More than a best friend pet dogs can help us cure cancer
Transcriber: Gabriela Moreno Polacov
Reviewer: David DeRuwe
Raise your hands if you own a dog.
Get them up.
One third of those dogs will get cancer.
But they can help us find a cure.
We all know a friend,
a family member or a colleague
who has battled the disease,
but it might surprise you
to learn that dogs get cancer too.
In fact, one in three pet dogs get cancer.
And this is what happened
to my patient Griffin.
But imagine being forced into the position
which providing that cancer treatment
for your best mate,
a boisterous, adorable young Rottweiler,
would risk the safety of your baby girl.
That’s precisely the situation
that Griffin’s owner, Adam, faced
when four-year-old Griffin
unexpectedly developed
an aggressive cancer invading his skin.
Adam swung into action,
and Griffin had surgery immediately,
removing a large area
of skin from his chest.
But by the time he returned
to the vet to have his stitches out,
the cancer had already spread.
Further surgery wasn’t an option.
Griffin was given just weeks
to live without treatment
and only three months
to live with chemotherapy.
But chemotherapy uses toxic chemicals
that would make touching
the dog or his waste poisonous
to Adam’s baby girl.
She wouldn’t be able to play
with the dog or go out in the yard.
Griffin’s treatment
would be a danger to the family.
So Adam made the heartbreaking decision
not to get Griffin the chemo.
So what’s gone wrong in Griffin’s body?
We know that cancer
causes tumors in the body.
Smoking causes lung cancer,
sometimes breast and bowel cancer
can run in families,
but what has gone wrong
can seem a mystery.
Normally, our bodies exist
in a harmonious state,
balancing cells that divide
with those that are lost,
and this keeps the number of cells steady.
But with cancer,
this balance is destroyed
and the cells divide uncontrollably.
They become a runaway car,
dividing faster and faster.
This runaway out-of-control behavior
is caused by the DNA
in the cells mutating.
So they ignore all the signals
that tell them
to stop growing and dividing.
So cancer is actually a genetic disease
because it’s caused by defective DNA.
In cancer, two major gene families fail:
Oncogenes drive the cells
to divide and divide,
so they’re our car’s accelerator,
flat to the floor.
But in the car,
the brakes have failed too,
and those brakes
are the tumor suppressor genes
who no longer act to slow and stop
the division of the damaged cells.
The end result is a group of cells
growing in size,
number and destructiveness,
a car speeding past stop signs
towards an inevitable crash.
Cancer damages the body
by invading into adjacent normal tissue
and spreading to vital organs
like the liver and the lungs.
OK, so if we know what’s going wrong,
why haven’t we cured cancer?
Because of this unstable DNA
that cancers have,
any one tumor in a body
is going to consist of lots
of different groups of mutated cells
that all share the same
bad DNA called “clones.”
You can think of clones as being
like different car brands -
some clones are VWs
and others are Lamborghinis.
Because of this clones effect,
when we treat a cancer
with a single type of treatment,
not all the cells might be killed.
There may be a clone that has a mutation
that makes it resistant
to the chemotherapy
or better able to shrug off
the damage from the radiation.
These clone effects
are even more pronounced
when we look at a whole population
of cancer sufferers,
like women with breast cancer.
Mutations differ from person to person,
and that means a treatment can work
in one patient but not another.
Now, sometimes our cancer cells
aren’t just an out-of-control regular car;
they become the Batmobile -
they’ve acquired superpowers
to invade into normal tissues,
create their own blood supply,
evade the immune system
and even suppress the body’s defenses
against the cancer.
To combat these different
“Batmobile” superpowers,
we use multiple different treatments
all at the same time
to try and kill a cancer,
the main ones being surgery,
radiation and chemotherapy,
or as the oncologists call it,
“slash, burn and poison.”
Boop!
But even with these
combinations of treatments,
there might still be that one nasty cell,
the most pimped-out Batmobile
that can survive everything
the doctors have to throw at it.
The cancer will seem to disappear,
and the patient will go into remission.
But if even one nasty cell survives,
the cancer can potentially reform itself,
and it’ll come back
even nastier than before
because it’s already resistant
to everything the doctors
had to throw at it.
For nearly a century now,
the main treatments we had
were surgery, radiation and chemotherapy,
but recently a new strategy
has emerged called immunotherapy.
As a veterinarian,
I became interested in immunotherapy
after doing a Ph.D. in immunology
and specialty training in pathology.
I developed new cancer treatments
that are designed
using bacterial and plant products
to wake up the body’s immune system,
so it recognizes the dangerous invader,
that’s the cancer, and starts to fight it.
My goal is to gain an ally
of the immune system,
like a police officer
to chase down the out-of-control car,
and the bacterial
and plant products we use
are our crime alert
called “two triple zero.”
So OK, how do scientists usually
develop cancer treatments?
Well, traditionally,
cancer treatments are developed
in laboratory-based experiments
using rats and mice.
So these rodents
have their tumors artificially created
by being injected with tumor cells,
sometimes extracted from a human cancer,
that go into a healthy
but often immunocompromised rodent.
Or sometimes mice are genetically
engineered to have a gene defect,
so they develop cancers at an early age.
Many times scientists
have cured these rats and mice,
but when you try that treatment
in a human patient, it fails.
This is because the artificial
cancers in these rodents -
they don’t interact
with the body’s tissues, blood vessels
and immune systems like a human cancer.
Because of this,
only 5%, or one in 20 treatments,
make it from the laboratory
to treating cancer patients.
This is much worse than
the success rate for heart disease,
which is one in five drugs.
