Department of Epidemiology, Istituto di Ricerche Farmacologiche "Mario Negri", Milan, Italy; Department of Clinical Sciences and Community Health, Università degli Studi di Milan, Milan, Italy.
& Aims: Coffee consumption has been proposed to reduce risk for hepatocellular carcinoma (HCC). We performed a meta-analysis of articles published through 2012 to provide updated information on how coffee drinking affects risk for HCC.
We performed a PubMed/MEDLINE search of the papers published from 1966 through September 2012 for original articles, in English, on case-control or cohort studies that associated coffee consumption with liver cancer or HCC. We calculated the summary relative risk (RR) for any, low, and high consumption of coffee vs no consumption. The cut-off point for low vs high consumption was set to 3 cups per day in 9 studies and 1 cup per day in 5 studies.
The summary RR for any coffee consumption vs no consumption was 0.60 from 16 studies, comprising a total of 3153 HCC cases (95% confidence interval [CI], 0.50-0.71); the RRs were 0.56 from 8 case-control studies (95% CI, 0.42-0.75) and 0.64 from 8 cohort studies (95% CI, 0.52-0.78). Compared with no coffee consumption, the summary RR was 0.72 (95% CI, 0.61-0.84) for low consumption and 0.44 (95% CI, 0.39-0.50) for high consumption. The summary RR was 0.80 (95% CI, 0.77-0.84) for an increment of 1 cup of coffee per day. The inverse relationship between coffee and HCC risk was consistent regardless of subjects' sex, alcohol drinking, or history of hepatitis or liver disease.
Based on a meta-analysis of 16 studies, the RR for any coffee consumption vs no consumption is 0.60. The association might partly or largely exist because patients with liver and digestive diseases reduce their coffee intake. However, coffee has been shown to affect liver enzymes and development of cirrhosis, and could therefore protect against liver carcinogenesis.