Beyond Sterility: the Urinary Microbiome in Bladder Cancer Carcinogenesis and Treatment.

Bladder cancer is a highly prevalent disease worldwide and is associated with a high mortality rate. Across all stages of bladder cancer, immunotherapy has now become the cornerstone of treatment. The commensal microbiome has become a major focus of research given its impact on numerous states of human health and disease. Many links between commensal microbes and immune function have been reported. Recently a commensal urinary microbiome has been identified and characterized in healthy individuals by several research groups. The urinary microbiome is now emerging as an important factor influencing bladder cancer development and therapeutic responsiveness. In this report, we identify findings from important clinical and mechanistic studies on the urinary microbiome and future opportunities to impact prevention and treatment of bladder cancer.

THE PLACE OF RADIATION THERAPY AS DEFINITIVE TREATMENT OF BLADDER CANCER

The recent discovery of the urinary microbiome has led to an emerging field of investigation about the potential role of microorganisms in the pathogenesis of urinary bladder cancer. Few preliminary data have been reported so far implicating urobiome as causative and prognostic factor of bladder tumorigenesis. In the present study, a review of the current evidence is presented about microbiome composition among patients with bladder cancer and healthy individuals as well as possible implications of microbiome on urothelial carcinoma of the bladder. A literature review was conducted using PubMed/MEDLINE, Scopus, and the Cochrane library until December 2023. Search algorithm was constructed using the following terms and their associated Mesh terms and Boolean operators: "urinary microbiome" and "urinary microbiota". Studies written in English language, identifying, and comparing urinary microbiome among bladder cancer patients and healthy control group were included in the review. A total of 2,356 reports were identified. From this total 16 articles complied with the inclusion criteria were selected for analysis. These articles represent a total of about 486 bladder cancer patients. Recent studies revealed the colonization of the urinary tract and the bladder by micro-organisms using both enhanced culture- and molecular-based techniques for microbial characterization. However, several limitations exist in the literature decreasing the reliability of the current reports. As a result, urinary microbiome consist an ambitious era in bladder cancer research with an increasing number of evidence about its potential pathogenetic, prognostic and therapeutic role.

Bladder cancer is the 10th most common cancer worldwide. Approximately 75% of patients with bladder cancer will present with non-muscle invasive disease. Patients are usually treated with transurethral resection of bladder tumor (TURBT), in addition to adjuvant intravesical therapy (chemotherapy or anti-cancer immunotherapy with Bacillus Calmette Guerin- BCG) for those at intermediate-risk and high-risk of recurrence and progression. For many years, urine has been thought to be "sterile"; however, advanced microbiological and molecular techniques, including 16S ribosomal RNA (16S rRNA) sequencing, have negated that previous paradigm and confirmed the presence of a urinary microbiome. The urinary microbiome has been associated with several urological diseases, including interstitial cystitis, urgency urinary incontinence, neurogenic bladder dysfunction, and others. More recently, many reports are emerging about the role of the urinary microbiome in urothelial carcinogenesis, including gender disparity in bladder cancer and responses to treatments. The urinary microbiome may serve as a biomarker that can help with risk stratification as well as prediction of the response to intravesical therapies. However, the microbiome literature has been hampered by the lack of a unified standardized methodology for sample collection, type, preservation, processing, as well as bioinformatics analysis. Herein we describe and critique the literature on the association between urinary microbiome and bladder cancer and highlight some of the future directions.

Investigating the association between the urinary microbiome and bladder cancer: An exploratory study

Prostaglandin E2 Production and Cyclooxygenase-2 Induction in Human Urinary Tract Infections and Bladder Cancer

