Dimethylhydrazine model is not appropriate for evaluating effect of ethanol on colorectal cancer.

1,2 dimethylhydrazine (DMH) rat model has been proven to be a valuable animal model of colorectal cancer. Because of its morphological similarity to human colorectal cancer, DMH rat model was used to produce information in histology and biochemistry of tumours development as well as on factors that retard or enhance tumorigenesis. Nevertheless, it has been shown that DMH model has limitations, which raise the question, whether experiments evaluating effect of ethanol on DMH model are ethically justified. In this paper authors summarize experimental results evaluating effect of ethanol consumption on DMH rat model with aim to prevent unnecessary duplication of animal experimentation or execution of ethically unjustified animal experiments in the future and to warn scientists that results from studies evaluating ethanol on DMH rat model can not be generalized to humans.