Biomarkers of oral premalignant epithelial lesions for clinical application.

Oral cancer is the sixth most common form of cancer worldwide, and the majority of cases occur in India and Southeast Asia. Its major risk factors in the western world include smoking and drinking alcohol, whereas in Asia, it is primarily caused by tobacco/areca nut/betel leaf chewing and/or human papillomavirus (HPV) infections. Little is known about this type of cancer despite recent advances in cancer biology. The generally asymptomatic nature of the early oral lesions causes them to remain undetected in many cases. Thus, the disease progresses substantially before the patients seek treatment and is a major contributing factor to the severity of this disease. Therefore, there is a great need to create awareness for its prevention and early diagnosis. The application of advanced molecular biological and biochemical methodologies to elucidate its biomarkers may aid in early detection; however, much more work must be done for this information to be effectively applied in the clinical setting. This review focuses on the need for systematic diagnoses in the early detection of oral cancer using molecular and biochemical approaches, thereby reducing the number of advanced cases in the chewing tobacco-dominated oral cancer population.