A meta-analysis of coffee consumption and pancreatic cancer.

BACKGROUND: Since when in 1981 a case-control study showed a positive association between coffee and pancreatic cancer, several studies reported inconsistent results on this issue. MATERIALS AND METHODS: We conducted a systematic bibliography search updated March 2011 to identify observational studies providing quantitative estimates for pancreatic cancer risk in relation to coffee consumption. We used a meta-analytic approach to estimate overall relative risk (RR) and 95% confidence interval (CI) for the highest versus the lowest coffee consumption categories, using random-effects models. RESULTS: Based on 37 case-control and 17 cohort studies (10,594 cases), the pooled RR for the highest versus lowest intake was 1.13 (95% CI 0.99-1.29). Considering only the smoking-adjusting studies, the pooled RRs were 1.10 (95% CI 0.92-1.31) for the 22 case-control, 1.04 (95% CI 0.80-1.36) for the 15 cohort, and 1.08 (95% CI 0.94-1.25) for all studies. The pooled RR for the increment of one cup of coffee per day was 1.03 (95% CI 0.99-1.06) for the 28 smoking-adjusting studies reporting three or more coffee consumption categories. No significant heterogeneity was observed across strata of study design, sex, geographic region, and other selected characteristics. CONCLUSIONS: This meta-analysis provides quantitative evidence that coffee consumption is not appreciably related to pancreatic cancer risk, even at high intakes.