There have been many studies. A meta-analysis was published in JAMA 
in 1998 (smith-warner sa, et al, 279:539-540) 
<http://www.ncbi.nlm.nih.gov:80/entrez/query.fcgi?cmd=Retrieve&db=PubM 
ed&list_uids=9480365&dopt=Abstract> found a relative risk of 1.4 at 
doses of 2-5 drinks per day. The risk is dose related. Small risk at 
one drink per day. Negligible effect from several drinks per week.

Brian Katcher

>Does anyone know the research base for the claim that there is a link
>between alcohol and breast cancer? In popular magazines, particularly those
>directed at women of course, there have been many references to this claim.
>Yesterday I read one that said the link existed even if a woman consumed
>only one glass of wine a day. Some of my interest is personal as it is my
>wife who has drawn this material to my attention.
>
>Yet I have historical/social interest as well. As we know, access to alcohol
>has been used to regulate the behaviour of targeted groups, be they women,
>aboriginal people or minors. A few years ago a Vancouver bar began to refuse
>service to women who were obviously pregnant, ostensibly out of concerns
>about FAS. Maybe the link between alcohol and breast cancer is strong, but I
>would like to pursue it a little further.
>
>Thanks,
>Robert Campbell