Altered cervicovaginal microbiota in premenopausal ovarian cancer patients

Highly specific vaginal microbiome signature for gynecological cancers

To investigate the vaginal microbiota signature of patients with gynecologic cancer and evaluate its diagnostic biomarker potential. We incorporated vaginal 16S rRNA-seq data from 529 women and utilized VSEARCH to analyze the raw data. α-Diversity was evaluated utilizing the Chao1, Shannon, and Simpson indices, and β-diversity was evaluated through principal component analysis using Bray-Curtis distances. Linear discriminant analysis effect size (LEfSe) was utilized to determine species differences between groups. A bacterial co-abundance network was constructed utilizing Spearman correlation analysis. A random forest model of gynecologic tumor risk based on genus was constructed and validated to test its diagnostic efficacy. In gynecologic cancer patients, vaginal α-diversity was significantly greater than in controls, and vaginal β-diversity was significantly separated from that of controls; there was no correlation between these characteristics and menopause status among the subject women. Women diagnosed with gynecological cancer exhibited a reduction in the abundance of vaginal Firmicutes and Lactobacillus, while an increase was observed in the proportions of Bacteroidetes, Proteobacteria, Prevotella, Streptococcus, and Anaerococcus. A random forest model constructed based on 56 genus achieved high accuracy (area under the curve = 84.96%) in gynecological cancer risk prediction. Furthermore, there were discrepancies observed in the community complexity of co-abundance networks between gynecologic cancer patients and the control group. Our study provides evidence that women with gynecologic cancer have a unique vaginal flora structure and microorganisms may be involved in the gynecologic carcinogenesis process. A gynecological cancer risk prediction model based on characteristic genera has good diagnostic value.

High-Grade Serous Ovarian Cancer-A Risk Factor Puzzle and Screening Fugitive

High-grade serous ovarian cancer (HGSOC) is the most lethal tumor of the female genital tract. Despite extensive studies and the identification of some precursor lesions like serous tubal intraepithelial cancer (STIC) or the deviated mutational status of the patients (BRCA germinal mutation), the pathophysiology of HGSOC and the existence of particular risk factors is still a puzzle. Moreover, a lack of screening programs results in delayed diagnosis, which is accompanied by a secondary chemo-resistance of the tumor and usually results in a high recurrence rate after the primary therapy. Therefore, there is an urgent need to identify the substantial risk factors for both predisposed and low-risk populations of women, as well as to create an economically and clinically justified screening program. This paper reviews the classic and novel risk factors for HGSOC and methods of diagnosis and prediction, including serum biomarkers, the liquid biopsy of circulating tumor cells or circulating tumor DNA, epigenetic markers, exosomes, and genomic and proteomic biomarkers. The novel future complex approach to ovarian cancer diagnosis should be devised based on these findings, and the general outcome of such an approach is proposed and discussed in the paper.

The Role of the Human Microbiome in Epithelial Ovarian Cancer

Ovarian cancer is the fifth-leading cause of cancer deaths among women due to the absence of available screening methods to identify early disease. Thus, prevention and early disease detection investigations are of high priority, surrounding a critical window of opportunity to better understand important pathogenic mechanisms of disease progression. Microorganisms modulate molecular interactions in humans that can influence states of health and disease, including ovarian cancer. While the mechanisms of infectious microbial invasion that trigger the immune-inflammatory axis are well studied in cancer research, the complex interactions that promote the transition of noninfectious healthy microbes to pathobiont expansion are less understood. As traditional research has focused on the influences of infectious pathogens on ovarian cancer development and progression, the impact of noninfectious microbes has gained scientific attention. The objective of this chapter is to summarize current evidence on the role of microbiota in epithelial ovarian cancer throughout disease.

Microbiota as the unifying factor behind the hallmarks of cancer

The human microbiota is a complex ecosystem that colonizes body surfaces and interacts with host organ systems, especially the immune system. Since the composition of this ecosystem depends on a variety of internal and external factors, each individual harbors a unique set of microbes. These differences in microbiota composition make individuals either more or less susceptible to various diseases, including cancer. Specific microbes are associated with cancer etiology and pathogenesis and several mechanisms of how they drive the typical hallmarks of cancer were recently identified. Although most microbes reside in the distal gut, they can influence cancer initiation and progression in distant tissues, as well as modulate the outcomes of established cancer therapies. Here, we describe the mechanisms by which microbes influence carcinogenesis and discuss their current and potential future applications in cancer diagnostics and management.

