301P - Correlation between cervical cancer recurrence after radiation therapy and vaginal microbiome

Background

Cervical cancer is the most prevalent reproductive malignancy in women worldwide and estimated over 600,000 new cases and 340,000 deaths each year. Concurrent chemoradiotherapy is the standard treatment for locally advanced cervical cancer. Despite the great improvement this strategy has achieved, nearly 30% of patients will suffer distant metastases and 70% of patients may experience local recurrence. The dominance of Lactobacillus in the vaginal microenvironment of healthy women helps to establish a physiological barrier on the vaginal surface, Microbial biomarkers are effective for predicting the nonresponse for immune checkpoint inhibitor administration. It is intriguing to explore the alteration of vaginal microbial community challenged by chemoradiotherapy, also whether microorganism(s) could be used as biomarkers to predict the responsiveness of chemoradiotherapy.

Methods

A total of 126 patients with IB-IVB cervical cancer who received chemoradiotherapy in our hospital were enrolled in this study. The sampling of vaginal microbiome was carried out as we previously described, both pre- and post-treatment of each patient. Bacterial genomic DNA was extracted and 16S rRNA was sequenced from their vaginal secretions, and the results were analyzed bioinformatically.

Results

We found that the structure and composition of the vaginal microbiome changed significantly before and after radiotherapy, and radiotherapy treatment significantly changed the structure of the microorganisms, destroyed their physiological functions and disrupted the homeostasis of the microbial community. At the same time, we found that the beneficial microbial community in the vaginal microbiome decreased significantly in the relapsing group compared with the non-relapsing group before and after radiotherapy, and the microbial function and community homeostasis were significantly reduced, suggesting an unhealthy vaginal microbiome in the relapsing group.

Conclusions

We have shown that C-reactive protein and disease stage and other factors and biomarkers (such as L. iners) are important factors in predicting the recurrence of cervical cancer patients after radiotherapy.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Zhejiang Cancer Hospital.

Funding

Zhejiang medicine and health science and technology project.

Disclosure

The author has declared no conflicts of interest.