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From Gregor Mendel to the Human Genome
• Traits are inherited from your parents
• The genotype is expressed in the phenotype
• Phenylthiocarbamide (PTC) – are you a taster?
• A disease like CF is the result of a single ‘faulty’ gene
• The discovery of DNA
• 2003, the Human Genome was revealed
• Can we blame it on our genes?
Genetic risk, health and lifestyle
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Health: skin cancer
Do you like to tan?
Actions have consequences
Have you ever wondered what your risk of
aging prematurely is?
At 18 months sun damage is not yet
apparent.
At 4 yrs, early sun damage is
evident. Note freckling across the nose.
The photograph below shows that this 17year-old already has significant sun damage.
This 37-year-old woman has subsurface sun
damage, which is clearly visible in the photo
on the right.
At 52, this woman has "prematurely
aged" skin in visible light and significantly
sun-damaged skin in ultraviolet light.
This 64-year-old beach community resident
has skin that chronicles a lifetime of
chronic sun exposure.
UV photography is not necessary to see
that her skin is dry, inelastic, wrinkled, and
heavily mottled.
• High levels of UV exposure can cause more than
premature ageing…
• Ultra violet light can damage the DNA in your cells
• Use of sunbeds can increase the risk: WHO study in
France showed that use of sunbeds before the age of 30 can increase the
risk of skin cancer by 75%
An interview with…
Dr. Maureen Walsh
Dermatopathologist
Royal Victoria Hospital
Download the Video from Presentations
Skin Cancer
Malignant Melanoma
•Diagnosed in patients of all ages
including teenagers and young adults.
•Can result from periods of acute sun
burn and childhood exposure.
Non-Melanoma
Squamous Cell
Carcinoma
Basal Cell
Carcinoma
•Most commonly diagnosed in middle aged
and elderly patients
•More likely to result from chronic sun
exposure over many years
Melanoma and Non Melanoma
Incidence and Mortality
1. which has the higher incidence?
2. which has the greatest mortality rates?
3. complete the table to show the percentage rise or
decline in the incidence and mortality of melanoma and
non melanoma between 1993 and 2007
e.g.
If the incidence of melanoma was 58 in 1993 and 95 in
2007 then the percentage rise is (95-58/58 x 100) = 63.7%
% rise between 1993-2007
Incidence
Malignant
Melanoma
Male
Female
Males and
Female
63.7
Non Melanoma
% rise between 1993-2007
Mortality
Malignant
Melanoma
Non Melanoma
Male
Female
Males and
Female
% rise between 1993-2007
Incidence
Malignant
Melanoma
Non Melanoma
Male
Female
Males and
Female
(95-58/58 x
100)
(138-124/124 x
100)
(233-182/182 x
100)
(1462-994/994
x 100)
(13101086/1086 x
100)
(2,7722,080/2,080 x
100)
% rise between 1993-2007
Mortality
Malignant
Melanoma
Non Melanoma
Male
Female
Males and
Female
(24-7/7x100)
(31-20/20
x100)
(55-27/27 x
100)
(11-3/3 x 100)
0%
(19-11/11 x
100 )
% rise between 1993-2007
Incidence
Male
Female
Males and
Female
Malignant
Melanoma
63.7
11.3
28.02
Non Melanoma
47.08
20.6
33.26
% rise between 1993-2007
Mortality
Male
Female
Males and
Female
Malignant
Melanoma
242.8
55.0
103.0
Non Melanoma
266.6
0
72.7
4. Which form of cancer has its origins from being
sunburnt at a younger age?
5. Do you notice anything interesting from these
statistics?
6. Are there other trends in the number of cases of
malignant melanoma? Why might these have
occurred?
Epidemiologist – studies the factors affecting health and
Populations. Intervention and policy are based on their
Findings and advice.
7. What information is not represented within this data?
8. Why do you think the incidence for males is increasing more
than females?
9. Do you think that males and females are affected by skin cancer
equally on the same parts of the body?
In your groups, discuss where males and females
are most likely to develop skin cancer in terms of the percentage
breakdown, then put your results on the flip chart.
SITE DISTRIBUTION OF MELANOMA
SITE DISTRIBUTION OF MELANOMA IN
NORTHERN IRELAND 1984-88
Q: What is the main risk factor connected to skin cancer?
Skin Types and Risk, from Cancer UK website
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Type I - Often burns, rarely tans. Tends to have freckles, red or fair hair, and blue
or green eyes.
Type 2 - Usually burns, sometimes tans. Tends to have light hair, and blue or
brown eyes.
Type 3 - Sometimes burns, usually tans. Tends to have brown hair and eyes.
Type 4 - Rarely burns, often tans. Tends to have dark brown eyes and hair.
Type 5 - Naturally black-brown skin. Often has dark brown eyes and hair.
Type 6 - Naturally black-brown skin. Usually has black-brown eyes and hair.
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Which type are you?
Q: Who is
most at
risk?
‘Risk’ Factors
Evidence-based Estimates of Risk
Cancer - attributable proportions ( population ) estimates
Factor :
Cancer Deaths - Attributable
Proportion Estimate :
Tobacco
30%
Adult Diet / Obesity
30%
Sedentary Lifestyle
5%
Occupational Factors
5%
Family History of Cancer
5%
Infectious Agents
5%
Perinatal Factors / Growth
5%
Reproductive Factors
3%
Alcohol
3%
Socio-economic Status
5%
Environmental Pollution
2%
Ionising Ultraviolet Radiation
2%
Prescriptive Drugs / Medical Procedures
1%
Salt / Food Additive or Contaminant
1%
Ref. Harvard Report on Cancer Prevention 1996
So, can you blame it on your genes?