The use the same drugs. 90% of all drugs used to treat dogs for various issues are actually human drugs that are use on humans for the same thing. The are very few drugs created just for dogs. And only ONE cancer drug. The rest of the drugs used to treat cancer in dogs are human cancer drugs being use as "grey label or off label" when using a human drug on dogs.
If your method of treating dogs works well then why doesn't it work in humans? Drugs the same and probably have long approved by official medicine. People are being treated but many people continue to die of cancer. I do not argue that cancer is incurable at all. But there are different types and stages of cancer. Although the genome of dogs and humans are similar, but there are probably significant differences.