CANCER - Why?

FIB Autumn 2008

Outline

1. What is cancer?2. Who can get cancer?3. How does one develop cancer?4. How can cancer kill you?5. Which treatments exist?

1) What is CANCER?

• Cancer is a scaryscary word– Indeed there was a certain unwritten stigma

associated with death from the disease, until very recently

– “…died after a long illness”• Almost everyone knows someone who has

gotten very sick or died from cancer• Most of the time, cancer affects older people

1) What is CANCER?..

• A good way to understand cancer is to consider first, what happens to normal cells

1) What is CANCER?…• We are made of about 100 trillion cells

– 100,000,000,000 TRILLION• Many of these are organized into tissues

– Which are aggregations of cells performing common functions

• Liver• Pancreas• Brain• Blood

1) What is CANCER?….• Our bodies are extremely good at managing all

these cells• Such that the number of liver cells is more or less

constant, even though many die each day.• Some tissue does not change much - nerves• Other tissue has a very high rate of turn over -

i.e. immune system– Many millions of cells die each day– These are replaced by new ones made from existing

cells

1) What is CANCER?…..• Every cell is told when to divide, so as to produce

more cells, and when to stop dividing• This is known as the cell cycle

– Where one cell grows larger, copies its contents, and then divides into two new cells

• Brain cells are given instructions never to divide• Cell lining your gut divide almost constantly and

receive signals to perform the cell cycle daily

1) What is CANCER?……• Any cell which no longer obeys the signals from your body

not to divide will begin to divide uncontrollably• The loss of control over the cell cycle is a first necessary

step of cancer• One cell growing uncontrollably divides to give rise to two

cells growing uncontrollably• Each of these two cells divides to make two new cells• Each of these cells divides again, etc, etc.• ALL CANCER CELLS CAN GROW UNCONTROLLABLY• Scientists refer to these local growths as tumors

– Tumors just grow at the site of the original disobedient cell

1) What is CANCER?…….• Some cells then undergo another

breakdown in communications• They acquire the ability to break away

from the local tumor and leave• They travel to other regions of the

body and start a new colony• THIS IS CALLED CANCER• Scientists call this a malignant tumor,

or cancer

1) What is CANCER?……..• There are cancers of the;• Breast - many types• Brain - multiple types• Lung - many • Pancreas - hard to cure• Blood - • Bone -• In fact any cell can become cancerous• Cancer is a general term for many diseases

- all involving lose of cell control

1) So what is cancer in a nutshell?

• Cancer refers to any one of a large number of diseases,

• all characterized by the development of abnormal cells,

• which divide uncontrollably, • and have the ability to infiltrate, • and destroy normal body tissue

Fast Facts About Cancer• One in three people will develop cancer.• One in four people will die of cancer.• In 2007, about 1.4 million new cases of cancer

were diagnosed.• More than 1500 Americans died each day of

cancer this year.• Over 1,000,000 cases of skin cancer will be

diagnosed this year.• Cancer is the leading cause of death among

Americans under the age of 85.

2) Who can get cancer?• Any organism made of cells

may loss control of the cell cycle

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2) Who can get cancer?..• Generally the term cancer is reserved for multi-

cellular organisms, • where cells can travel to other regions and

disrupt the functionality of that tissue.

• So any multi-cellular organism can get cancerSo any multi-cellular organism can get cancer

• In fact we have fossils (such as those of dinosaurs) which show cancerous growths which may have killed that animal

• Plants are also made of cells and cancerous tumors can form there too.

2) Who can get cancer?…

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3) How does one develop cancer?

• It is now generally accepted that the conversion of healthy obedient cells to cancerous ones

happens due to two or more instances of damage

to critical regions of the DNA of that cell

3) How does one develop cancer?..• Once can consider the first defect

permits the cell to divide uncontrollably– It loses control over the cell cycle

• The second defect allows the cell to travel to distant sites– It becomes metastatic

• Your body has a natural ability in detecting many cancerous cells and killing them before you know it.

3) How does one develop cancer?…• Example A

– Breast cancer cells leave the breast tissue and travel through the lymph to the bone

– There they start many many new colonies – Eventually they become so large that they interfere

with the normal functioning of the bone tissue• The patients’ bones break• The patient cannot make new bone marrow products• The amount of calcium in the body changes

3) How does one develop cancer?..• Example B

– Lung cancer develops in the lung and spreads to other regions of both lungs

– There they start many many new colonies – Eventually they become so large that they interfere

with the normal functioning of the lungs• The patient does not get enough oxygen• The patient develops a lung infection• The weakened patient cannot fight the infection and dies

3) How does one develop cancer?.• The causes of this form of DNA damage

(mutation) are many and varied:– Cosmic radiation– Thermal heat - spontaneous– Environment – Diet– Viruses– Stress?

• This causes a failure in the chemical regulation of the cell

4) How can cancer kill you?

• Firstly, it is important to understand that not all cancers are fatal.– Some patients live whole lifetimes

• Secondly, cancer at an early stage does not kill you. – That is why so much effort is put into early

diagnosis so that treatment is much more likely to be effective

• Advanced cancers can and do kill!

4) How can cancer kill you?..

• Patients die either directly from the cancer– Liver cells become cancerous and continue to

secrete large amounts of liver chemicals– These upset the fine balances of the body

• Patients die either in-directly from the cancer– Cancer cells disrupt the normal functioning of other

regions– Weaken the body - blood vessels– Increase infection - immune system depletion

Which treatments exist?

• Until recently, there were only three major treatments options:– Surgery – Radiation– Chemotherapy

• Now, there are many more materializing:– Hormone Therapy– ‘Magic Bullet’ drugs– Kinases - enzymes– The Kanzius Machine - Heat/radiation (60 minutes)

Which treatments exist?

Surgery - to remove the tumors– If the tumor has not spread to other sites, one

can simply remove it along with some surrounding tissue

– The patient will be cancer free and cured– Must get it ALL before metastasis

Which treatments exist?Radiation - to kill cancer cells by destroying

their DNARadiation therapy is the use of high-energy

penetrating rays or subatomic particles to destroy the tumor

• The new equipment uses multiple beams at differing angles to focus precisely on the tumor and its immediate boundary

• Each beam is weak, but where they all meet is deadly!

Which treatments exist?

Chemotherapy - use of very potent (cytotoxic) drugs to kill all dividing cells - including non-cancerous normal ones

The side effects can be daunting• Loss of hair• Lining of gut and mouth• Anemia - Blood cells

Latest…

• The Kanzius Machine

Which treatments exist?

There are some promising new treatments appearing at this time, but they are limited in scope and fragmented at best - some patients respond better then others.

Our video this week looks at a promising new and controversial angle on tackling cancer…

Video Questions1. How many days per week do the two patients

have to attend hospital?2. What is one of the problems of using

chemotherapy?3. How long ago did Dr. Judah Folkman first realize

the importance of blood vessels in cancer biology?

4. What did the experiment on the eye show?5. What does thalidomide have to do with this story?6. What happened to each of the two patients

followed by this story?

Group Questions1. Do you know of someone who has had

cancer? Was it scary for them or you?2. Cancer rates worldwide continue to rise

rapidly. Why?3. Treatments of advanced cancers are not

considered cures, just remissions. Why?4. Do you think we will ever eliminate cancers

in the future? Discuss.5. Which kinds of lifestyle changes would

reduce your chances of developing cancer?