The role of alcohol in oral and pharyngeal cancer in non-smokers, and of tobacco in non-drinkers.

Data from a hospital-based case-control study of oral and pharyngeal cancer conducted in Northern Italy were used to analyse the risk associated with alcohol in non-smokers and with tobacco in non-drinkers. Out of a total of 336 cases (291 males and 45 females) and 1,652 controls (1,272 males and 380 females) 27 cases and 572 controls described themselves as lifelong non-smokers. Odds ratios (ORs) were 1.5 for 14-55 vs. 0-13 alcoholic drinks per week and 2.2 for 56 or over; the trend in risk was statistically significant. Among 19 cases and 213 controls who described themselves as non-drinkers, the ORs were 3.8 and 12.9 for smokers of less than 15 and greater than or equal to 15 cigarettes per day, with a highly significant trend. This study therefore confirms that tobacco has an independent role in the aetiology of oral and pharyngeal cancer, and suggests that alcohol may have an independent role as well, even where, as in Northern Italy, wine is its predominant source. Indeed, ORs were similar to those for tobacco and alcohol individually, each adjusted for the other factor, in the overall data-set.