The main treatment for MCTs is surgery
Radiation treatment is an option for tumours that cannot be completely removed, or cannot be operated on
A tablet treatment is another option for tumours that cannot be operated on, and for tumours that grow back after removal
A new injection can used directly on individual masses
There are pros and cons to each type of treatment - your vet will discuss these with you and come to a decision together.
The main treatment for a Mast Cell Tumour (MCT) is surgical removal of the lump. You may be surprised by how big the surgical wound is when your dog comes home from the vets - this is because with MCTs we need to take a large amount of tissue away to ensure, as far as possible, that all the cancer cells have been removed. Your vet may also take some samples from lymph nodes or glands that are nearby to check for cancer cells - this will help them determine if the cancer is likely to have spread to anywhere else.
Once the mass has been removed your vet will need to wait for the lab to confirm the diagnosis and to provide a grade between 1 and 3 - this will indicate whether more treatment is needed or whether the surgery is likely to be enough to cure the problem.
But what if the mass is too big or somewhere like a toe so that surgery is going to be of limited benefit?
In these cases your vet may still want to take a surgical biopsy of the mass to have it graded so that alternative treatments can be targeted more effectively.
Radiation treatment is an option for masses that cannot be completely removed or that cannot be operated on. In the case that the mass was very large and there is concern of cancer cells remaining at the surgical site, radiation therapy can be an excellent option as a belt-and-braces approach after the surgical wound has healed. Your dog will need to go to a specialist centre regularly for radiation but it is generally a very safe treatment option to ensure that any nasty cells left behind are killed.
There are tablet chemotherapy medications that can be used for MCTs that are eiinoperable, have come back following surgery, or where they have spread to other parts of the body. The biopsied or removed mass will need to have specialist tests done by the lab to ensure that it is suitable for treatment by these drugs; this is because they are very specific to certain cell types. The chemotherapy tablets used for MCTs are not as harsh as the chemotherapy that we know from human medicine. They are a low-grade medication that is taken every day. They are not without side effects though and your vet will want to take regular blood and urine samples to check your dog is coping well with the treatment.
A newer medication for MCTs is an injection that is given directly into the mass. The drug works within 7 days but it’s not a pretty process! Initially the tumour seems to get bigger and angrier than ever, before disintegrating and leaving a wound that will heal gradually. Unfortunately it will only kill the mass of cells that it is injected into so if the tumour has been spread to other organs then additional chemotherapy tablets may be needed.
All-in-all, while receiving a Mast Cell Tumour diagnosis is a very worrying time, hopefully you can be reassured that there are lots of different options for treatment and management so that even the nastier Grade 3 lumps can be effectively managed and your dog can have a good quality life despite a cancer diagnosis.
The vets at MyDogDoc know just how worrying a diagnosis of cancer can be, and we’re here to offer an understanding ear and support to you and your pet whenever you need us.