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CELL BIOLOGY AND
CANCER
.01 Cancer types, incidence,
pre-disposition, and risk
factors
CANCER
• WHERE DID IT GET ITS NAME?
• Hippocrates observed 2300 years ago that
the long, distended veins that radiate out
from some breast tumors look like the
limbs of a crab – from that observation
came the term KARKINOMA in Greek, and
later, CANCER in Latin.
A. Cancer facts
1. Group of 100 diseases that develop
across time
2. Can develop in virtually
any of the body’s tissues
3. Characterized by
uncontrolled cell division
4. Hereditary & environmental
factors contribute to cancer
development
•
5. Second leading cause of
death in U.S.
6. Men have one in two
lifetime risk, women one in
three
•
ACTIVITY 1 – FACES OF CANCER
Type of Information
FAMILY HISTORY
(write in the number of “yes” and “no”
answers for all teams)
YES _____
NO ______
NUMBER OF PEOPLE
DIAGNOSED WITH CANCER
TOTAL OF ALL TEAMS
0-19 YEARS _____
20-39 YEARS ______
40-59 YEARS ______
60 AND OLDER ______
TYPE OF CANCER
WRITE IN THE NUMBER OF EACH
BLADDER __
LEUKEMIA __PROSTATE ___
BRAIN ___ LUNG ___ RETINOBLASTOMA ___
BREAST ___
ORAL CAVITY ___ SKIN ___
CERVICAL ___ OVARIAN ___ UTERINE ___
COLON ___
PANCREATIC __ OTHER ___
POSSIBLE RISK FACTORS
(LIST ANY POSSIBLE RISK FACTORS)
B. Types of cancer
1. Benign – not cancerous, does not
invade nearby tissue or spread to other
parts of the body (will grow & push
organs out of way)
2. Malignant – cancerous; can invade
nearby tissue and spread to other parts
of the body (will invade organs by
enzymes eating through tissue)
3. Metastatic – spread through body
by hemogenic (blood) or
lymphogenic (lymph)
4. Type depends on cause & location
5. Each type has its own growth rate,
prognosis, and treatability
C. Incidence increases with
age
• (old men have better chance of
developing cancer)
• Develops over time and could
result from different causes
• Can occur at any age and in any
location
D. Inherited predisposition
1. Can inherit a cancer – susceptible
mutation
2. Occurs in all the body’s cells
E. Risk Factors
Increase a person’s risk for
developing cancer
–Cigarette smoking
–Exposure to the sun
–Exposure to carcinogens
–Females – family history of breast
cancer
–Fair skin
–Chemicals, radiation, & viruses
Risk Factors We Can Control
~Excessive exposure to UV radiation
especially for those with fair complexion
~Occupational exposure to substances like
coal tar, creosote, arsenic compounds &
radium
~Poor nutrition & improper body weight
~Risky sexual behavior
~Substance abuse
~Prolonged exposure to stress
Risk Factors We Cannot Control
~ Aging (Which is one of the biggest
risk factor)
~ Males are more likely than females to
develop cancer
~ Heredity (Inherited Predisposition)
F. Chance of surviving cancer
increases with early detection &
treatment
1. Incidence rate – number of new cases
per year per 100,000 persons
2. Mortality rate – number of deaths per
100,000 persons per year
3. Survival rate – proportion of patients
alive at some point after their diagnosis
of cancer (chance of cure)
4. Morbidity - disease
.02 Causes & development of cancer
A. Many different agents can cause cancer
(Carcinogens)
sun
Radiation
Chemicals
smoking
B. Cancer represents a breakdown of the
processes that regulate the growth of normal
cells & tissues.
1.Cancer involves the uncontrolled
division of body cells.
