Canned tuna can be frozen for three to four months. To freeze tuna properly, it should be removed from the original can or pouch and placed in an airtight, freezer-proof bag or container, with all excess air removed before freezing.
Place a freezer label on each container of tuna, and use a permanent marker to add an expiration date up to four months ahead. Defrost frozen tuna in the refrigerator until it is completely thawed.
The U.S Department of Agriculture warns that food frozen in cans can present a health hazard because cans may bulge, rust or split open, causing the canned food to spoil.