Two years is a very long time to be missing.  Yet there are always stories of cats returning after being away for many years. 

Did you post fliers and check Humane Societies?  Did you go door to door to your neighbors asking if they had seen the kitty? Is your kitty microchipped?  Was he an indoor only cat or did he have access to outside?

Was he neutered?  These are all factors which play on roll on why he might be missing.

Never give up hope as you just never know what might happen.  I am so sorry your sweet kitty has been missing for so long.

i know im late but i dont think anyone should lose hope. Our cat returned to our mountain house after being lost in the woods for 10 years. If you can make sure that no one took him (check with vets and shelters in your town and towns near) then put up posters with an award (as sad as it sounds more people will be interested to look for the cat)

I've heard of amazing stories of cats turning up.

But it's highly likely that some cat lover thought he was lost and made him an indoor kitty so he or she wouldn't lose him either.