Transcript Cancer Prevention

Intrinsic vs. extrinsic factors
Cancer caused by intrinsic
factors, i.e. inherited mutations,
can only be prevented by
screening and appropriate early
intervention
Cancer caused by extrinsic
factors can be prevented by
reducing or eliminating exposure
to these factors (e.g. chemicals,
tobacco, radiation, viruses)
Cancer Prevention
Radiation
Viruses
or bacteria
1. National Cancer Institute, Understanding Cancer, 2009.
Carcinogenic
chemicals
Tobacco products
The use of tobacco products
is implicated in ~33% of all cancer
deaths1
~1 person dies every 6 seconds
Lung Cancer Risk Increases with
Cigarette Consumption1
due to tobacco2
15x
The combination of tobacco
and alcohol products appears to
be particularly dangerous1
As well as lung cancer,
tobacco products have also been
implicated in cancer of the mouth,
larynx, oesophagus, stomach,
pancreas, kidney, and bladder1
Avoiding tobacco is the single
10x
Lung
Cancer
Risk
5x
0
Non-smoker
15
Cigarettes Smoked per Day
most important factor in reducing
cancer risk
1. National Cancer Institute, Understanding Cancer, 2009. 2. WHO Fact Sheet 339, 2012.
Artwork originally created for the National Cancer Institute.
Reprinted with permission of the artist, Jeanne Kelly. Copyright 2013.
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Excessive exposure to UV radiation
Excessive UV exposure,
particularly in fairskinned individuals can
cause:1
• cutaneous malignant
melanoma
• squamous cell
carcinoma
• basal cell carcinoma
In 2000, >200,000 cases
of melanoma were
diagnosed worldwide1
Sun
exposure
Stratosphere
UV-C
Ozone
UV-B
Epidermis
Dermis
Hypodermis
1. WHO Fact Sheet 305, 2009.
UV-A
Diet
radiation and alcohol, dietary
components that influence
cancer risk have been difficult
to determine1
Limiting fat and calorie
intake appears to reduce
cancer risk1
A diet rich in meat
increases cancer risk,
especially colon cancer1
Correlation Between Meat
Consumption and Colon Cancer
Rates in Different Countries1
Number of Cases (per 100,00 People)
Unlike tobacco products, UV
40
N.Z.
U.S.A.
30
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CAN
G.B.
SWE
NETH
NOR
20
JAM
10
ISR
GERMANY
ICE
FIN P.R.
POL 15
YUG
CHILE ROM HUNG
JAPAN
COL
NIG
0
80
100
200
300
Grams (per person per day)
National Cancer Institute, Understanding Cancer, 2009.
Artwork originally created for the National Cancer Institute.
Reprinted with permission of the artist, Jeanne Kelly. Copyright 2013.
Viruses
Worldwide, 15% of all cancers
may be caused by viruses,
including:1
• Epstein-Barr virus
• Human papilloma virus (HPV)
• Hepatitis B virus
HPV Infection Increases Risk for
Cervical Cancer2
High
• Human herpes virus-8
• Human T lymphotrophic virus
type 1
• Hepatitis C virus
Cervical
Cancer
Risk
Reducing exposure to these
viruses reduces cancer risk
In the case of HPV, avoiding
unprotected sex with many
partners reduces the risk of
contracting this virus2
Low
Non-infected
women
Women infected
with HPV
1. Liao JB. Viruses and Human Cancer. YJBM 2006 (79);115-122. 2.National Cancer Institute, Understanding Cancer, 2009.
Artwork originally created for the National Cancer Institute. Reprinted with permission of the artist, Jeanne Kelly. Copyright 2013.
Strategies for prevention
Education
about cancer and risk factors (warnings on cigarette packets,
campaigns about sun and exposure to UV radiation)
Awareness pink ribbons for breast cancer,
campaigns world cancer day
Risk
avoidance
don’t smoke, stay out of the sun, avoid toxic chemicals and
polluted areas
Screening
cervical smear, mammography, colonoscopy
Vaccines
HPV vaccine to reduce risk of cervical cancer; Hep B
vaccine to reduce risk of liver cancer
Lifestyle
normal weight, healthy diet, exercise
Healthcare regular check-ups, seek medical attention early