Cigarette smoking as a risk factor associated with oral leukoplakia

BACKGROUND: It is well known that oral leukoplakia is the most common precancerous lesion of the oral mucosa. Although tobacco and alcohol are known to be major risk factors for oral leukoplakia worldwide, there are no data on risk factors for oral leukoplakia in our country. The aim of our study was to analyze the association between oral leukoplakia and smoking habit, with attention to the duration and quantity of smoking. METHODS: The study population consisted of 352 patients aged 40-70 years. Prior to the clinical examination, each subject answered a standardized questionnaire regarding tobacco-smoking habits. Oral leukoplakia was diagnosed and grouped according to internationally accepted criteria. Chisquare test was used for statistical analysis. RESULTS: Of the entire sample, 279 were smokers and 73 non-smokers. Oral leukoplaka was found in 53 subjects and among them 50 were smokers and 3 were nonsmokers. All smokers had only used cigarettes. The relative risk of developing oral leukoplakia increased with duration of cigarette smoking habit. The majority of smokers with leukoplakia (74.0%) smoked more than 20 cigarettes per day compared to 34.5% of those without leukoplakia. The highest prevalence of leukoplakia (33.3%) was found in subjects who used cigarettes and alcohol. CONCLUSION: In view of these results, cigarette smoking is significantly related to the etiology of oral leukoplakia