Intratumor Microbiome and Its Correction With Tumor Response After Concurrent Chemoradiotherapy in Locally Advanced Cervical Cancer

Purpose/Objective(s) Microbiome in cervical cancer tissue remains largely unknown, although cervicovaginal microbiome was investigated in various studies. We investigated the microbiome in cancer tissues and vagina, and its impact on tumor response after concurrent chemoradiotherapy (CCRT) in locally advanced cervical cancer (LACC) patients. Materials/Methods We prospectively enrolled 63 LACC patients who received CCRT and collected their tumor biopsies and vaginal swabs before and during CCRT. 16S rRNA gene sequencing was used to evaluated the microbiome in samples. Tumor response was evaluated based on RECIST 1.1 guidelines at one month after CCRT. Results Complete response (CR) was found in 50 (79%) patients, while partial response (PR) or stable disease (SD) was shown in 13 (21%) patients after CCRT. Patients with CR showed higher beta-diversity (P = 0.021) but not alpha-diversity (P > 0.05) in pretreatment tumor tissues than patients with PR/SD. Different microbiome composition in tumor tissues and vaginal swabs was observed between patients with CR and PR/SD at the two time points. KEGG showed significantly increased metabolic pathways, such as amino acid metabolism, energy metabolism, nucleotide metabolism, and lipid metabolism, in patients with CR than with PR/SD. Interestingly, alpha-diversity was significantly higher in cervical cancer tissues than in vaginal swabs during CCRT (P 0.05). Conclusion Our work reveals the microbiome in tumor microenvironment and vagina and its correction with tumor response after CCRT in LACC patients. Further study was warranted to explore which microbe regulates tumor response by which metabolic pathway. Author Disclosure C. Liu: None. A. Li: None. C. Wang: None. W. Zou: None. J. Yu: None. L. Zhang: None. X. Zhang: None. J. Yue: None.