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What are the risks and causes of melanoma?

The main cause of all types of skin cancer is overexposure to UV radiation from the sun or another source, such as solariums (tanning beds). Solariums are now banned in Australia for commercial use because research shows that people who use solariums have a significantly greater risk of developing melanoma.

When your unprotected skin is exposed to UV radiation, the structure and behaviour of the cells can change.

Anyone can develop melanoma. However, the risk is higher in people who have:

  • unprotected exposure to the sun
  • a history of childhood tanning and sunburn
  • lots of moles (naevi) – more than 10 moles above the elbow on the arms and more than 100 on the body
  • pale, fair or freckled skin, especially if it burns easily and doesn’t tan
  • lots of moles with an irregular shape and uneven colour (dysplastic naevi)
  • a previous melanoma or other type of skin cancer
  • a strong family history of melanoma
  • a pattern of short, intense periods of exposure to UV radiation, such as on weekends and holidays, especially if it caused sunburn
  • light-coloured eyes (blue or green), and fair or red hair
  • a weakened immune system from using immune suppression medicines for a long time.

Overexposure to UV radiation can permanently damage the skin. This damage adds up over time. Childhood exposure to UV radiation increases the risk of skin cancer later in life, although sun protection will help prevent melanoma at any age.

Family history of melanoma

Sometimes melanoma runs in families. Often, this is because family members have a similar skin type or a similar pattern of sun exposure in childhood.

Only 1–2% of melanomas in Australia involve an inherited faulty gene. Some of these genes have been identified.

When two or more close relatives (parent, sibling or child) have been diagnosed with melanoma, especially if the person has been diagnosed with more than one melanoma on different areas of the skin and/or diagnosed with melanoma before the age of 40, then they may have an inherited faulty gene.

People with a strong family history of melanoma should protect and monitor their skin themselves, and have a professional skin check by a doctor every year from their early 20s. New moles after this age should be investigated.

If you are concerned about your family risk factors, talk to your doctor about having regular skin checks or ask for a referral to a family cancer clinic. Visit the Health Centre for Genetics Education to find a family cancer clinic near you. To find out more, call Cancer Council 13 11 20.