An important question is whether ethanol is a complete carcinogen in mammary tissue. The most compelling animal data is that of (Watabiki et al., 2000) who showed that 45% of female mice given 10–15 % ethanol in drinking water for 23 months developed mammary tumors, compared to 0% in control mice drinking water alone. While this is an impressive result, it is worth noting that the study design did not control for total caloric intake, and blood alcohol concentrations were not measured. Furthermore, the study used ICR mice, which are an outbred strain. In view of these issues, and the importance of this study, replication of this finding in a standard inbred mouse strain with control for total calories would be extremely valuable. Such a result would provide a foundation for future studies using genetically modified mice to rigorously address some of the clinically relevant mechanistic questions raised above, such as the potential role of CYP2E1.
