Extrahepatic bile duct cancer and smoking, beverage consumption, past medical history, and oral-contraceptive use.

Information on potential causal factors in 67 patients with histologically confirmed cancer of the extrahepatic bile ducts was compared with that from 273 patients with other cancers. The control group did not include subjects with tobacco- or alcohol-related cancers. The study subjects were interviewed at 11 large hospitals in eastern Massachusetts and Rhode Island between 1975 and 1979. Among the patients with extrahepatic bile duct cancer, the male-female ratio was 1.5. The use of cigarettes was associated with decreased risk of extrahepatic bile duct cancer. The use of alcohol and coffee was not related to risk of extrahepatic bile duct cancer. Fewer patients than controls reported tea consumption. A statistically significant association between the use of oral contraceptives and extrahepatic bile duct cancer was observed among women under 60 years of age. Patients reported significantly higher frequencies of history of ulcerative colitis or diseases of the gallbladder.