Review Article Pathobiology 2021;88:187–197 Microbiome and Cervical Cancer Cristina Paula Castanheira a Mayara Luciana Sallas b Rafaella Almeida Lima Nunes b Noely Paula Cristina Lorenzi c Lara Termini b a Department of Obstetrics and Gynecology, Conjunto Hospitalar Mandaqui, São Paulo, Brazil; b Innovation in Cancer Laboratory, Centro de Investigação Translacional em Oncologia, Instituto do Câncer do Estado de São Paulo Octavio Frias de Oliveira, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; c Department of Gynecology, Hospital Universitário da Universidade de São Paulo, São Paulo, Brazil Received: July 27, 2020 Accepted: September 7, 2020 Published online: November 23, 2020 Lara Termini Innovation in Cancer Laboratory, Centro de Investigação Translacional em Oncologia Instituto do Câncer do Estado de São Paulo Octavio Frias de Oliveira, Faculdade de Medicina da Universidade de São Paulo, Rua Dr. Ovídio Pires de Campos, 872-3 Andar Cerqueira César, São Paulo, SP CEP 05403-911 (Brazil) lara.termini @hc.fm.usp.br © 2020 S. Karger AG, Basel karger@karger.com www.karger.com/pat DOI: 10.1159/000511477 Keywords Microbiome · Cervical cancer · Human papillomavirus Abstract Persistent infection with some types of mucosal human pap- illomavirus (HPV) is the etiological factor for the develop- ment of cervical cancer and its precursor lesions. Besides, several cofactors are known to play a role in cervical disease onset and progression either by favoring or by preventing HPV infection and persistence. The microbiome of a healthy female genital tract is characterized by the presence of 1 or few varieties of lactobacilli. However, high-throughput stud- ies addressing the bacterial diversity and abundance in the female genital tract have shown that several factors, includ- ing hormonal levels, hygiene habits, and sexually transmit- ted diseases may disrupt the natural balance, favoring the outgrowth of some groups of bacteria, which in turn may favor some pathological states. Recently, the vaginal micro- biome has emerged as a new variable that could greatly in- fluence the natural history of HPV infections and their clinical impact. In this context, changes in the vaginal microbiome have been detected in women infected with HPV and wom- en with HPV-associated lesions and cancer. However, the role of specific bacteria groups in the development/progres- sion or prevention/regression of HPV-associated patholo- gies is not well understood. In this review we summarize the current knowledge concerning changes in vaginal microbi- ome and cervical disease. We discuss the potential function- al interplay between specific bacterial groups and HPV infec- tion outcomes. © 2020 S. Karger AG, Basel Introduction Cervical cancer (CC) represents the fourth most fre- quent malignant neoplasia among women worldwide and it is a serious public health problem. In 2018, approxi- mately 570,000 new cases and 311,000 deaths occurred, and most of them were in developing countries [1–4]. Persistent infection with human papillomavirus (HPV) types of high-oncogenic-risk HPV (hrHPV) is the main factor for the development of CC, and it has been found in 99.7% of CC samples [5]. Infection with hrHPV is highly prevalent in sexually active women. However, the occurrence of CC precursor lesions is relatively low [6, 7]. In fact, approximately 90% of infections by hrHPV are transient and regress spontaneously [8]. A woman’s risk of acquiring an infection by any type of HPV during her C.P.C., M.L.S., and R.A.L.N. contributed equally to this work.