Featuring Demian Dressler, DVM and Susan Ettinger, DVM, Dip. ACVIM (Oncology), authors of The Dog Cancer Survival Guide.

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Common Cancer Mistake: Starting Your Dog with Lymphoma on Prednisone Too Soon

Using Prednisone to Treat Dog Cancer

Should you start your dog with cancer on prednisone right away, or wait until you’ve staged the cancer and explored other treatment options?

It happens all the time, so don’t beat yourself up if you’ve done it. But if you can, avoid the use of steroids (such as prednisone) before chemotherapy, or before the diagnosis of lymphoma is confirmed.

Now, I’m not bashing prednisone across the board. Steroids are used for many things in veterinary medicine. For example, your dog has probably been on prednisone before. It’s great anti-inflammatory, and it is used for itchy skin, allergic reactions, and allergies. Prednisone is also immunosuppressive at higher doses, so it is used for things like inflammatory bowel disease or immune mediated disease  like anemias and platelet disorders.

Prednisone is also part of most lymphoma treatment protocols, because it actually kills lymphoma cells. It can even be taken as a standalone treatment for lymphoma — if a pet Guardian decides against chemo, I recommend they start prednisone. That’s because survival times for lymphoma without chemotherapy treatment are about one month, but prednisone will increase that to about two to three months with about 50% response rate. Sounds great, right? Why not start it right away?

There are two reasons.

Reason One to Wait to Start Prednisone: Steroids Complicate Diagnostics

If you start prednisone (often shortened to “pred”) before we complete other testing like chest X-rays and abdominal ultrasound, you are treating the cancer and those tests will now be less accurate.

For example, if the liver and spleen look normal on ultrasound, but the dog is already on prednisone, we can’t tell if the lymphoma was there before the steroid use started. That means that we don’t have a baseline of information to use when monitoring response to treatment. It also means we know less about the illness your dog has. Knowing what stage the lymphoma is in will help me make a more accurate prognosis about the probable outcome of treating your dog.

Another thought: if your dog is on prednisone before we finish testing and staging the cancer, it may be difficult for me later to distinguish whether symptoms and side effects are due to the chemotherapy or the cancer itself.

Prednisone can also affect the test for phenotype, or subtype. In this test, we look to see: is the lymphoma  of the B-cell subtype, or of the T-cells? This information matters a lot, because B-cells usually respond better to chemotherapy and have a longer survival time.

Unfortunately, if a dog is already on pred, and the lymph nodes are going into remission because of it, I will not be able to run this test. This test is the very best predictor we have for lymphoma: it helps us predict both the cancer’s likely response to treatment and the likely survival time we’re working with.

Not only that, but this information helps me to choose which protocol to use. The UW CHOP multi-agent protocol (the best protocol we have) does not work as well for T-cells as is does for B-cell lymphomas.So using it would be less effective in T-cell lymphoma, and I would have to adjust the protocol and the expectations for outcome.

Along the same lines, if the lymph node aspirates are inconclusive (non-confirmatory), I will need to re-aspirate or biopsy a lymph node to confirm the diagnosis. If the dog is on prednisone because we did not wait for diagnosis confirmation, getting a diagnosis becomes a challenge, and I don’t have the good data I need to make a protocol choice.

Reason Two to Wait to Start Prednisone: Steroids Can Make Chemo Less Effective

Steroids potentially make treatment with chemo less effective. Unfortunately, prednisone can interfere with later chemotherapy treatments, and can trigger a mechanism called Multi Drug Resistance (MDR). I cover this at length in The Dog Cancer Survival Guide, because it’s an important concept for you to understand if your dog is undergoing chemotherapy. Basically, MDR is a capacity some cancer cells have to pump chemotherapy agents OUT of the cell. No matter how much we throw at them, they just keep throwing it back.

Dogs with lymphoma who have MDR have a much worse prognosis than those who don’t. This is a very important reason to avoid the use of steroids before chemo starts — they can trigger that MDR. In fact, the use of pre-treatment prednisone has been demonstrated to be a strong negative-predictor for dogs with lymphoma – meaning they do not respond as well to chemo.

Our current lymphoma protocols can be very effective. The median survival time for dogs receiving chemotherapy is thirteen to fourteen months. Giving these protocols a chance — if you choose chemotherapy — means avoiding the use of prednisone.

Lymphoma is a very aggressive cancer in dogs, and the pressure to start treatment right away is (and should be) enormous. The reality is that every day you delay is a day lost to treatment. However, that urge to treat does NOT mean you should start prednisone immediately. Waiting to see what the test results are, allows you to choose from all of the relatively good options we have for treatment. On the other hand, jumping right in with prednisone can take some of those options off the table.

