Mast Cell Tumors in Dogs: some advances in conventional care
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.
Updated: May 6th, 2019
Hi! I have been getting feedback about mast cell tumors and I would like to get some info out there. I will focus on some conventional medicine advances for the time being that should be thoroughly checked into by dog lovers interested in mast cell tumors. These are not general cancer recommendations, rather just a window to full spectrum care, which is a phrase I coined to describe evidence-based selection of cancer fighting weapons from any source. I will focus on Western (allopathic) viewpoints today.
First, the traditional treatment is surgery…get ’em out. I wrote about pre-treatment with Benadryl before surgery, in a previous post, so remind your vet. Have any mass aspirated (needle biopsy) before surgery to diagnose most mast cell tumors so your vet surgeon has a general diagnosis before surgery.
Chemo consists of drugs like prednisolone, vinblastine, and others traditionally. Chemo in dogs is tolerated better than in humans as lower doses are used for cancer. The word “chemo” has a bad ring to it, but this is a prejudice developed from human medicine. Dogs generally handle it better, on the average, although everyone is different.
Note: if you have a Collie or related breed, make sure your vet tests for a MDR-1 gene mutation common in these herding dogs. This genetic issue may increase chances of side effects not only from vinblastine (above), but also vincristine and doxorubicin. Doses of these drugs shoud be lowered significantly if your dog is positive on this test. For more information, see the post on 8/30/08.
Predisolone or prednisone (“pred”, ) are cheap, common, side effects are most often not too bad, and they are tablets so you can change the dose easily depending on your dog’s responses. Vinblastine is a stronger chemo vinca alkaloid chemo agent, more potent than pred, which requires the dog to be in the hospital for injections. Some oncologists like cyclophosphamide and L-asparaginase (you’ll get different opinions and preferences from different oncologists). These are all used for mast cell tumors.
Some stats for Grade 3 mast cell tumors treated with surgery, pred, and vinblastine: At 1 year after surgery, 57% of dogs were still alive, and at 2 years 45% were still alive. Average remission times are about 10 weeks to 5 months with surgery, prednisolone, and vinblastine. Remember, every dog is different, however.
Radiation is used for mast cell tumors that are difficult to remove completely, or any grade 3. This can be high voltage radiation, or brachytherapy, which involves the use of radioactive implants within the tumor site. Yes, a little weird, involved, and costly, but long remissions in the literature.
For more helpful information and tools on Mast Cell Tumors, get a copy of the Dog Cancer Survival Guide
Many are not into invasive care, so take a look below:
One that should be considered for a less intensive protocol is Lomustine or CCNU. This drug has gotten a lot of attention in the last couple of years for good reason. It is a pill,and can be given every 3 weeks. Pretty easy and non-invasive, unlike most chemo protocols, and is a single agent so it is simple. About 40% of dogs with mast cell tumors respond to CCNU all by itself, which is pretty darn good.
Cimetidine should be used in dogs with mast cell tumors, especially those with decreases in appetite or vomiting. This is an antacid which kills two birds with one stone. Mast cell tumors cause excessive acid production in the stomach when they get bad, which cimetidine counters. Additionally, cimetidine has some good anticancer effects that have nothing to do with acid stomach. Finally, it is cheap and easy to get.
Ask your vet about intralesional triamcinolone. They may have not used it before, so do not be surprised, but they can access the info easily (1 mg per cm q 2-3 weeks SQ). It is an simple injection of a form of cortisone that most vets will have sitting on their shelves. It is not very expensive, and very common. Every 2-3 weeks, your vet can inject the mast cell tumor, or infuse the area where the mast cell tumor was removed, with a small dose of this drug. The direct contact of the triamcinolone with any mast cells left in the body will blast them pretty good.
A new drug called SU 111654 (great name eh?) is being worked on at Michegan State University. Looks promising. There is also a technique out there consisting of injecting the mast cell tumor sites with deionized water. Cheap as dirt, but mixed reviews.
This post is just a piece of full spectrum cancer care for mast cell tumors folks. There is a lot more, but I’ll let you sink your teeth into this…
Best to all,
Dr Dressler
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.
Dear Dr. Dressler,
Our 6 year old Schnauzer Benny was diagnosed with MCT in November 2007. A small lump appeared on his right side in May 2006 and was recognized by the vet and nothing was done. It grew and nothing was done! Then it was biopsied in November 2007 and removed the following day. The pathology report came back as Stake 2 MCT.Almost a year later, in June he was given a “clean bill of health” but the tumors returned ( 2 small ones ) in the same area in August of 2008. No surgery, chemo or radiation was recommended.
