- Once a cancer has spread we often tell owners
one to two to three months.
And I've had patients live six to eight months,
I've had some live over a year,
I've had some live over two years,
and I've had some live three and four years.
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Today's vlog is about metastatic lung cancer
and metronomic chemotherapy.
And if you were searching for different videos
you may have come across two videos
of when we're talking about lung cancer.
So a recent video that I just did
was about primary lung cancer in dogs,
which is very uncommon in dogs.
And guys, I've actually seen a lot of appointments recently
and when in my appointment book,
which is actually a computer nowadays,
lung cancer, lung cancer, lung cancer is listed
as the reason that the pets are coming in.
But usually those patients have metastatic lung cancer
'cause, as I was saying, that is way more common
than primary lung cancer.
If you're looking for information about primary lung cancer,
we'll put the link below because, like I said,
I just did a recent video about that.
So there is information here for you.
And again, I'll put links below.
But today's video is about metastatic cancer to the lungs
and how I typically recommend treating it
with something called "metronomic chemotherapy."
So let's break it down, let's talk about
what metronomic chemotherapy is,
what are the chemotherapy drugs that we typically use,
and how we will often see responses.
So what is metronomic chemotherapy?
So, you will often hear that term
or low-dose oral chemotherapy,
which explains what it is.
Remember the metronome?
Which is what keeps the beat,
if you ever took piano lessons when you were a little kid.
I did.
So again, it's meant to be pulse,
low-dose oral chemotherapy.
So that's where the phrase "metronomic" comes from.
So it's uninterrupted administration of oral chemotherapy,
done at home by the pet owner.
It's usually associated with less toxicity,
but that can vary from pet to pet depending on
which drugs that we're using.
And classically less expense, but again,
depending on which drugs we're using
and some of the drugs that we use
in the metronomic chemotherapy protocols
have changed in the recent years.
So not always less expensive, but that is the idea.
So it's oral, so ease of administration.
You don't have to bring your pet in to a specialty clinic.
The hospital doesn't have to have all of the, you know,
chemotherapy hood and gowns and specialty-trained nurses
to administer chemotherapy, so that is helpful.
One of the key differences is
there's no breaks in treatments.
So if your pet is going in for lymphoma treatment,
it's weekly.
Or bone cancer, osteosarcoma treatment,
they're getting chemo either weekly,
every two weeks, every three weeks.
This is, there's no breaks between treatments.
So we're giving it at lower doses,
but at very frequent, regular intervals,
which is usually daily or every other day
as we'll go through.
So that is sort of the gist
of what metronomic chemotherapy is.
Now, let's talk about how it's different
than the other chemotherapy,
what I'm gonna call, "classic chemotherapy,"
which is that maximum-tolerated dose chemotherapy.
And when I think about that, you know,
most of the other chemotherapy protocols
that I talk about in most of the videos.
So again like osteosarcoma,
where your dog is going in every three weeks.
Or lymphoma, where we're giving high doses of chemo.
It doesn't have to be injectable,
it can also be oral as well,
like lomustine and things like that.
So classic chemotherapy is maximum-tolerated dose,
where we're giving the dog or cat
maximum-tolerated doses.
And again, this is that low-dose oral chemotherapy.
When we're giving maximum-tolerated dose chemotherapy,
the goal is to directly kill those cancers cells.
So you know sort of zap, kill the cancer cells.
It's a little bit more technical than that
and different chemotherapy drugs
have different mechanisms of action.
But the reason that we space the chemotherapy treatments out
either weekly, every two weeks, every three weeks,
is to give the normal tissues time to recover.
Like the gastrointestinal tract.
The white blood cells, which is usually what we call
the "dose limiting toxicity."
During that time those tumor cells repopulate,
they repair the damage that the chemotherapy has caused
and it allows those cancer cells to grow back.
But again, the goal of maximum-tolerated dose chemotherapy,
like doxorubicin, vincristine, lomustine,
and things like that is direct tumor kill.
With metronomic chemotherapy,
with that low-dose, pulse chemotherapy,
we are not directly killing the cancer cells.
We are actually targeting the blood vessels,
so the endothelial cells that line
the actual tumor blood vessels.
And the goal is often that
the tumor will stay the same size,
I'm very happy, more happy when it shrinks,
or completely goes away.
But stable disease is often a success
as long as the pet is tolerating the protocol well
and you know, they're having a good quality of life.
So it's really different than how we think about like,
lymphoma where we want those patients
to go into a complete remission.
And it's really changed the way that I've thought
about treating patients over the last 10+ years
that I've been using metronomic chemotherapy.
And we'll talk about which are the cases that are ideal.
But dogs and cats that come to see me with metastatic cancer
that has spread to the lungs, for example,
is really to me an ideal case
where I'm often using metronomic chemotherapy.
There are some other situations as well,
like soft-tissues sarcomas
that have been incompletely removed
and radiation is not an option for other reasons.
That would be another place for some of
the metronomic chemotherapy protocols.
And that's why you'll hear it called antiangiogenic,
which is a fancy doctor word
for targeting the blood vessels.
For the purpose of this video,
I think that's a good comparison
in that maximum-tolerated dose chemo
directly kills the cancer cells.
And this is targeted to cut off the blood supply.
So the way that I often describe it
is that we're trying to starve the cancer cells
by cutting off their blood supply
so they're not gonna get the nutrients, the blood sugar,
the glucose that they need to grow.
