Skin Cancer Causes and Risk Factors
A personal or family history of skin cancer
5–10% of melanomas are influenced by genetics. Be aware of your family’s skin cancer history to help inform your own risk.
People who’ve had skin cancer have a higher risk of developing more skin cancers. It’s important to prevent further damage to your skin by using sun protection during sun protection times. Your doctor will recommend a surveillance program for you, but you will need to check your skin regularly for any changes.
UV damage is the cause of most skin cancers. Using regular sun protection and developing a surveillance plan with your doctor can help reduce your risk.
A large number of moles
The more moles you have on your skin, the higher the risk of the most dangerous type of skin cancer – melanoma.
Moles are overgrowths of melanocytes (a type of skin cell). We are not normally born with moles, but most of us will develop some on our skin by 15 years of age.
The number of moles we develop is determined by genetic (inherited) factors and exposure to ultraviolet (UV) radiation.
Australians tend to have more moles than people living in other countries, possibly because of childhood sun exposure.
What do moles look like?
Moles are usually medium to dark brown but can also be pale or black.
The majority of moles are flat and have an even shape and colouring. Some moles are raised and these are usually soft to touch and lighter in colour.
‘Dysplastic naevi’ is a medical term which means ‘unusual moles’. These moles look different to ordinary moles and can evolve to melanomas. If you have multiple dysplastic moles you are at greater risk of melanoma. Your doctor may recommend regular checks with a dermatologist (skin specialist).
See your doctor if you think you have moles with the following ‘dysplastic’ features:
- larger than most moles
- smudgy and irregular edges
- uneven in colour
- may have some pinkness.
A compromised immune system or are on immunosuppression medication
Some medical conditions impacting your immune system and associated medications can increase your skin cancer risk. Your doctor can advise you on the best steps to protect your skin from UV damage and appropriate skin check and surveillance activities for your condition.
A fair skin type and skin colour
Some people are at higher risk of skin cancer because they have a skin type that is more sensitive to UV damage.
People with light-coloured eyes and red or fair hair also have an increased risk of melanoma, compared to people with darker hair and eyes.
A history of bad sunburns
While sun exposure in the first 10 years of life determines a person’s lifetime potential for skin cancer, sun exposure in later life determines the extent to which this potential is realised. You can reduce your risk of skin cancer at any age by improving your sun protection use, whether you are 6, 16 or 60.
Spent lots of time outdoors unprotected or work outdoors
Within Australia, it is estimated that 95% of melanomas are caused by overexposure to UV radiation. Outdoor workers in Australia receive up to 10 times more sun exposure than indoor workers, placing them at an increased risk of skin damage and skin cancer.
Suntanned, use or have used solariums and/or sunlamps
Solariums can emit ultraviolet (UV) radiation up to six times as strong as the midday summer sun. This is equivalent to a UV level of 36, whereas the UV levels in Victoria rarely exceed 12. Exposure to UV radiation from the sun or a solarium increases your risk of skin cancer and ages your skin. Tanning without burning can still cause skin damage, premature ageing and will increase your risk of skin cancer. Research shows that using solariums before the age of 35 increases the risk of melanoma by 59%. Commercial solariums were banned in Victoria on 1 January 2015.
Skin cancer can usually be successfully treated if found early. But without treatment, skin cancer can be deadly.
Calculate your melanoma risk
What to do if you are ‘at risk’
If you meet any of the above criteria, see your doctor to develop a surveillance plan and check your skin regularly for any changes.
Some people (such as transplant recipient patients, people with compromised immune systems and genetic skin cancer risk) are at high risk of skin cancer and may require additional sun protection and early detection strategies specific to their health needs. Please consult your doctor for specific health advice.