A study investigating the risk of bladder cancer at different levels of alcohol consumption conducted a meta-analysis of epidemiological studies. 16 case-control and 3 cohort studies were indentified with a total of 11,219 cases of bladder cancer, satisfying the inclusion criteria for this meta-analysis. Moderate alcohol intake was defined as < 3 drinks per day (i.e. < 37.5 g of ethanol per day) and heavy intake as >/= 3 drinks/day. Pooled estimates of the relative risks (RR) and the corresponding 95% confidence intervals (CI) were calculated using random effects models.
Source: Alcohol drinking and bladder cancer risk: a meta-analysis Pelucchi C; Galeone C; Tramacere I; Bagnardi V; Negri E; Islami F; Scotti L; Bellocco R; Corrao G; Boffetta P; La Vecchia C Annals of Oncology, published early online 29 October 2011.
Compared with non-drinkers, the pooled RRs of bladder cancer were 1.00 (95% CI 0.92-1.09) for moderate and 1.02 (95% CI 0.78-1.33) for heavy alcohol drinkers. The authors conclude that this meta-analysis of epidemiological studies provides definite evidence on the absence of any material association between alcohol drinking and bladder cancer risk, even at high levels of consumption.