Body features that are risk factors for skin cancer are: fair skin; blue, green or hazel eyes; light coloured hair; freckles; and many moles. Mole count is one of the most important markers of risk for skin cancer.
One in every three cancers diagnosed is skin cancer. Anyone can be at risk of skin cancer, though the risk increases as you get older. The majority of skin cancers are caused by exposure to ultraviolet (UV) radiation in the sun. Melanoma, the most dangerous form of skin cancer, is associated with sunburn. Sunburn is a sign of short-term overexposure to UV radiation. You can also be sunburnt on cooler or overcast days when you would mistakenly believe UV radiation is not as strong.
UV rays are strongest in areas closer to the equator. Because the sun is directly over the equator, UV rays only travel a short distance through the atmosphere to reach these areas. The ozone layer, which absorbs the sun’s harmful radiation, is naturally thinner near the equator. Australia’s relative proximity to the equator makes it people overexposed to UV radiation. At least two in three Australians will be diagnosed with skin cancer by the time they are 70. It’s one of the highest incidences of skin cancer in the world, two to three times the rates in Canada, the US and the UK. In Japan and China incidences of skin are much lower.
Everyone, regardless of skin colour, can get a sunburn. Some individual risk factors for skin cancer, according to the World Health Organisation, are:
- fair skin
- blue, green or hazel eyes
- light-coloured hair
- many moles
- a tendency to burn rather than suntan
- history of severe sunburns
- a family history of skin cancer
When 11 is a critical number
Freckles, small pale brown areas of skin, are often temporary and are usually linked to sun exposure. Moles are small coloured spots on the body and are made of the same melanocytes cells that produce pigment in your skin. They are long-lasting and are not directly linked to sun exposure, but excess sun exposure can make a mole turn malignant increasing risk of skin cancer.
Twenty to 40 per cent of skin cancer arises from pre-existing moles. Hence, the mole count is the most important risk factor for skin cancer. Risk increases by 2 to 4 per cent per additional mole on the body, counting moles on the whole body is time consuming. After studying 3,694 female twins in the UK over a period of eight years, Researchers from King’s College London have now come up with an easier method of counting moles on the entire body. They say that counting moles on the right arm is a good indicator of the total number on the whole body.
More than 11 moles on right arm indicates 100 on the entire body, which indicates a higher-than-average risk of skin cancer. Seven moles on the right arm indicates nine times the risk of having more than 50 on the whole body.
The findings would help medical practitioners to more accurately estimate the total number of moles in patients extremely quickly via an easily accessible body part, says Simone Ribero, the lead researcher.
Health professionals warn that don’t just look at your arms as skin cancer can develop anywhere in the body. Always look for any change in the size, shape, colour or feel of a mole — and also any variation from normal on any patch of skin.
© Surendra Verma 2016