Gonorrhoea and male bladder cancer in a prospective study

The potential for bacteriophages and prophage elements in fighting and preventing the gonorrhea

Bacteriophages are the most numerous entities on earth and are found everywhere their bacterial hosts live. As natural bacteria killers, phages are extensively investigated as a potential cure for bacterial infections. Neisseria gonorrhoeae (the gonococcus) is the etiologic agent of a sexually transmitted disease: gonorrhea. The rapid increase of resistance of N. gonorrhoeae to antibiotics urges scientists to look for alternative treatments to combat gonococcal infections. Phage therapy has not been tested as an anti-gonococcal therapy so far. To date, no lytic phage has been discovered against N. gonorrhoeae. Nevertheless, gonococcal genomes contain both dsDNA and ssDNA prophages, and viral particle induction has been documented. In this review, we consider literature data about the attempts of hunting for a bacteriophage specific for gonococci - the gonophage. We also discuss the potential application of prophage elements in the fight against N. gonorrhoeae. Temperate phages may be useful in preventing and treating gonorrhea as a scaffold for anti-gonococcal vaccine development and as a source of lytic enzymes with anti-gonococcal activity.

Bladder Cancer Carcinogens: Opportunities for Risk Reduction

Bladder cancer at an individual level is likely to be the consequence of repeated, long-term exposure to one or more known bladder carcinogens, some of which are endemic or unavoidable in daily life, in addition to host factors. This Mini-Review highlights exposures that are associated with higher risk of bladder cancer, summarizes the evidence for each association, and suggests strategies to decrease risk at both individual and population levels. PATIENT SUMMARY: Tobacco smoking, exposure to certain chemicals in your diet, environment, or workplace, urinary infections, and certain medications can increase your risk of bladder cancer.

A Review of the Etiology and Epidemiology of Bladder Cancer: All You Need To Know

Bladder cancer is any tumor that originates in the urinary bladder. It is the most prevalent tumor of the urinary system, with urothelial carcinoma being the most prevalent histologic subtype. It impacts both men and women. The development of bladder cancer was influenced by several risk factors, including advanced age, male sex, cigarette smoking, and occupational and environmental toxin exposure. Bladder tumors may manifest as gross or microscopic hematuria, which is assessed using cystoscopy, urine analysis, and other specialized tests. Due to the large number of cases related to environmental causes, bladder cancer is an appropriate target for public health preventative interventions. Cessation of smoking, adequate occupational safety procedures, diet, weight loss, and schistosomiasis prevention may mitigate the rising global incidence.

Bacteria-Cancer Interface: Awaiting the Perfect Storm

Epidemiological evidence reveal a very close association of malignancies with chronic inflammation as a result of persistent bacterial infection. Recently, more studies have provided experimental evidence for an etiological role of bacterial factors disposing infected tissue towards carcinoma. When healthy cells accumulate genomic insults resulting in DNA damage, they may sustain proliferative signalling, resist apoptotic signals, evade growth suppressors, enable replicative immortality, and induce angiogenesis, thus boosting active invasion and metastasis. Moreover, these cells must be able to deregulate cellular energetics and have the ability to evade immune destruction. How bacterial infection leads to mutations and enriches a tumour-promoting inflammatory response or micro-environment is still not clear. In this review we showcase well-studied bacteria and their virulence factors that are tightly associated with carcinoma and the various mechanisms and pathways that could have carcinogenic properties.

Clinical and therapeutic implications of sex steroid hormone receptor status in urothelial bladder cancer

Studies on the clinical profile of urothelial bladder cancer (UBC) have shown significant gender differences, namely, higher occurrence in males (male-to-female ratio of 3.5:1) and an advanced stage of disease at the time of diagnosis with rapid progression of the disease after initial diagnosis seen more commonly in females. The relationship between gender and UBC is complex and probably influenced by biological and epidemiological factors. Potential contributory factors such as sex steroid hormone pathway, gender difference in environmental carcinogen exposure, metabolic enzyme activity, and disparities in the intensity of diagnostic evaluation could probably explain the demographic trends in UBC. This comprehensive review of Medline publications during the period 2009–2019 attempts to identify the possible role of sex hormone receptors in gender variation and sexual dimorphism in the occurrence and progression of UBC. The clinical implications of identifying sex steroid receptors on factors such as disease prognostication and the therapeutic role of anti-androgens in the prevention and progression of UBC are critically reviewed. There is now significant evidence in literature to suggest the possible role of sex steroid hormone receptor-mediated signals in the genesis and progression of UBC. These receptors include androgen receptors, estrogen receptors, progesterone receptors, and various other orphan receptors. Excessive or reduced expression of these receptors, as well as alterations in their upstream or downstream pathways, correlate well with the clinical and therapeutic outcomes of UBC.

Positive association between hypertension and urinary bladder cancer: epidemiologic evidence involving 79,236 propensity score-matched individuals

INTRODUCTION

We hypothesized that hypertensive patients harbor a higher risk of urinary bladder (UB) cancer.

