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The Great Diseases
A collaborative approach to real
world science in the classroom
Infectious Disease
Neurological Disorders
Metabolic Disease
Cancer
Workbook
CANCER
Revati Masilamani, Ravi Subramanian and Karina Meiri
Table of Contents
Cancer
Student Workbook
Unit 1: What is cancer and why should we care? 4
Lesson 1.1 5
Lesson 1.2 12
Lesson 1.3 19
Lesson 1.4 27
Lesson 1.5 35
Unit 5: How do we treat cancer?
143
Lesson 5.1
144
Lesson 5.2153
Lesson 5.3160
Lesson 5.4168
Lesson 5.5175
Lesson 5.6182
Unit 2: What does it mean to be a 'normal' cell? 42
Lesson 2.1 43
Lesson 2.2 50
Lesson 2.3 57
Lesson 2.4 65
Lesson 2.5 72
Unit 3: How do normal cells become cancerous?
79
Lesson 3.1 80
Lesson 3.2 88
Lesson 3.3 95
Lesson 3.4101
Lesson 3.5107
Unit 4: How does cancer make us sick?
114
Lesson 4.1
115
Lesson 4.2122
Lesson 4.3129
Lesson 4.4136
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Welcome to the
Cancer Module!
Outline
This module focuses on understanding cancer as a disease and the
challenges of diagnosing and treating it. The Cancer Module has five
units, each of which builds upon the others that came before it. The goal
of each unit is to answer a new question about cancer, and what this
means for our health.
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Throughout this module, you’ll have not only class lessons, but
also this workbook to guide you through your exploration of
Cancer. This workbook is designed to provide you with readings
to complement your class lessons. We have helped make your
reading of this workbook interactive by encouraging you to take
notes and answer questions throughout.
Unit 1: What is cancer and why should we care?
Unit 2: What does it mean to be a normal cell?
Unit 3: How do normal cells become cancerous?
Unit 4: How does cancer make us sick?
Unit 5: How do we treat cancer?
In Unit 1, we’ll begin our discussion by investigating how our understanding of what cancer is has changed over time, and what we currently
understand about the role of random mutation in causing cancer. From
there, in Unit 2, we’ll focus on how normal cells behave in their tissue
communities, and in particular their vulnerabilities to mutation. Then, in
Unit 3, we’ll zoom in on how cell function is disrupted in cancer. Next, in
Unit 4, we’ll take a broader approach and examine cancer as a disease
and the challenges of diagnosis. Finally, in Unit 5, we'll look at how we
diagnose and treat cancer and the challenges and opportunities for
designing better screens and treatments in the future.
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Unit 1:
Unit 1: Introduction
Where are we heading?
Unit 1: What is cancer and why should we care?
Unit 2: What does it mean to be a 'normal' cell?
Unit 3: How does a normal cell become cancerous?
Unit 4: How does cancer make us sick?
Unit 5: How is cancer diagnosed and treated?
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Unit 1 focuses on what we currently understand
about cancer and how our perception of cancer has
changed over time.
Lesson 1.1 engages you with the idea that cancer is relevant to you,
and is not simply a disease of old age. Lesson 1.2 explores how
the historical context has always influenced how cancer has been
understood and will investigate the technological breakthroughs that
have led to our current understanding of cancer biology. Lesson 1.3
investigates how the three main theories of how cancer is caused
were reconciled when we finally understood that cancer is a disease
of DNA damage. Lesson 1.4 grapples with the challenges of establishing causation rather than correlation when dealing with diseases
of unknown and complex origins such as cancer. Lesson 1.5 will
explore how to assess the risk of developing cancer in order to make
informed choices about how to minimize that risk.
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LESSON 1.1 WORKBOOK
Why should we care about cancer?
DEFINITIONS OF TERMS
Mortality rate – The rate at
which people die from a specific
cancer.
For a complete list of defined
terms, see the Glossary.