And it’s even more shocking
when you consider
that over a 100 billion dollars
is spent globally
on cancer research every single year.
Scientists widely
acknowledge that the problem
is these preclinical models
being used are suboptimal.
Basically, they’re saying that the rats
and the mice don’t work so well
because the tumors are too artificial.
The average rodent with cancer
lives just weeks,
not the months and years
a human patient battles their cancer.
So these rodent tumors -
they don’t reflect the complex genetics
and resistance to treatment
we see in our human patients.
For developing immunotherapy,
it’s even worse,
as most laboratory animals
have compromised immune systems,
so they’re not useful
for developing the treatments.
Knowing these failings
and the time and money
we waste trying to develop
cancer therapies that don’t work,
scientists demand that preclinical models
must be more representative
of the clinical situation,
even if it lengthens
the time to develop treatments.
What they’re saying
is they want a better mouse.
But I say these scientists are ignoring
something that’s sitting
right beside us on the couch.
Because pet dogs naturally
develop their cancer over a long period,
the way that that cancer
interacts with the dog’s blood vessels,
immune system, tissues in the body -
it’s really similar to human cancer.
In fact, the types of cancer
that dogs get are similar to people too;
for almost every type of human cancer,
there’s a canine counterpart.
In fact, sometimes the cancer
is even more common in dogs than people,
and it means there’s plenty
of dogs out there for us to study.
Osteosarcoma, an aggressive cancer of bone
that typically affects teenagers
is 27 times more common
in dogs than people,
really common in large breed dogs
like Great Danes and Rottweilers.
Dogs also get brain cancer,
the leading cause
of cancer death in young children,
so they can help us study
the disease and future treatments.
This means dogs can serve as a model
to help us understand cancer
and try to cure it.
Now, I know what you’re thinking:
this doesn’t mean we have to experiment
on our dogs like rats in the lab.
The fact that the dogs are home with us
sitting on the couch,
and they’re watching Netflix
and they’re eating kitchen scraps -
it actually strengthens their claim
to being our greatest ally
to fight cancer.
Dog cancer trials
are typically conducted in a way
that allows the dog
to participate as an outpatient.
They go to the vet,
they have the future medicine,
the experimental medicine,
they’re monitored
to see that it’s safe and it works,
and then they head home
with their owners.
This means that dog cancer trials
are cost-effective too.
The dogs just pop into the vet clinic,
and then they go home.
So there’s no need for expensive
traditional laboratories.
I’d like to introduce
two key concepts to you now:
The study of cancer
in one species to help another
in our case, dogs and people,
is called “comparative oncology,”
and progressing research
from the laboratory
through to a useful treatment
or test for patients
is called “translational medicine.”
Dog cancers have the same appearance,
behavior and genetics as human cancer.
Dogs age faster than us.
Cancer is common
and it runs in certain breeds,
and this means we can easily identify
candidate dogs
to recruit to clinical trials.
This means we can learn a lot
very efficiently and effectively
from studying cancer in pet dogs.
Now, I mentioned before
that my team and I develop immunotherapies
and only a natural immune system
like a pet dog is likely to interact
with the cancer in a way
that’s beneficial for our research.
In fact, my team and I have cured dogs
which had what were considered
incurable cancers
on our clinical trials.
So the dogs that enrolled
in our clinical trials -
they either couldn’t have surgery
because of the tumor’s location,
their chemotherapy had failed,
many times, their owners
couldn’t afford the treatment
or considered treatments like chemotherapy
dangerous to their kids.
In our modern day and age,
we must be conscious of how ethically
we humans interact with other animals.
By using pet dogs,
we’re not creating an artificial tumor
in a laboratory animal;
we’re merely trying
to help an animal that’s naturally ill.
Cancer treatment is really expensive.
It’s typically in the thousands to tens
of thousands of dollars for a single dog,
so many owners don’t have any option
but to put down their pet.
By using pet dogs,
we’ve created a more ethical,
a more scientifically robust
and a faster pathway
to develop future medicines
for both dogs and people simultaneously.
Now, many dogs
and their owners have benefited
from enrolling in our clinical trials.
One treatment we developed
showed reductions in tumor size
with remissions
in 30 to 40 percent of patients,
and another treatment
benefited 30 percent of dogs.
In this trial, Jackson, a “rotti” -
he was only given 8 to 12 weeks
to live off to his chemo failed,
but the immunotherapy allowed him
to make it to 12 months.
Henry, the pointer, he was similarly
given 8 to 12 weeks to live,
but with immunotherapy,
his cancers disappeared,
and he had another
17 months with his family
before succumbing to old age.
To prove that dogs make great
translational models,
doctors have already tried two
about-pet-dog-tested immunotherapies
in human cancer patients who had
no options left to treat their cancers,
and they showed beneficial results,
like reductions in mass size
and fluids produced by the tumor.
These dogs gave us the confidence to say
that those treatments would be safe,
and they would likely
benefit those patients.
Now,
what happened to Griffin?
With just weeks to live, Griffin enrolled
in one of our comparative oncology trials,
a personalized vaccine
was made out of his cancer cells
and given back to him with needles
like a puppy gets their vaccination.
Within four weeks,
all his tumor cells had disappeared,
and he’s alive and well to this day,
more than three years later.
That little baby girl -
she isn’t a baby anymore,
and she’s had the opportunity
to grow up with her best mate.
We need to stop ignoring this opportunity
that’s sitting beside us on the sofa.
Dogs are our best friends,
and they’re our perfect companions
for curing cancer.
Thank you.
(Applause)