Coffee intake and risk of pancreatic cancer: an updated meta-analysis of prospective studies

INTRODUCTION: Inconsistent results on the relationship between coffee consumption and pancreatic cancer risk has been reported in both epidemiological studies and previous meta-analyses. This updated meta-analysis was conducted to assess the association of coffee intake with pancreatic cancer risk. EVIDENCE ACQUISITION: We evaluated the relationship of coffee ingestion and pancreatic cancer risk by performing a meta-analysis of prospective cohort studies and made an explicit document search in the PubMed database before November 2015. We also obtained prospective cohort studies of previous meta-analyses. A random-effects model was used for pooling overall relative risk. Twenty articles of coffee ingestion and pancreatic cancer were contained in our meta-analysis. EVIDENCE SYNTHESIS: The summary relative risk (RR) of pancreatic cancer and coffee intake of the highest compared with lowest category was 0.99 (95% CI=0.81-1.21), with statistically moderate heterogeneity (P=47.9%, P=0.008). The heterogeneity reduced to P=38.5% after excluding one study, and the RR was 1.06 (95% CI=0.94-1.20). The relationships of coffee intake and pancreatic risk did not modified by geographic areas, sex of participants, number of cases, follow-up years, and the number of adjusted confounders. CONCLUSIONS: Dose-response analysis indicated that every one-cup increase in coffee consumption was associated with an 1% increase in pancreatic cancer risk. No statistically significant publication biases existed. Coffee consumption may weakly increase the risk of pancreatic cancer.