MATERIAL AND METHODS

We performed a population-based cohort study on adults using a National Health Insurance Research Database (NHIRD) dataset. Hypertension and comparison non-hypertensive (COMP) groups comprising 39,618 patients each were propensity score-matched by age, sex, index date, and medical comorbidities. The outcome was incident UB cancer validated using procedure codes. We constructed multivariable Cox models to derive adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs). Cumulative incidence was compared using a log-rank test.

RESULTS

During a total follow-up duration of 380,525 and 372,020 person-years in the hypertension and COMP groups, 248 and 186 patients developed UB cancer, respectively, representing a 32% increase in the risk (aHR, 1.32; 95% CI, 1.09-1.60). Hypertensive women harbored a significantly increased risk of UB cancer (aHR, 1.55; 95% CI, 1.12-2.13) compared with non-hypertensive women, whereas men with hypertension had a statistically non-significant increased risk (aHR, 1.22; 95% CI, 0.96-1.55). The sensitivity analysis demonstrated that the increased risk was sustained throughout different follow-up durations for the entire cohort; a statistical increase in the risk was also noted among hypertensive men.

CONCLUSION

This nationwide population-based propensity score-matched cohort study supports a positive association between hypertension and subsequent UB cancer development.

The potential role of infectious agents and pelvic inflammatory disease in ovarian carcinogenesis

Background

The etiological cause of ovarian cancer is poorly understood. It has been theorized that bacterial or viral infection as well as pelvic inflammatory disease could play a role in ovarian carcinogenesis.

Aim

To review the literature on studies examining the association between ovarian cancer and bacterial or viral infection or pelvic inflammatory disease.

Methods

Database search through MEDLINE, applying the medical subject headings: “Ovarian neoplasms”, AND “Chlamydia infections”, “Neisseria gonorrhoeae”, “Mycoplasma genitalium”, “Papillomaviridae”, or “pelvic inflammatory disease”. Corresponding searches were performed in EMBASE, and Web of Science. The literature search identified 935 articles of which 40 were eligible for inclusion in this review.

Results

Seven studies examined the association between bacterial infection and ovarian cancer. A single study found a significant association between chlamydial infection and ovarian cancer, while another study identified Mycoplasma genitalium in a large proportion of ovarian cancer cases. The remaining studies found no association. Human papillomavirus detection rates varied from 0 to 67% and were generally higher in the Asian studies than in studies from Western countries. Cytomegalovirus was the only other virus to be detected and was found in 50% of cases in a case-control study. The association between ovarian cancer and pelvic inflammatory disease was examined in seven epidemiological studies, two of which, reported a statistically significant association.

Conclusions

Data indicate a potential association between pelvic inflammatory disease and ovarian cancer. An association between ovarian cancer and high-risk human papillomavirus genotypes may exist in Asia, whereas an association in Western countries seems unlikely due to the low reported prevalence. Potential carcinogenic bacteria were found, but results were inconsistent, and further research is warranted.

Electronic supplementary material

The online version of this article (doi:10.1186/s13027-017-0134-9) contains supplementary material, which is available to authorized users.

Female with bladder cancer: what and why is there a difference?

While men are at a considerable higher risk of developing urothelial carcinoma of the bladder (UCB), women present with more advanced disease stages and seem to experience unfavorable outcomes. Evaluating specific differences in the UCB incidence and outcomes between both genders in the non-muscle invasive, muscle-invasive or locally advanced and metastatic setting, as well as determining the underlying causes of disease, may allow optimizing treatment and improving the quality of urological care among both genders. In this review we summarize the best evidence and most recent findings on gender-specific differences in UCB incidence and outcomes. In addition, we present a comprehensive overview on established and potential reasons for differences in gender-specific UCB outcomes, including disparities in the pelvic anatomy, the diagnostic work-up, the modality and quality of treatment, the exposure to risk factors, the degradation of carcinogens as well as the sex-hormone signaling.

Predicting risk of bladder cancer using clinical and demographic information from prostate, lung, colorectal, and ovarian cancer screening trial participants

BACKGROUND

Effective screening and prevention strategies for bladder cancer require accurate risk stratification models. We developed models to predict the risk of bladder cancer based on clinical and sociodemographic data on participants in the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) screening trial.

METHODS

Baseline clinical and sociodemographic data were obtained from 149,542 PLCO participants, ages 55 to 74 years, without a prior history of bladder cancer. Cox proportional hazards models were used to predict the risk of all bladder cancers (ABC) and of high-grade bladder cancers (HGBC) from baseline information. We used the HGBC risk model to design a hypothetical bladder cancer mortality prevention trial.

RESULTS

Over a median follow-up of 12 years, 1,124 men and 259 women developed bladder cancer (including 392 and 72 with HGBC, respectively). The incidence in men and in women was 133.6 and 29.6 cases per 100,000 person-years, respectively. Nomograms constructed for predicting the risk of ABC and HGBC had c-indices of 0.746 and 0.759, respectively. Age, race, education, smoking (intensity and duration), comorbidity, prostatitis, syphilis, and hormone replacement therapy use were statistically significant predictors in the models. We show that our risk model can be used to design a bladder cancer mortality prevention trial half the size of a trial designed without risk stratification.

