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Home Topics A–Z Melanoma. What causes melanoma? Sunlight!
Author: Vanessa Ngan, Staff Writer; Copy Editor: Clare Morrison; Chief Editor: Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand, October 2013. About Melanoma is sponsored by the New Zealand Dermatological Society Incorporated.
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In New Zealand, most melanomas are related in some way to ultraviolet radiation (UVR). UVR comes from the sun or from man-made sources such as sunbeds and tanning salons. UVR on the earth's surface is composed of short wavelength UVB and long wavelength UVA rays.
Sun at the beach | Reflection from snow | High altitude | Artificial UV |
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Damage from UVR begins as soon as the sun's rays reach our skin. UVR causes many visible and invisible changes in skin cells. These include:
Skin cells include keratinocytes, which produce keratin (a protein that is the building-block in skin, hair, nails and horn) and melanocytes, which produce melanin (a brown pigment). Melanin protects the skin by absorbing UVR before it can cause any damage.
Sunburn | Actinic keratoses | Basal cell carcinoma | Squamous cell carcinoma |
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The main cause of melanoma is the sun, but genetic factors are also important. Genes determine:
Cancer can occur when genes are damaged.
What is melanoma video (Dr Tina Tian).
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