Page 20 - Withrow and MacEwen's Small Animal Clinical Oncology, 6th Edition

Introduction

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Why Worry About Cancer in Companion a demand for similar care for their animals. Increased longevity
Animals? of companion animals, the increasing prevalence of cancer, and
enhanced caregiver expectations require that the veterinary profes-
Why should health care professionals in general, and veterinar- sion be prepared to meet these challenges and opportunities.
ians in particular, be concerned about cancer in companion ani- Because cancer is a common and serious disease for human
mals? Several compelling motivations and opportunities exist for beings, many owners have had or will have a personal experience
the profession as a whole to continue, and indeed expand on, the with cancer in themselves, a family member, or a close friend. Real-
significant role we play in the understanding, prevention, and izing the importance of companion animals to our clients, it must
elimination or control of this devastating constellation of disease be appreciated that they value the veterinarian’s ability to care as
processes. Although, as veterinarians, our prime directive is to much as his or her ability to cure. Keeping this in mind, the vet-
ensure the health and quality of life of the companions under our erinarian should approach the patient with cancer in a positive,
care, the needs of our client caregivers during the difficult times compassionate, and knowledgeable manner. Frequently, the vet-
of cancer diagnosis, treatment, and outcome (whether optimistic erinary profession has taken a pessimistic approach to cancer. This
or pessimistic) should be of nearly equal importance. Because can- attitude is not only a detriment to the companion but may also
cer is a disease that knows no species boundaries, our profession negatively reinforce unfounded fears in the client about the disease
has considerable opportunity to play a key role in comparative in humans. We owe it to our companion animal patients and their
oncologic investigations, with the ultimate goal of effecting cure caregivers to be well informed and up-to-date on current treatment
or, in the absence of cure, transforming cancer from an acute life- methods to prevent imparting unnecessary feelings of hopelessness.
threatening disorder into a manageable chronic condition (much Perhaps the greatest opportunity presented to our profession,
like diabetes) in all species; essentially the basis of the “One Medi- beyond the immediate care of our patients’ and clients’ needs, is
cine” approach to disease investigation. the more global role (and responsibility) we play in advancing the
The sheer numbers involved highlight the magnitude of the understanding of cancer biology, prevention, and treatment from
problem of cancer in companion species. The prevalence of cancer a comparative oncology standpoint. Companion animals with
in companion animals continues to rise for a variety of reasons, spontaneously developing cancer provide an excellent opportu-
not the least of which is related to animals living longer thanks nity to investigate many aspects of cancer, from etiology to treat-
to the increasing care offered by caregivers and the advanced vet- ment. Indeed, the role of comparative oncology was highlighted
erinary care they seek. There are more than 165 million dogs and at a National Cancer Policy Forum hosted by the National Acad-
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cats at risk in the United States, and cancer remains a major cause emy of Sciences in 2015 entitled “The Role of Clinical Studies
of companion animal morbidity and mortality (see Chapter 4), for Pets with Naturally Occurring Tumors in Translational Can-
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with at least 4 million dogs and 4 million cats developing cancer cer Research”. One of the most exciting achievements in veteri-
each year. 2–6 Although the true incidence or prevalence of com- nary oncology over the past 15 years has been the development
panion animal cancer is currently not known, based on necropsy of successful and collaborative consortia groups that are purposed
surveys describing proportional mortality, 45% of dogs that live to perform multicenter clinical trials and prospective tumor bio-
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to 10 years or older die of cancer. With no age adjustment, 23% specimen repository collections. These include the Comparative
of patients presenting for necropsy died of cancer. In a 1998 Oncology Trials Consortium (COTC; https://ccrod.cancer.gov/
Morris Animal Foundation (MAF) Animal Health Survey, more confluence/display/CCRCOPWeb/Comparative+Oncology+
than 2000 respondents stated that cancer was the leading cause Trials+Consortium) and the Canine Comparative Oncology and
of disease-related death in both dogs (47%) and cats (32%). Genomics Consortium (CCOGC, www.ccogc.net) centrally
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Another MAF survey performed in 2005 revealed that cancer was managed by the National Institutes of Health (NIH)-National
by far the largest health concern among dog owners (41%), with Cancer Institute’s Comparative Oncology Program (NCI-COP)
heart disease the number two concern at 7%. Regardless of the and discussed in Chapter 18. Their infrastructure allows larger
exact numbers, both the reality and the perception support the scale clinical trials and provides the voice for collective advo-
clients’ point of view that cancer remains the number one concern cacy in veterinary and comparative oncology. Their success is an
in their minds with respect to the health and quality of life of example of the growing importance of the study of comparative
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their companions—the so called “emperor of all maladies”. Fur- tumor biology and clinical investigations. Access to novel drugs
thermore, breakthroughs in the management of human cancers and biologics will speed clinical applications for both veterinary
have received a great deal of exposure through the Internet, news species and humans. Ultimately, including companion animal
media, and popular press, which further serves to educate com- populations in clinical trials assessing novel drugs and biologics
panion caregivers and raise the level of expectations as to thera- of interest to the National Cancer Institute, the U.S. Food and
peutic possibilities and promote an atmosphere of optimism and Drug Administration, and the pharmaceutical industry will both

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