The first lesson focuses on two key issues you will
encounter as you move through the module: First,
cancer is not solely a disease of old age: Although
cancers usually reveal clinical symptoms in older
patients, they may have originated when that
patient was quite young. Second, a tumor that has
originated in a young person and spread from its
primary location soon after it develops will cause
significant mortality if it escapes detection and
evolves to resist treatment. For effective prevention we need to identify which tumors will evolve to
spread before they actually do so, as we shall see
in this lesson about Steve Jobs.
Why should I care about cancer?
About 8.2 million people die of cancer each year, making cancer the leading cause of death worldwide,
and the second leading cause of death in the United States (behind heart disease).
Many people believe that cancer is a disease of elderly people, and it is - if we confine our discussion to
clinical symptoms, which most typically appear at around 60 years of age. Even so, about 72,000 cases
of cancer are diagnosed in adolescents and young adults each year. Unfortunately while mortality rates
(frequency that people die from a particular cancer) have declined in older patients, they remain largely
unchanged in the 15-39 age group.
Wo r k b o o k
Lesson 1.1
This is largely due to misdiagnosis: young adults are simply not expected to develop cancer, so symptoms
may be left untreated for longer periods than in the elderly. As we will see, early identification of cancer is
the key to survival.
Notes:
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LESSON READINGS
DEFINITIONS OF TERMS
Carcinogen – An agent able to
cause cancer.
Wo r k b o o k
Lesson 1.1
A further issue that has only recently become apparent is that
there may be a significant delay between when a cancer develops
and when symptoms appear. During this time, as we will see, the
cancer is evolving so that it can resist the treatments we currently
have available. It follows then that it is critical to minimize the risks
of cancer developing in the first place, and this means becoming
aware of what these risks are. Some are undoubtedly genetic and
thus beyond our control, but others, such as exposure to cancercausing agents – carcinogens - are often avoidable. Thus, you may
have choices now that will profoundly impact your health in the
future. As we will, see minimizing cancer risks means being aware
of what those choices are.
MC Questions:
Figure 1: Steve Jobs
died of pancreatic cancer
at the age of 56. Building
computers with heavy
metals increased his
exposure to
cancer-causing materials.
We don’t have to look far for examples: Celebrities, who are under
constant media scrutiny, provide numerous instances of choices
made that turn out to have unfortunate consequences. Sometimes
are inadvertent: Steve Jobs was diagnosed with pancreatic cancer
in 2003, and died 8 years later at only 56, a relatively young age. As we all know, Jobs spent his teens
and twenties developing computer hardware, in the process exposing himself to heavy metals such
as cadmium and lead, which are now, but were not at the time, appreciated to be carcinogens. Did this
exposure increase his chances of developing cancer?
Figure 2: Patrick Swayze also
died of pancreatic cancer. He
exposed himself to cigarette
smoke almost 100 times a day
– another well-known cancer
causing agent.
Another example seems more clear-cut. Patrick Swayze
also died of pancreatic cancer at a young age - 57. Swayze
regularly smoked more than 60-80 cigarettes a day, exposing himself to tar compounds that have been well-known
carcinogens for over 70 years. While cigarette smoking is
linked primarily to lung cancer, it also leads to increased
risk of cancer in the throat, colon, breast, and other organs,
such as the pancreas. As a nicotine addict, could Swayze
have chosen to stop smoking?
1. Which of the following is NOT a
reason high-schoolers should care
about cancer?
aa. Cancer is often misdiagnosed
for people age 15-39;
bb. Cancer is the leading cause of
death in the US;
cc. Cancer mortality rates have not
decreased for young adults; or
dd. Choices made in high school
can affect the risk of developing
cancer later.
2. Which of the following might
increase your risk of developing
cancer?
aa. Heavy metals.
bb. Smoking.
cc. Excessive tanning.
dd. All of the above.
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LESSON READINGS
DEFINITIONS OF TERMS
Cancer – a disease caused by
an overgrowth of abnormal cells
with the capacity to spread to
other parts of the body.
