When to Avoid Chemo for Canine Mast Cell Tumors?
ByThere has been much online talk these days about dogs with mast cell tumors (read, Palladia) which are the most common canine cancer.
So I thought I’d just add some fuel to the fire and give my readers some overall guidelines about mast cell tumors and chemotherapy.
As many already know, these cancers come in different grades (1, 2 and 3). Grade 1 are almost always benign, grade 2 are intermediate (some benign and some malignant) and grade 3 are universally malignant.
Your vet will give you the grade following receipt of the biopsy report, which is completed by a path lab after submission of tissue from the tumor.
Wide excision (removal of a large swath of normal-appearing tissue around the tumor) cures many mast cell tumors. Pretty much all grade 1, and about 90% or so of grade 2 mast cell tumors are gone permanently after wide excision. Grade 3 mast cell tumors are candidates for chemo and possibly radiation and more as they will often come back and spread even after surgery.
The tricky guys are those grade 2 mast cell tumors. Since some behave like benign tumors and some like real cancers, what are we supposed to do?
Well, the key is in getting more information about your dog’s individual tumor. There are a couple of bits of information that are valuable that can help you predict the behavior of your dog’s grade 2 mast cell tumor.
The single most important one is called the mitotic index. This is the number of cells that are actually dividing seen by the pathologist under the microscope.
The magical cut off is somewhere around 5. This means that if the tumor has a mitotic index of less than 5, it usually will behave less aggressively and in my opinion do not require surgery, as long as you have clean margins on the removed tumor.
More than 5? We need to now consider hitting these guys with the full spectrum approach (diet, supplements, chemo, and other strategies discussed in The Dog Cancer Survival Guide).
You may read about other markers (kit, AgNORs, Ki67) but these are much less useful than mitotic index. If the mitotic index is around 5 though, consider these other markers for more data.
By the way, not all vets may know about this stuff, so remember to be your dogs primary health care advocate and speak up! You vet is the one who has to order this testing of the biopsy specimen from your dog.
The squeaky wheel gets the oil!
Best to all,
Dr D
About the Author
Dr. Demian Dressler, DVM is known as the "dog cancer vet" and is author of Dog Cancer Survival Guide: Beyond Surgery, Chemotherapy & Radiation. Visit his blog and sign up free to get the latest information about canine cancer. Go to http://DogCancerBlog.com.
19 Comments
October 31st, 2009 at 1:29 pm
Please help me…my 8 year old female lab has had 8 mast cells removed and 1 lymph node .
I am at a loss – but no more surgery for her.
When can chemo be helpful and what kind?
Biopsies were done on liver, spleen and bone – they are clean.
White cells are high and red are low.
Her brother…is now showing just large bumps (noncancerous)
What food do I change them too? Is pallidia an option?
November 2nd, 2009 at 10:39 pm
Colleen, did your dog have a mast cell tumor removed recently?
D
November 3rd, 2009 at 8:18 pm
Hi Dr. D,
Palladia looks like it’s going to be an interesting drug. Wonder what the cost will be when it’s released.
Some food for thought, and I’d like to open up a dialogue. I posted on an earlier blog about this….
Why not treat dogs with mast cell inhibitors like ketotifen or rupatadine and H2 blockers (pepcid or zantac) in addition to low histamine/tryptase diets?
For the dogs that have class one and two tumors, would it be possible to slow them down by mediating the mast cells that cause the tumors to proliferate?
There is a human market in the US for both drugs (especially for ketotifen) for an orphan disease (rare disease), but no drug company interested in the profitability due to perceived competition from other popular antihistamines that do not possess mast cell inhibitor properties.
If Ketotifen were marketed here for dogs, it would possibly save pet guardians thousands of dollars on treatment of MCTs in early stages. Studies would need to be done to prove the efficacy of the drug for MCTs, of course. And someone would need to get a manufacturer interested in a different on-label usage.
