A population-based case-control study of cancer of the bile ducts and gallbladder in Quebec, Canada

In a population-based case-control study of pancreatic cancer in Greater Montreal between 1984 and 1988, a total of 24 patients with cancer of the bile ducts and 33 patients suffering from cancer of the gallbladder were compared to 239 population-based controls. This study was part of the SEARCH program of the International Agency for Research on Cancer. In cases of cancer of the bile ducts, smoking nonfiltered cigarettes produced a relative risk of 2.82 and a 95% confidence interval of 1.01-7.86 after adjustment for age, sex, other smoking habits, alcohol consumption, schooling, and respondent status. Laxative intake was associated with a risk of 2.87 (1.00-8.22). Coffee drinkers were collectively at lower risk than non-drinkers: OR = 0.26 (0.07-0.95). In patients with cancer of the gallbladder, constipation was related to a risk of 3.19 (1.02-9.95) after adjustment for the same factors. In cases with previous gallbladder problems, the risk was found to be significant [OR = 7.96 (2.03-31.2)], 8 times greater in cases than in controls.