There are many gray areas in veterinary cancer care. Rarely am I certain that a particular treatment option or surgical strategy or chemotherapy protocol is “the absolute best” plan of action for any given patient.
My uncertainty stems not from a lack of knowledge or experience; it arises from a dearth of evidence based information to guide my decision making process.
Practicing evidence based medicine means I would conscientiously explore only the current best proof in making decisions about the care of my patients. This requires scouring research summaries and scrutinizing details contained within the reports to define the applicability of such work to the specific pet presented to me in the exam room.
As an example, evidence based tells me that the optimal treatment plan for a dog diagnosed with multicentric lymphoma is a multidrug chemotherapy protocol administered over a six month period. This combines the lowest chance of side effects with the longest anticipated survival time. Similarly, research tells me the patient’s prognosis without treatment is only 2-3 months.
These statistics are based off of data accrued during studies designed specifically to look at the outcome of many dogs diagnosed with lymphoma treated in a similar fashion, allowing conclusions to be drawn that are applicable to a wider subset of patients.
The contrary of evidence based medicine is incorporating the idea that “anything that could help, and doesn’t hurt” is a valid option for a patient’s treatment regimen. This approach relies not on factual information but on “soft findings,” such as personal experience, anecdotes, or even ambiguous best guesses.
There are several flaws with this latter approach to practicing medicine, namely the assumption of a failure to cause harm. Even when there is a lack of a positive response to therapy, this doesn’t imply an absence of a potentially negative outcome.
Owners frequently approach me with questions about untested remedies they’ve read about on the internet or that were suggested by a caring friend, relative, breeder, therapist, etc. While some of these purportedly “harmless” options are likely to be truly harmless, my concern is that the negative effects of others are potentially vastly underestimated.
For example, owners inquiring about feeding their dogs Gatorade when they are feeling ill are unlikely to harm their pets by doing so. I inform them that the small volume of fluid they are able to feed to their pet orally will not provide enough glucose (sugar) and electrolytes to reverse acute dehydration, but as long as there’s no artificial xylitol sweetener in the product, the chance of causing harm is minimal. I can’t think of a specific study proving my assumption, but I’m comfortable with my conclusion nonetheless.
The bigger problems are those seemingly innocuous therapies where evidence based information in scarce but questionable enough to raise concern for a detrimental effect. Consider the supposed benefits of antioxidant supplements for dogs and cats.
Research supports the concept that antioxidants are able to protect cells from free-radical damage — in test tubes and living animals. However, opposing research has shown that antioxidants can potentially increase risk for disease (e.g., cancer), as well as counteract the beneficial effects of treatments such as chemotherapy.
It’s surprisingly difficult for a doctor to know how to keep the evidence-based medicine in check and ensure that the optimal standard of care is offered for their patients. I may not always be able to use research based information to make decisions about my patients’ care, but I also am wary of accepting an option simply because “it couldn't hurt.”
I spend a lot of time researching options, hitting walls, and being frustrated in the lack of confirmative data to guide the decision making process. This process allows me to maintain the greatest responsibility I have to my patients: to “first, do no harm.”
Dr. Joanne Intile