Coffee consumption and risk of pancreatic cancer

The relationship between pancreatic cancer and coffee, decaffeinated coffee and tea drinking habits was evaluated using data from a hospital-based case-control study conducted in Northern Italy on ISO histologically confirmed cases and 605 controls with acute, non-neoplastic, other than digestive tract diseases unrelated to coffee consumption or to any of the known or potential risk factors for cancer of the pancreas. Compared with subjects who did not drink coffee, the multivariate relative risks were 1.7 for those who drank less than 2 cups per day, but only 1.4, and 1.1 respectively for drinkers of 3 or 4 and 5 or more cups. Likewise, there was no association with duration of consumption of coffee, decaffeinated coffee or tea. These findings were reviewed together with published evidence from other case-control studies (or cohort studies analyzed as case-control) of coffee and pancreatic cancer. When appropriate statistical methods were used to pool information, and the data from the first study which was the basis of the hypothesis were omitted, the relative risk of pancreatic cancer based on 1,464 cases was 1.2 for moderate coffee drinkers and 1.4 for heavy drinkers, and we suspect that at least part of this moderate residual association is confounded by cigarette smoking. Thus, although the present investigation and a general overview of published epidemiological evidence are compatible with a small effect of coffee on pancreatic carcinogenesis, interpretation of these findings is not obvious on account of the possibility of residual confounding and other sources of bias.