November 3rd, 2009 at 10:43 pm
Doctor, I recently filled out a survey and included a suggestion for your book, but was unable to finally ’submit’ the survey because I am already a subscriber to your “Dog Cancer News” email service. No other option was offered.
November 4th, 2009 at 2:17 am
dear dr
added complication of ADDISONS DISEASE
my northern inuit male dog, broch, nearly 3 and half had his front leg amputated nearly three weeks ago due to a suspected osteosrcoma in his distral radius. he has recovered well from this but the biopsy have not been clear enough to say which type or grade of cancer he has. there was a lot of dead tissue, and the initial biopsy said the cells where not dividing very rapidly. initially the recommmended treatment was carbopalatin but now the oncologist is suggesting using a combination of two treatments instead. i have an appointment with the oncologist next week to discuss this and would really appreciate some advice from you as he has addisons disease too, i wondered if that creates any other issues to his treatment or recovery.
thanks in advance
Lynn Allardyce
November 4th, 2009 at 8:09 am
Dr. how are you.
My situation is the following. I have a poodle who in frebruary will be 13 years. A month ago was diagnosed with mass cell tumor behind his right shoulder. this is the first time something happen to him.
Now. unfortunatelly my economic situation is not the best at this point. Besides it, I am as of today six months pregnant and live by myself. father of baby, mother father and family live in another country. So I don’t have anyone who can tace care of my dog but me. I was told by the oncolgyst at that time that we have to do a surgery which it will cost me 3,000. us. I ‘ve been looking for some help to pay for it and in the meantime I have my dog with a drug that help to reduce the tumor. I guess the name is prednisone, if I am not mistaken. this medicine was doing good on him, but when a finished, and I need more. it took me two days to get the appointment and the tumor grew up bigger in this two days. The oncologyst told meis too big for surgery now, and we need to do chimio asap. She told me about Palladia pills. But unfortunatelly because of my pregnancy I cannot handle them of clean after him. I am giving him right now the prednisone again. But I don’t know until when this medicine is gonna work.
Another thing is that he has a little injury right on the tumor and I have to keep him with bandage because when they did thy test on the tumor he scratched himself and started bledding. So I have to cover the tumor for him not touch it. I was changeing the bandage every three days but the injury was getting worse. They said because it needs to be ventilate it and since is covered i am changing it every day. The vet was using nitrofurazone as onitment in his injury but again, because of my pregnancy a cannot use this ointment. I am putting on him neosporine instead. So I would like to have your opinion on what should I do and also if the neosporin will be a good replacement or which other antibacterial ointment could I used on him that is not bad for my current status.
I haven’t had any final answer in the foundation I am trying to get help from. Other two they coulnd’t help me because of his age and other because is not doing any help for now.
I really feel bad that because I cannot give him the medicine or clean him up right now, he might die. If it would be a hope for me that at least can give me three months once my mother come she might be able to help me. At that point I would have my baby born already….. Please if you can give me any advise I would really appreciate it. Thank you
November 11th, 2009 at 7:05 pm
Aloha Dr. D~
My 12 year-old Lhasa Apso recently had a MST surgically excised. The biopsy reported clean margins, a mitotic index of 3 (less than 5 yea!!!) but a not so fabulous, cryptic grade of 2/ borderline 3. Her vet suggested chemo as a precautionary measure to prevent other MST’s from developing…but I am hesitant to agree given the low MI and a few other factors. For example, I first discovered the tumor a little more than a year ago and brought her her to have it aspirated. I was told it was a little hematoma and not to worry…so I didn’t. I mention this because most of the research I’ve done on MST’s revealed that tumors which have been present for any great length of time are usually benign…so there’s the year-long time factor in our favor in addition to the low MI. The 2 / 3 grade is really the only thing worrying me and leaving me a bit perplexed as far as whether or not to further medicate my dog and would be grateful if you could please advise…
I should also probably mention that–prior to surgery–her tumor suddenly started increasing in size from 2cm to 5cm in less than a month. We put her on a protocol of Prednisone & Benadryll 1 1/2 weeks prior to surgery to shrink the tumor which, by the way, had also ruptured and was seeping and turning necrotic before it started shrinking down.
