Mutt-tastesis; a Discussion of Comparative Oncology

Dogs are much more than man’s best friend, as surprisingly enough, they can provide significant insight into the field of oncology. Many species, both wild and domesticated, have documented cases of developing cancer (Abu-Helil and van der Weyden, 2019). There has been significantly more research conducted on cancer incidence in house pets, as 80-90% of pet owners order autopsies following the sudden departure of their canine companions (Abu-Helil and van der Weyden, 2019). Cancer is a major health burden in dogs, as 30% of dogs, across all breeds, die from cancer (Nolan et al., 2019). The unfortunate prominence of cancer in dogs presents a unique research opportunity into the mutation and metastasis of a multitude of different types of cancers; thereby establishing the basis of comparative oncology.

One of the reasons why cancer research in house pets is so relevant to modern medicine is that their living conditions basically mirror our own; we share the same spaces, drink the same water, are exposed to the same airborne pollutants, and likely have a great deal of overlap in our diets (Nolan et al., 2019). Additionally, the diagnostic imaging and treatments for domestic animals are nearly identical to those associated with human cancer (Nolan et al., 2019). Mice have also been used to study cancer, but their life span and size vastly differ from our own, making juxtaposed analysis difficult (Abu-Helil and van der Weyden, 2019). The advantage of studying spontaneous cancers in non-laboratory animals is the fact that both the cancers and the animals themselves are found to be genetically-heterogenous, just like humans (Abu-Helil and van der Weyden, 2019).

Melanomas, lymphomas, breast cancer, and some sub types of skin cancer are all examples of cancers affecting other species as well (Nolan et al., 2019). In the case of melanomas in particular, humans and dogs share striking similarities, even at the cellular level (Figure 1). For instance, canine melanomas present several interesting areas of research. In humans, we have correlated melanoma incidence with fair skin types and increased UV exposure, but this trend is not supported when it comes to melanoma occurrence in dogs (Andre and Prouteau, 2019). With dogs, while most breeds are covered in fur, light skin pigment is not thought as a contributing factor to melanoma incidence and conversely, darker-furred dogs have higher rates of melanoma incidence (Andre and Prouteau, 2019). What is most fascinating, is possibly that certain breeds are shown to have a higher predisposition to melanomas (Andre and Prouteau, 2019).

Our pet companions are a great model for the development of spontaneous cancers that often bridge the species division, providing a unique opportunity to deliver and monitor the effectiveness of treatments, as well as identify new genes and loci that play a role in the incidence of cancer, guiding the development of new diagnostic and treatment approaches to achieve better prognosis in both humans and our pets. Comparative oncology therefore suggests a collaboration between human oncologists and veterinary oncologists, united against a common enemy.

Works Cited

Abu-Helil, B. and van der Weyden, L., 2019. Metastasis in the wild: investigating metastasis in non-laboratory animals. Clinical & Experimental Metastasis, 36(1), pp.15–28.

Andre, C. and Prouteau, A., 2019. Canine Melanomas as Models for Human Melanomas: Clinical, Histological, and Genetic Comparison, 10(7), pp.501-554

Nolan, M., Kent, M., and Boss, MK., 2019. Emerging Translational Opportunities in Comparative Oncology With Companion Canine Cancers: Radiation Oncology. [online] Available at: <https://www.frontiersin.org/articles/10.3389/fonc.2019.01291/full> [Accessed 14 Jan. 2020].