The Vaginal Microbiome and Cervical Cancer Screening in Low- and Middle-Income Countries

Abstract

Globally, cervical cancer affects more than a half-million women each year, with disproportionate incidence and mortality for women in low- and middle-income countries. Early detection through cervical cancer screening saves lives but is hampered by poor coverage, suboptimal detection accuracy, and lack of access to and delays in effective treatment. Emerging evidence that indicates how the vaginal microbiome can modify progression of human papillomavirus (HPV) infection and cervical cancer pathogenesis is surveyed. This presentation features a discussion of how the vaginal microbiome may affect cervical cancer screening and how cervical cancer screening may incorporate vaginal microbiome health in low- and middle-income countries. Vaginal dysbiosis as a clinical syndrome may be called bacterial vaginosis (BV), a condition that represents a shift from a Lactobacillus-dominant vaginal microbiome to one that is polymicrobial and often associated with increased mucosal inflammation. Meta-analyses and prospective studies demonstrate an association between vaginal dysbiosis and increased risk of HPV incidence and persistence and high-grade lesions and cancer. Increasing vaginal microbiome diversity is associated with progression of cervical intraepithelial neoplasia. Vaginal microbiota that are associated with greater likelihood of HPV detection in molecular studies are also commonly associated with BV. There are numerous challenges to incorporating microbiome measurement in population-level cervical cancer screening and unanswered research questions on its immediate utility. BV may serve as a measure of vaginal microbiome health, although there are no guidelines or recommendations for regular BV screening and treatment. Ongoing and planned longitudinal studies should evaluate BV screening in association with high-risk HPV, results of cervical cancer screening, and progression of cervical intraepithelial neoplasia to assess the utility of BV screening and treatment as an adjunct to cervical cancer screening and potential intervention.