Analysis of <i>Fusobacterium nucleatum</i> Driven Modulation of c-Myc Pathways in Oral Carcinogenesis

Objective: To evaluate the association between Fusobacterium nucleatum and c-Myc expression in Oral Potentially Malignant Disorders (OPMDs) and Oral Squamous Cell Carcinoma (OSCC), and to explore its potential role in oral carcinogenesis. Materials and Methods: A total of 32 histopathologically confirmed cases (18 OPMDs, 14 OSCC) were analysed. Anaerobic culture and PCR were used to detect F. nucleatum. Immunohistochemistry (IHC) was performed to assess c-Myc expression. Statistical analysis was conducted using Mann-Whitney and Chi-square tests, with p < 0.05 considered significant. Results: F. nucleatum was detected in 8 OSCC cases and 2 OPMD cases, with higher colony counts in OSCC. All samples exhibited c-Myc positivity, but expression levels varied. In OPMDs, positivity was mainly seen in basal and suprabasal epithelial layers, whereas OSCC showed both peripheral and central tumor cell localization. F. nucleatum–positive OSCC cases demonstrated strong nuclear c-Myc staining (50–75% positive cells). Tobacco habits, particularly combined smoking and smokeless use, were more common in F. nucleatum–positive OSCC cases. Conclusion: F. nucleatum colonization correlates with increased c-Myc expression in OPMDs and OSCC, supporting its possible role in microbial-driven oral carcinogenesis. These findings suggest its potential as a prognostic biomarker and therapeutic target.