Should I put my 9 yr old Labrador through a 2nd surgery for a mast cell tumor cancer. Or make him comfortable.?

The first surgery was so hard for him. I don't know that I want to put him through that again. An if it's come back again in less than 6 months. It'll probably come back again. So should I just make him comfortable an let him live his life. Hes the happiest dog so full of energy an life right now. He was rippin around the yard today. Gosh this is so hard. I just hate having him go through surgery. He is 9 yr old 95 lb Labrador. He's my everything. His name is Jojo.