Now we are “flying by the seat of our pants” and reading everything possible ro try and extend the life of this wonderful pup.
After researching MUCH, we are purchasing CANINE LIFE muffins (cancer recipe) from BARK & FITZ. These were approved by the Veterinary Hospital in Guelph ON, CANADA. Along with this Benny gets 1000mg. salmon pill per day, i modified citrus pectin pill, flaxseed oil with pressed cottage cheese ( 1/4 cup) once a day. To his evening “muffin meal” we add a small amount of his HILLS DIET DRY rd dog food and a little steamed broccoli. He also gets shitake mushrooms twice weekly, chicken with turmeric and a little canned tomato and sometimes a little chicken liver,Essiac tea (1 ounce twice daily) and lots of love. We purchase organic meats and broccoli and wash the vegetable well before steaming.
He is energetic and appears healthy and happy and loves his food and his walks twice a day.
However, he is very itchy and although Benadryl helps to ease the itching, it makes him constipated. could you suggest another treatment. Our vet is not at all helpful and has more or less “given up” on Benny. We are not going to do that. Please help us if you can.
Sincerely,
Joanne
Krishna, answer to mast cell tumor within a lymph node (and likely lymphatics): The lymphatics are a circulatory system, like blood. When cancer cells are within lymph nodes, there is a pretty high probability they are in the body, circulating in lymphatics…but as micrometastasis, which are hard to pick up because they are just cells imbedded in places they should not be, or circulating, not doing much…but later they pop up as cancer metatstases.
I believe, although I cannot be sure, that that is why they suggest radiation instead of surgery at this time.
You are welcome!
Hm. If a mast cell tumor is in the lymphatics, it is likely in the body…I believe based on what you wrote that your oncologist likely does not want to do surgery because the cells are already in the body, and if one is doing surgery one of the main goals is getting the cancer out of the body (or debulking the growth because it is a problem based on size, getting infected, etc). So perhaps that is why they are choosing radiation instead of surgery at this stage- getting the cells out is not likely since they have spread..although without a bit more info I cannot give you a certain answer.
Hope that helps!
Dr D
Yay!!
Good!
Again, don’t forget the soy lecithin for curcumin absorption enhancement..
D
Dr. Dressler,
Thank you so much for the advice. Your dosing instructions are right on, I believe. Immediately after my last post, I actually sat down and did a second set of calculations, decided that I would give my dog roughly 75mg of EGCG and 100mg of curcumin. I ran this past our Oncologist, and she, while issuing the disclaimer that I was operating outside her realm of expertise, did not see any issues with the 75mg EGCG and 100mg curcumin dosing.
With your input, however, I’ll now lower it even more to the levels you have advised.
Again, thank you so much for the advice.
Chris, there are no published doses in dogs for any of these. But I will give you my opinion on what you wrote:
1. The dose of EGCG is way too high for a Boston. I would give about 125 mg of EGCG daily for a large dog. You have 400 mg daily for a dog about 1/4 of this size. I think that is way. I would give 25-50 mg, once daily, on an empty stomach (or with as little food as you can).
2. I also think the dose of Curcumin is high also. An average supplement dose for a human is about, very roughly and depending on manufacturer, 250-500 mg daily of Curcumin itself. If you assume a 150 lb human, the supplement dose (antioxidant dose, which true is too low but just FYI) for a 25 lb dog is 1/6 that amount, or roughly 45-85 mg daily. You are proposing giving 750 mg of curcuminoids daily. Okay, true, most of this stuff will get passes in the feces, but…even so, seems pretty high to me. Why don’t you give 1/2 of the capsule you ordered daily mixed in soy lecithin, which you can get from the health food store. Use a turkey baster of a syringe from your oncologist to dose your dog. Give on an empty stomach please.
Get their input and approval before doing this so you can be sure everything is okay before starting (sounds like you are doing so..)!!
Sounds like you are working on getting the oncologists up to speed on cancer treatment beyond surgery, chemo and radiation!! Nice!
Glad to hear no grade 3, but keep on those tumor sites regardless, as sometimes (rarely) the grade does not always indicate tumor behavior..
“Good on you” for taking the time to be your dog’s health advocate!!
Dr D
Hi again,
Mystik had a checkup at Massey today and prednisone was injected into
what is left of the lesion. Her tests 3 weeks ago showed 4 mast cells in the
lesion and zero in her lymph node. 2 weeks ago there was 1 mast cell in
the lesion and still zero in the lymph node. Today she has absolutely
no mast cells in the lesion!!