Like many teenagers in the 60’s Diane Keaton, the Oscarwinning actress, describes herself as being “tan-obsessed”.
She was undoubtedly not helped by tanning creams and
lotions that were designed to increase sun exposure rather
than protect from it. It is only as the ozone layer has become
compromised that we have become aware how much UV
radiation from the sun contributes to skin cancer developing.
Diane Keaton paid the price for our lack of understanding when
she was making critical choices that would impact her later
health, but fortunately we all now have access to the information that sun exposure can be a cancer risk factor.
So even though cancer symptoms most frequently appear in
older people, cancer can, and often does, originate when we
are young. Fortunately we can make choices now that can influence the later outcome. The challenge is to identify all the risk
factors for cancer, so we can understand what all these choices
might be, and to develop effective treatments for when a choice
cannot be made.
Oncology – the study of cancer
as a disease.
3. What is true about cancer?
aa. It is a fatal disease.
cc. It is an infectious disease.
dd. It is a disease of abnormal cells.
dd. All of the above.
Figure 3: Diane
Keaton was diagnosed
with skin cancer at age
21. At that time sun
creams promoted exposure to UV radiation
rather than protecting
from it.
What is cancer?
Figure 4: Advanced tumors such as
the adrenal tumor above (left) are fed
by swollen tubes of blood that look like
legs on a crab (right: Blue King Crab). Our
modern term 'cancer' is Latin for crab.
Wo r k b o o k
Lesson 1.1
MC Questions:
It was the Greek physician Hippocrates (of
Hippocratic Oath fame) who came up with the
name 'cancer'. Some of his patients had large
red swellings under the skin with swollen blood
vessels protruding from the bulge. Hippocrates
thought that these swellings looked just like a crab
digging into sand, so he called them karkinos,
which was later modified to the Latin cancer. The
study of cancer as a disease is called 'oncology'
from the Greek word 'onkos', meaning 'swelling' or
burden.
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LESSON READINGS
Cancer is a disease caused by the rapid growth of
abnormal cells which may initially form a swelling or
tumor, but which eventually spread throughout the body.
By the end of this module we will understand more
clearly what causes drives the "abnormal" behavior.
DEFINITIONS OF TERMS
Tumor – a mass of rapidly
growing cells.
Benign tumor – a tumor that is
localized to a specific area of the
body and is not harmful.
Malignant tumor – a tumor that
is capable of spreading to
surrounding tissues and organs
and will cause disease.
Lymphatic system – the system
of vessels that moves immune
cells throughout the body. Like
the blood stream, but just for
white blood cells.
Wo r k b o o k
Lesson 1.1
What is the difference between cancer and a
tumor?
Figure 5: Warts (left) and moles
(right) are two examples of benign
tumors. They are localized and don’t
cause severe disease.
It is important from the outset to understand that there is
a critical distinction between a “tumor” and “cancer”.
A tumor is simply an overgrowth of cells that form a mass. Tumors are quite common and remain localized in one place without causing disease. This kind of tumor is called a benign tumor. A clear example of
a benign tumor is a wart or a mole.
On the other hand cancers are tumors that have evolved so they are now able to spread to other parts of
the body. These mobile tumors are called malignant tumors. It is important to note that even malignant
tumors are not necessarily life threatening. Some malignant cancers are not very mobile, and only spread
a little within the tissue, behaving essentially like benign tumors. These kinds of tumors are detectable and
if the whole tumor is removed, the patient will
be cured. It is tumors that migrate far away
from the primary site so that they escape
detection that are the most problematic.
Figure 6: Tumors can progress from benign
(not harmful) to metastatic (cancer causing),
but not all do. The challenge is identifying
which benign tumors will become malignant.
Once cancers enter the blood stream or
lymphatic system (the system that moves
immune cells throughout the body) they are
able to spread extensively throughout the
body. This movement is called metastasis,
from the Greek word for “next place”, and
cancers that have acquired this ability are
called metastatic tumors. Thus while all
cancers are tumors, but not all tumors are
cancers.
