Associations among HPV persistence, the vaginal microbiome, and cervical cancer recurrence

In the US, up to 60% of cervical cancer (CxCa) survivors will have persistent HPV infection, the causative agent of CxCa, and up to 35% will develop recurrent local CxCa within 4 years after chemo-radiation therapy. Preliminary studies suggest healthy vaginal microbiome (VM) could affect the acquisition, persistence, and clearance of HPV. Through longitudinal studies, we investigate associations between the dynamics of VM, HPV persistence, cancer recurrence (CR), and outcomes in gynecologic cancer survivors who completed cancer treatments.

We enrolled 49 patients with Stage IB-IIIC CxCa who completed radiation therapy (RT) alone or concurrent chemoradiation (chemoRT). VM sequencing and HPV typing were performed on samples obtained at baseline (T0, pre-treatment), T1, T2, and T3 (3, 6, and 12 months after the completion of cancer treatment). Patients were evaluated for CR up to 4 years following the end of treatment.

Among all patients, 33% (16/49) had CxCa recurrence within 2-3 years post-therapy. The vaginal microbiome exhibited high diversity, Prevotella-dominant communities; only 20% were dominated by lactobacilli at any time. Post-treatment hrHPV was detected in 17 out of 41 women (41.5%) with follow-up samples. We identified key taxa, such as Prevotella species, which were highly associated with CxCa recurrence and post-treatment detection of hrHPV.

Our findings link Prevotella-dominant, high diversity vaginal microbiome communities with post-therapy hrHPV persistence and cervical cancer recurrence in gynecologic cancer survivors. Such findings warrant further research into the role of the microbiome in modulating cervical cancer progression and response to therapy, suggesting modulation of the microbiome with probiotics or other methods could be considered a novel approach to improve cervical cancer treatment outcomes.