One of the problems with chemotherapy, in addition to cost and trips in and out of the hospital is toxicity. It can be especially difficult to handle a toxic event when the whole point of chemo in treating dog cancer is palliation.
Palliation is defined as a reduction in the signs or symptoms of a disease. Note that nowhere is the word “cure” used.
This is something many may have not heard before. Chemotherapy in dogs, unlike in some cases of human medicine, is not geared towards a cure. The toxicities resulting from “cure” doses delivered by vein or as pills are too high for our dogs.
So, it makes a lot of sense to do everything we can to lower toxic events, since we are simply trying to make something better for a period of time.
In previous blogs I focused on things like chemotherapy timing (chronotherapy), which got very little response from readers (I found this puzzling). We are talking about simply changing the time of day for the chemo treatment and getting much better outcomes. Higher margins, less toxicity, no increase in cost or life quality reduction. What more could one ask for?
Everyone likes the idea of supplements to help lower toxicities (L-acetyl carnitine, coenzyme Q-10, beta glucans, ginger, milk thistle, and others..). Supplements are a hit.
Here’s another one that will need the cooperation of your vet or oncologist:
Suppose we want to get a chemo drug in high concentrations to the lungs. Why the lungs? Well, the lungs are the site of many secondary tumors which have spread from a primary location. These are called pulmonary metastasis.
If your dog had, for example, a malignant melanoma in his toe, it could easily end up sending melanoma cells to the lungs to grow. These cells are said to have metastasized to the lungs.
Sometimes tumors start in the lungs. These are called primary lung tumors. They are not especially common, much less common than pulmonary metastasis.
At any rate, it would seem logical to get the chemo drugs right to where the tumors are for a couple of reasons. First, if you cluster all drugs, only about 5% of what is taken as an IV injection and only about 2% of what is taken as a pill actually gets to the lungs. So very little ends up where you want it.
From a conventional medical standpoint, the more anticancer substance that arrives at the site of the tumor, the higher the desired effect in that area.
Second, if you can target your potentially toxic chemo drug so it acts as a “silver bullet”, and avoids contacting non-cancerous (healthy) body parts, you can limit toxicity to those healthy body parts.
If a veterinarian or oncologist is presented with a dog having a lungful of cancer, one way to get the cancer fighting substance to the tumor would be to aerosolize it. This is commonly done with asthma inhalers in human medicine (which we use sometimes in veterinary medicine too).
Aerosolization is simply making a substance able to travel in the air, as a vapor. You mix your drugs in some liquid, dump it in a machine called a nebulizer, and out comes a moist mist with your drugs in the mist. Neat.
Lots of things can be aerosolized. Antibiotics, antifungals, anti inflammatories, and more. And yes, chemotherapy drugs have been aerosolozed too.
And we see results., here, here and here are a few of publications for you (and your oncologist) to check out if you are interested. The results of the aerosolized chemo drugs were clearly better than those given by traditional routes.
The main barrier to entry? Equipment for delivery simultaneous with prevention of aerosolized chemo drugs in room air. Nobody wants to be inhaling chemo drugs themselves.
Another possible resource is the use of a compressor set up described in the article about IL-2 and osteosarcoma metastasis. A Bunn 400A compressor from the John Bunn Company in Happauge, New York, was used with a Puritan Bennet Twin Jet Nebulizer from Puritan Bennet in Carlsbad, California. A polyethylene rebreathing bag was used to cover the dogs’ muzzles. These dogs were trained to receive the IL-2 administration via this route.
Please, if any have success with this information, let me know so it can be shared with others.
Best to all,
Dr. Demian Dressler is internationally recognized as “the dog cancer vet” because of his innovations in the field of dog cancer management, and the popularity of his blog here at Dog Cancer Blog. The owner of South Shore Veterinary Care, a full-service veterinary hospital in Maui, Hawaii, Dr. Dressler studied Animal Physiology and received a Bachelor of Science degree from the University of California at Davis before earning his Doctorate in Veterinary Medicine from Cornell University. After practicing at Killewald Animal Hospital in Amherst, New York, he returned to his home state, Hawaii, to practice at the East Honolulu Pet Hospital before heading home to Maui to open his own hospital. Dr. Dressler consults both dog lovers and veterinary professionals, and is sought after as a speaker on topics ranging from the links between lifestyle choices and disease, nutrition and cancer, and animal ethics. His television appearances include “Ask the Vet” segments on local news programs. He is the author of The Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog’s Life Quality and Longevity. He is a member of the American Veterinary Medical Association, the Hawaii Veterinary Medical Association, the American Association of Avian Veterinarians, the National Animal Supplement Council and CORE (Comparative Orthopedic Research Evaluation). He is also an advisory board member for Pacific Primate Sanctuary.