My dog has a spleen tumour that is cancer. He was diagnosed in December just before Christmas and given a maximum of 30 days to live, by my vet. This type of cancer has episodes of internal bleeding until the animal has one final major bleed that they can't recover from. The bleeding is usually a result of their blood pressure suddenly elevating for a variety of reasons, or just the tumours getting larger and rupturing.
I searched all the websites I could find for a diet for canine cancer and found the same one you found with the book about curing canine cancer. Based on the diet included on that website and other sites that were Veterinarian approved, I started a home made diet that included many alternative medicine supplements that were recommended including Essiac tea and Green tea. When I added the final group of herbs, he had an episode of vomiting. That episode took a great deal out of him and I suspected he had a bleed from the stress of vomiting, because he spent the next several days lying in bed and only going outside to relieve himself or lying in his bed while he ate. I immediately removed all the herbs and alternative supplements I had added but kept him on the home made food which including chicken livers every day and vitamins and minerals.
As he is 13 years old and I don't believe in chemotherapy or radiation for anyone, let alone an animal, I didn't consider them as a treatment for his cancer. I have seen too many people spend their final days in distress from the "treatment" and having virtually no quality time at all. I decided to use diet alone and he is still alive today almost 3 months later, albeit somewhat weaker, but still the happy boy that he's always been. As far as I can tell he is pain free so I haven't considered euthanizing him unless I see that he is in pain. Just my 2 cents
I wish you good luck with everything you are doing for Matsi and hope she lives a long time for you. I send both of you good vibes and prayers