2.Cell division is normally precisely
regulated
3.Cell cycle regulation is
accomplished by two major types of
genes
4. Cancer causing agents often
damage genes
5. When damage occurs to genes that
regulate the cell cycle, signals that
inhibit cell division can change
leading the cell to divide more often
that it normally would
•
(cancer cells multiply rapidly, taking up
space and nutrients from the normal cells
C. Cancer develops from genetic
damage to cells across time
• Cigarette smoke can damage genes
that regulate growth of normal cells
D. Cancer research leads to
understanding normal cell cycle
and new strategies for treating
cancer
E. Stages of tumor development
tumor – mass of cancer cells
adenoma – noncancerous tumor
Ovarian mucinous cyst adenoma
This tumor weighed 35 pounds.
1. Mutation – damage to genes causing cells to
alter (1st stage of tumor development)
2. Hyperplasia – altered cells & its descendents
grow & divide too often
3. Dysplasia – one of these cells experiences
another mutation that further increases its
tendency to divide. This cell’s descendents
divide excessively & look abnormal
4. In situ (tumor) – Tumor formed from
these mutated, rapidly dividing cells stays
contained within its tissue of origin
5. Invasive cancer (malignant) – if some
cells experience additional mutations
that allow the tumor to invade
neighboring tissues & shed cells into
the blood or lymph, the tumor is
malignant.
6. Metastases – escaped cells may
establish new tumors at other locations
in body
Cancer has been described as a single
disease and a hundred diseases
Single disease – all cancers display
uncontrolled growth, the ability to expand
without limit.
Hundred diseases – cancer can appear as a
result of different causes, in a variety of
sites within the body, and that each type of
cancer displays its own growth rate,
prognosis, and treatability.
The discovery that all cancer involves a
fundamental disruption in the growth of
cells and tissues suggests that to
understand cancer, we need to
understand the events and processes that
occur as both normal and abnormal cells
grow and divide.
In fact, much cancer research across the
past two decades has focused on this
challenge. This research has revealed a
complex picture of how two classes of
genes, called proto-oncogenes and tumor
suppressor genes, normally regulate the
intricate sequence of cell cycle events.
And it also has revealed how the
accumulation of mutations in these genes
can contribute to the development of an
altered cell, a cell that has lost the normal
controls on cell division.
Activity 2
.03 Genetic damage & mutation
A. Cancer results from the
accumulation of genetic damage to
cells across time
• multiple exposure over time
• Mutation causes change in the way
the cell functions or develops
B. Cancer cells differ from normal
cells
1. Shape changes (appearance
changes)
2. Changes in their dependence on
growth factors
3. Multitude of biochemical
differences
Know the ABCDs of early detection
Learn your ABCDs, the changes in a mole or skin growth
that are warning signs of melanoma:
Asymmetry
Border Irregularity
Color:
: One half doesn't match the other half.
: The edges are ragged, notched, or blurred.
The pigmentation is not uniform. Shades of tan, brown,
and black are present. Dashes of red, white, and blue
add to the mottled appearance. Color may spread from
the edge of a mole into the surrounding skin.
D
iameter: The size of the mole is greater than 6 mm (0.2 in.), or
about the size of a pencil eraser.
C. Cancer is a multi-step process,
which explains:
1. Increased incidence of cancer with age
2. Development of cancer decades after
exposure to carcinogens (severe
sunburns as a child)
3. Increased incidence of cancer among
people with inherited dispositions (they
are more likely to develop cancer than
the general population)
Activity 3
.04 Improve personal and public
health
A. Good choices can reduce an
individual’s risk of developing
cancer
1. Levels of cancer prevention
A. Individual behavior changes – develop
healthy behavior habits
B. Health care providers – perform
counseling & routine screening
c. National level – government regulations to
minimize public exposure to known
carcinogens
d. International level – actions of developed
countries bring cancer worldwide
2. Attention to ethical & public
policy issues
• Children wear protective headwear &
clothing during peak hours of UV exposure
would prevent most skin cancers
B. Risk factors for skin cancer
1. Excessive exposure to UV (ultraviolet)
radiation – damages skin cells
2. Fair complexion
3. Occupational exposure to substances
Known carcinogens:
a. coal tar
b. Creosate
c. Arsenic Compounds
d. Radium
C. Good choices can improve an
individual’s chance of survival if
he/she develops cancer
1. Improved detection
2. Improved treatment
Activity 4
Early Detection
Cancer remains the 2nd leading cause of
death in the United States.
