As an oncologist, one of the most important questions, one that almost every client asks me, is, “Has my pet’s cancer spread?” If a tumor has spread to lymph nodes or lungs, it does not necessarily mean the end for your pet. Some tumors can be treated successfully, even after they spread. However, it will often change how we approach treatment for these pets.
One of the best ways to tell if your pet’s cancer has spread to other areas is for your veterinarian to get a good history and perform a thorough physical exam. However, we often have to rely on other tools to see if the cancer has spread internally. In recent years imaging tools such as CT and MRI have become extremely useful in trying to determine whether tumors have spread.
We often use radiographs (x-rays) of the lungs to see if there are metastases. However, this will only find tumors in the lung when they get to about 1 centimeter wide, about the size of a raisin. At this point that nodule has about 1 billion cancer cells. However, CT scans of the chest have been shown to detect nodules as small as 2 to 3 milimeters. This could easily change the course of treatment for a patient if these nodules are found earlier.
Imaging is also very important in determining exactly how big and where your pet’s tumor is. Sometimes when we see a mass or swelling on our pet we are only seeing the tip of the iceberg. Imaging tests such as CT scans can help figure out exactly where the tumor is and help direct the surgeon or the oncologist, so they know exactly what they need to treat.
It is great to be able to have tools like these to make sure that we can help owners of pets with cancer to decide on the best possible treatment options for their pet.