent fall from favor due to high rates of false positives, overdiagnosis, and overtreatment (as many as 20-50% of men diagnosed could have remained asymptomatic in their lifetimes). Though few risk factors have been characterized, the best known include race (men of African descent are at higher risk), genetics (e.g., BRCA1/2 mutations), and obesity. The Gleason scoring system is used for histopathological staging and is combined with clinical staging for prognosis and treatment. National guidelines have grown more conservative over the past decades in management, recommending watchful waiting and observation in older men with low to intermediate risk disease. Among higher risk patients, prostatectomy (robotic is preferred) and/or external beam radiotherapy is the most common interventions, followed by ADT maintenance. Following progression on androgen deprivation therapy (ADT) (known as castration-resistance), next generation endocrine therapies like enzalutamide, often in combination with cytotoxic agent docetaxel, are standard of care. Other promising treatments include Radium-223 for bone metastases, pembrolizumab for programmed death ligand-1 (PDL1) and microsatellite instability (MSI) high disease, and poly ADP ribose polymerase (PARP) inhibitors for those with mutations in homologous recombination (most commonly BRCA2).

Vasectomy and the risk of prostate cancer in a Finnish nationwide population-based cohort

INTRODUCTION & OBJECTIVES

There are conflicting reports on the association of vasectomy and the risk of prostate cancer (PCa). Our objective was to evaluate the association between vasectomy and PCa from a nationwide cohort in Finland.

MATERIALS & METHODS

Sterilization registry of Finland and the Finnish Cancer Registry data were utilized to identify all men who underwent vasectomy between years 1987-2014 in Finland. Standard incidence ratio (SIR) for PCa as well as all-cause standardized mortality ratios (SMR) were calculated.

RESULTS

We identified 38,124 men with vasectomy with a total of 429,937 person-years follow-up data. The median age at vasectomy was 39.7 years (interquartile range [IQR] 35.9-44.0), after vasectomy PCa was diagnosed in 413 men (122 cases 0-10 years, 219 cases 10-20 years and 72 cases >20 years from vasectomy). SIR for PCa for the vasectomy cohort was 1.15 (95% CI: 1.04-1.27). By the end of follow-up, 19 men had died from PCa, while the expected number was 20.5 (SMR 0.93 [95%CI: 0.56-1.44]). The overall mortality was decreased (SMR 0.54 [95%CI: 0.51-0.58]) among men with vasectomy.

CONCLUSION

We found a small statistically significant increase in PCa incidence after vasectomy, but in contrast the mortality of vasectomized men was significantly reduced. This may be due to higher likelihood of vasectomized men to undergo prostate-specific antigen testing, having healthier general lifestyle and other biological factors e.g. high reproductive fitness.

Physical activity and the risk of frailty among community-dwelling healthy older adults: A protocol for systematic review and meta-analysis

BACKGROUND

Frailty has become one of the biggest challenges in facilitating healthy aging. Our study aims to investigate the association between physical activity and the risk of frailty, meanwhile, conduct a dose-response to observe the relationship between physical activity volume and frailty.

METHOD

We will systematically search six databases to identify cohort studies assessing the association between physical activity and risk of frailty. Risk of bias of individual study will be assessed using the Newcastle-Ottawa Scale. Data will be analyzed by using STATA V.12.0.

RESULTS

The results of this study will be published in a peer-reviewed journal.

CONCLUSION

We will first investigate whether specific-physical activity reduce the risk to onset frailty in healthy older adults. However, predictable heterogeneity may exist in our study because of the inconsistent definitions of frailty.

Laparoscopic Nerve-Sparing Radical Hysterectomy vs Laparoscopic Radical Hysterectomy in Cervical Cancer: A Systematic Review and Meta-Analysis of Clinical Efficacy and Bladder Dysfunction

It is widely accepted that nerve-sparing radical hysterectomy is associated with less postoperative morbidity compared with radical hysterectomy, whereas clinical safety is similar in the 2 procedures. However, there is insufficient evidence to compare these procedures performed via a laparoscopic approach. We performed a systematic review and meta-analysis of studies to compare the clinical efficacy and the rate of bladder dysfunction, including urodynamic assessment, in laparoscopic nerve-sparing radical hysterectomy (LNSRH) and laparoscopic radical hysterectomy (LRH). Thirty articles including a total of 2743 participants were analyzed. Operating times were shorter (MD, 29.88 minutes; 95% confidence interval [CI], 11.92-47.83 minutes) and hospital stays were longer (MD, -1.56 days; 95% CI, -2.27 to -0.84 days) in the LRH group compared with the LNSRH group. In addition, blood loss and the number of resected lymph nodes were not significantly different between the 2 groups. However, resected parametrium length (MD, -0.02 cm; 95% CI, -0.05 to -0.00 cm) and vaginal cuff width (MD, -0.06 cm; 95% CI, -0.09 to -0.04) were smaller in the LNSRH group. Furthermore, LNSRH tended to result in more satisfactory micturition (odds ratio, 2.90; 95% CI, 2.01-4.19), shorter catheterization time (MD, -7.20 days; 95% CI, -8.10 to -6.29 days), and shorter recovery to normal postvoid residual urine time (MD, -7.71 days; 95% CI, -8.92 to -6.50 days). Other bladder dysfunction symptoms, including urinary retention, nocturia, dysuria, urinary incontinence, and frequency/urgency were more frequent in the LRH group. Furthermore, LNSRH achieved better results in urodynamic assessments (all p < .05). In conclusion, LNSRH was associated with lower rates of impaired bladder function and a shorter extent of resection compared with LRH. Clinical applications involving LNSRH should be explored with caution.

