Basal cell carcinoma

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Basal Cell Carcinoma

Overview - Skin cancer (non-melanoma)

Skin cancer is one of the most common cancers in the world. Non-melanoma skin cancer refers to a group of cancers that slowly develop in the upper layers of the skin.

The term non-melanoma distinguishes these more common types of skin cancer from the less common skin cancer known as melanoma, which can be more serious.

In the UK, around 147,000 new cases of non-melanoma skin cancer are diagnosed each year. It affects more men than women and is more common in the elderly.

Symptoms of non-melanoma cancer

The first sign of non-melanoma skin cancer is usually the appearance of a lump or discoloured patch on the skin that persists after a few weeks and slowly progresses over months or sometimes years. This is the cancer, or tumour.

Picture of non-melanoma skin cancer
Credit:

DR P. MARAZZI/SCIENCE PHOTO LIBRARY

In most cases, cancerous lumps are red and firm and sometimes turn into ulcers, while cancerous patches are usually flat and scaly.

Non-melanoma skin cancer most often develops on areas of skin regularly exposed to the sun, such as the face, ears, hands, shoulders, upper chest and back.

When to get medical advice

See a GP if you have any skin abnormality, such as a lump, ulcer, lesion or skin discolouration that has not healed after 4 weeks. While it's unlikely to be skin cancer, it's best to get it checked.

Types of non-melanoma skin cancer

Non-melanoma skin cancers usually develop in the outermost layer of skin (epidermis) and are often named after the type of skin cell from which they develop.

The 2 most common types of non-melanoma skin cancer are:

  • basal cell carcinoma (BCC), also known as a rodent ulcer, starts in the cells lining the bottom of the epidermis and accounts for about 75 in every 100 skin cancers
  • squamous cell carcinoma (SCC) starts in the cells lining the top of the epidermis and accounts for about 20 in every 100 skin cancers

Basal cell carcinoma

Basal cell carcinoma (BCC) usually appears as a small, shiny pink or pearly-white lump with a translucent or waxy appearance. It can also look like a red, scaly patch.

There's sometimes some brown or black pigment within the patch.

The lump slowly gets bigger and may become crusty, bleed or develop into a painless ulcer.

Basal cell carcinoma does not usually spread to other parts of the body. There's a small risk (up to 5%) of squamous cell carcinoma spreading to other parts of the body, usually the lymph nodes (small glands found throughout your body).

Squamous cell carcinoma

Squamous cell carcinoma (SCC) appears as a firm pink lump with a rough or crusted surface. There can be a lot of surface scale and sometimes even a spiky horn sticking up from the surface.

The lump often feels tender when touched, bleeds easily and may develop into an ulcer.

For both SCC and BCC there can sometimes be considerable skin damage if the tumour is not treated.

Bowen's disease

Bowen's disease is a precancerous form of Squamous cell carcinoma SCC sometimes referred to as squamous cell carcinoma in situ. It develops slowly and is easily treated. 

The main sign is a red, scaly patch on the skin that may itch. It most commonly affects elderly women and is often found on the lower leg. However, it can appear on any area of skin.

Although not classed as non-melanoma skin cancer, Bowen's disease can sometimes develop into SCC if left untreated.

Actinic keratoses

Actinic keratoses, also known as solar keratoses, are dry, scaly patches of skin caused by damage from years of sun exposure.

The patches can be pink, red or brown, and can vary in size from a few millimetres to a few centimetres across.

The affected skin can sometimes become very thick, and occasionally the patches can look like small horns or spikes.

Like Bowen's disease, actinic keratosis is not classed as non-melanoma skin cancer, but there's a small risk that the patches could develop into squamous cell carcinoma (SCC) if untreated.

What causes non-melanoma skin cancer?

Overexposure to ultraviolet (UV) light is the main cause of non-melanoma skin cancer. UV light comes from the sun, as well as from artificial tanning sunbeds and sunlamps.

Other risk factors that can increase your chances of developing non-melanoma skin cancer include:

  • a previous non-melanoma skin cancer
  • a family history of skin cancer
  • pale skin that burns easily
  • a large number of moles or freckles
  • taking medicine that suppresses your immune system
  • a co-existing medical condition that suppresses your immune system

Diagnosing non-melanoma skin cancer

A GP can examine your skin for signs of skin cancer. They may refer you to a skin specialist (dermatologist) or a specialist plastic surgeon if they're unsure or suspect skin cancer.

You'll have an urgent referral (within 2 weeks) if you have squamous cell skin cancer.

Basal cell skin cancers usually do not need an urgent referral, but you should still see a specialist within 18 weeks.

Find out more about NHS waiting times

The specialist will examine your skin and may do a biopsy to confirm a diagnosis of skin cancer.

A biopsy is a procedure where some of the affected skin is removed so it can be examined.

Treating non-melanoma skin cancer

Surgery is the main treatment for non-melanoma skin cancer. It involves removing the cancerous tumour and some of the surrounding skin.

Other treatments for non-melanoma skin cancer include freezing (cryotherapy), anti-cancer creams, radiotherapy and a form of light treatment called photodynamic therapy (PDT).

