Figure 1.

Factors contributing to oral cancer. Unhealthy lifestyle choices such as smoking, consumption of alcohol, obesity, and poor oral hygiene increase the incidence of periodontal disease and inflammation in the oral mucosa. Porphyromonas gingivalis, as a major contributor in the etiology of periodontal disease, is a keystone pathogen, which facilitates dysbiosis, and can also invade epithelial cells and modify the cellular environment intra-and extra-cellularly. Additionally, the increase of danger signals, such as ATP and other alarmins, and release of pro-inflammatory cytokines and chemokines create a chronic inflammatory state in the oral cavity associated with periodontal disease. Microbial factors, chronic inflammation associated with periodontal disease, and general poor lifestyle choices induce genetic and epigenetic changes in the cell, which may promote orodigestive cancer development and progression.