Abstract 5143: Characterization of the cervicovaginal, endometrial and anorectal microbiota and mycobiota of post-menopausal women with endometrioid and serous endometrial cancers

Abstract

Abstract Objectives: Dysbiosis is thought to promote endothelial dysfunction and chronic inflammation, resulting in many chronic human diseases including cancer. This pilot study sought to characterize the cervicovaginal, endometrial and anorectal micro- and mycobiota of post-menopausal women with endometrioid endometrial adenocarcinoma (EAC), uterine serous carcinoma (USC), and controls without cancer. Methods: Post-menopausal patients undergoing hysterectomy for endometrial cancer or non-cancerous disease were enrolled after informed consent. Women were excluded if they reported history of prior cancer, recent urinary or gynecologic infection, antibiotic or probiotic use. Microbial swabs were obtained from the cervicovaginal, the anorectal, and the endometrial cavity after removal of the uterus. DNA was extracted and PCR amplified using barcoded 16SV4 (bacterial) and ITS1 (fungal) primers. Next generation libraries were prepared and sequenced on an Illumina MiSeq 2x300. Sequence reads were processed using our internally developed bioinformatics pipeline and publically available software. Results: Next-generation sequencing of bacterial and fungal DNA revealed substantial differences of cervicovaginal, endometrial and anorectal microbiota in patients with USC (n= 8) compared to those with EAC (n= 13) or benign disease (n= 6). Uterine fungal reads were much higher in patients with USC than EAC (average of 3237 reads versus 938 reads respectively, p = 0.05 Wilcox test). Candida species were reduced, but not eliminated in cervicovaginal samples, and there was a dominance of Malassezia restrica in USC and EAC. A non-significant predominance of Porphyromonas species was noted in USC specimens compared to EAC specimens (p = 0.063). Conclusions: Alpha-diversity of 16S bacterial rRNA and fungal species of the cervicovaginal microbiome was significantly associated with endometrial cancer in our study. USC had a fundamentally different microbiome from control samples and demonstrated a predominance of Porphyromonas species. Further sampling and analysis is needed to confirm these results and to identify rare pathogens. Characterization of microbiota in women with endometrial cancer may help identify risk factors for gynecologic malignancy, and drive investigation regarding preventative and therapeutic intervention. Citation Format: Gregory M. Gressel, Marina Frimer, Christine P. Zolnik, Mykhaylo Usyk, Devin T. Miller, Eirwen M. Miller, D. Y.S. Kuo, Robert D. Burk. Characterization of the cervicovaginal, endometrial and anorectal microbiota and mycobiota of post-menopausal women with endometrioid and serous endometrial cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5143.