Characterization of the vaginal microbiome of postmenopausal patients receiving chemoradiation for locally advanced cervical cancer.

The standard-of-care treatment of locally advanced cervical cancer includes pelvic radiation therapy with concurrent cisplatin-based chemotherapy and is associated with a 30%-50% failure rate. New prognostic and therapeutic targets are needed to improve clinical outcomes. The vaginal microbiome has been linked to the pathogenesis of cervical cancer, but little is known about the vaginal microbiome in locally advanced cervical cancer as it relates to chemoradiation. In this pilot study, we utilized 16S rRNA gene community profiling to characterize the vaginal microbiomes of 26 postmenopausal women with locally advanced cervical cancer receiving chemoradiation. Our analysis revealed diverse anaerobe-dominated communities whose taxonomic composition, diversity, or bacterial abundance did not change with treatment. We hypothesized that characteristics of the microbiome might correlate with treatment response. Pretreatment microbial diversity and bacterial abundance were not associated with disease recurrence. We observed a greater relative abundance of Fusobacterium in patients who later had cancer recurrence, suggesting that Fusobacterium could play a role in modifying treatment response. Taken together, this hypothesis-generating pilot study provides insight into the composition and dynamics of the vaginal microbiome, offering proof of concept for the future study of the microbiome and its relationship with treatment outcomes in locally advanced cervical cancer.