Objective: This nested case-control study in the NIH-AARP Diet and Health Study was carried out to prospectively investigate the relationship of oral microbiome with head and neck cancer.

Methods: Among 34,262 participants with oral wash samples, 60 incident head and neck cancer cases were identified during a mean of 6.25±1.28 years of follow-up. Two controls were matched to each case by age at sample collection, sex, and baseline smoking history, and available controls were not diagnosed with head and neck cancer over follow-up. Whole genome shotgun metagenomic sequencing was used to measure the overall oral microbiome, and ITS2 gene qPCR was used to measure the presence of fungi in pre-diagnostic oral wash samples. ITS2 gene sequencing was performed on ITS2 qPCR positive samples. Taxonomic and functional alpha-diversity and beta-diversity metrics were computed. Presence/absence and relative abundance of groups of red- and/or orange-complex periodontal pathogens were also calculated. Conditional logistic regression models and MiRKAT were used to investigate the case-control associations.

Results: Participants with higher taxonomic microbial alpha-diversity had a decreased risk of head and neck cancer with odds ratios per every 10 observed species of 0.87 (95% CI=0.75-1.004, P=0.057), and per one unit of Faith’s PD and the Shannon index of 0.84 (95% CI=0.72-0.99, P=0.032) and 0.52 (95% CI=0.29-0.94, P=0.032), respectively. No case-control differences were found for beta diversity (all p>0.05). The presence of red-complex periodontal pathogens was non-significantly associated with reduced risk of head and neck cancer (OR=0.41, 95% CI=0.17-1.01, P=0.052). Greater relative abundance of red-complex (OR=0.29, 95% CI=0.09-0.94, P=0.040), orange-complex (OR=0.45, 95% CI=0.22-0.89, P=0.022), and both complexes combined (OR=0.46, 95% CI=0.25-0.82, P=0.009), were associated with reduced risk of head and neck cancer. The presence of oral fungi was also strongly associated with reduced risk of head and neck cancer compared with controls (OR=0.39, 95% CI=0.17-0.87, P=0.022).

Conclusions: Greater taxonomic alpha-diversity and the presence or relative abundance of multiple bacterial or fungal species, including the red- and orange-complex periodontal pathogens, were associated with reduced risk of head and neck cancer.

Citation Format: Zeni Wu, Yongli Han, Yunhu Wan, Xing Hua, Casey L. Dagnall, Kristine Jones, Amy Hutchinson, Belynda D. Hicks, Weiyin Zhou, Linda Liao, Heather Hallen-Adams, Jianxin Shi, Christian C. Abnet, Rashmi Sinha, Anil Chaturvedi, Emily Vogtmann. The oral microbiome and the risk of head and neck cancer: A nested case-control study in the NIH-AARP [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 687.