When a veterinary oncologist is evaluating treatment options for a particular patient, we use information published in peer-reviewed scientific journals whenever possible.
It's important to make treatment decisions (as well as to give clients estimates of how long their dog will live) based on published studies. These studies are significantly more reliable than our experience of having (for example) one dog do incredibly well with treatment "x" or live very long with treatment "y".
There are always going to be outliers (dogs that live much longer or much shorter with a particular disease and particular treatment than average). There are many factors at play, including, some dogs have more aggressive forms of cancer than others.
Information Has A Different Value Depending On The Source
When we're choosing which type of information to rely on in veterinary oncology, (in general) prospective randomized trials are considered best, then retrospective studies, and far down on the list is anecdotal evidence.
A prospective study involves taking two groups of dogs with the same disease; one group receives a treatment you're testing and another either doesn't receive any treatment or receives a different treatment. It's always best if the patients are blinded; this means that the investigators (the people running the study and the dog owners for that matter) don't know which dogs are receiving which treatments. This type of study produces the most reliable results. These studies are expensive and time consuming; because of this they are conducted less frequently than they should be.
A retrospective study is (unfortunately) common in veterinary medicine. It involves trying to answer a question using information from the past. If I was trying to figure out how long dogs with osteosarcoma live after surgery and carboplatin chemotherapy (just as an example, because we already know this), I would collect as many patient records as possible (likely multiple veterinary teaching hospitals would have to share records) to mine the data. Since we are going back in time, there will inevitably be missing information. Since the doctors (and dog owners) didn't know these patients were going to be in a study, the information isn't going to be as accurate as we would like. Maybe tests weren't done on time (x-rays or ultrasound). Maybe many of the dogs never had an abdominal ultrasound initially or a necropsy and we don't actually know why that patient died. Maybe visits were missed or we don't know the exact date that many patients passed. We do our best with retrospective studies, but the available information usually leaves something to be desired.
When we get stuck in daily practice or when have tried all recommended treatments based on published literature, we typically turn to the oncology listserv. This is a way for all of the board certified oncologists throughout the world to communicate with each other. If someone is looking for treatment options that aren't published, but that might be helpful, or help with a difficult case, they turn here.
Access To Veterinary Oncology Studies
So where do we go to find all of the published peer-reviewed veterinary oncology studies? We typically go to PubMed.
PubMed is a compilation of the latest human and veterinary literature. Anyone can access the website and perform a search. Just like in Google, a list of possible "matches" to your query will populate. When you click on each link, the paper's abstract (or summary) will come up. If you want access the full article, you could pay a one-time fee (usually about $30), unless you have a subscription to that journal; some articles are free, but not the majority.
If you work at or live near a university, you may have free journal access. Many universities will grant online journal access automatically when you log-in to their wifi.
How To Use PubMed
Let's go over how a quick search would work. Go to the PubMed homepage: https://www.ncbi.nlm.nih.gov/pubmed/
Search for an answer. Be certain to use words as they would in a journal or study. Use the word "canine" instead of "dog". If you are trying to find out how long a dog might live with a certain treatment, you'll want to write "prognosis". Sometimes it takes a bit of trial an error to find what you're looking for, and sometimes it just hasn't been studied yet.
Then scroll down for the search results. You'll find the "best matches" right below the search bar.
The remaining matches are below that. Many of the results are likely going to involve molecular tests that are not available in day-to-day practice; they are being tested to determine if it's worth making them available or looking at them further in the future.
When you click on the link, the abstract (below) will populate, which is a summary of the paper. Check the upper right hand corner; sometimes there are icons there which allow you to access the entire article for free.
Feel free to try out PubMed either for your dog's or your own health issues. The more you try it, the easier it will be and the less overwhelming it will be.
I think it can be especially helpful in cases where you have a doctor (vet) that has told you that there isn't a treatment for a certain type of cancer; now you can do your own quick research.
Or, if someone online is touting the amazing life saving benefits of a certain supplement. Go ahead, see if there's any science to back up that claim.
Enjoy learning with PubMed!
Have questions about this article? Reach out!
Dr. Lori Cesario
Board Certified Veterinary Oncologist
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