1. Skin cancer: An introduction
Prof JL Marnewick
Prof WCA Gelderblom
Institute of Biomedical and Microbial Biotechnology
Cape Peninsula University of Technology
Panel members:
Dr S Abel
Dr M Lilly
Dr T Magcwebeba
Dr S Samodien
Ms L Keet
Rooibos Science Café
2 April 2019

2. INTRODUCTION The skin is our first line of defense! SKIN
Skin largest organ m2
Adult: ~3.6 kg of skin
Different layers of the skin:
Epidermis - Top/outer layer
- Make new skin cells every month
- Protecting the body (has immune cells)
Dermis - Deeper layer
- Making sweat to keep you cool
- Help feel things (nerve endings)
- Growing hair
- Making oil
- Bringing blood to the skin
Fat layer - Attached dermis to muscles & bones
- Help blood vessels & nerve cells
- Control body temperature
- Protects you from bumps & falls
The skin is our
first line
of defense!
INTRODUCTION

3. INTRODUCTION SUN Ultraviolet (UV) rays damage skin: UVA; UVB UVA:
known as the “aging rays”
it penetrates deeper skin layers, cause ageing, increased risk for
cancer
dominant ray used in tanning salons
UVB:
known as the “tanning rays”,
cause sever damage to the epidermis
redness, cancer- causing
UVC:
most dangerous, BUT completely filtered out by the ozone layer
INTRODUCTION

4. INTRODUCTION Adverse effects of chronic exposure to the sun
Induce oxidative stress
DNA damage
Premature ageing
Effects immune system
Skin disease
Melanoma skin cancer
Non-melanoma cancer, e.g.
SCC (connected to tanning beds)
Skin cancer STATS
Most common cancer in SA
Everyone is at risk
WHO predicts increase in skin cancer as the ozone levels decrease
reported cases annually, 700 deaths
2nd highest incidence SA, Australia has highest incidence
INTRODUCTION

5. Current prevention strategies: (also refer to recommendations by CANSA):
Avoid sun exposure between 10am to 3pm
Stay in the shade/under the umbrella
Remember: UV reflects off cement/water/sand/grass – you can still burn
Apply and re-apply your sunscreen often
We can’t change the environment, but we can change our attitude towards the sun, by taking an additional prevention approach, that of
Photo chemoprevention: a strategy in which the occurrence of skin cancer is reduced by using naturally occurring or synthetic compounds
Use of to prevent or slow down the development of certain cancers is gaining popularity
Plant components/polyphenol properties
Anti-inflammatory
Immune modulatory
Redox modulation/Antioxidant
Popular compounds to explore
Rooibos and honeybush rich in polyphenols
INTRODUCTION

6. INTRODUCTION Interesting facts:
The International Agency for Research on Cancer (IARC) in France has classified UV-emitting tanning devices (such as sunbeds “carcinogenic to humans” and classified it as a class 1 carcinogen (2009)
Australia has banned the use of sun beds in certain states of their country since the 1st of January 2015
The Cancer Association of South Africa (CANSA) has made a request to the Minister of Health to ban the use of sunbeds at least by our youth (<18yrs of age)
INTRODUCTION

7. INTRODUCTION Treatment/Costs
Most skin cancers found at an early stage can be treated successfully.
Treatment depends on the type of skin cancer and the stage of the disease.
Common Treatment for Skin Cancer:
• Surgery
• Various chemotherapies
• Radiation
• Biological drug treatments
Other Possible Treatment:
• Immunotherapy (for melanoma skin cancer)
• Photodynamic therapy (for non-melanoma skin cancer)
In 2015 alone, skin cancer cost the South African health system more than R90 million (more than US$6 million) - BMC Health Services Research Journal.
INTRODUCTION

8. Fig. 1. The cellular composition of the skin
Fig. 1. The cellular composition of the skin. Keratinocytes are a major source of IL-1. When activated and secreted, the cytokine induces an inflammatory response through activation and recruitment of immune cells (inspired from Nestle et al., 2009a).

10. Panel discussion Skin Cancer Chemoprevention South African Herbal Teas
Panel members:
Prof Wentzel Gelderblom (Chair - CPUT)
Prof Jeanine Marnewick (CPUT) – co-chair
Dr Stefan Abel (CPUT)
Dr Mariska Lilly (CPUT)
Dr Tandeka Magcwebeba (US - post doc)
Dr Sedicka Samodien (CPUT – post doc)
Ms L Keet (US - PhD candidate)
Panel discussion

11. Rooibos against cancer development in skin
Inflammation
Free radicals (oxidative stress)
Cell growth
Removes inflamed and damaged precancerous cells via programmed cell death

13. References References and information sheets
Skin Cancer Fact Sheet (Prevention and Cancer Foundation)
Fact Sheet – Skin Cancer (CANSA)
Major findings: rooibos protects against adverse effects of UVB exposure. SARC media release;
December 2016 (Prof WCA Gelderblom)
SA children more at risk from sunburn at school due to inadequate sun protection policies. SARC media release;
January 2017 (Dr T Magcwebeba)
References