Not a professional on this subject just know from personal experience. I had a small mole come up and it was malignant melanoma 7 years ago. I did all kinds of research and read everything I could get my hands on. From what I have gather, a malignant melanoma is nothing more than a mutated cell. A scar obtained from falling down even years ago can turn into a melanoma. A burn place you received from the stove, years from now can turn into melanoma....There is so much controversy about this type of cancer, but the majority of cancer Drs says its from over exposure /sun damage. If this were true, then tell me how dogs get it on their paws? I do agree that going into the sun without sunscreen or protection and burning your skin is like asking for it. But in reality, I know its not just from the sun. Hope this helps......