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

• 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.

This 37-year-old woman has subsurface sun damage, which is clearly visible in the photo on the right.

The photograph below shows that this 17-year-old already has significant sun damage.

At 52, this woman has "prematurelyaged" skin in visible light and significantlysun-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 WalshDermatopathologist

Royal Victoria Hospital

Download the Video from Presentations

Malignant Melanoma Non-Melanoma

Squamous Cell Carcinoma

Basal Cell Carcinoma

Skin Cancer

•Most commonly diagnosed in middle aged and elderly patients

•More likely to result from chronic sun exposure over many years

•Diagnosed in patients of all ages including teenagers and young adults.

•Can result from periods of acute sun burn and childhood exposure.

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

Incidence% rise between 1993-2007

Male FemaleMales and

Female

Malignant Melanoma 63.7

Non Melanoma

 

Mortality% rise between 1993-2007

Male FemaleMales and

Female

Malignant Melanoma

Non Melanoma

e.g. If the incidence of melanoma was 58 in 1993 and

95 in2007 then the percentage rise is (95-58/58 x 100)

= 63.7%

Incidence

% rise between 1993-2007

Male FemaleMales and

Female

Malignant Melanoma

(95-58/58 x 100)

(138-124/124 x

100)

(233-182/182 x

100)

Non Melanoma

(1462-994/994 x

100)

(1310-1086/1086 x

100)

(2,772-2,080/2,080

x 100)

 

Mortality% rise between 1993-2007

Male FemaleMales and

Female

Malignant Melanoma

(24-7/7x100)

 

(31-20/20 x100)

(55-27/27 x 100)

Non Melanoma

(11-3/3 x 100)

0%(19-11/11 x

100 )

Incidence

% rise between 1993-2007

Male FemaleMales and

Female

Malignant Melanoma

63.7 11.3 28.02

Non Melanoma

47.08 20.6 33.26

 

Mortality

% rise between 1993-2007

Male FemaleMales 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

• Type I - Often burns, rarely tans. Tends to have freckles, red or fair hair, and blueor green eyes.

• Type 2 - Usually burns, sometimes tans. Tends to have light hair, and blue orbrown 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.

• 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?