There are two considerations I have before making treatment recommendations for patients diagnosed with what are known as “solid tumors” (i.e., those that develop in one tissue and can spread throughout the body).
The first is predicting how the tumor will behave in a localized sense, meaning directly at the same anatomical site where it began growing.
The second is anticipating the risk of metastasis (spread) to distant site(s) in the body.
This leaves me with several potential algorithms of outcome for any particular cancer:
1. A tumor that grows locally but has little potential for recurrence after removal and little chance for spread.
2. A tumor that grows locally and has a significant potential for recurrence after removal and little chance for spread.
3. A tumor that grows locally but has little potential for recurrence after removal and significant chance for spread
4. A tumor that grows locally and has significant potential for recurrence after removal and significant chance for spread.
Of each of those scenarios, it’s most challenging for owners to comprehend the recommendations made for treating tumors where there’s a high likelihood of regrowth after surgery and spread to distant sites in the body (#4).
For those cases, I try to clarify the muddy waters by emphasizing why it’s imperative to focus on both the “smaller” and the “bigger” pictures.
Addressing the smaller picture means we are dealing with the best way to control the local tumor itself. Examples of localized tumors include a skin growth, a bone tumor, or an intestinal mass.
The bigger picture entails assessing the patient for the presence of metastasis, either in the setting of “gross” disease (measurable tumors in other sites of the body), or “microscopic” disease (non-measurable tumor cells that we are nearly certain escaped from the primary tumor, but have not yet grown into anything we are able to visualize).
For tumors that require smaller and bigger picture treatments, ideally we obtain adequate local control over the primary tumor via aggressive surgery and/or radiation therapy and also administer systemic treatment (e.g., chemotherapy and/or immunotherapy) to address the metastatic disease.
The concept of combining localized and systemic treatments can be difficult for owners, owing to lack of access (radiation therapy is available only in select geographical areas), their own personal preference (not wanting to “put their pet through too much”), and most often finances (such combinations of treatments can easily run over $10,000 per pet).
When such limitations present themselves, I’m obligated to offer a different plan of action with the hope that I can find the “happy medium” that fits the needs of the owner and still affords their pet the best chance for long term survival.
Another complicating factor of the smaller/bigger picture tumor is that it’s difficult to predict how pets with tumors with both aggressive localized and metastatic potential might ultimately succumb to their disease.
People readily understand that cancer is a potentially fatal disease. However, the typical assumption is the end stages of disease will entail obvious outward signs of illness, weakness, loss of appetite, pain, etc. Though often true for tumors that spread around the body, however localized tumors can be equally problematic, and ultimately life limiting for that animal.
A cat with an oral mass will still be bright and happy and purr and sleep in its favorite spot in the house. But it will eventually stop attempting to eat because it becomes too painful to ingest food.
A dog with a tumor in its urinary bladder will continue to wag its tail, ask to go for walks, eat its meals, and lie on the couch with its owners, but it will constantly painfully strain to urinate, have accidents in the home, and produce a bloody urine stream.
Whether keeping my sight short on issues related to the smaller picture of local disease or focusing on the bigger picture potential for distant spread, I have to keep an open mind regarding the health of my patients, and treat them as a whole rather than a series of specific symptoms.
This is true for making recommendations for the ideal way to treat their cancer from the time of diagnosis to the delicate treatment approach to their final days or weeks of life, and for all the days of their care in between.
As always, communication is the most important aspect of managing these patients in order to ensure everyone’s expectations are met. That way I can guarantee the short and long-term pictures remain as clear as possible during the journey we embark upon when treating a pet with cancer.
Dr. Joanne Intile
Image: Ivonne Wierink / Shutterstock