Coffee and pancreatic cancer in a rural California county.

In a study of the risk of fatal pancreatic cancer according to intake of regular and decaffeinated coffee, cases (N = 30) and controls (N = 47) were identified from death certificates and matched for age (+/- 5 years), sex, ethnicity, and date of death (+/- 5 years). Telephone interviews were completed with survivors of about 80% of both groups. In smokers, the relative risk for high (3 + cups) versus low (<3 cups) intake of regular coffee was 4.3 (P < .05), and high verus low decaffeinated coffee, 5.5 (P < .05). In nonsmokers, neither type of coffee influenced the risk. Mean daily intakes of alcohol and cigarettes were virtually identical in cases and controls, although cases had accumulated nonsignificantly more pack-years. Intakes of regular and decaffeinated coffee were uncorrelated, and the smoking-coffee interaction could not be readily explained by recall bias. If coffee intake increases the risk of pancreatic cancer, the mechanism could depend heavily on smoking.