Current Trends and Challenges of Microbiome Research in Bladder Cancer.

PURPOSE OF THE REVIEW: Microbiome research has provided valuable insights into the associations between microbial communities and bladder cancer. However, this field faces significant challenges that hinder the interpretation, generalization, and translation of findings into clinical practice. This review aims to elucidate these challenges and highlight the importance of addressing them for the advancement of microbiome research in bladder cancer. RECENT FINDINGS: Recent findings underscore the complexities involved in microbiome research, particularly in the context of bladder cancer. Challenges include low microbial biomass in urine samples, potential contamination issues during collection and processing, variability in sequencing methods and primer selection, and the difficulty of establishing causality between microbiota and bladder cancer. Studies have shown the impact of sample storage conditions and DNA isolation kits on microbiome analysis, emphasizing the need for standardization. Additionally, variations in urine collection methods can introduce contamination and affect results. The choice of 16S rRNA gene amplicon sequencing or shotgun metagenomic sequencing introduces technical challenges, including primer selection and sequencing read length. Establishing causality between the microbiota and bladder cancer requires experimental methods like fecal microbiota transplantation and human microbiota-associated murine models, which face their own set of challenges. Translating microbiome research into therapeutic applications is hindered by methodological variability, incomplete understanding of bioactive molecules, imperfect animal models, and the inherent heterogeneity of microbiome communities among individuals. Microbiome research in bladder cancer presents significant challenges stemming from technical and conceptual complexities. Addressing these challenges through standardization, improved experimental models, and advanced analytical approaches is essential for advancing our understanding of the microbiome's role in bladder cancer and its potential clinical applications. Achieving this goal can lead to improved patient outcomes and novel therapeutic strategies in the future.

Neovaginal Human Papillomavirus Prevalence in Transfeminine Individuals: A Systematic Review.

OBJECTIVE: To assess the prevalence of high-risk human papillomavirus (hrHPV) and human papillomavirus (HPV)-associated abnormalities in the neovaginas of postvaginoplasty transfeminine patients to inform potential HPV-screening guidelines for this patient population. DATA SOURCES: MEDLINE, ClinicalTrials.gov , the Cochrane Library, Scopus, and Google Scholar were searched through September 30, 2022. METHODS OF STUDY SELECTION: The population included transfeminine individuals who had undergone vaginoplasty with an outcome of subsequent positive HPV diagnosis or HPV-related lesions. Randomized clinical trials, cohort studies, cross-sectional studies, and case reports available in English were included in the analysis. Identified articles were doubly screened, and accepted articles were doubly extracted. TABULATION, INTEGRATION, AND RESULTS: Of 59 abstracts identified, 30 were screened for eligibility, of which 15 met the criteria for review. Included studies were assessed for vaginoplasty procedure type, time elapsed between vaginoplasty and HPV testing, HPV type, location and manner of sample collection, method of HPV diagnosis, and classification and location of HPV-associated neovaginal lesions. Studies were assigned a grade of evidence of very low, low, moderate, or high based on study design, precision, directness, and risk of bias. Prevalence of neovaginal hrHPV ranged from 8.3% to 20% in identified studies, and per-study prevalence of HPV-related neovaginal abnormalities ranged from 0% to 8.3% in patients. CONCLUSION: The current body of research demonstrates that, after vaginoplasty, transfeminine individuals may develop neovaginal HPV infection with associated cytologic abnormalities or grossly apparent lesions. In some included studies, neovaginal HPV-associated lesions were highly advanced before they were identified. A small number of studies assessed neovaginal HPV prevalence in transfeminine individuals, with hrHPV prevalence ranging from 8.3% to 20%. However, broader conclusions about neovaginal HPV prevalence are limited by a lack of high-grade evidence in the existing literature. More rigorous prevalence research is needed to inform preventative care guidelines for transfeminine individuals at risk of developing HPV-related neovaginal complications. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42022379977.