I've eaten tinned stewed beef from cows that were butchered and canned before I was even born and still none the worse for that. A dollop of curry powder and some dried garlic and it was fit for a king. God bless the British Army's attitude to food!
If cans are kept dry and are made from stainless steel rather than cheap iron, and the contents aren't too acidid, there's no reason why they shouldn't be an alost everlasting food.
If you're keeping dried food - grains and pulses - it's worth vac-packing them, if you've access to the kit, to keep vermin at bay and to prevent oxidation.
Salted meat lasts a fair while, too, if kept in dry conditions - I've had five-year-old salt cod which was pretty tasty.
Damp is the main enemy of food preservations.