I have a 5 year old 4-in-1 peach tree with a problem. The trunk is swollen and cracked, pictures are attached. It's otherwise VERY healthy. It's put on over a foot of new growth this spring and I had to thin out about 100 peaches so far. There are no other signs of this elsewhere on the tree.

I'm afraid it may be canker and might not survive. Can someone help me identify this problem and suggest a treatment approach please?