Cannabis Extract Topicals for Mast Cell Tumors on Dogs

Hello, I'm new here and curious to see if anyone has had experience treating Mast Cell tumors on dogs using topicals. My pup of 11 years has one on his head and I would rather not have surgery in fear of it spreading faster after surgery.

Any luck using high dose cannabis extracts as topicals? Looking for educated answers and experience please. Thank you!✌ *