Environmental and genetic risk factors of oral cancer: an updated review

Oral cancer poses a significant public health concern throughout the world. In terms of cancer incidence rates, it is ranked among the top ten. The risk of oral cancer increases with age, with the majority of cases occurring in people over 50. Since most patients do not have symptoms in the earliest stages, they do not seek medical attention unless they experience obvious symptoms like bleeding and pain. Generally, prognoses deteriorate as the condition worsens and the tumor's location becomes more difficult to reach. Heavy tobacco use (which includes smokeless tobacco), betel chewing, alcohol drinking, and persistent inflammatory conditions pose risks to the oral cavity and increase cancer risk. Tobacco usage has been associated with changes in functions and proliferation of periodontal cells, including gingival fibroblasts, periodontal membrane cells, periodontal ligament cells, et cetera, leading to cell apoptosis. Interference with the host cell cycle machinery in latent or chronic viral infections leads to malignant transformation. Also, numerous studies have been conducted to determine how chronic trauma affects the development of cancer. Finally, we provided a narrative review of the main genetic and non-genetic risk factors for oral cancer with new insight.