Vaginal and tumor microbiomes in gynecological cancer (Review)

Cervical, ovarian and endometrial cancer are the three most common types of gynecologic cancer. As a hub, the vagina connects the site of gynecological cancer with the external environment. Lactobacilli participate in the formation of a healthy vaginal microenvironment as the first line of defense against pathogen invasion; a dysbiotic vaginal microenvironment loses its original protective function and is associated with the onset, metastasis, poor efficacy and poor prognosis of gynecological cancer. The early diagnosis of cancer is the key to improve the survival time of patients with cancer. The screening of Porphyromonas, Sneathia and Atopobium vaginae, and other microbial markers, can assist the diagnosis of gynecological cancer, and screen out the high-risk population as early as possible. With the in-depth study of the microbes in tumor tissues, reasearchers have analyzed the immunological associations of microorganisms in tumor tissues. Due to the structural-functional interconnection between the organ of gynecological tumorigenesis and the vagina, the present study aims to review the relationship between vaginal and tumor microorganisms and gynecological cancer in terms of occurrence, screening, treatment and prognosis.

Potential Role of Vaginal Microbiota in Ovarian Cancer Carcinogenesis, Progression and Treatment

Ovarian cancer represents one of the most challenging gynecologic cancers which still has numerous unknowns on the underlying pathogenesis. In addition to the verified contributors such as genomic predisposition and medical history in the carcinogenesis, emerging evidence points out the potential role of vaginal microbiota in ovarian cancer. Recent studies have underlined the presence of vaginal microbial dysbiosis in cancer cases. Increasing research also indicates the potential correlations between vaginal microbes and cancer carcinogenesis, progression and treatment. Currently, compared with other gynecologic cancers, reports on the roles of vaginal microbiota in ovarian cancer remain scarce and fragmentary. Therefore, in this review, we summarize the roles of vaginal microbiota in various gynecologic diseases, particularly focusing on the potential mechanisms and possible applications of vaginal microbiota in ovarian cancer, giving insight into the involvement of vaginal microbiota in gynecologic cancer treatment.

Immune-Onco-Microbiome: A New Revolution for Gynecological Cancers

Despite significant advances in understanding the pathogenetic mechanisms underlying gynaecological cancers, these cancers still remain widespread. Recent research points to a possible link between microbiota and cancer, and the most recent attention is focusing on the relationship between the microbiome, the immune system, and cancer. The microbiome diversity can affect carcinogenesis and the patient’s immune response, modulating the inflammatory cascade and the severity of adverse events. In this review, we presented the recent evidence regarding microbiome alterations in patients with gynaecological tumours to understand if the link that exists between microbiome, immunity, and cancer can guide the prophylactic, diagnostic, and therapeutic management of gynaecological cancers.

Human microbiomes in cancer development and therapy

Colonies formed by bacteria, archaea, fungi, and viral groups and their genomes, metabolites, and expressed proteins constitute complex human microbiomes. An increasing evidences showed that carcinogenesis and disease progression were link to microbiomes. Different organ sources, their microbial species, and their metabolites are different; the mechanisms of carcinogenic or procancerous are also different. Here, we summarize how microbiomes contribute to carcinogenesis and disease progression in cancers of the skin, mouth, esophagus, lung, gastrointestinal, genital, blood, and lymph malignancy. We also insight into the molecular mechanisms of triggering, promoting, or inhibiting carcinogenesis and disease progress induced by microbiomes or/and their secretions of bioactive metabolites. And then, the strategies of application of microorganisms in cancer treatment were discussed in detail. However, the mechanisms by which human microbiomes function are still poorly understood. The bidirectional interactions between microbiotas and endocrine systems need to be clarified. Probiotics and prebiotics are believed to benefit human health via a variety of mechanisms, in particular, in tumor inhibition. It is largely unknown how microbial agents cause cancer or how cancer progresses. We expect this review may open new perspectives on possible therapeutic approaches of patients with cancer.

Microbiome in cancer: An exploration of carcinogenesis, immune responses and immunotherapy

Cancer is a major disease endangering human health. More and more studies have shown that microorganisms play an extremely important role in the occurrence, development and treatment of tumors. As a very promising tumor treatment strategy, immunotherapy has also been proved to have a great relationship with microorganisms. Here, the authors review the contribution of the microbiota to cancer and the research on its impact on cancer immunotherapy. We also highlight the possible mechanism of their interaction and outlined the potential application of microbiota in tumor immunotherapy.