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 multiple 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 4-6 weeks.

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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 alert the body to an invader.
• 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, bacteria, or foreign substances 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; aggressive treatment T-cell lymphoma can respond to therapy.
• 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 such as decreased appetite, vomiting, and diarrhea.

The most commonly diagnosed stages for dogs are 3 and 4, and many dogs that start in Substage A can progress into Substage B as the lymphoma progresses 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 for a short time. Steroids are used to lead to lymphoma cell death and also help with secondary effects of the lymphoma such as low appetite and energy.

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 does not bring a dog into a remission (where the cancerous cells are no longer active and the lymph nodes are much smaller to normal in size) but sadly, survival times 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, there are multiple modes of killing the lymphoma cells so 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 depending on the stage, location of lymphoma, and response to therapy.

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. There are risks with radiation therapy and side effects which can develop, so it is important to weight the pros and cons with your veterinarian.

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Treatment after a relapse: The future of canine medicine is here

While there has been an established “gold standard” for treatment for an initial diagnosis of canine lymphoma with the CHOP protocol, there has yet to be a go-to treatment for dogs who have relapsed. As with any medical practice, learning more and developing processes is the way of the world. Finding the best treatment comes from trial and error and learning more about the disease as more patients are helped.

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma in both dogs and humans, typically responding well to initial therapies like CHOP. However, when patients relapse, there's no standard treatment protocol. To address this gap, ImpriMed has developed machine learning models that predict outcomes for 10 chemotherapy drugs commonly used for DLBCL in dogs. These models integrate data from two tumor profiling methods: flow cytometry and ex vivo drug sensitivity testing. ImpriMed’s study is the first to demonstrate how this multimodal machine learning approach can help identify effective treatments for cancer patients, representing a significant advancement in precision oncology. 

Our study relied on a special computer system to create prediction reports for treating cancer in dogs. These reports were sent to vets across the US starting in 2020. They predicted how tumors might respond to different drugs. Vets could use these predictions along with their own knowledge to plan treatments.

For dogs with relapsed B-cell lymphoma, a particularly common diagnosis, these prediction reports proved to be a game-changer. When the vets' treatment choices closely matched the predictions made by the computer system, the dogs tended to live longer and respond better to treatment.

This means that the AI system played a crucial role in helping the vets choose the best treatments for these dogs. By tailoring treatments based on the predictions, the relapsed patients had a better chance of beating cancer.

What this means for your pet

The findings from this study are incredibly reassuring for pet parents facing a lymphoma diagnosis in their dogs. It shows a significant step forward in veterinary medicine, offering both hope and practical guidance during an immensely challenging time. With the use of advanced technologies like machine learning and artificial intelligence, veterinarians can now make more informed decisions about treatment plans. This means pet parents can have greater confidence in the effectiveness of the chosen treatments for their furry companions.

By leveraging AI models to predict treatment outcomes, veterinarians can tailor therapies to suit each dog's individual needs. This personalized approach not only enhances the chances of a positive response to treatment but also improves the overall quality of life for the dogs. Additionally, the study's success highlights the growing importance of integrating cutting-edge technologies into veterinary oncology.

Ultimately, these advancements bring comfort and reassurance to pet parents, knowing that they are doing everything possible to help their beloved pets. As research in this field continues to evolve, pet parents can anticipate even more refined and effective treatment options for their furry family members, strengthening the bond between humans and their animal companions.

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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.