I read that one of the ways alcohol is carcinogenic is via accelerated mitosis due to acetaldehyde, I was wondering what pathway caused this acceleration?
First of all Alcohol and Acetaldehyde are both cytotoxic. Along in our development we learned to deal with both substances, which is shown by specific metabolism pathways to break them down (for example alcohol dehydrogenase, acetaldehyde dehydrogenase, Cytochrom P450 and so on).
Alcohol and Acetaldehyde both have a negative effect on mitosis (which explains a good part of the negative effect which alcohol has on developing embryos). Examples can be the following articles:
Alcohol also has some effect on cancer - probably not by directly causing it, but at least as an additional risk factor. One article I found ("Alcohol and Cancer") mentions the following possibilities:
Using Pubmed you can find more articles on that topic.