Find out about who gets melanoma skin cancer, where it starts and how common it is.
Melanoma is a type of skin cancer.
The skin is a body organ. It does several jobs for us. It:
- protects the inside of the body from damage
- helps to keep our body temperature more or less the same
- gets rid of some waste products through sweat
The skin is made up of 2 main layers, the epidermis and the dermis.
The thickness of the epidermis and the dermis varies from about 2mm to 4mm. This depends on the part of the body the skin is covering. For example, the skin on the back is quite thick, with an epidermis and dermis of about 4mm. The skin on the face is much thinner.
Where melanoma starts
Melanoma starts in cells in the skin called melanocytes. These cells are found between the dermis and epidermis.
Melanocytes make a pigment called melanin. This gives skin its natural colour. The pigment helps to protect the body from ultraviolet light (UV radiation) from the sun.
UV radiation can cause sunburn. This is a sign of damage to the genetic material in skin cells, the DNA. Over time, enough DNA damage can cause cells to grow out of control and lead to cancer.
People who originally come from hotter climates with more sunshine tend to have naturally darker skins. They do not have more of the melanocyte cells than people with pale skin. But their melanocytes are more active and make more of the pigment.
In paler people, the pigment gives you a suntan. Exposing your skin to the sun makes the melanocytes make more pigment. The pigment is then transferred to the other skin cells to protect them against the sun's rays.
Who gets melanoma
Melanoma is more common in older people. But compared to most other cancer types, it is also quite common in younger people.
Ultraviolet radiation from the sun or sunbeds is the main environmental factor that increases the risk of developing melanoma.
Other risk factors include:
- skin type
- hair and eye colour
- number of moles
- family history of melanoma
- certain medical conditions, including having a weakened immune system
How common melanoma is
In 2015, around 15,900 people were diagnosed with melanoma in the UK. Over the last 10 years, the number of people diagnosed with melanoma in the UK has increased by almost half.
Melanoma is the 5th most common cancer in the UK.