Life-time history of smoking and exocrine carcinoma of the pancreas: a population-based case-control study in The Netherlands.

From 1984 to 1988 a population-based case-control study was carried out in the Netherlands in collaboration with the International Agency for Research on Cancer, to examine the possible relationship between habitual, life-time consumption of varieties of tobacco and exocrine pancreatic carcinoma in 176 cases and 487 controls. An interviewer-administered questionnaire was used to list major life events and obtain estimates of usual frequency of tobacco consumption throughout life. About 58% of patients were interviewed directly. After adjustment for age, gender, response status, energy intake and consumption of vegetables compared with never-smokers, a positive dose-response effect of smoking of life-time number of total cigarettes, i.e. non-filter and filter, emerged (OR 1.00, 1.35, 1.40 and 2.10, p-value trend less than 0.05). Results of simultaneous estimation of the effects of life-time smoking of non-filter and filter cigarettes suggest that the effect was present primarily in non-filter cigarettes. The dose-response relationship was present in current smokers only. Compared with never-smokers, the risk pattern among relatively recent quitters, i.e. 2 to 14 years previously, still suggested a positive effect of past smoking (OR for low smokers 1.99, 95% CI 0.79-4.99 and for high smokers 1.69, 95% CI 0.63-4.58). The risk of quitting 15 years or more could be examined in the low smoking group only and was no different from those who had never smoked (OR 1.02, 95% CI 0.47-2.20). In brief, our results suggest that, independent of usual past intake of energy and vegetables, life-time smoking of cigarettes influences the development of exocrine pancreatic cancer, whereas cessation of smoking of cigarettes for 15 years or more reduces the risk to the levels found among those who have never smoked.