Background: Currently, there are many meta-analyses on the correlation between alcohol conception and the risk of colorectal cancer, but the findings are inconsistent. We conducted a dose-response meta-analysis to investigate the association between alcohol intake and the risk of colorectal cancer.
Methods: A literature search was performed on PubMed and EMBASE databases to identify relevant articles published before December 09, 2019. Summarized relative risks (RRs) and 95% confidence intervals (CIs) were calculated using a fixed or random-effects model for the dose-response meta-analysis. The Cochran Q and I2 statistics were used to assess statistical heterogeneity among studies.
Results: Five cohort and 19 case-control studies were included in the meta-analysis. An increased intake of 15-39.9g of daily alcohol was related to a 21% growth risk of CRC(RR=1.21, 95% CI: 1.05-1.38).Our dose-response analysis indicated that for drinkers of light, moderate and heavy level of alcohol drinking, the estimated RRs of CRC were 0.94( 95% CI: 0.69-1.27), 1.08( 95% CI: 0.93-1.26) and 1.90( 95% CI: 1.29-2.97) respectively and for drinkers of moderate beer, heavy beer, moderate wine and heavy wine intake, the estimated RRs of CRC were 0.98 (95% CI: 0.72-1.34), 1.48 (95% CI: 1.05-2.07), 0.86(95% CI: 0.56-1.34) and 1.04 (95% CI: 0.83-1.29) respectively. The risks with no significant association were consistent in the subgroup analyses of general alcohol consumption status and frequency.
Conclusions: Heavy level of alcohol consumption, especially heavy beer intake seems to be associated with an increased the risk of CRC.