The oral microbiome and its role in oral squamous cell carcinoma: a systematic review of microbial alterations and potential biomarkers

Background. Oral squamous cell carcinoma (OSCC) is one of the most common cancers worldwide. Despite advances in diagnosis and treatment, the incidence of OSCC is increasing, and the mortality rate remains high. This systematic review aims to examine the potential association between the composition of the oral microbiota and OSCC. Materials and methods. This study's protocol was developed according to the PRISMA guidelines. Several search engines, including Medline-PubMed, Scopus (via Elsevier), and Google Scholar, were used to identify original studies that analyzed differences in the oral microbiome between OSCC patients and controls. Twenty-seven studies were identified that reported significant differences in microbial abundance between OSCC and controls. Results. The systematic review highlights a complex relationship between the oral micro- biome and the pathogenesis of OSCC. Significant changes in the microbial composition were identified, with a predominance of phyla such as Bacteroidetes and Fusobacteria, which are associated with inflammatory mechanisms facilitating tumor progression. A remarkable variability in microbial profiles emerged based on the different stages of the disease and the types of samples analyzed, demonstrating the complexity of the oral microbial ecosystem. Conclusion. Although alterations in the oral cavity microbiome composition are evident in patients with OSCC, identifying a specific pattern remains challenging. However, the integration of advanced analytical techniques, such as artificial intelligence, could overcome this problem, allowing the identification of crucial biomarkers and improving the understanding of the role of the microbiome in carcinogenesis. This approach could transform microbiome analysis into a useful tool for screening and monitoring patients with OSCC.