If you really want to boil your canned tuna for some reason you certainly can, but it absolutely isn’t necessary.
This is because most canned foods are cooked before they are canned. This is usually done by boiling the food, which of course kills off bacteria and microbes as part of the process, making the food safe to eat once opened.
The canning process is completed by sealing the food completely, preventing any new bacteria from entering your can of tuna. So canned tuna is automatically sterile and safe to eat once it's opened.
The only time this isn’t the case is if the can your tuna is in has been damaged or tampered with, which will usually be noticeable and should be checked before you use canned tuna.
If you think your canned food has ever been improperly canned or damaged don’t eat it at all, even boiled, as this can have really bad consequences.