Endometrial cancer rates are rising rapidly said Melissa Herbst-Kralovetz PhD professor at the University of Arizona College of Medicine  Phoenix and director of the Women’s Health Research Program and Microbiome Initiative. She noted that in developed countries like the U.S. endometrial cancer is now the most common gynecologic cancer and the fourth most common cancer overall in women having recently surpassed ovarian cancer in mortality.

By 2030 an estimated 122,000 new cases will be diagnosed annually in the U.S. A 2019 study highlighted a disproportionate impact on Native American and Latina women in Arizona while nationwide African American and Latina women face higher mortality rates largely due to limited access to care and diagnoses at later stages.

In this cross-sectional study researchers from the University of Arizona and Northern Arizona University examined vaginal and rectal swabs from 192 women undergoing hysterectomy for newly diagnosed cancer or benign gynecologic conditions. They identified a link between certain bacteria such as Anaerococcus Prevotella Porphyromonas and Peptoniphilus and endometrial cancer along with the role of reduced vaginal lactobacilli in facilitating bacterial transfer between sites.

The study also revealed that bacterial movement between the rectum and vagina was associated with a shift toward more invasive species like Prevotella and Peptoniphilus and a decline in protective lactobacilli. The bacteria we saw transferring most between these sites were also those linked to endometrial cancer said Herbst-Kralovetz.

Researchers found that patients with endometrial cancer showed increased microbe-to-microbe correlations particularly within the Peptoniphilaceae family. Distinct microbial signatures of endometrial cancer included Anaerococcus Porphyromonas and Peptoniphilus in vaginal samples and Buttiaxella in rectal samples.

They also observed microbial transfer between mucosal sites with Prevotella timonensis and Peptoniphilus A sp. being the most commonly shared. This microbial swapping was reduced when Lactobacillus was dominant. Additionally they identified potential metabolic pathways linked to dysregulated amino acid processing complex carbohydrate breakdown and hormone metabolism in cancer patients.

According to Herbst-Kralovetz these findings highlight the importance of studying multiple anatomical sites and the dynamic interactions between the urogenital rectal and upper reproductive tract microbiomes. Gaining a deeper understanding of these microbial relationships is key to improving women’s health and developing targeted therapies.

The findings may eventually pave the way for using the vaginal microbiome as a biomarker in endometrial cancer screening.

We must continue raising awareness about endometrial cancer it’s not going away Herbst-Kralovetz emphasized. A deeper understanding of this disease is essential for developing more effective diagnostics and interventions.

Source: https://cancercenter.arizona.edu/news/2025/06/microbiomes-may-provide-biomarker-endometrial-cancer#:~:text=Scientists%20Think%20So.-,Could%20microbiomes%20be%20a%20potential%20biomarker%20for%20endometrial%20cancer,of%20A%20scientists%20think%20so.&text=A%20study%20by%20researchers%20from,and%20other%20benign%20endometrial%20conditions.