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.

Management and outcomes of pregnancy with or without lupus nephritis: a systematic review and meta-analysis

Background

Although it is well established that systemic lupus erythematosus (SLE) negatively affects pregnancy outcomes, there is insufficient evidence on the effect of lupus nephritis (LN) on antenatal management and pregnancy outcomes. We performed a systematic review and meta-analysis to determine the association of LN with management and pregnancy outcomes in SLE patients.

Methods

Embase, Medline, Cochrane, and ClinicalTrials.gov were carefully searched for relevant English and Chinese language studies. A total of 2,987 articles were reviewed. Data were extracted that compared management and pregnancy outcomes in SLE pregnant women with LN vs without LN. Risk of bias was assessed by a modified version of the Newcastle-Ottawa Scale and the STROBE checklist. Combined odds ratios (OR) and 95% confidence intervals (CI) were obtained and sensitivity analysis was performed using RevMan 5.3 software.

Results

Sixteen studies, including 1,760 pregnant patients with SLE, were included. Gestational hypertension (OR=5.65, 95% CI=2.94–10.84), preeclampsia (OR=2.84, 95% CI=1.87–4.30), SLE flare (OR=2.66, 95% CI=1.51–4.70), renal flare (OR=15.18, 95% CI=5.89–39.14), proteinuria (OR=8.86, 95% CI=4.75–16.52), and hypocomplementemia (OR=2.86, 95% CI=1.68–4.87) were significantly affected in pregnant women with LN. Anti-Sjögren’s syndrome-related antigen A/Ro autoantibodies were negatively associated with pregnant women with LN (OR=0.57, 95% CI=0.33–0.98). Pregnant women with LN presented a significant decrease in live births (OR=0.62, 95% CI=0.49–0.80) and a significant increase in preterm births (OR=1.92, 95% CI=1.49–2.49) and fetal growth restriction (OR=1.43, 95% CI=1.08–1.91). Regarding antenatal management, steroids (OR=2.48, 95% CI=1.59–3.87) and immunosuppressant treatment (OR=6.77, 95% CI=3.30–13.89) were more frequently used in women with LN.

Conclusion

This review identified a significant association between the aforementioned outcomes and SLE pregnant patients with LN. In patients with SLE, LN increased the risks for adverse pregnancy outcomes and the use of medication. Therefore, special treatment and close monitoring should be allocated to pregnant women with LN.

Can the evolution of male contraception lead to a revolution? Review of the current state of knowledge

Introduction

Great advances in medical research concerning methods of contraception have been achieved in recent years, however, more than 25% of couples worldwide still rely on condoms - a method with poor efficacy. Even though there is a spectrum of 11 different contraceptive methods for women, there are only 4 commonly used by men (condoms, periodic abstinence, withdrawal and vasectomy). In this review, advances and present, state-of-the-art, both hormonal and non-hormonal male contraceptive methods will be presented and evaluated. Potential novel targets that warrant greater research will be highlighted.

Material and methods

A comprehensive literature search without a time limit was performed using the Medline database on May 2017. The terms 'male contraception' in conjunction with 'reversible inhibition of sperm under guidance' (RISUG), 'hormonal', 'non-hormonal', 'vasectomy' or 'testosterone' were used. The articles were limited to those published in English, Polish or French.

Results

There are various contraceptives currently available to regulate male fertility. Vasectomy is still the most effective permanent form of male contraceptive with a failure rate lower than 1%. Reversible, non hormonal methods of male contraception, like reversible inhibition of sperm under guidance, are very promising and close to being introduced into the market. In regards to hormonal contraception research, the use of testosterone injections has been widely studied yet they often harbor undesirable side effects and require further development.

Conclusions

Despite continuous efforts worldwide, it seems that another several years of research is needed to provide safe, effective and affordable male contraceptives which will allow both men and women to participate fully in family planning.

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.

The Effect of Vasectomy Reversal on Prostate Cancer Risk: International Meta-Analysis of 684,660 Vasectomized Men

PURPOSE

Evidence of the effect of vasectomy on prostate cancer is conflicting with the issue of detection bias a key criticism. We examined the effect of vasectomy reversal on prostate cancer risk in a cohort of vasectomized men. Evidence of a protective effect would be consistent with a harmful effect of vasectomy on prostate cancer risk while nullifying the issue of detection bias.

MATERIALS AND METHODS

Data were sourced from a total of 5 population level linked health databases in Australia, Canada and the United Kingdom. Cox proportional hazards regression analysis was used to compare the risk of prostate cancer in 9,754 men with vasectomy reversal to the risk in 684,660 with vasectomy but no reversal. Data from each jurisdiction were combined in a meta-analysis.

RESULTS

The combined analysis showed no protective effect of vasectomy reversal on the incidence of prostate cancer compared to that in men with vasectomy alone (HR 0.92, 95% CI 0.70-1.21).

CONCLUSIONS

These results align with those of previous studies showing no evidence of a link between vasectomy and prostate cancer.