However, the threat posed by the majority is tiny - although medical attention is still required. But it is one type in particular, malignant melanoma, which accounts for a relatively small number of cases, and the vast majority of deaths from skin cancer. Malignant melanoma tends to spread much more rapidly through the bloodstream than the other two types of skin cancer. If an adult has a growing, changing, brown or black mark which cannot be covered by the blunt end of a pencil, this should be shown to the doctor without too much delay.
Doctors advise people to cover up in sunny weather, and to avoid sunburn if at all possible.
There are three principal types of skin cancer, and different cancers can have different appearances. It is a slow growing cancer, and does not often spread to other parts of the body. Melanoma is a different matter - it affects the cells which produce the skin's colouring, and can spread to affect the liver, lungs or brain. Doctors warn patients to look out for changes in the appearance of moles, or new growths or sores which fail to heal. They are rarely painful, although they can be scaly or itchy - so it is mistake to await pain before consulting a doctor.