Background: Oral squamous cell carcinoma (OSCC) is a highly prevalent malignancy with increasing global incidence. Oral potentially malignant disorders (OPMDs), often precede OSCC. Emerging evidence suggests that oral microbial dysbiosis (OMD) may play a significant role in the pathogenesis through modulation of inflammation, immune response, and epithelial transformation. Objective: Our systematic review brings attention to oral microbiome dysbiosis in the context of OPMDs and OSCC and evaluates certain microbes for their utility as early markers of malignancy. Methods: Following PRISMA2020 guidelines, a comprehensive literature search was performed across PubMed, Scopus, Web of Science, and Google Scholar. Studies utilizing next-generation sequencing for oral microbiome profiling in OSCC and OPMDs were included. Of the 386 articles initially screened, 11 were included for systematic review. Data extraction focused on microbial shifts at the genus level, sequencing methods, and study populations. Results: The majority of research found that OSCC had higher levels of “ Fusobacterium , Capnocytophaga , Prevotella , and Campylobacter ” alongside reduced Streptococcus levels. OPMDs, such as proliferative verrucous leucoplakia (PVL) and oral lichen planus, also showed microbial shifts similar to those in OSCC. Diversity was notably reduced in OSCC and PVL-OSCC, with some protective associations observed for Corynebacterium and Kingella . Conclusion: This review consolidated existing evidence linking oral microbial dysbiosis to the evolution and progression of OSCC and OPMDs. Key genera such as Fusobacterium , Capnocytophaga , Prevotella , and Campylobacter appeared consistently altered in disease states, suggesting potential as biomarkers.
Murugan et al. (Thu,) studied this question.