What are the chances of a 21 year old heavy drinker, and smoker having/developing esophageal cancer.?

High, if you continu. Cancer of the mouth, throat and esophagus is very common among folks who smoke and also drink. You are basically adding two potent poisons and committing a slow suicide. It is still time to save yourself if you can taper off over a few months and then STOP them both completely in .