CONCLUSION

Models to predict the risk of ABC and HGBC have been developed and validated.

IMPACT

Using the upper 40th percentile from the HGBC model, a suitable cohort for a screening or chemoprevention trial could be identified, although the size and follow-up of such a trial would be costly.

Role of bacteria in oncogenesis

Although scientific knowledge in viral oncology has exploded in the 20th century, the role of bacteria as mediators of oncogenesis has been less well elucidated. Understanding bacterial carcinogenesis has become increasingly important as a possible means of cancer prevention. This review summarizes clinical, epidemiological, and experimental evidence as well as possible mechanisms of bacterial induction of or protection from malignancy.

Correlates of sexually transmitted infection histories in a cohort of American male health professionals

OBJECTIVE

Several epidemiologic studies have investigated sexually transmitted infections (STIs) and later risk of genitourinary conditions with suggestive positive results. While these results may reflect causal associations, other possible explanations include confounding by factors possibly related to both STI acquisition and genitourinary condition risk such as recognized STI-risk factors/correlates, and other factors not typically considered in relation to STIs (e.g., general health-related behaviors or markers of such behaviors). Very few of these factors have been investigated in older populations in which STIs and genitourinary conditions are typically studied. Therefore, we investigated STI history correlates in one such population, the Health Professionals Follow-up Study.

METHODS

We ascertained histories of potential correlates, gonorrhea, syphilis by questionnaire (n = 36,032), and performed serologic testing for Chlamydia trachomatis, Trichomonas vaginalis, human papillomavirus, and human herpesvirus type 8 infection in a subset (n = 651).

RESULTS

Positive correlations were observed for African-American race, foreign birth, southern residence, smoking, alcohol consumption, ejaculation frequency, vasectomy, and high cholesterol. Inverse correlations were observed for social integration and routine health-related examinations.

CONCLUSIONS

These findings provide useful information on potential confounders for epidemiologic investigations of STIs and chronic diseases, and interesting new hypotheses for STI prevention (e.g., STI counseling before vasectomy).

Infection: is it a cause of bladder cancer?

This article reviews the literature regarding the possible correlation between infection and occurrence of bladder cancer. The PubMed literature database was searched from inception to January 2008. Keywords of bladder, cancer, parasitic, bacterial, viral and infection, were used. Forty studies were included in the review. Several investigators support the idea that schistosomiasis is aetiologically related to the development of bladder cancer in individuals infected with Schistosoma haematobium. Approximately 70% of those with chronic schistosomiasis who have bladder cancer develop squamous cell rather than transitional cell carcinoma. Several investigators suggest that bacteria may play a role in inducing bladder cancer. Clinically, researchers have linked the development of infection, urinary stones and indwelling catheters with bladder cancer. Nevertheless, to date, no prospective study has examined the association between urinary tract infection and bladder cancer risk. The possibility that infection by human papilloma virus (HPV) is a risk factor contributing to bladder cancer has been investigated but no definite conclusions have been drawn. Thus, the debate remains open as to whether there is any direct link between chronic HPV infection and bladder cancer. Only 15 cases of vesical carcinoma have been reported, to date, in the setting of human immunodeficiency virus (HIV). The rare occurrence of bladder cancer during HIV infection and the lack of correlation with the laboratory markers of HIV disease progression may suggest a trivial association between two unrelated disorders. BK virus is oncogenic in newborn hamsters and can transfer to mammalian cells in vitro, but there is little consistent evidence of a link with human bladder cancer. Studies showed no correlation between herpes simplex virus (HSV) and bladder cancer, but bladder cancer becomes infected with HSV much more easily than non-neoplastic urothelium. In conclusion, with the exception of chronic infection with S. haematobium, the association between the occurrence of bladder cancer and chronic bacterial or viral infections could not be confirmed. Prospective studies with large numbers of patients and controls are required to confirm this issue.

Urinary tract infections and reduced risk of bladder cancer in Los Angeles

We investigated the association between urinary tract infections (UTIs) and transitional cell carcinoma of the bladder in a population-based case–control study in Los Angeles covering 1586 cases and age-, gender-, and race-matched neighbourhood controls. A history of bladder infection was associated with a reduced risk of bladder cancer among women (odds ratio (OR), 0.66; 95% confidence interval (CI), 0.46–0.96). No effect was found in men, perhaps due to power limitations. A greater reduction in bladder cancer risk was observed among women with multiple infections (OR, 0.37; 95% CI, 0.18–0.78). Exclusion of subjects with a history of diabetes, kidney or bladder stones did not change the inverse association. A history of kidney infections was not associated with bladder cancer risk, but there was a weak association between a history of other UTIs and slightly increased risk among men. Our results suggest that a history of bladder infection is associated with a reduced risk of bladder cancer among women. Cytotoxicity from antibiotics commonly used to treat bladder infections is proposed as one possible explanation.