Risk factors for oral epithelial dysplasia - the role of smoking and alcohol

The present study provides an assessment of the importance of tobacco and a lcohol consumption upon the development of oral epithelial dysplasia (OED) in a large group of European patients. Data were collected in a case-contro l study based upon 630 patients with OED and 643 control subjects selected from UK dental hospital patients with oral disease not caused by tobacco or alcohol. Logistic regression was used to determine the association of seve ral independent factors on the risk of OED. No relationship emerged between patient's gender, age or ethnicity and risk of OED. The regression model d emonstrated a combined effect of tobacco smoking and alcohol drinking upon the risk of OED. Non-filter cigarette smoking was a significant predictor o f OED, as was alcohol consumption, and the two habits compounded one anothe r in the overall risk of disease. When both factors combined were included in the model through interaction terms, their individual impact was only mo derately reduced, illustrating the importance of both factors in their own right. However, more detailed analysis of tobacco smoking habits revealed t hat the increased risk of OED from smoking was largely attributable to heav y smoking (20 cigarettes per day, OR = 4.38, 95% C.I. = 2.6, 7.2) especiall y non-filter cigarettes (OR = 1.95, 95% C.I. = 0.9, 4.0) relative to non-sm oking. Both heavy smoking and non-filtered tobacco were higher risks for OE D than alcohol consumption alone. Tobacco cessation was associated with a s ignificant decline in risk of OED, the reduction being rapid and marked. Fo r alcohol consumption the association with OED was considerably stronger fo r drinkers of fortified wines and spirits (OR = 3.75, 95% C.I. = 1.40, 10.0 5 and OR = 1.36, 95% C.I. = 0.76, 2.45, respectively). It is concluded that , while tobacco and alcohol synergistically influence the development of OE D, exclusive tobacco consumption is more likely than exclusive alcohol cons umption to give rise to OED. The risk of OED may thus be significantly redu ced by behavioural changes such as moderation of tobacco and alcohol use. ( C) 1999 Elsevier Science Ltd. All rights reserved.