Sun exposure and skin cancer
Some sunlight is important for our health as the sun's rays help the body produce vitamin D. However, too much sun exposure without the right protection can harm the skin. This may increase the signs of ageing, or in serious cases lead to skin cancer.
Over time, the sun’s ultraviolet (UV) light damages the fibres in the skin called elastin. When these fibres break down, the skin begins to sag, stretch and lose its ability to go back into place after stretching. The skin also bruises and tears more easily - and takes longer to heal. So while sun damage to the skin may not be apparent when you’re young, it will definitely show later in life.
How does the sun change my skin?
Exposure to the sun causes:
- Pre-cancerous (actinic keratosis) and cancerous (basal cell carcinoma, squamous cell carcinoma and malignant melanoma) skin lesions
- Benign tumours
- Fine and coarse wrinkles
- Discoloured areas of the skin, called mottled pigmentation
- Sallowness - a yellow discolouration of the skin
- Telangiectasias - the dilation of small blood vessels under the skin
- Elastosis - the destruction of the elastic tissue, causing lines and wrinkles
What causes skin cancer?
In skin tumours, there is uncontrolled growth of skin cells. Tumours can be either benign (the cells do not spread outside the tumour) or malignant (the cells have the ability to spread). The term “malignant skin tumour” is synonymous with the term “skin cancer”. The incidence of skin cancer is increasing in the UK and it is now the commonest form of cancer.
There are three main types of skin cancer: basal cell carcinoma (sometimes known as “rodent ulcer”), squamous cell carcinoma and malignant melanoma. Basal cell and squamous cell cancers are less serious forms of skin cancer. Also referred to as non-melanoma skin cancers, they are highly curable when treated early. Malignant melanoma - made up of abnormal skin pigment cells, called melanocytes - accounts for just 10% of all cases of skin cancer in the UK. However, left untreated it can spread to other organs and be difficult to control. It is responsible for most of the deaths from skin cancer.
Ultraviolet (UV) radiation from the sun is the number one cause of skin cancer, but UV light from sunbeds is also harmful.
Cumulative sun exposure causes mainly basal cell and squamous cell skin cancer, while episodes of severe sunburn, usually before the age of 18, can cause malignant melanoma later in life. Other less common causes are repeated X-ray exposure and occupational exposure to certain chemicals.
Who is at risk?
Although anyone can get skin cancer, the risk is greatest for people who have fair or freckled skin that burns easily, light eyes and blond or red hair. Darker skinned individuals are also susceptible to all types of skin cancer, although their risk is substantially lower.
Other risk factors include:
- A family history or personal history of skin cancer
- Having an outdoor job
- Living in a sunny climate
- A history of severe sunburns
- An abundance of large and irregularly shaped moles