The Dog Cancer Survival Guide (20 page)

In Vivo
: Literally translated as “in life,” this often refers to a treatment that is tested in a living body. If a tested cancer treatment works
in vivo,
it is more promising.

Inflammation
: This refers to a protective response of body tissues to injury or irritation. There are many factors involved in creating inflammation; the main characteristics are pain, warmth, swelling and redness. But if inflammation becomes chronic or excessive, it can become problematic; arthritis, asthma, allergies, and other diseases are associated with inflammation. Inflammation is also implicated in cancer promotion, which is why managing it is an important part of Full Spectrum cancer care.

Initiation
: According to the genetic mutation theory of cancer, initiation is the first stage of cancer development. In this stage, a cell’s
DNA
is damaged beyond repair, often including the DNA involved with
apoptosis
(natural cell death).

Local Invasion
: When cancer tumors spread to the healthy tissues immediately surrounding the tumor, we call it local invasion. Local invasion is therefore different from
metastasis
, which is cancer that has spread to distant locations in the body.

Lymphatic System
: The lymphatic system is a type of circulatory system that runs throughout the body. A vast network of tubes that are connected to body organs and tissues, the lymphatics carry a clear fluid called lymph. The lymph carries white blood cells, making it a crucial component of the
immune system
. A map of the lymphatics resembles a busy subway system, with the tubes, the tracks, and the lymph glands or nodes (filters that catch viruses, bacteria, and other invaders so that white blood cells can destroy and dispose of them), the stations. Because the lymphatics reach nearly every organ, cancers that occur in the lymph cells – lymphomas – are by definition
systemic cancers
. Other types of cancer may also use the lymph system as a means to
metastasize
. For this reason, lymph nodes are often aspirated or biopsied during cancer diagnosis, to check for spread.

Malignant
: A tumor, which is dangerous and growing uncontrollably, is called malignant. This word is a synonym for cancerous. Another word used to refer to a malignant tumor or a cancer is malignancy.

Margin
: This refers to the area of normal-seeming tissue surrounding a tumor that has been removed during a biopsy or other surgery. This area may contain microscopic cancer cells, so, a pathologist examines it during a
comprehensive margin evaluation
. If the margins are narrow (one or two millimeters), malignant tumors are more likely to recur. For this reason,
wide margins
of two to three centimeters are preferred.

Maximum Tolerated Dose
: In conventional treatment, this phrase is used to describe the highest dose of
chemotherapy
that can be given without the patient’s having unacceptable, severe
side effects
or dying from the treatment. The higher the chemotherapy dose is the more cancer cells are killed; therefore, the aim of chemotherapy is to give as high a dose as possible with the fewest (manageable) side effects. There is a great deal of information on chemotherapy side effects and how to manage them in
Chapter 11
.

Measurable Disease
: This refers to a tumor that can be measured for size with calipers or imaging techniques; also called macroscopic disease. You can see these tumors with the eye, unlike microscopic tumors, which are too small to see without magnification.

Median Survival Time
: The time, from either diagnosis or treatment, at which no more than half of the patients with a given cancer are expected to be alive. For example, if a group of dogs all have lymphoma and all start the conventional chemotherapy protocol that Dr. Ettinger recommends, she would expect half of those dogs to be alive after fourteen months, and half of them to have passed. It is useful for the guardian to know this number, but it is also important to remember that it is only a guide. It does not apply directly to any particular dog. Some vets use the term “median overall survival” or the term “median survival.”

Metastasis
: When cancer spreads to distant sites in the body by slipping tumor cells into the circulatory system (the blood or the lymph), we call it metastasis.

Metronomic Chemotherapy
: A relatively new approach to chemotherapy, which doesn’t attempt to kill cancer cells directly (like
maximum tolerated dose
does), but instead attempts to cut them off from their supply of oxygen and nutrition. Low doses of drugs are given on a regular basis to target the lining of the blood vessels feeding the tumor. This can stop the tumor from building new blood vessels (
angiogenesis
). Some tumors may stop growing, while others may shrink. The low doses mean that the normal tissues of the body are rarely affected, and side effects greatly reduced. See
page 137
for more details.

Micrometastasis
: This is the spread of very small numbers of cancer cells to distant sites through the circulatory system. Micrometastasis is usually undetectable (or undetectable with our current diagnostic tools), due to the small numbers of cells that have spread when the diagnostic tool is applied

MRI
: MRI stands for magnetic resonance imaging, which is an imaging technique that uses powerful magnets to generate electromagnetic fields. These fields pick up information in the body and broadcast it to a radio antenna. The resulting image is a series of “slices” much like what is seen in a CT scan, with much more detail. MRI is an advanced imaging device and is typically only available in very large veterinary hospitals or specialty hospitals. Dogs usually require general anesthesia while the MRI is conducted.

Natural
: This indicates not synthetic: originating from a source found in nature. While many guardians have a bias towards using natural substances in cancer treatments, it is important to remember that not all natural substances are safe. There are naturally occurring deadly poisons in mushrooms, a form of cyanide in peach pits, and toxins in frogs in the Amazon that can cause paralysis. All natural substances are not necessarily effective, either. While there are many natural substances recommended for
Full Spectrum
care,
Appendix B
lists natural remedies that are less effective than their proponents often claim.

Nutraceutical
: Originally, nutraceutical was defined as any substance from dietary ingredients that could yield health benefits. Today, the word’s meaning has been expanded to include purified agents from many sources, including botanical (plant) sources. For example, a nutraceutical agent in Apocaps, luteolin, comes from peanut hulls. Most people who eat peanuts (dietary) do not eat their hulls (botanical). Another familiar nutraceutical is glucosamine chondroitin, a popular joint supplement. A nutraceutical tends to have higher concentrations of the agent than are commonly found in nature, and therefore more potent effect. Generally, the intensity of a nutraceutical’s effect on the body is somewhere between that of a supplement and a pharmaceutical. While pharmaceuticals – usually purely synthetic agents – are assumed to be fast acting, nutraceuticals can take a little longer to build up in the system and produce their full effect (usually a week or more).