Bladder cancer (BC) is the 9th most common cancer in the world that makes it 3% of the global neoplasms. BC is prevalent in the developed countries. BC is nearly 3.7 times more common in men than in women. External risk factors and internal triggers contribute to the development of BC. Thus, comprehensive analysis of these risk factors leads to timely prevention of indicated oncologic pathology. New approaches in understanding the role of urine microbiome allow us to correctly estimate bacterial spectrum changes from healthy individual to the patient with BC. This offers us new opportunities in receiving bacterial markers in diagnostics of BC and application perspective therapeutic options. Despite the fact that urinary microbiome is mainly similar to microbiome of healthy person, there are some differences in the urine microbiome between BC and various control groups. These distinctions include dominance of Howardella, Streptococcus, Sphingobacterium, Actinomyces, Achromobacter, Brevibacterium, Anaerococcus, Pseudomonas, Fusobacterium nucleatum and Ralstonia at the genus level, with prevalence of Cutibacterium, Proteobacteria, Firmicutes and Actinobacteria at the phylum level. Appropriate urinary microbiome may influence an extracellular matrix that promotes further tumor metastasis. The article is devoted to a review of literary sources on the role of urinary microbiome as a potential risk factor of BC. We conducted a systemic review of the role of the microbiome as a risk factor for the development of BC using PubMed, Embase аnd Scopus (up to August 2024). Histologically all patients suffered from the urothelial BC. We used both human and animal models. All studies that respond next criteria were included to our study: research that compared patients with BC and control group (case-controlled studies); clinical studies that used meta-analysis; studies which gave data with increased or decreased uropathogens in oncologic or control groups. Studies with insufficient data were excluded from our research. We analyzed a total of 214 papers that studied the role of microbiome in the epidemiology of BC. After deduplication, 128 studies were excluded from our work. 61 studies were included in our review after additional screening. According to GLOBOCAN, there were 573,000 new BC cases and 213,000 deaths worldwide in 2020. Smoking and occupational exposures (aromatic amines and polycyclic aromatic hydrocarbons) are the most common risk factors. Urinary microbiome is able to cause the BC. Cutibacterium, Proteobacteria, Firmicutes and Actinobacteria had prevalence at the genus level. Howardella, Streptococcus, Sphingobacterium, Actinomyces, Achromobacter, Brevibacterium, Anaerococcus and Pseudomonas were risk factor at the phylum level. Additional risk markers at the species (gene) level were Fusobacterium and Ralstonia. Thus, smoking tobacco and specific occupational exposures are the most important risk factors for BC. Urinary microbiome in the patients with BC may be the result of smoking exposure, pollution of external environment and diet. The presence of polycyclic aromatic hydrocarbons provides a specific metabolic niche and supports necessary metabolic resources for survival of appropriate bacterial genus, which inhibits the reproduction of other taxonomic units. But additional high-quality studies with useful 16S rRNA gene sequencing are required to confirm initial results that will support timely prevention and BC treatment.

Background: Despite being actively investigated for several other malignancies, the impact of the microbiome on tumorigenesis, response to therapy, and patient outcomes has not been thoroughly assessed in urothelial bladder cancer (BCa). Of note, the relationship between urinary and bladder tissue microbiomes has not yet been investigated. Herein, we aimed to assess: i) the gender-specific microbiome differences in the urine and bladder tissue; ii) the extent to which paired urine samples mirror the bladder tissue-associated microbiome. Methods: A total of 166 biologic samples were analyzed: morning, mid-stream voided urines from 49 therapy-naïve patients (36 males, 13 females) undergoing radical cystectomy for MIBC and from 59 age-matched healthy controls (34 males, 25 females), plus bladder tissue specimens (paired BCa/non-BCa tissues) of 29 patients (21 males, 8 females). Exclusion criteria included history of recurrent urinary tract infections, positive urine dipstick test at the time of sample collection, recent antibiotic therapy, history of intravesical or neoadjuvant treatment for BCa. Microbiome was analyzed by amplicon-based approach. Sequences with a high-quality score >Q30 and length >250bp were used for the taxonomic analysis and were processed using the QIIME (Quantitative Insights Into Microbial Ecology) software package (v1.9.1). Intra- and interdiversity between samples and identification of taxonomic biomarkers by using the linear discriminant analysis (LDA) effect size (LEfSe) were considered significant at p-value ≤0.05. Results: Comparing neoplastic vs. non-neoplastic paired tissues, beta-diversity did not show distinct clustering of the samples. At the taxonomic level, the genus Burkholderia was enriched in the neoplastic specimens in both genders. When we compared urines of patients vs. controls, the male and female urinary microbiome was dominated by members of the three major bacterial phyla Proteobacteria, Firmicutes, and Bacteroidetes. At lower taxonomic levels, the bacterial taxa differently enriched in BCa vs. controls were gender-specific, with 18 and 36 bacterial taxa differentially represented in BCa and controls in men and women, respectively. Comparing paired urinary and tissue-associated microbiome, we defined the “common BCa microbiome,” representing 34 and 16 bacterial families (>80% of total relative abundance) shared in the urines and tissues of male and female patients, respectively. Conclusions: We provide novel characterization of the gender-specific microbiome in the urines and paired bladder tissues of BCa patients. A gender-specific “common BCa microbiome” was detailed, highlighting potentially actionable bacterial taxa. Citation Format: Filippo Pederzoli, Roberto Ferrarese, Virginia Amato, Irene Locatelli, Elisa Alchera, Roberta Lucianò, Manuela Nebuloni, Alberto Briganti, Andrea Gallina, Valentina Murdica, Renzo Colombo, Andrea Necchi, Massimo Clementi, Francesco Montorsi, Nicasio Mancini, Andrea Salonia, Massimo Alfano. Intratissutal and urinary microbiome in therapy-naive bladder cancer patients: Definition of a gender-specific common microbiome [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr A33.