Mystik will have another checkup in 2 weeks time and tests will be done
again to ascertain where she is at and treatment will be discussed if
need be.
I am relieved and so inspired by her spirit. She truly is a legend and
what has happened has made me believe in miracles.
Regards
Nardine
Just an addendum:
For both the curcumin and EGCG, I made sure to find reputable vegetarian formulas (as they contain no sugar, salt, starch, yeast, wheat, gluten, corn, soy, milk, egg or preservatives).
The Curcumin supplement I am going to use contains:
Total Curcuminoids 665 mg {from 700 mg of Standardized Turmeric Root Extract (Curcuma longaL.} (Min. 95.0% Curcuminoids (containing Curcumin, Demethoxycurcumin and Bisdemethoxycurcumin)}
The EGCG supplement contains the following:
KEY INGREDIENT(S): Green tea extract (Camellia sinensis) 400 mg
Total EGCg content: 50% (200 mg.) (Epigallocatechin gallate, a Catechin) # Total Catechins content: 80% (by HPLC method) (Catechins are a form of Polyphenol) # Total Polyphenols content: 98% (by UV method)
Less than 1% caffeine content, naturally occurring (versus one cup of green tea’s roughly 40 mg. of caffeine). There should be only around 3 mg. of caffeine, per capsule.
Dr. Dressler,
My dog is under the supervision of the Onocology team at the University of Florida’s Small Animal Hospital (Lucky for both my furry child and I, we live in the area).
The histopath results for my dog’s masses came back quite good. Of 12 masses removed, only 5 were MST. 3 were Grade 1, excised with clean margins. 2 were graded as low Grade 2, excised with clean margins. The onocologist recommended discontinuing any H2 blockers for the time being.
However, I went ahead and ordered a number of supplements to help my little boy along. He’s been taking 1000mg of purified fish oil daily (which seems to be the indicated dosage, from what I’ve been able to cobble together, for an 11kg canine). The Oncologist indicated that this was a good treatment option, as eha/dha have a number of concurrent health benefits beyond MST “starvation.” In addition, I now have a 99% decaffeinated EGCG supplement (4mg total caffeine content per softgel), and I’m going to start him on 200mg twice a day. I also ordered softgels of 750mg curcumin extract. My read is that 375mg 2x daily is about the right dosage for his size and weight.
Even our Oncologists was not aware of the recent literature on EGCG and Curcumin. I sent them links to a few selected articles (PubMed).
I’m feeling good about both my Boston’s prognosis, and the combination of supplements I have arrayed for him. I am curious, however, if I have the dosage right. I know I’m not at a level where toxicity would be an issue, but I would like to know if there is any other literature out there re: the proper dosing.
My vet doesn’t want to upset my dog’s system right now by changing his diet prior to radiation, but she was willing to consider the luteolin after I gave her some links from some research I did online. However, I could not find anything about dosing info, and this was new info for her. He ways approximately 65 pounds. Any advice?
He takes benadryl twice a day andhas been getting dermcaps forever due to skin dryness and allergies, so I don’t think that he would need a new fish oil supplement. When he was undergoing chemo, she put him on famotadine instead of cimetidine. What is it that the latter offers, that the former does not, and is there any research to document this? She had us take him off of the famotadine once we stopped with the chemo. Should we request that he start back up with the cimetidine? She didn’t tell us the protocol yet, so that may be part of it.
I’m concerned, mostly because of his age, that she wants him to undergo radiation 5 days a week every week for a month. Doesn’t that seem like an awful lot? It will be in a small area just around his lip where the tumor appeared / reappeared, but still.
Chris,
I would most definitely ask your oncologist to consider cimetidine. Your findings parallel my own, which are that the other H2 blockers lack the anti-cancer effects of cimetidine. By the way, are you working with a veterinary oncologist or a veterinarian?
Cimetidine, like other drugs, needs to be considered in conjunction with whatever other treatments are provided to your dog and his or her individual needs.
Best,
Dr Dressler
I can’t believe my stupid typo – ways not weighs. Don’t tell anyone at Cornell.
Hello, Dr. Dressler:
My 6 year old Boston Terrier just had a number of small masses removed, several identified by needle aspirate as MST. Our onocologist recommended fametidine (5mg for an 11kg dog).
What are your thoughts on Cimetidine versus Fametidine?
My brief lit review of available journals seemed to indicate that the inhibiting factors found in Cimetidine are not present in other H2 blockers. Would you advise asking my onocolgist about switching my dog over to Cimetidine? Or are there other factors that might preferentially indicate fametidine?
Thanks so much,
Chris