The sutures were removed today and she seems to be healing quite nicely. She is still taking the Prednisone (though a much lower dosage so it doesn’t interfere with her post-surgical healing) 2.5 mg every other day & 25mg Benadryll. I also have her on a grain-free diet…organic meats & veggies…broccoli sprouts, sardines, 1200mg Omega 3’s & a few alkalizing supplements. Ideally, I would like to ween her off the Prednisone and just stick to Benadryll & the specialized diet and hopefully avoid the other chemo protocols my vet suggested (Vinblastine, Palladia, etc.) entirely as I do not want to give her something I am not even sure she really needs…
Mahalo for your time…and your wonderfully informative website!
Sincerely,
KAT
November 26th, 2009 at 9:30 am
Dear Dr. Dressler:
I am so grateful to have found your website and hope you can be of some assistance.
I have a 10 year old female beagle that up until now, has been a very healthy and active dog. She presented herself 3 months ago with what appeared to be an insect bite on her rear large pad. It took the 3 vets all of this time to finally diagnose her with a Mast Cell Tumor Grade 2 after biopsy. We also learned it had spread to the lymph node of the same leg. I have already spent over $3,500 dollars (more than I could afford) to finaly get this diagnosis. The last vet to see her was an oncologist who told me I had to do radiation, surgical removal of the pad(even though they cannot get clean margins), pad reconstruction, chemo, prednisone and weekly labs which she “guestimated” would cost be between 8 to 13 thousand dollars. I cannot aford this and I’ve become desperate. This dog means more to me than I can explain in this Email. She has been with me through thick and thin. I want to do everything within my means to save her.
I have read nearly every blog on your website and searched the internet for hours hoping I could find something that would help me determine the correct course of action to take. She is currently on Prednisone 15mgs BID, Pepcid 10mg QD, and Benadryl 10mg TID. She’s been on these meds for 2 weeks now. I have not changed her food because I’m confused as to what best to give/prepare for her and have gotten no direction from my vet to do so.
Is Chemo a way to go without doing radiation and tumor excision? What do you think her chances of survival would be based on doing these things alone. I cannot afford radiation, labs and surgery and if I were to find the money to do that, the vet gave me a 40% chance of remission/survival. Please help me. What would you advise I do and/or not do?
Thank you very much,
Bill and Bessie.
November 29th, 2009 at 9:10 pm
Bill
Have your vet (or yourself, but that is second best) contact Dr. Albert Ahn at AB sciences in New Jersey. Have your vet tell Dr. Ahn I sent you.
It is important to have your vet in on this. Have your vet tell Dr. Ahn you are interested in the compassionate use program for masitinib.
Dr. Ahn will know what to do from there.
Best,
Dr D
December 8th, 2009 at 4:48 pm
Hi Dr. Dressler. Our wonderful dog Lucky just had a MCT removed from his arm pit. The biopsy report indicated the miotic index was 14. We have seen an oncologist and he does not give him more than 2 years to live even if we put him on a new chemo therapy pill and continue with the Benadryl and Pepcid. Our regular vet is going in in a few days to remove the local lymph node and some muscle tissue that indicate cancer cells still remain there. The spleen and all other tests were fine. Our regular vet thinks we should try the Prednisone and maybe hold off on the Chemo treatment. I have heard of a lab in Michigan that can further test the tumor to determine what it is likely to do. Please advise us with your opinion, we would appreciate it so much. We so want to save Lucky and any discomfort, but like other people in these posts, we are confused.
Thanks so much, Jeannie
December 8th, 2009 at 4:54 pm
Hi Dr Dressler, I forgot to provide some other details in my previous post. Lucky is only about 4 1/2 years old. I first felt the lump under his skin about 5 months ago, and it slowly came to the surface. I took him to the vet (saw a different Dr.) in September and it was diagnosed as a wart-mole. I was advised to watch it and if it changed or bothered the dog, I should have it removed. I did just that 2 weeks ago and that’s when they biopsied it and it came back as MCT. we are so upset about this, especially since he is incredibly healthy. Please let us know your opinion.
