Tobacco and other risk factors for oesophageal cancer in alcohol non-drinkers.

Information on the aetiology of oesophageal cancer in alcohol non-drinkers will help us to understand and quantitate risk factors for the disease in the absence of alcohol. Out of a total of 316 cases with histologically confirmed incident cancers of the oesophagus, 40 (22 men and 18 women) who described themselves as alcohol non-drinkers were considered. These patients were compared with 151 alcohol non-drinkers (79 men and 72 women) admitted to hospital for acute, non-neoplastic, non-alcohol-, non-smoking-related conditions. The major risk factor for cancer of the oesophagus in non-drinkers was current elevated cigarette smoking: compared with never smokers, the odds ratio (OR) for all current smokers was 3.4 [95% confidence interval (CI), 1.5-8.1]. The OR was 0.8 (95% CI 0.2-3.4) for ex-smokers, 1.3 (95% CI 0.4-4.2) for current smokers of fewer than 20 cigarettes per day and 7.5 (95% CI 2.7-20.4) for current smokers of more than 20 cigarettes per day. Risk also increased with duration of smoking (OR 4.9 for more than 30 years smoking), and in smokers starting the habit when aged 25 or younger (OR 3.9). Few years of education and gastrectomy were also associated with elevated risk, while a high fruit intake was associated with reduced risk (OR 0.6 and 0.4, respectively, for 7-13 and > 13 portions per week compared with < 7). When the combined effect of smoking and fruit intake on the risk of oesophageal cancer was considered, compared with non-smokers eating more than 7 fruit portions per week, the OR for current smokers eating 7 or less fruit portions per week was 7.3. Thus, even in the absence of alcohol drinking, cigarette smoking and a diet poor in fruit are important avoidable risk factors for oesophageal cancer.