Bacterial Involvement in Oral Squamous Cell Carcinoma and Potentially Malignant Oral Disorders.

OBJECTIVE

To clarify the relationship between oral squamous cell carcinoma (OSCC), potentially malignant oral disease (OPMD), and bacterial flora using metagenomic analysis.

METHODS

This cross-sectional observational study included 50 patients in the control group and 77 patients with OPMDs, 41 with early OSCCs, and 20 with advanced OSCCs. Patient saliva samples were subjected to high-throughput sequencing of 16S rRNA gene amplicons to evaluate the composition and diversity of the oral microbiome.

RESULTS

No significant differences were observed in patient backgrounds, other than sex. Patients with advanced OSCCs had greater oral bacterial diversity than those with early OSCC or OPMD. The advanced OSCC group formed a distinct cluster separate from the other groups. Sixteen and 275 species were identified at the phylum and genus levels, respectively. Compared with the control group, Actinomycetia and Streptococcus were significantly elevated in the early OSCC and OPMD groups. Peptostreptococcus and Fusobacterium were significantly higher in the advanced OSCC group than in the control, OPMD, and early OSCC groups.

CONCLUSIONS

The composition and diversity of oral microbiota may be associated with OPMD development and progression to OSCC. Consequently, the salivary microbiome may serve as a biomarker for oral cancer and help predict cancer progression.