Endometrial cancer rates are rising rapidly said Melissa Herbst-Kralovetz professor at the University of Arizona College of Medicine  Phoenix director of the Women’s Health Research Program and Microbiome Initiative and senior author of the study. In countries like the U.S., it’s now the most common gynecologic cancer and the fourth most common cancer among women. Alarmingly it has overtaken ovarian cancer in mortality.

By 2030 the U.S. is projected to see 122,000 new cases annually. In Arizona Native American and Latina women are disproportionately affected while nationwide African American and Latina women face higher mortality rates due to barriers in healthcare access and late-stage diagnoses Herbst-Kralovetz noted.

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 specific bacterial associations with endometrial cancer including Anaerococcus Prevotella Porphyromonas and Peptoniphilus and noted that dominance of vaginal lactobacilli influenced bacterial transfer between nearby sites.

The study revealed a pattern of bacterial exchange between the rectum and vagina with a rise in invasive bacteria like Prevotella and Peptoniphilus and a decrease in protective lactobacilli. The bacteria that were most frequently swapped between sites in this cohort were also those linked to endometrial cancer said Dr. Herbst-Kralovetz.

Additionally women with endometrial cancer showed increased microbe-to-microbe interactions particularly within the Peptoniphilaceae family. Distinct microbial markers included Anaerococcus Porphyromonas and Peptoniphilus in vaginal samples and Buttiaxella in rectal samples.

The researchers observed potential microbiota transfer between mucosal sites with Prevotella timonensis and Peptoniphilus A sp. being the most commonly shared. This microbial exchange was less frequent in women with higher levels of protective Lactobacillus. The team also identified disrupted metabolic pathways in endometrial cancer patients related to amino acid imbalance complex carbohydrate breakdown and hormone metabolism.

Dr. Herbst-Kralovetz emphasized the importance of investigating multiple anatomical sites to understand the dynamic relationships between the urogenital rectal and upper reproductive tract microbiomes. Gaining insight into these interactions is crucial for advancing women’s health and creating targeted treatments.

Our collaborative team of clinicians bioinformaticians and scientists helped push these translational questions forward said Herbst-Kralovetz. These findings may pave the way for future vaginal microbiome-based screening tools for endometrial cancer.

We must continue to raise awareness about endometrial cancer it’s not going away she added. A deeper understanding of the disease is key to developing effective diagnostics and stronger interventions.

Source: https://cancercenter.arizona.edu/news/2025/06/could-microbiomes-be-potential-biomarker-endometrial-cancer-u-scientists-think-so