Role of Tobacco in the Development of Oral Leukoplakia and Oral Cancer

leukoplakia (OL) is the most well-known potentially malignant condition, which is transformed into oral cavity cancer [8].The probability of transformation from leukoplakia into an oral cavity cancer is 0.3% to 25% [9].• As mentioned above, leukoplakia is pre-cancerous condition.So smoking cessation contributes to the regression of Leukoplakia (up to 60%) and reduces the risk of cancer development [10,11].Leukoplakia decreases gradually and completely disappears within 8-12 months of smoking cessation [12].• Tobacco use is the main reason for development of both diseases.Smoking and alcohol consumption increases the risk of cancer in 80% of the population.This has been confirmed by the International Agency for Research on Cancer [13].Side effects of smoking are serious.It leads to the development of disease and disability and harms nearly every organ of the body.Smoking causes cancer, heart disease, stroke, lung diseases, diabetes, and chronic obstructive pulmonary disease (COPD), which includes emphysema and chronic bronchitis.Smoking also increases risk for tuberculosis, certain eye diseases (Graves' ophthalmopathy, Dry Eye Syndrome), and diseases of the immune system, including rheumatoid arthritis.Smoking doubles the risk of developing rheumatoid arthritis [14].Cancer can be developed in the following organs: nose, mouth, throat, trachea, esophageal, bronchials, liver, stomach, pancreas, kidneys, urinary bladder, throat, bone marrow and blood, intestines.Tobacco also affects the autoimmune system, cardiovascular system, reproductive system, respiratory system.Infectious diseases are frequently developed in smokers.Smoking also causes several autoimmune diseases, including Crohn's disease.Many studies have shown a relation between smoking and mental illness.Half of them reported that depression/anxiety is closely linked