What is skin cancer?

Non melanoma skin cancer includes:

• basal cell skin cancer - this is also called basal cell carcinoma (BCC)

• squamous cell skin cancer - this is also called squamous cell carcinoma (SCC)

• some other rare types

This section of the website is about non melanoma skin cancer. We have another section for melanoma skin cancer. 

Find out about melanoma skin cancer

How cancer starts

Cancer is when abnormal cells start to divide and grow in an uncontrolled way. The cells can grow into surrounding tissues or organs and may spread to other areas of the body.  

Find out more about cancer and how it starts

The skin and what it does

The skin does several jobs including:

• protecting the inside of the body from damage

• helping to keep our body temperature more or less the same

• getting rid of some body waste products through sweat

• making vitamin D which helps form and maintain our bones

The layers and cells of the skin

The skin is made up of 2 main layers:

• The epidermis is the outer layer.

• The dermis is the inner layer and is under the epidermis.

Sun damage is the cause of most skin cancers. The cells in the epidermis are most at risk of sun damage.

The thickness of the epidermis and the dermis varies depending on the part of the body the skin is covering. For example, the skin on the sole of your foot is quite thick, about 5mm. The skin on your eyelid is much thinner, only about 0.5mm.

The skin contains different types of cells including:

• keratinocytes – these are the most common cell in the epidermis and include basal cells and squamous cells

• melanocytes

Basal cells

Basal cells are a type of keratinocyte found at the bottom of the epidermis. This is the basal layer and is where all normal skin cells come from.

Basal cell skin cancer develops in the basal cells. This is also called basal cell carcinoma (BCC). BCC is the most common type of skin cancer. It mostly develops in areas of skin exposed to the sun such as the head, face, ears and neck.

Squamous cells

As the basal cells divide, the new basal cells push older ones up into the layer above. The top layers of the epidermis are made up of these cells that have died.

Squamous cell skin cancer develops from these keratinocytes in the epidermis, above the basal layer. It is also called squamous cell carcinoma (SCC).

Melanocytes

The basal cell layer also contains melanocytes. Melanocytes are a type of skin cell that make melanin. This is the brown substance (pigment) that makes skin look darker. The melanocytes produce melanin when the skin is exposed to the sun.

Melanoma skin cancer starts in the skin melanocytes.

Read more about the types of skin cancer

Who gets skin cancer?

Most skin cancers are caused by exposure to the sun. This may be long term exposure, or short periods of intense sun exposure and burning. There are several factors that affect your risk from sun exposure including:

• how much time you spend outdoors

• your natural skin colour

• whether you have moles or freckles

Sun exposure can also be in the form of sunbeds (artificial UV radiation). People who use sunbeds are also at risk of developing skin cancer.

Age is also a factor. The older you are, the more likely you are to get non melanoma skin cancer. 

Find out more about other risks and causes

People with naturally darker skin tones, such as brown or black skin, burn less easily and have a lower risk of skin cancer. This is because their skin produces more melanin which protects the skin from the sun.

But lower risk doesn’t mean there’s no risk. People with darker skin tones can still get sunburnt. And people of all skin tones can get skin cancer, so it’s important for everyone to think about protecting their skin when the sun is strong.

How common is skin cancer?

Around 156,000 cases of non melanoma skin cancer are diagnosed in the UK each year. The number could be higher as we know that they are under reported. This makes it the most common type of cancer by far. Because non melanoma skin cancers are easy to treat and cure, they're often left out of national cancer statistics.