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.