Review Article: Disrupted Oral Microbiota and Its Implications in Cancer Onset and Progression: A Narrative Review.

The oral microbiota plays a pivotal role in maintaining oral health, but its dysbiosis has been increasingly implicated in the development of systemic diseases, including cancer. Emerging evidence highlights the potential contribution of oral microorganisms to carcinogenesis in the oral cavity and distant organs, such as the lungs, pancreas, and genitourinary tract. This review explores the mechanisms through which the oral microbiota influences cancer development and treatment response, mainly driven by microbial translocation, systemic inflammation, immune modulation, and the release of carcinogenic metabolites. Additionally, the review discusses how oral microbiota perturbations interact with host factors, such as diet, systemic diseases, genetics, and cancer therapies, to influence tumor initiation, progression, and response to treatment. A critical analysis of past and emerging literature shows that specific microbial taxa potentially influence tumor progression and immune responses, including Fusobacterium, Porphyromonas, Aggregatibacter and Treponema. The detection of these microorganisms and the study of oral microbiome profiling in cancer care may offer new diagnostic and therapeutic strategies; however, further studies with homogeneous patient populations are needed to fully understand the contributions of oral dysbiosis in cancer development and treatment responses.