Transitions in oral and gut microbiome of HPV+ oropharyngeal squamous cell carcinoma following definitive chemoradiotherapy (ROMA LA-OPSCC study)
Menée à partir d'échantillons salivaires, d'échantillons fécaux et de prélèvements buccaux au niveau du site tumoral (132 échantillons provenant de 22 patients), cette étude analyse l'évolution du microbiote intestinal et du microbiote de la cavité buccale après une chimioradiothérapie définitive pour traiter un carcinome épidermoïde de l'oropharynx lié au papillomavirus humain
Background : Oral and gut microbiomes have emerged as potential biomarkers in cancer. We characterised the oral and gut microbiomes in a prospective observational cohort of HPV+ oropharyngeal squamous cell carcinoma (OPSCC) patients and evaluated the impact of chemoradiotherapy (CRT).
Methods : Saliva, oropharyngeal swabs over the tumour site and stool were collected at baseline and post-CRT. 16S RNA and shotgun metagenomic sequencing were used to generate taxonomic profiles, including relative abundance (RA), bacterial density,
α-diversity and β-diversity.
Results
:
A total of 132 samples from 22 patients were analysed. Baseline saliva and swabs had similar taxonomic composition (R2
= 0.006; p = 0.827). Oropharyngeal swabs and stool taxonomic composition varied significantly by stage, with increased oral RA of Fusobacterium nucleatum observed in stage III disease (p < 0.05). CRT significantly reduced the species richness and increased the RA of gut-associated taxa in oropharyngeal swabs (p < 0.05), while it had no effect in stool samples. These findings remained significant when adjusted by stage, smoking status and antibiotic use.
Conclusions : Baseline oral and gut microbiomes differ by stage in this HPV+ cohort. CRT caused a shift towards a gut-like microbiome composition in oropharyngeal swabs. Stage-specific features and the transitions in oral microbiome might have prognostic and therapeutic implications.
British Journal of Cancer , article en libre accès, 2021