Too Old for Cancer Treatment?

By Joanne Lynn Intile, DVM, MS, DACVIM on Jan. 30, 2013

I’ve just completed a particularly lengthy and emotionally charged new consult with a middle aged couple, and a soft silence fills the room. Ben, their beloved 13-year-old Golden retriever, was recently diagnosed with lymphoma, and they are here to learn everything they can about his disease and what options are available for treatment.

Overall he’s feeling fairly well. However, subtle signs of disease have started to set in. He’s showing a slight but perceptible reluctance to rise from bed in the morning. Meals are still being consumed, but at a less than usual frenetic pace. Ben’s been panting more, and his owners noted two instances where he stopped abruptly during their routine two-mile evening walk, where he seemed to “need to catch his breath.”

Ben is currently lying on the floor, with his head resting patiently over his paws, awaiting a cue from either of his owners that it’s time to go home. His soft brown eyes anxiously dart between mom, dad, and me, yet he remains simultaneously calm. For a moment, likely because the silence is proverbially deafening to my ears, I consider the scene from his perspective. I think about how during his 13 years of life, Ben must have experienced his fair share of veterinarians and exam rooms, but how many times would he have spent over an hour in the same room while a doctor did so much talking? What could he possibly make of his owners’ tears or their frequent sad glances in his direction? What does he think about the strange scene before him?

I’ve always felt animals have powers of perception far greater than anything we humans are even capable of understanding, and I’m thinking about this old dog and what his life at home on a "normal" day must be like when Ben’s female owner finally breaks the silence:

"You know, if he were a 5-year-old dog we might consider treating him, but Ben’s 13 now, and we just can’t see putting him through all of that just for another year or two of time. He’s been a great dog, and we love him very much, but I think we’re just going to let things happen naturally, and when it’s time, we will let him go."

I’ve heard these words so many times before, maybe not following the exact same dialogue or tone, but I’m familiar with the phrasing. I glance downwards at Ben and smile. "I understand completely," I say. I state this plainly, but inside I’m thinking, Do I really understand choosing to not treat cancer based on age?

As a veterinary oncologist, I find it interesting how age factors into the decision for owners to pursue diagnostic tests or treatment for their pets with cancer. Owners often raise concerns about their elderly pets’ ability to withstand surgery, chemotherapy or radiation therapy. They are worried the side effects will be magnified or their pet won’t do as well overall because they are "too old."

The age of an animal doesn't particularly influence my recommendations or my opinion of a prognosis as long as the pet is systemically healthy otherwise. I would much rather treat a healthy older pet with cancer than manage a young pet with diabetes or Cushing’s disease or heart failure. Ultimately, I feel as though I can actually better predict how an older, relatively healthy animal will do with treatment than a younger animal with concurrent health issues.

As in people, cancer occurs more frequently in older animals. In fact, it is estimated that close to 50 percent of dogs living to 10 years of age or older will die from cancer. Although the average age at the time of diagnosis will vary with a particular tumor type, most cancers occur in older animals. Therefore, the majority of statistics reporting efficacy and/or side effect rates pertain most accurately to older pets. When I explain this to owners, I often see their relief in knowing they are not alone in considering treatment for their elderly companions.

There is certainly an emotional angle when considering treating geriatric pets with cancer. But what I think is most fascinating is how truly double-edged the angle really is. I’ve treated pets as "youthful" as 18 months and as "ancient" as 18 years. I’ve heard owners of young pets say, "We have to give him a chance! He’s so full of life" just as easily as they say "I can’t see him going through so many months of treatment just to have his already too short life cut even shorter."

Owners of beloved senior animals are just as likely to treat their pet because "he was such a great companion for 15 years, I need to take care of him now” as they are to not treat because “he’s too old and frail to undergo treatment, and I wouldn’t want that for myself if I were his age."

The right choice isn’t always the easiest one for owners, and so rarely would such decisions be defined in black and white. The best I can hope for is to help guide owners through the difficult times and help provide as much factual information and support as possible. Even if my instinct doesn’t agree with their conclusion, ultimately, we all have the animal’s best interests in mind.

Ben’s owners ultimately elected for palliative care for him, and I’ll admit, it was hard for me to see this. I knew that despite his advanced age he would probably do very well with treatment, and chemotherapy would likely afford him the chance of being able to enjoy another summer chasing waves at the beach and going for hikes in the park. I also knew it was not my place to pass judgment and no matter how much I wish I could, I am never able to predict the outcome for my patients, and he might not do as well as the "average dog."

What mattered most for his owners was Ben’s happiness now, not the prospect of his happiness six months from now, and that kind of logic, though slightly difficult to swallow, will always remain perfectly acceptable to me.