Assessment of risk factors for oral leukoplakia in West Virginia

Objective: To assess risk factors associated with oral leukoplakia in a US population with high use of smoked tobacco and smokeless tobacco. Methods: The RJ Gorlin Leukoplakia Tissue Registry was used to identify individuals with oral leukoplakia in West Virginia, USA. This case-control study consisted of 90 cases with oral leukoplakia and 78 controls with periapical cysts. Univariate-univariable (one dependent variable and one independent variable) and univariate-multivariable (one dependent variable and multiple independent variables) logistic regression modeling quantified the association between oral leukoplakia and potential explanatory variables. Results: Unadjusted measures of association indicate that those with oral leukoplakia were more likely to be older [odds ratio of crude: OR_Crude = 2.72; 95% confidence interval (CI): 1.45-5.11], more likely to currently use smokeless tobacco (OR _Crude = 3.16; 95% CI: 1.10-9.07), and more likely to currently use snuff (OR_Crude = 832; 95% CI: 1.83-37.80). Individuals currently using smokeless tobacco or currently using snuff were more likely to have oral leukoplakia [adjusted odds ratio, OR_Adj = 9.21 and 30.08; 95% CI: 1.49-57.00 and 2.67-338.48, respectively], after simultaneously adjusting for age, gender, currently using smoked tobacco, currently using alcohol daily, and dental prostheses use. Conclusions: Generalizability is an issue when studying risk factors associated with oral leukoplakia because of geographical variations in the composition of smokeless tobacco (i.e. betel, lime, ash, and N-nitrosamines) and cultural variations in the use of tobacco (i.e. reverse smoking). Snuff was the main smokeless tobacco product currently used in West Virginia, and was strongly associated with oral leukoplakia, after adjusting for potential explanatory variables.