Dr Colin Michie, Deputy Head of the University of Central Lancashire's School of Medicine and Dentistry, discusses skin cancer
After a wet few months most are dreaming of sunshine, dry warmth, and blue skies. Solar energies will open up those amazing views, lift the mists, dispel the blues.
Summer sun brings more ultraviolet light too. These are short wavelengths of sunlight that deliver high energies into our skin, passing through clouds and clothing too. Traditional linen or wool clothing, particularly if a dark colour, will absorb or block ultraviolet, but these are rarely fashionable.
Our skins typically respond to sunshine – or sun lamps - by becoming darker. The pigment melanin is produced by melanocytes, packaged, and shared with other skin cells to ensure the skin develops an even and browner colour (unless, of course, you have freckles). Protection by melanin is limited: after a few hours of sun exposure we develop sunburn. These inflammatory changes accelerate ageing processes in the skin, damaging its foundations and collagen supports.
Ultraviolet light can easily damage the DNA of skin cells and can cause a mutation that gives rise to a skin cancer. About 5% of skin cancers will be the most lethal type, melanoma. Sunshine is not the only source of damaging ultraviolet light - tanning beds and sun lamps can be a source of damaging ultraviolet light too. These carcinogenic effects were highlighted by the World Health Organisation in 2009. The cosmetic use of these needs to be balanced against the risks of developing skin lesions.
Numbers of melanoma cases continue to grow in the UK. Each year there are over 16,000 new cases and 2,300 deaths from this cancer. Rates in Cumbria are higher too than most other counties. What are the causes of this?
"Numbers of melanoma cases continue to grow in the UK. Each year there are over 16,000 new cases and 2,300 deaths from this cancer"
— Dr Colin Michie, Deputy Head of the University of Central Lancashire's School of Medicine and Dentistry
Those working with patients report that the great majority of melanomas are caused by sun exposure; they present late to health care services. They are more common in those with fair skin and with moles. Some have family histories of melanoma too. Melanomas may be small, they may seem flat; some can cause changes in existing moles.
An NHS checklist can be used for any skin marking you may be worried about. It is important to check your skin regularly and carefully to ensure you know of any changes that may be taking place and to use this checklist:
- Asymmetrical – melanomas have two very different halves and are an irregular shape
- Border – melanomas have a notched or ragged border
- Colours – melanomas will be a mix of two or more colours
- Diameter – most melanomas are larger than 6mm (1/4 inch) in diameter
- Enlargement or elevation – moles that change size are more likely to be a melanoma
It is difficult to look at all of your own skin. Since 2008 the Germans have started a preventative approach and required an annual skin check-up of all citizens. Skin cancers are now the most commonly identified malignancy in Germany; outcomes have improved for melanomas there because of early detection. This crucial first step is to have all worrisome skin problems checked by a doctor and examined carefully.
Melanoma is a particularly lethal tumour, metastasising aggressively to bones, liver, lungs, and brain. It causes the majority of all cancer deaths. Newer immunotherapies block the signals that drive melanoma cells; these are proving more effective than conventional chemotherapy. Earlier treatments remain more effective. If you have any concerns about signs and symptoms of skin cancer, please visit your GP. This summer, wearing a hat and sun protection when you venture out will protect you.