Waiting and watching — but for how long?

Have you been told to “just watch” a lump or mass on your dog by a veterinarian? I wouldn’t be surprised if you have. I too have advised that to my pet Guardians.  But how long is ok? What size is too big?  Are there actual guidelines?

In my veterinary training, I was taught that if a mass is not growing or changing in appearance, it is likely ok to do nothing and leave it – “just continue to monitor.” It’s been ten plus years since I started my medical oncology residency, and from my experience treating dogs and cats with cancer, that is not always the best advice.

While many skin masses are benign, some of these masses may also be slow-growing malignant tumors and it is better to remove them early, when it is more likely that the tumor can be completely removed with wide margins with the FIRST surgery.  I feel we are waiting too long, for too many masses.

This week I saw two cases that really depressed and frustrated me. Both were cats. I know this is a blog about dog cancer, but these cases illustrate exactly why it can be problematic to wait too long to take action – no matter what species we’re talking about.

Earlier in the week, I met Tiger, a big 16 year old cat with a recurrent tumor on his lower jaw, up front by the incisors.  It was first removed exactly a year ago. And now, it was back, and 3 cm wide. Think about how big a cat’s head is, and you’ll see that is a big tumor.

The tumor was a low grade fibrosarcoma, which, as in in dogs, is a malignant connective tissue cancer with tentacle-like projections that extend out from the visible tumor. It is these tentacles that make recurrence after surgery common if the surgery does not also remove a large amount of tissue around the tumor. We need a wide, clean “margin” of tissue. How big a margin? That’s what can be tricky to figure out by “just monitoring” it.

This week, as I visually inspected Tiger’s mouth with our surgeon at our practice, I was cautiously optimistic that surgery was an option. But just looking at a tumor doesn’t tell the whole story, so, to be sure, we did a CT scan. Unfortunately, based on the CT scan, the tumor and its tentacles extended too far back. Surgery was no longer an option, as there was no way to get wide enough margins, and (most importantly) leave a functional mouth so the kitty could eat once he recovered. The surgery last year did not get wide enough margins. We didn’t want to do another resection (surgery), because we would end up with a minimal margin, and that would lead to another recurrence.

The second kitty I saw this week was Tulip. She also had a low grade sarcoma, a peripheral nerve sheath tumor, on the right side of muzzle. Tulip’s Guardian first visited her vet five months ago, after she noticed a small mass on the side of her face. Her vet prescribed steroids and antibiotics, which did not help for long. A month later, the mass was biopsied. At that point, the mass was still small, about 1cm, and likely still a good candidate for surgical removal.  Unfortunately, I did not see the case until this week, four months after that biopsy. At this point, the mass is greater than 3 cm.

The point I’m making here is that for both of these cases, the cancers might have (essentially) been cured if they had been treated with more assertive methods early, while they were still small tumors. Tiger’s first surgery should have had much wider margins, to reduce the risk of recurrence. Tulip should have had a big surgery with wide margins on that small, 1 cm tumor, rather than taking a wait-and-see approach.

Big surgeries, early, on small tumors, can be really helpful for these sarcomas. As in dogs, the metastasis rate is low for sarcomas, and chemotherapy is typically not recommended once the surgery removes the tumor.

Instead, I had to deliver the frustrating news that we are now beyond surgery as an option, in both cases. We now have palliative radiation, palliative pain medications, and anti-inflammatories. Palliative techniques are not designed to remove the cancer, remember. They are meant to help the dog, or in this case, cat, feel better while the cancer continues to do what cancer does.

Understandably, both guardians wept when I explained the situation. My heart was heavy, as I outlined the lack of good therapeutic options to rid these cats of their once-treatable cancers.

Dr. Dressler and I write in our book that there’s always something you can do to help your dog with cancer – and there is. You can always improve quality of life, change the diet, start supplements, and, of course, take advantage of palliative and therapeutic treatments.

But please – if you’ve landed on this page because your dog (or cat, in honor of Tulip and Tiger) has a lump or a bump, and you have been told to wait and watch it … rethink that.

In my next post, I’ll give you some guidelines for how to handle a “wait and see” situation.

Best,

Dr. Sue