MC Questions:
4. Which is the first stage of developing
cancer?
aa. Benign tumor;
bb. Malignant tumor; or
cc. Metastatic tumor.
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5. True or false: Benign tumors always
become metastatic tumors
aa. True.
bb. False.
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LESSON READINGS
Why is cancer so hard to treat?
In 1971, President Nixon a plan to cure cancer within the next 30 years. Fifty years later after billions of
dollars spent in research, we have made significant progress in the “War on Cancer” but by no means do
we have a cure. Has the American public got value for money? Why has cancer been such a challenge?
DEFINITIONS OF TERMS
Metastasis – the spread of malignant tumor cells from the site of
the primary tumor through blood/
lymph vessels.
Metastatic tumor – a cancer
that has acquired the ability to
enter the blood or lymph, and
spread through the body.
We can only begin to answer this question if we have a clear idea how much our ideas about what cancer
actually is have developed over the last fifty years. In fact the very notion that cancer as a disease evolves
over time – benign tumors acquire the ability to become mobile and metastasize, becoming malignant
in the process – is relatively recent. For more than thirty years our efforts focused almost exclusively on
the primary tumors, failing to appreciate how insidious metastases can develop very early and become
resistant to treatment. Thanks to the evolution in our understanding we can now appreciate that in order to
treat a cancer successfully we need to have answers two fundamental questions:
■■ When did the tumor first from?
■■ When did the tumor spread?
It is not enough to be able to locate the primary tumor. Often times we first notice a tumor indirectly
because it has disrupted bodily functions and caused symptoms such as breathlessness, pain and
nausea. But at this point the tumor has often already metastasized and become resistant to treatment.
It is critical to be able to identify a cancer before it metastasizes, which is often before it becomes
symptomatic.
The notion that it is critical to understand the progression from benign tumor to metastasis raises another
critical question: “How do we know which benign tumor will become metastatic?” We don’t need to treat
benign tumors that will never be problematic. Conversely we also don’t want to ignore a tumor that might
become metastatic. As we shall see in the next lesson (and in rest of the module), while our understanding of cancer as a disease has evolved significantly, until we can identify what causes a tumor to spread,
the ultimate challenge – of curing cancer will remain.
Wo r k b o o k
Lesson 1.1
MC Questions:
6. Why is cancer so hard to treat?
aa. We haven’t spent enough money
on research;
bb. Scientists are lazy; or
cc. We don’t know what causes
cancer to spread.
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7. What is the most important question
remaining in our understanding of
cancer?
aa. What causes cancer?
bb. What causes tumors to spread?
cc. What causes tumors to form?
dd. All of the above are important.
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STUDENT RESPONSES
List 3-4 behaviors that you have heard that increase the risk of developing cancer, and what types of cancer they are linked to.
To what extent are these behaviors under our control?
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Remember to identify your
sources
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Wo r k b o o k
Lesson 1.1
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TERMS
TERM
For a complete list of defined
terms, see the Glossary.
Wo r k b o o k
Lesson 1.1
DEFINITION
Benign tumor
A tumor that is localized to a specific area of the body and is not harmful.
Cancer
A disease caused by an overgrowth of abnormal cells with the capacity to spread to other parts of the body.
Lymphatic system
The system of vessels that moves immune cells throughout the body. Like the blood stream, but for white
blood cells.
Malignant tumor
A tumor that is capable of spreading to surrounding tissues and organs and will cause disease.
Metastasis
The spread of malignant tumor cells from the site of the primary tumor through blood/lymph vessels.
Metastatic tumor
A cancer that has acquired the ability to enter the blood or lymph and spread through the body.
Mortality rate
The rate at which people will die from a specific cancer.
Oncology
The study of cancer as a disease.
Tumor
A mass of rapidly growing cells in the body.
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