Cancer is a multi-stage disease.
The earlier stages of the disease are now
more manageable and curable.
Breast cancer screening
The type and frequency of breast cancer
screening that is best for you changes as you
age.
• Ages 18 to 39: You should have a clinical
breast exam every 3 years. If you have a high
risk for developing breast cancer, talk to
your health professional about when to begin
having annual mammograms.
• Ages 40 to 69: Annual clinical breast exams
are recommended by all experts for women
in this age group.
Cervical cancer screening
The Pap test is the most effective screening test for cervical
cancer and is often part of a pelvic exam.
• Testing should start within 3 years of a
woman beginning sexual intercourse,
whatever age that may be, but no later than
21 years of age.
• Women older than 30 should have different
screening recommendations based on their risk
factors.
Testicular and Prostate cancer screening
• The American Cancer Society (ACS) recommends that
all men between the ages of 15 and 40 have a testicular
exam as part of a regular physical exam by their health
professionals.
• Prostate exams are part of regular physical exams which
should be done annually.
• A blood test called PSA (Prostate Specific Antigen) is
available now and can detect the presence of prostate
cancer earlier than physical exam. It is generally
recommended for men over age 50 or those with risk
factors for the disease.
Skin cancer screening
• Screening guidelines from the American
Cancer Society and other expert groups
recommend that adults older than 40 have
their skin checked by a health professional
at least once a year, as well as during any
other health exam.
Colon and rectal cancer screening
• After age 50 the recommendations include
annual screening of stool for occult blood.
• Colonoscopy, sigmoidoscopy and/or
barium enema once every 5 years or as
recommended by your health
professionall.
• Look for any abnormal skin growth or any
change in the color, shape, size, or
appearance of a skin growth. Check for
any area of injured skin (lesion) that does
not heal.
• Have your spouse or someone such as a
close friend help you monitor your skin,
especially places that are hard to see such
as your scalp and back.
People
People of all ages should get to
know their skin. of all ages should
get
know their
skin.
Skin to
self-exam
is a good
way to detect early
skin changes that may indicate melanoma,
because most primary melanomas are
easily seen on the surface of the skin.
Skin cancer often appears on the trunk of
men and on the legs of women.
Awareness of Treatment Options
Seek education and stay current about new
research and discoveries on your own by
reading, listening and asking questions.
D. Ethical values sometimes conflict in
public policy debated about strategies for
reducing the risk of cancer
1. Ethics is a process of rational
inquiry
2. Ethics requires a solid foundation of
information & careful interpretation
of that information
3. There are often competing, wellreasoned answers to what is right &
wrong, or good or bad
Ex:
– Public policy may invade an
individual’s freedom and
autonomy
– Banning smoking in public
places
A PROPOSED STATUTE
MANDATORY USE OF SKIN
PROTECTION FOR ALL INDIVIDUALS
UNDER THE AGE OF 18
Whereas it is well documented that only
15 percent of Americans regularly wear a
sunscreen when they are outside, and 25
percent never wear sunscreen.
Whereas there is a direct link between
the sun’s ultraviolet (UV) rays and
melanoma, the deadliest form of skin
cancer.
Whereas there were more than 42,000
new cases of malignant melanoma
diagnosed in 1999.
Whereas more than 7,000 Americans die
each year from melanoma.
Whereas disruption of the earth’s ozone
layer by atmospheric chemical pollution
may lead to rising levels of UV radiation.
Whereas 80 percent of a person’s UV
exposure occurs prior to age 18.
Be it enacted by the Federal Statues that:
All individuals under the age of 18 are
required to wear headgear and clothing
that covers 90 percent of the extremities
while outside during peak hours of UV
exposure. This covering shall occur in all
public locations that are currently under
federal jurisdiction, including public school
property, recreation sites, federal
buildings, and work sites supervised by
employers that are overseen by OSHA
regulations.