What Affects Survival Time and Life Expectancy for Dogs with Lymphoma?

How lymphoma affects your dog’s life expectancy

Lymphoma is a systemic cancer, meaning that it affects the whole body rather than just one area. Systemic cancers are harder to cure because they spread throughout the body and impact different systems. Lymphoma affects the immune system and lymphocyte cells, making it more adaptive to treatment; adaptive, in this case, is not a positive attribute. Lymphocyte cells are a part of the immune system that fight off infections and diseases, but when they adapt to cancer as a normal part of the process and not an illness, those same lymphocytes will then protect the cancer cells and fight off any medication that is being given to your pet to treat the cancer. 

Because lymphoma is not curable, it can be easy to assume that treatment is a waste of time or effort. But that is not the case. Many dogs can lead happy, healthy lives while in a state of remission, meaning that there are no active cancer cells in their body. 

In fact, dogs diagnosed with lymphoma that do not receive treatment will have a very short survival time. The average length of time that a dog can live after diagnosis without any treatment is about 1-2 months.

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Different types of lymphoma can change survival times

Lymphoma is classified by many different variables: where the lymphoma is affecting the body, what kind of cells are cancerous, what stage the cancer is in, and whether or not the patient is showing symptoms. All of those classifications, when combined together, lead to different treatment methods and expected outcomes of that treatment. 

There are four main categories of lymphoma: 

• Multicentric—commonly referred to as systemic lymphoma, which accounts for 80-85% of all lymphoma cases in dogs. It is characterized by the presence of superficial lymphadenopathy. Because it is the most common, there is a lot more information to pull from when deciding treatment and discussing options with an oncologist. There are many more tested and trusted treatments because we know how the disease will likely behave, which can often lead to better survival times
• Alimentary—lymphoma in the gastrointestinal tract, which only accounts for 5-7% of all lymphoma cases
• Mediastinal—lymphoma involving organs within the chest, such as lymph nodes and thymus gland. It can affect breathing and lung functions; commonly it is an addition to other lymphomas, adding to about 22-36% of all cases
• Extranodal—when lymphoma presents itself outside of the lymph nodes; takes place most often in the skin in the form of cutaneous lymphoma; the rarest form of all the lymphomas

Within those categories of lymphoma there are also cell types:

B-cell 

• B-cells are the part of the immune system that produces antibodies, which are a protein that works to either destroy a virus or communicate to other cells for help in destroying a virus
• Within lymphoma, they are usually on the more mild side of the diagnosis spectrum because they are less likely to be aggressive and more likely to respond well to treatment 
• Small Cell— Smaller cells are able to have a bit more leniency between diagnosis and treatment; they tend to have a better survival time than their larger counterparts
• Large Cell— When larger cells are affected, the lymphoma develops much faster and more aggressively. Without immediate treatment survival time can be as short as 6 weeks.

T-cell 

• An important addition to the immune system, these target and destroy a specific kind of virus or bacteria and each T-cell is designed to destroy one specific threat to the body 
• T-cell lymphomas are more aggressive, but that doesn’t always mean that the survival time will lower; with aggressive treatment T-cell lymphoma cases can have years of survival time post-treatment 
• T-zone lymphoma is a type of T-cell cancer that progresses very slowly and is managed as chronic, indolent disease. Chemotherapy should be used cautiously in such cases.

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Progression of canine lymphoma 

Lymphoma is diagnosed in stages, depending on when the cancer is discovered, the stages may progress into others, or be treated into remission without advancing. The way that staging for lymphoma works is based on how many lymph nodes or organs are affected. 

• Stage 1: There is only one lymph node that is affected 
• Stage 2: Multiple lymph nodes on the same side of the body are affected (diaphragm as the dividing point)
• Stage 3: Multiple lymph nodes on both sides of the diaphragm are affected
• Stage 4: The liver and/or spleen are impacted, either with or without swollen lymph nodes 
• Stage 5: Bone marrow, blood, or another organ is involved 

There are two substages that will impact your dog’s individual experience with Substage A being the dog shows no external signs of illness; Substage B being there are impacts on the dog’s daily life. 

The most commonly diagnosed stages for dogs are 3 and 4, and many dogs that start in Substage A will progress into Substage B and begin showing symptoms of their ailment. However, dogs who begin treatment in Substage A have a much greater chance of achieving long-term survival.

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Different treatments and their overall prognosis

Lymphoma is unfortunately a cancer without a cure at this time. The goal of all treatments is to achieve remission, during which the cancer cells are dormant in the body and do not affect your dog’s day-to-day life. 

The prognosis of a lymphoma treatment is determined by the likelihood of achieving remission and the duration of time spent in remission before a relapse occurs and the cancer cells become active again.

Steroid treatment

While it is not the standard, nor most effective treatment, canine lymphoma can be treated with steroid drugs to keep the effects of lymphoma at bay. Steroids are used to prevent inflammation and cancerous cells behave similarly to immune cell flare-ups. 

When a dog is given prednisone—a steroid drug—as their lymphoma treatment it is more so to give the dog a bit more time with a better quality of life. Treatment on prednisone alone can bring a dog into a remission (where the cancerous cells are no longer active) but they typically only last an average of 4-6 weeks before a relapse.

Chemotherapy treatment (CHOP)

The most effective treatment for lymphoma is chemotherapy—specifically multiagent chemotherapy—because lymphoma affects the whole body and chemotherapy is a systemic treatment. Multiagent chemotherapy—using multiple different drugs—is beneficial because of the nature of the immune system. The cells that become cancerous, when healthy, are designed to fight off potential threats to the body, so once those cells become cancerous any threat to the cancer is one that they will now be fighting off. When only using one medication, those cells learn that the treatment is hurtful to the cancer, and as a result, they quickly adapt to be able to fight against it. By using multiple drugs, the cells don't get enough time to adapt to each form of treatment, effectively stopping the spread and lowering the number of cancerous cells.

CHOP is the “Gold Standard'' treatment for canine lymphoma because of its high efficacy rates. Dogs treated with a CHOP protocol (or another effective multiagent chemotherapy) can live anywhere from 10-14 months or more in remission. 

Radiation therapy 

Some canine lymphoma patients may benefit from the addition of radiation to a chemotherapy treatment. Radiation is a highly toxic form of treatment that is usually reserved for more localized forms of cancer. When using radiation therapy on lymphoma patients it’s performed in a ‘half-body’ method, where half of the body receives the treatment, and then the patient has at least 2 weeks to recover before receiving the treatment on the other half of the body.

If chemotherapy alone isn’t working, radiation therapy can be that final ‘push’ into remission. While there is not much data on how radiation therapy affects survival times, it can be expected to have a similar length of remission time as a successful chemotherapy treatment.

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Choosing the best treatment for your pet and knowing what to expect

That’s what ImpriMed sets out to do. Our high tech labs and advanced systems help your vet find the very best treatment options to get your dog into remission in the most efficient way possible and keep them in remission for as long as we can. 

Using AI technology, a large database of canine lymphoma patients and their treatments, and your dog’s live cancer cells we’re able to put together a Personalized Prediction Profile which allows us to help your vet find the best combination of drugs for your dog’s lymphoma. 

The Personalized Prediction Profile also helps your vet to predict when a future relapse is likely,  so they can be best prepared to help you and your dog throughout your entire lymphoma journey.

Find out how to get your vet involved with ImpriMed