Non-resectable
: This word refers to a tumor that cannot be removed with surgery. Non-resectable tumors, also called inoperable tumors, must be treated with other methods.

Normal Life Expectancy
: The general expectation for a given dog’s natural lifespan, this number is based on the breed and/or weight of the dog. In general, small dogs live longer than big dogs. Taking exceptions into account, knowing your dog’s
general
life expectancy can be helpful when making treatment plans.

Oncologist
: A veterinary oncologist is a veterinarian who has completed additional specialized training in conventional oncology. A general medicine and surgery internship is required, plus a residency in their chosen focus: chemotherapy (oncologist), surgery (surgical oncologist), or radiation (radiation oncologist). Once the internship and residency are complete – which can take three to five years – the oncologist must pass special exams to become certified by their college. For example, Dr. Ettinger is Board Certified by the American College of Veterinary Internal Medicine, with a subspecialty in oncology. Oncologists focus exclusively on cancer and become very skilled at using their tool of choice. According to the Bureau of Labor Statistics, in 2008 (the last year for which data is available) there were 59,700 veterinarians in the United States. As of this writing only about two hundred of those are board certified veterinary oncologists, most of them located in large urban centers.

Oncology
: Oncology literally means “the study of cancer.” This word is commonly used to describe the conventional veterinary approach to cancer care. Three primary treatment tools are used: surgery, chemotherapy and radiation. Other possible tools include some nutritional support and more recently, genetic therapy and immunotherapy. While oncology has some success with certain kinds of cancer at certain stages, outcomes are generally not as desirable as those associated with other medical conditions (for example, treating infections).

Pain
: During cancer and/or cancer treatments, pain can have several sources, including tumors pressing on organs or tissues such as bones and nerves, tissues stretched beyond their normal lengths, blocking of circulation, inflammation resulting from cancers, and surgical incision healing. A dog in pain may isolate himself, seem apathetic, or limit his movement. Some dogs may vocalize. Some treatments may cause temporary pain (such as surgery) – but, in the end, if the treatment prevents more pain than it causes, there can be higher overall life quality. Unmanaged or chronic pain, however, can cause a decrease in life quality. Pain management is part of a Full Spectrum cancer care plan, and is addressed in
Chapter 17
.

Palliative
: A palliative treatment is one that alleviates symptoms associated with the illness. It improves the quality of life, but does not extend survival time or cure the illness. A familiar example is the use of painkillers, which do not treat the cancer, but do help to reduce discomfort. Another example is palliative radiation therapy, which aims at slowing tumor growth and, more importantly, decreasing pain and improving quality of life. While most oncologists do not think of conventional treatments as palliative treatments, I do, because they usually do not provide a “cure” for systemic cancer at this time. This is why I have come to think of cancer as a chronic disease to be managed, rather than a disease that can be cured. We’ll talk a little more about this later.

Partial Remission:
This is said to occur when some of the measurable signs of cancer are gone. Most oncologists call a remission partial when they see between 50% and 100%
response
to treatment.

Pathologist
: A specialist in pathology (the study of disease), pathologists examine and evaluate cells, tissues or organs in order to come to a diagnosis. They usually work in pathology labs or very large hospitals. When your vet or oncologist submits a
biopsy
, for example, a pathologist is the one who actually examines the tissue under a microscope.

Primary Health advocate
: In
Full Spectrum
cancer care, I urge every guardian to take this leadership role (discussed on
page 254
). I do this because we do not yet have a cure for systemic cancer, and vets and oncologists are usually unable to provide a treatment recommendation that will yield a cure. With this sad fact in mind, it’s logical that the guardian needs to be active in decision-making. After all, only the guardian can take into account what may be gained with treatment and balance it against life quality concerns, age of the dog, personal values, available time, and financial resources. As primary health advocates, guardians have the eventual final responsibility for all health care decisions. Reading this book will prepare you to become your dog’s primary health advocate and conduct your own
Treatment Plan analysis.

Prognosis
: The overall expected outcome of the cancer case under consideration, prognosis can include the median survival time, a description of how life functions will be affected, and whether the disease will cause a lingering decline, a sudden crisis, or neither of these. A prognosis is usually classified somewhere along the continuum of “excellent” to “poor.” It is useful to note that “prognosis” means “prediction.” While it is very helpful to know your dog’s prognosis, it is neither a promise nor a sentence; it is an educated guess. The more information your vet or oncologist has, the more accurate the prognosis tends to be.

Progression
: The final stage in cancer development (after
promotion
), when cancer cells have multiplied to become full-fledged cancers and can now divide uncontrollably, invade normal tissues, and may metastasize.

Promotion
: This is the second stage in cancer development (after
initiation
and before
progression
). If the
immune system
is unable to dispose of damaged cells, and if
apoptosis
genes fail to induce cell suicide, damaged cells persist. They also begin to grow and replicate, forming tumors or cancers.

Pyschoimmunoneurology
: This field of study examines the complex connections between mental function (stress, depression, anger, happiness) and body function and disease. It brings together the fields of endocrinology, psychology, immunology and physiology to elucidate how the body interacts with itself and its environment. In short, this is the scientific study of a facet of the mind-body connection. Full Spectrum cancer care incorporates pyschoimmunoneurology into treatment plans because it has been documented that supporting the mind-body connection helps to battle cancer in humans.