Skin cancer

Overview

Skin cancer is a group of cancers that start in the skin, divided into melanoma and non-melanoma types. In the UK, basal cell carcinoma is the most common type of non-melanoma skin cancer. Ultraviolet (UV) light from the sun or sunbeds is the most common cause. Surgery is the main treatment for non-melanoma skin cancer and for early melanoma. A mole that has changed, or a new or unusual mark or growth that does not go away, is a reason to see a GP.

Symptoms

What a clinician may find

• A new mole, or a change in an existing mole
• A mole that changes in size, shape or colour
• A mole that is swollen, sore, bleeding, itchy or crusty
• A growth or unusual patch on the skin that varies in colour, size and texture
• A dark area under a nail that was not caused by an injury
• A sore or broken (ulcerated) area, which can occur in melanoma on brown or black skin

Complications

• Melanoma that is very deep or has spread to the lymph nodes is more likely to return after treatment
• Spread of the cancer beyond the skin, which scans or blood tests may be used to assess

Diagnosis

If a GP suspects melanoma, the NHS says the person should see a specialist within two weeks of seeing the GP. At the specialist appointment the mole may be removed and sent for testing (a biopsy) to check whether it is cancerous. For non-melanoma skin cancer, the specialist may recommend cutting out a small area of affected skin so that it can be checked in a laboratory for cancer, which is called an excision biopsy. If melanoma is confirmed, the NHS lists CT or MRI scans, tests of the lymph nodes and blood tests to find out whether it has spread.

Treatment

Surgery to remove the cancer is the main treatment for non-melanoma skin cancer, according to the NHS. Radiotherapy, medicines, photodynamic therapy and chemotherapy are also sometimes used. For melanoma, the NHS says the surgeon removes the melanoma and an area of healthy skin around it, and Cancer Research UK calls surgery the main treatment for melanoma in situ and early melanomas. Targeted medicines or immunotherapy are sometimes used for melanomas that cannot be treated with surgery.

Prevention

A British Association of Dermatologists leaflet says that shielding the skin from ultraviolet light lowers the number of new actinic keratoses and the risk of skin cancer. It advises clothing, a hat, UV-protective sunglasses and shade in the middle of the day, with sunscreen as extra protection rather than a replacement for them. It also advises avoiding sunlamps, sunbeds and UV tanning cabinets.

Key facts

What is skin cancer?

The NHS describes two broad groups, melanoma and non-melanoma skin cancer, and gives each its own information. The NHS lists basal cell carcinoma and squamous cell carcinoma as the two main types of non-melanoma skin cancer. In the UK, basal cell carcinoma is the most common type, with squamous cell carcinoma the second most common.

Ultraviolet (UV) light is the most common cause of both melanoma and non-melanoma skin cancer, and it comes from the sun and from sunbeds. Surgery is the main treatment for non-melanoma skin cancer, and for early melanoma. For non-melanoma skin cancer, the NHS says that finding it early can mean it is easier to treat. The NHS adds that these two main types can often be treated easily. Melanoma and non-melanoma skin cancer differ in how they look, so their signs are described separately below.

What are the signs of melanoma?

The NHS says a new mole, or a change in an existing mole, can be an early sign of melanoma. It describes normal moles as usually round with smooth edges and one colour, while melanomas are often an uneven shape and a mix of two or more colours. Other signs to look out for include a mole that is swollen, sore, bleeding, itchy or crusty. The NHS advises seeing a GP about a mole that has changed in size, shape or colour. It also lists a new or unusual mark on the skin that has not gone away after a few weeks, and a dark area under a nail that was not caused by an injury.

A checklist called ABCDE is often used to describe the features to look for, standing for asymmetry, border, colour, diameter and evolving. Cancer Research UK says melanoma can be harder to spot in people with brown or black skin. In these cases it may appear under a nail or on the palm of the hand or sole of the foot. It may not show the usual ABCD signs, or it may have a sore or broken (ulcerated) surface.

What are the signs of non-melanoma skin cancer?

The NHS says the main symptom of non-melanoma skin cancer is a growth or unusual patch on the skin. These growths and patches can vary in colour, size and texture, and they appear mostly on sun-exposed areas. The NHS advises seeing a GP about a growth that is getting bigger or has changed colour or texture. It gives the same advice for a growth or area of skin that hurts, itches, bleeds, crusts or scabs for more than four weeks.

A British Association of Dermatologists leaflet says actinic keratoses, a sun-related skin change, are caused by sun exposure over many years. The leaflet lists sunbathing, sunbed use and outdoor work or leisure activities among the sources of that exposure. It advises examining the skin every few months and seeing a doctor about anything new that looks abnormal. It also advises visiting a GP if an actinic keratosis starts to become a lump or to bleed.

What causes skin cancer and who is at higher risk?

The NHS names ultraviolet (UV) light as the most common cause of melanoma and of non-melanoma skin cancer. The light comes from the sun and is also used in sunbeds. For melanoma, the NHS lists pale skin that burns easily in the sun, red or blonde hair, and blue or green eyes as risk factors. A large number of freckles or moles and a family history of skin cancer also raise the risk. Melanoma is more common in older people, though younger people can also get it.

Having brown or black skin lowers the chance of non-melanoma skin cancer, but it does not remove it. The NHS lists pale skin that burns easily, red or fair hair, using sunbeds a lot and having had a non-melanoma skin cancer before among its risk factors. Non-melanoma skin cancer is more common in older people, and people who work outdoors are at increased risk, according to Cancer Research UK. A British Association of Dermatologists leaflet says shielding the skin from UV light lowers the risk of skin cancer.

How is skin cancer diagnosed?

If a GP suspects melanoma, the NHS says the person should see a specialist within two weeks of seeing the GP. At the specialist appointment the mole may be removed and sent for testing, called a biopsy, to check whether it is cancerous. The NHS says results should take about two weeks, though it may sometimes be longer. For non-melanoma skin cancer, the specialist may recommend cutting out a small area of affected skin to be checked in a laboratory. The NHS says basal cell carcinoma rarely spreads, so more tests are only needed if it is very large.

If melanoma is confirmed, the NHS lists CT or MRI scans, tests to see whether it has spread to the lymph nodes, and blood tests. Cancer Research UK adds that a PET scan can also be used. The results show how deep the cancer is and how far it has spread, which is called the stage. MedlinePlus says melanoma that is very deep, or has spread to the lymph nodes, is more likely to return after treatment.

How is skin cancer treated?

For melanoma, the NHS says the surgeon removes the melanoma and an area of healthy skin around it, and may also remove affected lymph nodes. Cancer Research UK calls surgery the main treatment for melanoma in situ and early melanomas. Targeted medicines or immunotherapy are sometimes used for melanomas that cannot be treated with surgery, and Cancer Research UK says they are the main treatments for stage 4 melanoma. The NHS says radiotherapy is sometimes used to reduce the size of large melanomas and relieve symptoms. Chemotherapy is sometimes used for advanced melanoma but does not work as well as targeted medicines and immunotherapy.

Surgery is the main treatment for non-melanoma skin cancer. Radiotherapy, medicines, photodynamic therapy and chemotherapy are also sometimes used. The treatment depends on the type of skin cancer, where it is, whether it has spread and the general health of the person. If a large area of skin is removed, skin may be taken from another part of the body to cover the area.

Frequently asked questions