Can we eat to starve cancer?

William Li presents a new way to think about cancer treatment: angiogenesis, targeting the blood vessels that feed a tumor. The crucial first (and best) step: Eating cancer-fighting foods that beat cancer at its own game.

Good afternoon.

There's a medical revolution happening all around us,

and it's one that's going to help us conquer

some of society's most dreaded conditions,

including cancer.

The revolution is called angiogenesis,

and it's based on the process

that our bodies use to grow blood vessels.

So why should we care about blood vessels?

Well, the human body is literally packed with them:

60,000 miles worth in a typical adult.

End to end, that would form a line

that would circle the earth twice.

The smallest blood vessels are called capillaries;

we've got 19 billion of them in our bodies.

And these are the vessels of life, and,

as I'll show you,

they can also be the vessels of death.

Now the remarkable thing about blood vessels

is that they have this ability

to adapt to whatever environment they're growing in.

For example, in the liver they form channels

to detoxify the blood;

in the lung they line air sacs for gas exchange;

in muscle they corkscrew so that muscles can contract

without cutting off circulation;

and in nerves they course along like power lines,

keeping those nerves alive.

We get most of these blood vessels

when we're actually still in the womb,

And what that means is that as adults,

blood vessels don't normally grow.

Except in a few special circumstances:

In women, blood vessels grow every month

to build the lining of the uterus;

during pregnancy, they form the placenta,

which connects mom and baby.

And after injury, blood vessels

actually have to grow under the scab

in order to heal a wound.

And this is actually what it looks like,

hundreds of blood vessels

all growing toward the center of the wound.

So the body has the ability to regulate

the amount of blood vessels that are present at any given time.

It does this through an elaborate

and elegant system of checks and balances,

stimulators and inhibitors of angiogenesis,

such that, when we need a brief burst of blood vessels,

the body can do this by releasing stimulators,

proteins called angiogenic factors

that act as natural fertilizer

and stimulate new blood vessels to sprout.

And when those excess vessels are no longer needed,

the body prunes them back to baseline

using naturally occurring inhibitors of angiogenesis.

Now there are other situations where we start beneath the baseline

and we need to grow more blood vessels just to get back to normal levels --

for example, after an injury --

and a body can do that too,

but only to that normal level,

that set point.

But what we now know is that for a number of diseases,

there are defects in the system

where the body can't prune back extra blood vessels

or can't grow enough new ones

in the right place at the right time.

And in these situations, angiogenesis

is out of balance.

And when angiogenesis is out of balance,

a myriad of diseases result.

For example, insufficient angiogenesis --

not enough blood vessels --

leads to wounds that don't heal, heart attacks,

legs without circulation, death from stroke,

nerve damage.

And on the other end, excessive angiogenesis --

too many blood vessels -- drives disease,

and we see this in cancer, blindness,

arthritis, obesity,

Alzheimer's disease.

In total, there are more than 70 major diseases

affecting more than a billion people worldwide,

that all look on the surface to be different from one another,

but all actually share

abnormal angiogenesis

as their common denominator.

And this realization is allowing us

to reconceptualize

the way that we actually approach these diseases

by controlling angiogenesis.

Now I'm going to focus on cancer

because angiogenesis is a hallmark of cancer,

every type of cancer.

So here we go.

This is a tumor: dark, gray, ominous mass

growing inside a brain.

And under the microscope, you can see

hundreds of these brown staining blood vessels,

capillaries that are feeding cancer cells,

bringing oxygen and nutrients.

But cancers don't start out like this.

And, in fact, cancers don't start out

with a blood supply.

They start out as small, microscopic nests of cells

that can only grow to

one half a cubic millimeter in size;

that's the tip of a ballpoint pen.

Then they can't get any larger because they don't have a blood supply,

so they don't have enough oxygen or nutrients.

In fact, we're probably forming these

microscopic cancers all the time in our body.

Autopsy studies from people who died in car accidents

have shown that about 40 percent of women

between the ages of 40 and 50

actually have microscopic

cancers in their breasts,

about 50 percent of men in their 50s and 60s

have microscopic prostate cancers,

and virtually 100 percent of us,

by the time we reach our 70s,

will have microscopic cancers growing in our thyroid.

