Vaginal Microbes Denote Early Detection of Endometrial Cancer

Endometrial cancer triggers remain elusive, but given the typical inflammatory profile in these cases, microbes in the uterine environment are suspected to play a role in the development of this disease.

The microbial partners along the female reproductive tract have been long known to play an important role in health and disease along the woman’s reproductive tract. Lactic acid producing microbes have a strong role in determining the microbial community membership of the vaginal microbiome and have been shown to protect against infection.

Medical scientists at the Mayo Clinic studied 31 Caucasian women undergoing hysterectomy. Of those, 10 women were diagnosed with a benign gynecologic condition, four women were diagnosed with endometrial hyperplasia, and 17 women were diagnosed with endometrial cancer. All diagnoses were made based on the final surgical pathology following hysterectomy. Vaginal, cervical, Fallopian, ovarian, peritoneal, and urine samples were collected aseptically both in the operating room and the pathology laboratory.

All genomic DNA extractions were performed by using the MoBio PowerSoil Kit and the DNA content was measured using High Sensitivity Qubit. The V3-V5 region of the 16S rDNA was then amplified through a polymerase chain reaction (PCR) and the products of the amplification were verified by a TapeStation D1K Tape.

The microbiome sequencing (16S rDNA V3-V5 region) revealed that the microbiomes of all organs (vagina, cervix, Fallopian tubes, and ovaries) are significantly correlated and that there is a structural microbiome shift in the cancer and hyperplasia cases, distinguishable from the benign cases. Several taxa were found to be significantly enriched in samples belonging to the endometrial cancer cohort: Firmicutes (Anaerostipes, Dialister, Peptoniphilus, Ruminococcus, and Anaerotruncus), Spirochetes (Treponema), Actinobacteria (Atopobium), Bacteroidetes (Bacteroides and Porphyromonas), and Proteobacteria (Arthrospira). Of particular relevance, the simultaneous presence of Atopobium vaginae and an uncultured representative of the Porphyromonas sp. (99 % match to P. somerae) were found to be associated with disease status, especially if combined with a high vaginal pH (>4.5).

The authors concluded that the detection of A. vaginae and the identified Porphyromonas sp. in the gynecologic tract combined with a high vaginal pH is statistically associated with the presence of endometrial cancer. Given the documented association of the identified microorganisms with other pathologies, these findings raise the possibility of a microbiome role in the manifestation, etiology, or progression of endometrial cancer that should be further investigated. The study was published on November 25, 2016, in the journal Genome Medicine.