In addition to standard biopsy or fine needle aspiration tests to determine whether your dog has Canine Lymphoma, in most cases your vet will recommend that you perform further tests to determine what “stage” the Lymphoma has progressed to.
In basic terms, this staging is intended to provide more information about the “level” of Canine Lymphoma your dog has, to determine how far the cancer has progressed and spread throughout the patient’s body.
The primary purposes for assigning Canine Lymphoma staging is to:
- give the caregiver a sense of how far the disease has developed,
- help define the types of treatments that might work best in each individual case,
- provide a general sense of the potential effectiveness of those treatments – both in terms of likelihood of remission and life expectancy, and
- It can also help rule out other concurrent medical problems which could affect the prognosis and options for therapy.
In general the further the cancer has spread (as designated by a higher level or stage), the poorer the effectiveness of most conventional treatments. However, even at higher, more advanced stages of the disease, treatment is still generally possible (although the chance of effectiveness, and the expected duration of healing, may be smaller).
In addition, staging can help vets determine whether your dog has other medical issues or conditions that might affect decisions about the types of treatments available or the potential effectiveness of those treatments.
The “5-level” clinical staging definitions most commonly used for Canine Lymphoma were developed by the World Health Organization (“WHO”) and are essentially the same as those used for staging human Lymphoma patients.
And while, in general the increasing stage numbers are intended to represent deeper and more progressed levels of the disease, it’s not always the case that a higher stage of the disease will result in worse results. In fact, in many cases, the expected results and prognosis for certain types of treatments may be similar regardless of the particular stage assigned to your pet’s Canine Lymphoma.
The 5 primary stages designated to represent Canine Lymphoma progression are:
- Stage I: Involvement of a single lymph node (or lymphoid tissue in a single organ) only;
- Stage II: Regional involvement of multiple lymph nodes (either in the front half or back half of the body);
- Stage III: Generalized lymph node enlargement (this typically refers to enlargement of lymph nodes in BOTH the front half and back half of the body);
- Stage IV: Involvement of the liver and/or spleen; and
- Stage V: Involvement of blood, bone marrow, central nervous system, or other organs
With respect to Canine Lymphoma, the most common stage by far is “Stage III.” Stage I and Stage II diagnoses are much more rare. And dogs that start at one stage can progress to other (usually more advanced) stages of the disease over time.
In addition to the five stages designated above, each numbered stage is generally further divided into one of two “substages:”
- “Substage a”: Where there are no systemic signs of disease (i.e., the patient generally seems healthy and symptom free); and
- “Substage b”: Where there ARE systemic signs of disease (i.e., the patient demonstrates general symptoms of feeling not well).
The most consistent predictor of whether or not a dog will go into remission using conventional dog cancer care is whether the patient feels well or sick (Substage a or b) when diagnosed with Lymphoma . Dogs that feel well when first diagnosed tend to do the best for long term care.
The good news is that most dogs diagnosed with Canine Lymphoma are diagnosed with a “Substage a” (no visible symptoms of the disease) – and dogs with “Substage a” tend to respond most favorably to currently available conventional Canine Lymphoma treatments.
Although recommended Canine Lymphoma treatment options are essentially the same regardless of the Stage (or substage) of the disease diagnosis, these stage designations can help predict how well the patient will respond to conventional Canine Lymphoma care.
For example, dogs diagnosed with Stage V Lymphoma, and dogs that have been diagnosed in Subcategory b, generally have a statistically worse chance of going into remission using conventional chemotherapy treatments (and if they do go into remission, the length of that remission is generally much shorter than in the other categories).
Fortunately, however, the vast majority of Canine lymphoma cases fall into the Stage III or IV category, and most fall into Subcategory a, which, of all staging categories, are among the best predictors for long term remission success when treated with standard conventional chemotherapy treatments.
Diagnostic tests used to determine Canine Lymphoma Staging
Technically, the tests required to do a full Canine Lymphoma staging include ALL of the following:
- Chest X-Rays
- Abdominal Ultrasound
- Blood Tests (Full Blood Panel)
- Bone Marrow Aspirate
However many vets, including Dr. Freeman, do not require all of these staging tests. The reason is primarily the cost of these tests (it can be really expensive to fully stage a patient (see Canine Lymphoma Treatment Care) compared to the actual benefits gained from each test.
