Vaginal and Cervical Microbiota Composition in Patients with Endometrial Cancer

Abstract

According to recent data, changes in the vaginal microbiota could affect the risk of gynaecological cancers. Women suffering from endometrial cancer present significant changes in cervicovaginal microbiota composition. The objective of our study was to characterize the cervicovaginal microbiota of women undergoing hysterectomy due to benign disease, atypical hyperplasia, and endometrial cancer; The study included 96 patients, who undergone surgical treatment due to benign uterine disease, precancerous endometrial lesion, and endometrial cancer. Quantitative and qualitative real-time PCR analysis of DNA isolated from vaginal fornix and endocervical canal samples was performed to detect the 19 most commonly identified microorganisms, including different Lactobacillus spp., Atopobium, Bifidobacterium, Chlamydia, and Gardnerella; At least one of the tested microorganisms was identified in 88.5% of vaginal and 83.3% of cervical samples. Lactobacillus iners was significantly more frequent in patients with benign condition, whereas Dialister pneumosintes and Mobiluncus curtisii was more frequent in cancer patients; Mobiluncus curtisi and Dialister pneumosintes, which were identified as significantly more common in endometrial cancer vaginal samples, may be considered as potential endometrial cancer co-factors which promote/stimulate carcinogenesis. However, the exact mechanism of such activity remains unexplained and requires further investigations.

Keywords: Dialister; Lactobacillus; Mobiluncus; endometrial cancer; microbiome.

Figure 1

The distribution of microorganisms in the vaginal (V) and cervical (C) samples detected by molecular methods.

Figure 2

The distribution of microorganisms in the vaginal (V) and cervical (C) samples from patients with different entities obtained by molecular methods.

Figure 3

Accurate profiling of pathogenic and commensal microbes in patients with endometrial cancer, atypical hyperplasia, and benign uterine disease. Fold change in microbial species abundance in patients with different diagnoses (cancer and benign condition as well as cancer and hyperplasia groups) was calculated by the ∆∆CT method using human genomic DNA to normalize (HBB1 gene). At least a 5 to 10-fold increase or decrease in relative abundance may be considered significant. (V): vaginal; (C): cervical samples.

Figure 4

PLS-DA with vaginal (V)/cervical (C) samples was performed based on the 17 bacterial species tested. (A) Biplot of PLS-DA with vaginal samples. Different colours of points in plots were represented for different groups. (B) Coefficient overview plot displays how bacterial species take part in four created groups: M25DA4, green; M25DA5, blue; M25DA6, red; M25DA7, yellow.