If someone was a heavy drinker for some time and then quit drinking, is there any evidence that the increased risk of breast cancer will decrease or go away over time?

I don't think there is definite evidence that the increased risk of breast cancer will decrease or go away once a person has lowered or stopped alcohol intake (likewise, there is not specific evidence that it stays the same either). Studies have looked at years of alcohol intake (duration) and amount of alcohol intake over a lifetime. From research to date, "duration" of alcohol intake may have less impact on breast cancer risk than episodes of heavy daily drinking. It does seem that an increased risk with heavy drinking may continue after a woman stops drinking, but whether it stays the same is another question. There really are no answers at this point, research is pretty sketchy, and I'm not aware of studies that have specifically looked at "time since stopping" alcohol. Most physicians still advise heavy drinkers to stop or lower alcohol intake, probably with the idea that their risk for breast cancer might, at least, not increase.  more