While some tests, such as Chest X-Rays and the Blood Panel are reasonably priced and provide a lot of beneficial information related to the patient’s Canine Lymphoma care, other tests – in particular the Bone Marrow Biopsy are invasive, expensive procedures that put unnecessary stain on most dogs and often don’t provide enough useful information to justify the cost and impact of the procedure.
Beyond the cost, Dr. Freeman feels that “you need to have a really good reason to run a test” and that staging tests results generally won’t to change her recommended treatment protocols, so why spend the money or put your dog through the stress of extra tests that aren’t going to provide any significant value in the actual treatment process. If it’s not going to change the things you’re going to do to treat the cancer, then why not save the money and use it to pay for the treatments themselves.
“If we have a choice between spending a client’s money on an ultrasound for the purpose of staging the cancer, compared with actually having that money available to pay for the actual treatment itself,” Dr. Freeman generally comes down on spending the money on the therapy to make the patient feel better, without worrying about the marginally useful information she might receive as a result of these extra staging tests.
One test that Dr. Freeman DOES generally recommend for her patients before starting any chemotherapy treatment is a full blood panel, to look for certain telltale signs that might affect the treatment.
Although some blood panel information relates to the staging of the disease, many of these blood tests relate to the patient’s overall metabolic health – liver function, kidney function, bone marrow function, etc. – and can be helpful when looking at a chemotherapy protocol, because if a patient is compromised on one or more of those functions, it will impact the prognosis of the potential effectiveness of the treatment, or require certain adjustments to to account for these issues.
Having basic blood work is good to help guide the treatments undertaken, and to help guide dog owner expectations about potential side effects or likely chance of success of the treatment itself, so these things can be factored into the decisions about the best way (or in some cases whether or not) to treat the disease.
Dr. Freeman also generally recommends pre-staging chest x-rays, especially for her patients who are about to start the Madison Wisconsin Chemotherapy Protocol, because one of the drugs used in the Madison Wisconsin Protocol, doxorubicin, can be potentially heart/cardio-toxic. In those cases, confirmation that the patient’s heart looks healthy can be valuable to determine whether the patient can successfully handle this particular method of treatment.
And in certain limited cases, Dr. Freeman also recommends Abdominal Ultrasound tests.
This particular test can be useful if a patient is really sick and the vet is worried that the dog may have a gastrointestinal obstruction, or kidney involvement, etc. In those cases, Abdominal Ultrasound can help determine why the patient is struggling with these problems.
But in cases where patients look and feel healthy, and have no symptoms to indicate any gastrointestinal or kidney problems, Dr. Freeman generally chooses NOT to do this Abdominal Ultrasound test, because the odds of finding any particular problem (or perhaps more importantly, the odds of finding anything that would change the ultimate recommended treatment) are small, and generally don’t justify the cost of providing this additional test.
Note: One other potentially useful staging test is to help determine the phenotype of the particular Canine Lymphoma – T Cell vs. B Cell Lymphoma (for more information, please visit the Types of Canine Lymphoma page on this website). This is a special test that needs to be done before treatment is started. Some people want this information and others do not, because the information about Canine Lymphoma phenotype can give you a much better sense about the potential effectiveness of the treatment. As noted in the section on Canine Lymphoma Types, most Canine Lymphoma cases are B-Cell Lymphoma (the phenotype that responds best to conventional treatments that are available).
One staging test that Dr. Freeman usually does NOT recommend for her patients is a Bone Marrow Aspirate. This particular staging test is actually an invasive procedure that can put unnecessary stress and strain on the patient. And in most cases, if the patient’s blood tests come back normal, Dr. Freeman believes that the benefits of putting the patient through these Bone Marrow tests do not justify the stress or expense of the test itself. In some cases, a test called “Flow Cytometry” has replaced the need for a bone marrow aspirate and is a simple blood test.
While Dr. Freeman generally recommends balancing the costs vs. benefits of these staging tests for her patients, the ultimate decision about which tests to do and which not to do are always made on a case by case basis, and will vary depending on the patient and on factors such as finances, overall patient health, etc.
So while we recommend that you know the facts about these staging tests, and come to your vet informed about the advantages and disadvantages of each, we recommend that you work with your veterinarian (or veterinary oncologist) to decide what options are best for your dog under your particular circumstances.
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