Cancer Corner – What is Cancer?

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02- diagnostics

Cancer takes the lives of half of all pets over the age of ten. This terrible disease attacks the body from within. It causes pain and suffering as it gradually drags the animal relentlessly towards death. In order to deal with cancer, we must first understand it.

Cancer is the result of a good cell gone bad. A single, normal cell of any tissue of the body can transform into a seemingly unstoppable, fast-growing, spreading monster. The process starts due to mistakes that are made in the replication of the cell’s DNA (a process called transcription) as that cell divides.

These transcription mistakes, called mutations, can change the functioning of the cell. For example, cells contain genes called tumor suppressor genes that code for “programmed cell death” or apoptosis. Limiting a cell’s lifespan in this way allows for the replacement of old cells with new ones. In cancer cells tumor suppressor genes are turned off and the abnormal cells go right on living. This leads to the accumulation of “immortal” cancerous cells.

The good news is that the body has mechanisms for discovering and eliminating mutations as they happen. The bad news is that this correction mechanism does not always catch every mistake. Since the body contains trillions of cells that are all continuously reproducing, abnormal cells are created all the time. It takes somewhere between 40 and 80 mutations to create a cancer cell.

The body has one more trick up its sleeve to thwart cancer – the immune system. Free-ranging immune cells called natural killer cells, or NK cells, can quickly detect and kill cancer cells on first contact. NK cells can destroy cancer cells before they multiply and cause disease.

Any abnormal cell that makes it through all of the body’s defenses becomes cancer. That cell will reproduce uncontrollably causing a mass of defective cells. These cells often do not provide the needed function and begin to crowd out those that do function normally. Because of the out of control cellular replication, even more mutations occur resulting in more aggressiveness, or malignancy, and increased resistance to cancer treatments.

The frenetic growth and reproduction of cells requires high metabolic activity and energy consumption. As the tumor grows, the abnormal cells secrete substances which cause the formation of new blood vessels (a process called angiogenesis) to feed its voracious appetite. The increased blood supply makes it easier for cancerous cells to slip into the blood stream and travel to other parts of the body to form new tumors, or metastasize.

Cancer is named for the cell type with which it originated, no matter where tumors may spread. So, breast cancer cells that metastasize to the bones are still called breast cancer.

When a tumor is biopsied a pathologist examines the cells microscopically to determine the type and character of the cancer. Based on the degree of abnormality seen, the tumor can be graded for the level of malignancy from 1 to 4. Grade 1 tumors are mildly aggressive while grade 4 cancers are highly malignant.

The grade of the tumor is not to be confused with the stage of cancer. Staging is also done on a scale of 1 to 4 but is a reflection of the size of the tumor, its location, and whether it has metastasized. Again, stage 4 cancer is the worst of the worst.

I have now introduced some basic cancer terminology and concepts, laying the groundwork for more helpful information to come. Cancer is a scary disease but there is much that can be done naturally to prevent or treat it. This is the first of a series of “Cancer Corner” posts that will help you understand and deal with this disease.

Have you had a pet with cancer?


6 replies
  1. Linda
    Linda says:

    Yes – our first Greyhound was dx’d with Lymphosarcoma 90 days post adoption and lived another 5 months. Greyhound #4 was dx’d with Osteosarcoma on Dec 21, 2011 and went to The Bridge on Jan 2, 2012. We just couldn’t find anything that would give her any pain relief. I hate cancer.

  2. Maria
    Maria says:

    I had a Labrador Retriever who showed signs of illness too late (lack of appetite, vomiting)…and after some immediate testing by her vet, received a diagnosis of Liver and Pancreatic cancer. She only lasted about a week after that, and then became so lethargic that euthanasia was recommended.

    Since then I took in an older Shepherd Mix who came to me with some small tumors about a year an a half ago. Recently some of the tumors have grown, but some have not. A biopsy of one tumor revealed a slow growing cancer. At this time the cancers don’t seem to be affecting her quality of life, but she has developed some immobility of her hindquarters which may be due to spinal tumors or some other type of cancer, but may also be a generative neurological condition. Because of her age, her vet is not recommending any particular test or treatment; this decision has been left up to me. I am opting to keep her comfortable but not to try to “fix” her….however, this means that euthanasia will have to be considered in the near future. I am taking her for acupuncture, chiropractic adjustments and physical therapy in the meantime….and she is also taking gabapentin,
    chinese herbs for hindquarter weakness, and prednisone (but is being tapered off the prednisone.) The biggest question is: how to determine when her quality of life has dimished to the point that euthanasia would be the correct step to take! A difficult decision!

    • Dr. Doug
      Dr. Doug says:

      Yes, quality of life is difficult to determine in animals – especially when cancer or other chronic disease is involved. I always say that an animal does not have to be in pain to be suffering. Certainly when the appetite wanes it shows they are not fully enjoying life. Sometimes you have to have a talk with the pet and ask them to give you a sign as to whether they want to go on or not. Sometimes you can just see it in their eyes.

  3. Stephen Harness
    Stephen Harness says:

    Dr. Doug
    I have an eight year old Basette named Roscoe. he has Lymphoma. Heis last rounfd of conventional chemo wiped put his BM. he cbc is having a hard time recovering. Everyting is low. It has been since 11/11 and he is still fighting. He acts normal and is eating and drinking well. Last week he had some nose bleeding and high temps. I switched to Baytril and Yunnan Baiyao and they have resolved themselves. I was reading in your book and came across Rookie’s Story about Artemisinin. I have done some research and think it will be agood choice for Roscoe. His time is running out as his Lymphoma was in partial remision but is now progressing. I have questions about dosing and the best place to get the product. I am also concerened about the effects on the bodys iron supply as his RBC is at 18. I am in Dayton and could come to your clinc or would appreciate a refferal for the dayton area. Can you help?

    • Dr. Doug
      Dr. Doug says:

      Hi Stephen – I share your concern about using Artemisinin in this case. There is good evidence for melatonin, medicinal mushrooms and curcumin. It would be best to find a holistic vet in your area. Check out – they have a “find a vet” option. I do not personally know anyone in your area but there has to be someone closer than me who can help. – Best, Dr. Doug


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