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Cancer is a reality that many dogs and owners have to deal with. Although cancer is often associated with old age, results from recent studies have shown that the median age of cancer diagnosis in dogs is around 8.8 years, while many dogs still possess cancer. energy and mischievousness from their puppy years.1
As veterinarians know very well, cancer does not discriminate. Veterinarians play a central role in this journey. The importance of their work extends beyond the clinical environment, as they have the power to educate, empower, and help pet owners make informed decisions about their pet’s health.
With this responsibility in mind, navigating the vast landscape of canine cancer screening tests can seem overwhelming. Yet, by digging deeper into these tests, their evaluation, and their far-reaching impact, veterinarians can improve the quality of their care. Mastering this knowledge allows veterinary professionals to effectively relay these options to pet owners, thereby strengthening the vet-client bond and preserving the parent’s bond with their dog.
Think Buddy, a 9-year-old chocolate Labrador retriever who went to the vet clinic for a routine checkup. He showed no outward signs of illness and his vibrant energy belied his age. However, due to his race and age, which put him at a statistically higher risk of developing cancer, his vet suggested a cancer screening test in addition to routine blood work.2
Navigating the conversation about cancer, a topic often fraught with panic and anxiety, was a challenge for Buddy’s vet. Cancer can elicit strong reactions from pet owners and veterinarians. However, the power to detect, manage and potentially alter disease course begins with screening. And to wield that power effectively, an open dialogue about testing is necessary, however uncomfortable.
When the results came back, they pointed to suspicion of cancer, and confirmatory diagnoses revealed early-stage lymphoma. The news was a bitter pill to swallow, but the vet was not without hope. Early detection paved the way for quick treatment decisions, and Buddy quickly followed a treatment plan designed to provide the best possible outcome.
It’s important to recognize the reality that not all stories have a happy ending like Buddy’s. But it is precisely in this uncertainty that the importance of early detection tests appears. Although pet owners are increasingly receptive to preventative care for common illnesses,2 the specter of cancer always casts an ominous shadow. The significance of a potential cancer diagnosis can often deter pet owners from seeking these tests. However, veterinary professionals must bear in mind that the purpose of early detection tests is not to confirm fears, but rather to give everyone knowledge.
Early detection is a two-pronged concept. On the one hand, this means identifying the cancer before any clinical signs appear. On the other hand, it involves catching the disease in its early stages. Although we are still gathering strong data on the prognosis of dogs with presymptomatically detected cancer, compelling evidence shows that early detection of cancer improves the outlook. For example, results from a retrospective study of dogs with stage I and stage II splenic hemangiosarcoma reveal a significant difference in prognosis: dogs with stage I disease had a median time to progression almost two times longer than those with stage II disease (338 versus 151 days, respectively).3
Let us now draw some parallels with human medicine. Recent data suggest that early stage detection and diagnosis in humans paves the way for faster surgeries and resections compared to late stage diagnoses.4
Why is this important? Simply put, early intervention reduces the risk of death from cancer. This shows us the invaluable role that early detection plays – a goal within reach through regular cancer screening that benefits both ends of the leash.
If you’ve ever felt like searching for a tennis ball in a field full of Frisbees while trying to figure out the technical terms of canine cancer screening, you’re not alone. Let’s make sense of an oft-used term: liquid biopsy.
A liquid biopsy is a non-invasive test that detects cancerous mutations or changes using a sample of bodily fluid, usually blood. It’s like a newer and better model than traditional invasive tissue biopsy. It’s easier on the wallet, more flexible and readily available. But how do you know if a liquid biopsy is accurate? Enter 2 critical factors: sensitivity and specificity. This dynamic duo is the compass for determining test reliability.
Sensitivity and specificity: the pillars of precision
Imagine looking for red apples in a large basket full of various fruits. Sensitivity is akin to the ability to find all the red apples. If your search method is very sensitive, you will find all the red apples without missing any, which means fewer false negatives. However, if your method is not sensitive enough, apples may be overlooked and mistaken for other fruits.
Specificity, on the other hand, is akin to your ability to correctly exclude all fruits that are not red apples. A very specific method will correctly identify all non-apples, resulting in fewer false positives, meaning you are less likely to mistakenly identify a different fruit as a red apple.
Understanding the balance between sensitivity (not missing any red apples) and specificity (not confusing other fruits with red apples) is crucial to interpreting the performance of a test. It is equally important that veterinarians effectively communicate this balance to pet owners when discussing the benefits, limitations, and possible results of cancer screening tests.
Canine cancer test results can be thought of as pieces of a puzzle because they are valuable and informative, but they don’t tell the whole story. Instead of making a definitive diagnosis, these tests are best combined with physical exams and other blood tests. They lay the groundwork for veterinarians to establish a pet health baseline, a benchmark that becomes invaluable in detecting irregularities.
Such nuanced understanding forms the backbone of conversations with
pet owners about cancer screening results. These dialogues, although delicate, are an opportunity for veterinarians, as trusted advisors, to demonstrate their empathy. Emphasizing that results are benchmarks rather than final destinations can be difficult, but opens the possibility of building trust through honest and transparent communication.
This role of veterinarians becomes even more crucial when considering the emotional weight these discussions can have on all parties involved. It is the responsibility of each member of the veterinary team to ensure a favorable work environment, promoting respect for interpersonal relationships, effective stress management and open communication.
While the team presents a united front, their primary focus remains the best interests of the animals in their care. Guiding pet owners, managing expectations and building resilience is the cornerstone of their shared commitment: a future where every dog ​​has a fighting chance against cancer.
Devin DeVoue is a seasoned marketing executive at Volition Veterinary and a dedicated board member at Chestnut Hill College. With over a decade of experience working with veterinarians, he brings a unique blend of expertise and passion to his role. Outside of work, he enjoys spending quality time with his rescue pit bull, Ava.
The references
- Rafalko JM, Kruglyak KM, McCleary-Wheeler AL et al. Age at cancer diagnosis by breed, weight, sex and type of cancer in a cohort of over 3,000 dogs: determining the optimal age to initiate cancer screening in canine patients. PLOS ONE. 2023;18(2):e0280795-e0280795. do i10.1371/journal.pone.0280795
- Treggiari E, Borrego JF, Gramer I et al. Retrospective comparison of first-line adjuvant anthracycline versus metronomic chemotherapy protocols in the treatment of stage I and II canine splenic hemangiosarcoma. Vet Comp Oncol. 2020;18(1):43-51. do i:10.1111/vco.12548
- New data from Banfield Pet Hospital reinforces the power of preventive veterinary care. Press release. Banfield Pet Hospital. October 14, 2021. Accessed May 27, 2023. www.banfield.com/en/about-banfield/newsroom/press-releases/2021/new-data-from-banfield-pet-hospital-reinforces-the-power-of – preventive-veterinary-care
- Raoof S, Clarke CA, Hubbell E, Chang ET, Cusack J. Surgical resection as a predictor of cancer-specific survival by stage at diagnosis and by cancer type, United States, 2006-2015. Cancer epidemiole. 2023;84:102357. do I:10.1016/j.canep.2023.102357