Live longer, live well,

Dr. Sue

About the Author: Susan Ettinger, DVM, Dip. ACVIM (Oncology)


Susan Ettinger, DVM. Dip. ACVIM (Oncology) is a veterinarian oncologist at Animal Specialty Center in New York and the co-author of Dog Cancer Survival Guide: Full Spectrum Treatments to Optimize Your Dog's Life Quality and Longevity. She blogs about dog cancer at http://www.DogCancerBlog.com.

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  • Mary

    I’m confused. My dog’s oncologist also said that taking prednisone prior to therapy makes chemo less effective, but used prednisone after chemo was initiated. Are you saying that prednisone at any time during chemotherapy is not a good thing to do?

    Thanks!

    • DrSueCancerVet

      Mary, Sorry for the confusion, but the issue is ONLY USING PRED PRIOR to chemo. Using pred with chemo is not an issue and pred is included in many chemo protocols for lymphoma.
      Wishing your dog a great response to chemo and a long complete remission!
      All my best, Dr Sue

  • Susan Kazara Harper

    Hello,
    To help respond to your question I’m taking an excerpt from Dr Ettinger’s views in Dog Cancer Survival Guide:

    “Prednisone tends to activate a protein in the walls of cancer cells, called a multidrug resistance (MDR) pump (check out page 130 of the Dog Cancer Survival Guide). This protein pump kicks toxins out of cells on contact. For cancer cells, chemotherapy drugs are the toxins. If the dog is already on prednisone, this pump may be active, which means that it could interfere with the effectiveness of chemotherapy protocols.The problem is use prior to starting chemotherapy.”

    But don’t panic, Dr. Ettinger goes on to say:
    “Despite this negative predictor, I recommend starting treatment, even if your dog is on prednisone already, as any delay in treatment worsens the overall prognosis.”

    So if you’re comfortable in this discussion with your vet, you’re covering the bases. Well done for being proactive and protective of your pup.

    Regarding the MDR concern, you can discuss with your vet the possibility of testing for the mutated gene through Washington State University College
    of Veterinary Medicine. If chemo is already scheduled and you want to do this, act fast. More info can be found at http://www.vetmed.wsu.edu/depts-VCPL I hope this helps. Good luck to you both!

  • Susan Kazara Harper

    Hello Jason,
    Prednisone is an anti-inflammatory which is why it can be so effective in treating cancer. As cancer creates inflammation in and around a tumor, reducing it often makes your dog more comfortable. Dr. Dressler comments on page 407 in the Dog Cancer Survival Guide, so I’m drawing from that to help answer your questions.
    Just like us, when our dogs have medication that produces a change in the body, it can have a knock-on effect such as the body itself does not respond the way it normally would, because this other substance is doing a job for it, like inflammation control in this case. So we may see some side effects like blackened stools, increased appetite and thirst, etc.
    Dr. Dressler further explains “Another consideration, when using prednisone, is the potential necessity to taper off usage. After seven days of using prednisone, the body significantly decreases its own corticosteroid production. If prednisone is stopped abruptly, the body can be thrown into a kind of shock, with symptoms like nausea, vomiting, weakness, pain and fever. Tapering the use of prednisone, however, allows the adrenal glands (which produce corticosteroids) to gradually increase steroid production. This helps your dog’s hormones to stay in balance. The longer you have used prednisone, the longer the tapering period, so check with your vet or oncologist.”
    So I hope that makes sense, and goes some way to answering your questions. You asked why preds stops being effective after a time. Like many things, the body responds to a point, then balances out with the agent or medication being used. Just because preds is not a permanent or continuous treatment doesn’t mean it doesn’t have it’s place. You could consider using Apocaps, which has anti-inflammatory properties as you balance your dog’s treatment. http://www.apocaps.com Please don’t change your dog’s dosage or frequency of the preds without your vet’s advice, because you don’t want your dog’s system to be thrown into chaos as it tries to balance it all. Wishing you and your dog all the best. Get that nutrition as optimum as you can too, so your dog’s body has every available tool to stay strong!

  • Julie Birkholz

    Has anyone looked up unconventional methods of treating cancer? I have, and I found colloidal silver is being called the cure for cancer! Anybody else know of anything else that might save my sweet Boxer, Hennessey?

  • Julie Birkholz

    I have been using the colloidal silver and I saw a 100% improvement within the first 24 hours. Hennessey couldn’t walk and hadn’t been eating and within 24 hours she was up and walking…going up and down stairs and eating and even “playing” on the couch. It looked to be a miracle. The problem is…I dont know how much to give her and I dont know how to find the right brand of silver and how hard to hit her with it and when?? I know I have to get agressive with it and quick or she will still die. She has to kill it not the other way around!!. I also researched it more and I’m thinking she should be taking vitamin D and just a small amount of prednisone. The prednisone just gives you more time to kill the cancer. Any ideas or constructive help here? Thank you. Ps I forgot to mention that the tumors shrunk to one third of their original size in 24 hours and one side is almost completely gone