And sometimes these tumors will regress over time
and sometimes they will just stabilize
and we can maintain the patient's quality of life
and hopefully prolong how long that patient is with us
with that great quality of life.
Immunology was not my strong point in vet school at all.
But there are some cool immune responses
that some of these drugs, specifically cyclophosphamide
and then palladian cyclophosphamide together can cause.
And so they can change the T regulatory cells
and that can help the host, which is the dog or the cat
that's on these chemotherapy protocols fight the cancer.
So, there is also some cool immune responses.
Again, I'm not gonna dive too deep into that.
If you're a veterinarian or a veterinary professional,
I do talk about that in my metronomic chemotherapy lecture.
So pretty cool stuff, it's actually been studied
in the last couple years that
these protocols have been used.
Cyclophosphamide does down-regulate the T regulatory cells
and that allows the patient, the host,
to identify these cancer cells
and then hopefully destroy the cancerous cells.
And then we have seen when you use cyclophosphamide
and palladia together there's a cool, synergistic effect.
So even though I don't like the immune system,
I like when it helps our patients.
So again, hope that was a good enough explanation for you.
Let's move on to to the next thing
'cause immunology, not my favorite.
You know, I'm honest.
Okay, let's go on.
And the last major difference with metronomic chemotherapy.
In addition to not a major direct effect
on the cancer cells, like I said,
we're cutting off their blood supply,
tends not to effect the skin cells
and it also tends not to really effect
the neutrophils, the white blood cells.
So in general, we tend not to see
drastic low white blood cell counts,
the way that we do with some of the other chemotherapy,
the maximum-tolerated dose.
We still do watch the white blood cells,
sometimes with chronic usage,
and I have had some of these patients
successfully on these protocols for six months
to four-plus years.
We will have to give them a little bit of break
if we see progressive, low white blood cell counts.
Just to kind of give the bone marrow some time to recover.
But in general, we don't see a lot of side effects
to the cells that I just mentioned.
So that really summarizes how metronomic chemotherapy
is different than classic, conventional chemotherapy.
The other thing that I think is really important to know
is that it's slow acting.
What I find when you put patients on these protocols
is it's not gonna melt tumors away in the lungs
or in the abdomen, if they have metastatic disease there.
It takes time because you're, again, starving them
by cutting off the blood supply.
So often I will not do follow-up imaging,
whether it's chest x-ray or ultrasound,
for two to three months after starting the protocol
and usually space it out there.
But I will see the patients back.
In beginning, every two weeks.
But once they're on their maintenance dose,
usually every four weeks
and then eventually every six weeks.
But it does require consistent, you know, visits
with your oncologist, with your veterinarian to monitor.
So you're not just gonna go home
with three-months worth of medication,
at least under my direction, and not see me.
Because it requires close monitoring
of weight and things like that.
So that's really the palladia-based protocol.
Some of the other less intense metronomic protocols
that are, if you're just on like,
cyclophophamide and a non-steroidal.
I may be doing every six weeks.
So the point of this video is not give you
the exact protocol that I do,
it's just to let you know there are options
using metronomic chemotherapy for dogs
with metastatic disease.
Dogs that have measurable metastatic disease,
in my opinion, typically,
so nodules in the abdomen, in the lungs,
typically do not responds well to injectable chemotherapy.
Like a dog with metastatic osteosarcoma,
metastatic anal sack tumor, metastatic mammary tumor.
We wanna use those injectable chemotherapy
after primary tumors have been removed,
before the cancer has spread.
I have found more success with these protocols
in patients when their cancer has spread.
Once their cancer has spread,
we often tell owners one to two to three months,
And I've had patients live six to eight months,
I've had some live over a year,
I've had some live over two years,
and I've had some live three and four years.
So I'll be honest,
I've had some patients where the protocol has not worked.
Requires close monitoring, working with a specialist
because there are side effects.
We have to make sure they're eating,
that they're not losing weight,
and they're getting pills everyday.
So one of the things to be aware of
when you're going through this protocol
is you have to be able to pill your dog.
You have to be able to give them
diarrhea medications at times.
You have to be able to use the just-in-case medications.
So we'll put links to vlog number 93
and the video, I think it's number 70, on how to pill a dog.
Also, if your dog's not eating to start with,
I've found that these protocols tend to be harder
because we're giving medications
that could effect the appetite.
So, I'm a little less optimistic if we're having a dog
that comes in completely not eating.
We're gonna work really hard with the appetite stimulants,
like Entyce and Cerenia to get them eating
before we add some of these medications.
If the masses are causing a lot of pain
and discomfort for the patient,
that makes me worried about putting them on
this type of protocol.
So now I hope you really have an understanding
of how this chemotherapy protocol is different
than traditional chemotherapy.
And to me, it's really been a game-changer
for some of my patients with metastatic cancer.
And like I said, to have patients live six months and years,
one, two, three, even four years with metastatic cancer
has just been phenomenal.
And it's really different than how I think about
some of the cancers like lymphoma,
where we want them to get into a complete remission.
If they can have stable disease and a quality of life,
to me, you know, that is phenomenal.
So I hope that this has been helpful.
You know, to hear that your pet has metastatic cancer,
I know it's crushing, it's heartbreaking.
I hope that this is a protocol that will work for your dog
and for your cat as well.
So please, talk to your veterinarian.
Hopefully you can see a specialist.
There will be links below
with lots of different information about chemotherapy.
My chemotherapy information sheets.
But come on back for the next video,
we'll talk about the different drugs.
Thanks for watching and I look forward
to seeing you at the next video.
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