The oral microbiome plays a key role in oral cancer pathogenesis through mechanisms such as chronic inflammation, dysregulated proliferation, and increased tumor invasiveness. Dysbiosis, frequently present in premalignant and malignant lesions, may initiate or accelerate malignant transformation. Oral squamous cell carcinoma (OSCC), representing over 90% of oral cancers and affecting more than 350,000 people worldwide each year, is strongly linked to microbial shifts. Common periodontal pathogens such as Fusobacterium nucleatum and Porphyromonas gingivalis are often enriched in OSCC. These bacteria may promote tumorigenesis by activating NF-κB and STAT3 pathways, suppressing apoptosis, and modulating host immune responses. Additional potential mechanisms include the production of reactive oxygen species (ROS) and genotoxins, inhibition of tumor suppressors such as p53, disruption of cell-cycle regulation via cyclin-dependent kinase pathway, and upregulation of β-catenin and toll-like receptor signaling. These molecular alterations cause DNA damage, immune surveillance evasion, angiogenesis, promoting tumor progression. Microbiota-modulating therapies, such as Lactobacillus probiotics, may complement standard treatments by restoring balance, boosting immunity, and limiting tumor growth. Engineered bacteriotherapy, microbiome-targeted immunomodulators, and microbiota-based diagnostics expand therapeutic options in oral cancer and, combined with advances in precision medicine, may support more personalized treatments and improved outcomes.

Cannabinoids have incited scientific interest in different conditions, including malignancy, due to increased exposure to cannabis. Furthermore, cannabinoids are increasingly used to alleviate cancer-related symptoms. This review paper aims to clarify the recent findings on the relationship between cannabinoids and oral cancer, focusing on the molecular mechanisms that could link cannabinoids with oral cancer pathogenesis. In addition, we provide an overview of the current and future perspectives on the management of oral cancer patients using cannabinoid compounds. Epidemiological data on cannabis use and oral cancer development are conflicting. However, in vitro studies assessing the effects of cannabinoids on oral cancer cells have unveiled promising anti-cancer features, including apoptosis and inhibition of cell proliferation. Downregulation of various signaling pathways with anti-cancer effects has been identified in experimental models of oral cancer cells exposed to cannabinoids. Furthermore, in some countries, several synthetic or phytocannabinoids have been approved as medical adjuvants for the management of cancer patients undergoing chemoradiotherapy. Cannabinoids may improve overall well-being by relieving anxiety, depression, pain, and nausea. In conclusion, the link between cannabinoid compounds and oral cancer is complex, and further research is necessary to elucidate the potential risks or their protective impact on oral cancer.