Yet, without a blood supply,

most of these cancers

will never become dangerous.

Dr. Judah Folkman, who was my mentor

and who was the pioneer of the angiogenesis field,

once called this "cancer without disease."

So the body's ability to balance angiogenesis,

when it's working properly,

prevents blood vessels from feeding cancers.

And this turns out to be

one of our most important defense mechanisms

against cancer.

In fact, if you actually block angiogenesis

and prevent blood vessels from ever reaching cancer cells,

tumors simply can't grow up.

But once angiogenesis occurs,

cancers can grow exponentially.

And this is actually how

a cancer goes from being

harmless to deadly.

Cancer cells mutate

and they gain the ability to release

lots of those angiogenic factors, natural fertilizer,

that tip the balance in favor of blood vessels

invading the cancer.

And once those vessels invade the cancer,

it can expand, it can invade local tissues.

And the same vessels that are feeding tumors

allow cancer cells to exit into the circulation

as metastases.

And, unfortunately, this late stage of cancer

is the one at which it's most likely

to be diagnosed,

when angiogenesis is already turned on

and cancer cells are growing like wild.

So, if angiogenesis

is a tipping point

between a harmless cancer and a harmful one,

then one major part of the angiogenesis revolution

is a new approach to treating cancer

by cutting off the blood supply.

We call this antiangiogenic therapy,

and it's completely different from chemotherapy

because it selectively aims

at the blood vessels that are feeding the cancers.

And we can do this because

tumor blood vessels are unlike normal, healthy vessels

we see in other places of the body:

They're abnormal;

they're very poorly constructed;

and, because of that, they're highly vulnerable

to treatments that target them.

In effect, when we give cancer patients

antiangiogenic therapy --

here, an experimental drug for a glioma,

which is a type of brain tumor --

you can see that there are dramatic changes that occur

when the tumor is being starved.

Here's a woman with a breast cancer

being treated with the antiangiogenic drug called Avastin,

which is FDA approved.

And you can see that the halo of blood flow

disappears after treatment.

Well, I've just shown you

two very different types of cancer

that both responded to antiangiogenic therapy.

So, a few years ago, I asked myself,

"Can we take this one step further

and treat other cancers,

even in other species?"

So here is a nine year-old boxer named Milo

who had a very aggressive tumor

called a malignant neurofibroma growing on his shoulder.

It invaded into his lungs.

His veterinarian only gave him three months to live.

So we created a cocktail of antiangiogenic drugs

that could be mixed into his dog food

as well as an antiangiogenic cream

that could be applied on the surface of the tumor.

And within a few weeks of treatment,

we were able to slow down that cancer's growth

such that we were ultimately able to extend milo's survival

to six times what the veterinarian had initially predicted,

all with a very good quality of life.

And we subsequently treated more than 600 dogs.

We have about a 60 percent response rate

and improved survival for these pets

that were about to be euthanized.

So let me show you a couple of

even more interesting examples.

This is 20-year-old dolphin living in Florida,

and she had these lesions in her mouth

that, over the course of three years,

developed into invasive squamous cell cancers.

So we created an antiangiogenic paste.

We had it painted on top of the cancer

three times a week.

And over the course of seven months,

the cancers completely disappeared,

and the biopsies came back as normal.

Here's a cancer growing on the lip

of a Wuarter horse named Guinness.

It's a very, very deadly type of cancer called an angiosarcoma.

It had already spread to his lymph nodes,

so we used an antiangiogenic skin cream for the lip

and an oral cocktail, so we could treat from the inside

as well as the outside.

And over the course of six months,

he experienced a complete remission.

And here he is six years later,

Guinness, with his very happy owner.

(Applause)

Now, obviously, antiangiogenic therapy

could be used for a wide range of cancers.

And, in fact, the first pioneering treatments

for people, as well as dogs,

are already becoming available.

There's 12 different drugs, 11 different cancer types.

But the real question is:

How well do these work in practice?