Sex-specific Alterations in the Urinary and Tissue Microbiome in Therapy-naïve Urothelial Bladder Cancer Patients

Combinations of Urinary Biomarkers for Surveillance of Patients with Incident Nonmuscle Invasive Bladder Cancer: The European FP7 UROMOL Project

APOPTOSIS AND CHEMOTHERAPY FOR BLADDER CANCER

Bladder Cancer and the Urinary Microbiome—New Insights and Future Directions: A Review

New insights in the urinary microbiome have led to a better understanding being built of the shifts in bacterial representations from health to disease; these hold promise as markers for diagnosis and therapeutic responses. Although several efforts have been made to identify a "core urinary microbiome", different fingerprints have been identified in men and women that shift with age. The main bacterial groups overall include Firmicutes, Actinobacteria, Fusobacteria, and Bacteroidetes. Although patients with bladder cancer have a microbiome that is similar to that of healthy individuals, differences have been observed at the species level with Fusobacterium nucleatum and Ralstonia, and at the genus level with Cutibacterium. Different bacterial representations may influence extracellular matrix composition, affecting tumor metastatic spreading and tumorigenic metalloproteinase expression. Furthermore, gene expression affecting targets of immune therapy, such as PD-L1, has been associated with changes in bacterial representations and therapeutic response to BCG. This comprehensive review aims to examine the influence of the urinary microbiome in bladder cancer.

Global Meta-analysis of Urine Microbiome: Colonization of Polycyclic Aromatic Hydrocarbon–degrading Bacteria Among Bladder Cancer Patients

There are a total of 82,290 new cases and 16,710 deaths estimated for bladder cancer in the United States in 2023. Currently, urine cytology tests are widely used for bladder cancer diagnosis, though they suffer from variable sensitivity, ranging from 45 to 97%. More recently, the microbiome has become increasingly recognized for its role in human diseases, including cancers. This study attempts to characterize urinary microbiome bladder cancer-specific dysbiosis to explore its diagnostic potential. RNA-sequencing data of urine samples from patients with bladder cancer (n = 18) and matched controls (n = 12) were mapped to bacterial sequences to yield species-level abundance approximations. Urine samples were analyzed at both the population and species level to reveal dysbiosis associated with bladder cancer. A panel of 35 differentially abundant species was discovered, which may be useful as urinary biomarkers for this disease. We further assessed whether these species were of similar significance in a validation dataset (n = 81), revealing that the genera Escherichia, Acinetobacter, and Enterobacter were consistently differentially abundant. We discovered distinct patterns of microbial-associated immune modulation in these samples. Several immune pathways were found to be significantly enriched with respect to the abundance of these species, including antigen processing and presentation, cytosolic DNA sensing, and leukocyte transendothelial migration. Differential cytokine activity was similarly observed, suggesting the urinary microbiome's correlation to immune modulation. The adherens junction and WNT signaling pathways, both implicated in the development and progression of bladder cancer, were also enriched with these species. Our findings indicate that the urinary microbiome may reflect both microbial and immune dysregulations of the tumor microenvironment in bladder cancer. Given the potential biomarker species identified, the urinary microbiome may provide a non-invasive, more sensitive, and more specific diagnostic tool, allowing for the earlier diagnosis of patients with bladder cancer.