I once ate some home-jarred pasta sauce (with meat) that had been in my fridge for over a year (I know—sounds yukkie) and lived to tell the tale.
Home canned foods should last for years, once something is canned properly, then it is sealed, and sterile.
So something is either canned properly or not, anything that is damaged, or not canned properly doesn’t fit into the discussion on shelf life of the food in intact cans.
The steamboat Bertrand sunk to the bottom of the Missouri
river in 1865. It was found a century later in 1968 under 30 feet of silt near Omaha, Nebraska. Among its provisions were canned foods including brandied peaches, oysters, plum tomatoes, honey, and mixed vegetables. In 1974, the National Food Processors Association (NFPA) analyzed the canned foods for bacterial contamination and nutrient value. Although the food had lost its fresh smell and appearance, the NFPA chemists detected no microbial growth and determined that the foods were as safe to eat as they had been when canned more than 100 years earlier (Atkins, 2010).
http://extension.usu.edu/foodstorage/files/uploads/Food_Storage_Booklet.pdf