So here's actually the patient survival data

from eight different types of cancer.

The bars represent survival time

taken from the era

in which there was only chemotherapy,

or surgery, or radiation available.

But starting in 2004,

when antiangiogenic therapies first became available,

well you can see that there has been

a 70 to 100 percent

improvement in survival

for people with kidney cancer, multiple myeloma,

colorectal cancer, and gastrointestinal stromal tumors.

That's impressive.

But for other tumors and cancer types,

the improvements have only been modest.

So I started asking myself,

"Why haven't we been able to do better?"

And the answer, to me, is obvious;

we're treating cancer too late in the game,

when it's already established

and, oftentimes, it's already spread or metastasized.

And as a doctor, I know

that once a disease progresses to an advanced stage,

achieving a cure

can be difficult, if not impossible.

So I went back to the biology

of angiogenesis

and started thinking:

Could the answer to cancer

be preventing angiogenesis,

beating cancer at its own game

so the cancers could never become dangerous?

This could help healthy people

as well as people who've already beaten cancer

once or twice

and want to find a way to keep it from coming back.

So to look for a way to prevent angiogenesis in cancer,

I went back to look at cancer's causes.

And what really intrigued me

was when I saw that diet

accounts for 30 to 35 percent

of environmentally caused cancers.

Now, the obvious thing is to think about

what we could remove from our diet, what to strip out, take away.

But I actually took a completely opposite approach

and began asking: What could we be adding to our diet

that's naturally antiangiogenic,

that could boost the body's defense system

and beat back those blood vessels that are feeding cancers?

In other words, can we eat to starve cancer? (Laughter)

Well, the answer's yes,

and I'm going to show you how.

Our search for this

has taken us to the market, the farm and to the spice cabinet,

because what we've discovered

is that mother nature has laced a large number

of foods and beverages and herbs

with naturally occurring inhibitors

of angiogenesis.

So here's a test system we developed.

At the center is a ring from which hundreds of blood vessels

are growing out in a starburst fashion.

And we can use this system

to test dietary factors

at concentrations that are obtainable by eating.

So let me show you what happens when we put in

an extract from red grapes.

The active ingredient's resveratrol,

it's also found in red wine.

This inhibits abnormal angiogenesis

by 60 percent.

Here's what happens when we added an extract from strawberries;

it potently inhibits angiogenesis.

And extract from soybeans.

And here is a growing list of our

antiangiogenic foods and beverages

that we're interested in studying.

For each food type,

we believe that there are different potencies

within different strains and varietals.

And we want to measure this because,

well, while you're eating a strawberry

or drinking tea,

why not select the one that's most potent

for preventing cancer.

So here are four different teas that we've tested.

They're all common ones:

Chinese jasmine, Japanese sencha,

Earl Grey and a special blend that we prepared.

And you can see clearly

that the teas vary in their potency

from less potent to more potent.

But what's very cool

is when we actually combined the two

less potent teas together,

the combination, the blend,

is more potent than either one alone.

This means there's food synergy.

Here's some more data from our testing.

Now, in the lab, we can simulate tumor angiogenesis

represented here in a black bar.

And using this system, we can test the potency of cancer drugs.

So the shorter the bar,

less angiogenesis, that's good.

And here are some common drugs

that have been associated with reducing the risk

of cancer in people.

Statins, nonsteroidal anti-inflammatory drugs

and a few others,

they inhibit angiogenesis too.

And here are the dietary factors

going head to head against these drugs.

You can see, they clearly hold their own

and, in some cases, they're more potent

than the actual drugs.

Soy, parsley, garlic,

grapes, berries;

I could go home and cook a tasty meal

using these ingredients.

So imagine if we could create

the world's first rating system

in which we could score foods

according to their antiangiogenic,

cancer-preventative properties.

And that's what we're doing right now.

Now, I've shown you a bunch of lab data,

and so the real question is:

What is the evidence in people

that eating certain foods can reduce

angiogenesis in cancer?

Well, the best example I know

is a study of 79,000 men

followed over 20 years,

in which it was found that men who consumed

cooked tomatoes two to three times a week

had up to a 50 percent reduction

in their risk of developing prostate cancer.