Jeannie
December 10th, 2009 at 8:38 am
Hello Dr. Dressler, Thank you for being here.
You said ”
Bill
Have your vet (or yourself, but that is second best) contact Dr. Albert Ahn at AB sciences in New Jersey. Have your vet tell Dr. Ahn I sent you.
It is important to have your vet in on this. Have your vet tell Dr. Ahn you are interested in the compassionate use program for masitinib.
Dr. Ahn will know what to do from there.
Best,
Dr D”
Is Dr. Ahn a specialist for masitinib (now I have to look that up, new information)? for MC cancer? Do you know about Dr. Mauricio Couto’s work in the Greyhound Wellness and Oncology program at Ohio State University? My 2 vets have been consulting with him (at my request). I’ll keep this short. Thank you.
December 13th, 2009 at 12:21 pm
Dr Ahn is president of AB Sciences, located in New Jersey. AB Sciences is a pharmaceutical corporation. The are waiting for the FDA approval of masitinib. AB Sciences will sell it in the USA after FDA approval. Dr Ahn is the one who supervises the importation of masitinib from France under the auspices of the compassionate use program. Get your vet involved in this by having him/her contact Dr Ahn.
Dr D
December 13th, 2009 at 12:33 pm
Jeannie,
the mitotic index, in this case, is more predictive than the tests you are talking about . The odds statistically are high that this is an aggressive cancer at this stage and the Michigan panel will likely not yield further useful data. All we have to look at are stats. You certainly should make sure that a wide excision was done in the first place, and if not a second surgery should be performed to remove as wide margin of tissue around the tumor area in the hopes of removing as many cancer cells as possible.
You also need to read this post very carefully and then re-assess your situation:
http://www.dogcancerblog.com/the-most-important-question-in-dog-cancer-care/
The e-book I wrote may help as well.
Best,
Dr D
December 29th, 2009 at 8:38 pm
Thanks for the informative information – I enjoyed reading it! I always enjoy this blog.
Cheers, live-birth-video.com
January 3rd, 2010 at 6:28 pm
Dr. Dressler, I just found out that my English Bulldog, 7 years old, has a poorly differentiated Grade III mast cell tumor. The biopsy report said the “mast cell tumor appears completely excised.” However, it says her mitotic index is 6/10. How bad is that number? Thank you very much.
Gary
January 9th, 2010 at 7:47 am
Dear Gary,
you need to understand this is a very serious cancer. The statistics are rather dreadful: less than 2 month survival time for a grade 3 mast cell tumor with a mitotic index of greater than 5. I would consider the whole arsenal in a 7 year old Eglish Bulldog, depending on what type of person you are (how risk averse). I would utilize the full range of surgery, chemo, possibly radiation (the latter two under oncologist supervision), as well diet, supplements, life quality measures etc. that I describe in the Dog Cancer Survival Guide. You should also pay close attention to the treatment plan analysis portion of the book due to the grim numbers involved in cases like your dog’s, to make sure that what you do makes sense to you and feels right from an ethical standpoint.
Dr D
January 18th, 2010 at 10:52 am
Dr. D,
Our 5yr old Great Dane/Lab mix recently had a tumor roughly the size of a walnut removed from the back of her leg. The pathology came back as Grade I mast cell tumor, with a mitotic index of 0-1. However she has 3 other smaller growths the size of a pea in other surgically aceptable areas.
My question is are we likely to have ongoing tumors appear and what is the prognosis if we continue to see new tumors. Can we expect to have all of these sucessfully removed thru surgury given her pathology or is her outlook likely to deteriorate over time.
My vet seams optomistic but we don’t want to be caught of guard given this may not be the only malignant tumor.
January 31st, 2010 at 5:00 pm
fyi..i just purchase paladia from my vet for $220 for 30 pills for my schnauzer