Now, we know that tomatoes are a good source of lycopene,

and lycopene is antiangiogenic.

But what's even more interesting from this study

is that in those men who did develop prostate cancer,

those who ate more servings of tomato sauce

actually had fewer blood vessels

feeding their cancer.

So this human study is a prime example

of how antiangiogenic substances

present in food and consumed at practical levels

can impact on cancer.

And we're now studying

the role of a healthy diet

with Dean Ornish at UCSF and Tufts University

on the role of this healthy diet on markers of angiogenesis

that we can find in the bloodstream.

Now, obviously, what I've shared with you has some far-ranging implications,

even beyond cancer research.

Because if we're right, it could impact on consumer education,

food services, public health

and even the insurance industry.

And, in fact, some insurance companies

are already beginning to think along these lines.

Check out this ad from Blue Cross Blue Shield of Minnesota.

And for many people around the world,

dietary cancer prevention

may be the only practical solution

because not everybody can afford expensive end-stage cancer treatments,

but everybody could benefit from

a healthy diet based on local, sustainable,

antiangiogenic crops.

Now, finally,

I've talked to you about food,

and I've talked to you about cancer,

so there's just one more disease that I have to tell you about

and that's obesity.

Because it turns out that

adipose tissue, fat,

is highly angiogenesis dependent.

And, like a tumor, fat grows when blood vessels grow.

So the question is: Can we shrink fat

by cutting off its blood supply?

So the top curve shows the body weight

of a genetically obese mouse

that eats nonstop

until it turns fat, like this furry tennis ball.

And the bottom curve is the weight of a normal mouse.

If you take the obese mouse and give it

an angiogenesis inhibitor, it loses weight.

Stop the treatment, gains the weight back.

Restart the treatment, loses the weight again.

Stop the treatment, it gains the weight back.

And, in fact, you can cycle the weight up and down

simply by inhibiting angiogenesis.

So this approach that we're taking for cancer prevention

may also have an application

for obesity.

The really, truly interesting thing about this

is that we can't take these obese mice

and make them lose more weight

than what the normal mouse's weight is supposed to be.

In other words, we can't create supermodel mice.

(Laughter)

And this speaks to the role of angiogenesis

in regulating healthy set points.

Albert Szent-Gyorgi once said that,

"Discovery consists of seeing what everyone has seen,

and thinking what no one has thought."

I hope I've convinced you

that, for diseases like cancer, obesity and other conditions,

that there may be a great power

in attacking their common denominator: angiogenesis.

And that's what I think the world needs now. Thank you.

(Applause)

June Cohen: I have a quick question for you. So these drugs aren't exactly ...

they're not exactly in mainstream cancer treatments right now.

For anyone out here who has cancer,

what would you recommend?

Do you recommend pursuing these treatments now, for most cancer patients?

William Li: So there are antiangiogenic treatments

that are FDA approved,

and if you're a cancer patient

or working for one or advocating for one,

you should ask about them.

And there are many clinical trials.

The Angiogenesis Foundation is following almost 300 companies,

and there are about 100 more

drugs in that pipeline.

So consider the approved ones,

look for clinical trials,

but then between what the doctor can do for you,

we need to start asking what can we do for ourselves.

And this is one of the themes that I'm talking about

is we can empower ourselves to do the things

that doctors can't do for us,

which is to use knowledge and take action.

And if Mother Nature has given us some clues,

we think that there might be a new future

in the value of how we eat.

And what we eat is really our chemotherapy three times a day.

JC: Right. And along those lines,

for people who might have risk factors for cancer,

would you recommend pursuing any treatments sort of prophylactically

or simply pursuing the right diet

with lots of tomato sauce?

WL: Well, you know, there's abundant epidemiological evidence.

And I think in the information age,

it doesn't take long to go to a credible source

like PubMed, the National Library of Medicine,

to look for epidemiological studies

for cancer risk reduction

based on diet and based on common medications.

And that's certainly something that anybody can look into.

JC: Okay. Well, thank you so much.

(Applause)