The treatment used will depend on the type, size and location of the non-melanoma skin cancer you have.

Treatment for non-melanoma skin cancer is usually successful as, unlike most other types of cancer, there's a considerably lower risk that the cancer will spread to other parts of the body.

Basal cell carcinoma (BCC) does not usually spread to other parts of the body. There's a small risk (up to 5%) of squamous cell carcinoma (SCC) spreading to other parts of the body, usually the lymph nodes (small glands found throughout your body).

However, for both BCC and SCC there can sometimes be considerable skin damage if the tumour is not treated.

At least 9 out of 10 non-melanoma skin cancer cases are successfully cured.

Complications

If you've had non-melanoma skin cancer in the past, there's a chance the condition may return.

The chance of non-melanoma skin cancer returning is increased if your previous cancer was large in size and high grade (severe).

If your cancer team feels there's a significant risk of non-melanoma skin cancer returning, you'll probably need regular check-ups to monitor your health.

It's also important to be aware that if you've had a non-melanoma skin cancer, your risk of developing another one in the future is increased because these cancers are often multiple.

This means it's important to regularly examine your skin to check for new tumours.

Preventing non-melanoma skin cancer

Non-melanoma skin cancer is not always preventable, but you can reduce your chance of developing it by avoiding overexposure to UV light.

You can protect yourself from sunburn by using high-factor sunscreen, dressing sensibly in the sun, and limiting the amount of time you spend in the sun during the hottest part of the day.

Sunbeds and sunlamps should also be avoided.

Regularly checking your skin for signs of skin cancer can help lead to an early diagnosis and increase your chance of successful treatment.

Find out more about sunscreen and sun safety

Page last reviewed: 6 January 2020
Next review due: 6 January 2023

Causes - Skin cancer (non-melanoma)

Most skin cancer is caused by ultraviolet (UV) light damaging the DNA in skin cells. The main source of UV light is sunlight.

Sunlight contains three types of UV light:

  • ultraviolet A (UVA)
  • ultraviolet B (UVB)
  • ultraviolet C (UVC)

UVC is filtered out by the earth's atmosphere. UVA and UVB damage skin over time, making it more likely for skin cancers to develop. UVB is thought to be the main cause of non-melanoma skin cancer.

Artificial sources of UV light, such as sunlamps and tanning beds, also increase your risk of developing skin cancer.

Repeated sunburn, either by the sun or artificial sources of light, will make your skin more vulnerable to non-melanoma skin cancer.

Family history

In most cases, non-melanoma skin cancer does not run in families. However, research has shown that some families have a higher than average number of members who develop the condition.

For example, if you have a parent who's had squamous cell carcinoma (SCC), your risk of also getting SCC is 2 to 3 times higher than average.

Having a family history of melanoma also increases your risk of getting basal cell carcinoma.

Other risk factors

Certain factors are thought to increase your chances of developing all types of skin cancer.

These include:

  • having pale skin that does not tan easily
  • have blonde or red hair
  • having blue eyes
  • older age
  • having a large number of moles 
  • having a large number of freckles
  • having an area of skin previously damaged by burning or radiotherapy treatment
  • having a condition that suppresses your immune system, such as HIV
  • taking medicines that suppress your immune system (immunosuppressants), commonly used after organ transplants
  • exposure to certain chemicals, such as creosote and arsenic
  • having been previously diagnosed with skin cancer

The Cancer Research UK website has more information about skin cancer risks and causes.

Page last reviewed: 6 January 2020
Next review due: 6 January 2023

Diagnosis - Skin cancer (non-melanoma)

A diagnosis of non-melanoma skin cancer will usually begin with a visit to a GP, who will examine your skin and decide whether you need further assessment by a specialist.

Some GPs take digital photographs of suspected tumours so they can email them to a specialist for assessment.

Biopsy

If skin cancer is suspected, you may be referred to a skin specialist (dermatologist) or specialist plastic surgeon. The specialist should be able to confirm the diagnosis by doing a physical examination.

However, they'll probably also do a biopsy, which is a minor surgical procedure where either part or all of the tumour is removed so it can be studied under a microscope.

This is usually done after a local anaesthetic is given, which means you'll be conscious but the affected area will be numb, so you will not feel any pain.

A biopsy allows the dermatologist or plastic surgeon to determine the type of skin cancer you have and whether there's any chance of it spreading to other parts of your body.

Skin cancer can sometimes be diagnosed and treated at the same time. The tumour can be removed and tested, and you may not need further treatment because the cancer is unlikely to spread.

It's usually several weeks before you receive the results of a biopsy.

Further tests

If you have basal cell carcinoma, further tests are not usually required as it's very unlikely that the cancer will spread.

However, you may have a second basal cell carcinoma on a different area of skin, so it makes sense to have all of your skin examined by the skin expert.

In rare cases of squamous cell carcinoma, further tests may be needed to make sure the cancer has not spread to your lymph nodes or another part of your body.

These tests may include a physical examination of your lymph nodes. If cancer has spread, it may cause your glands to swell.

If the dermatologist or plastic surgeon thinks there's a significant risk of the cancer spreading, it may be necessary to do a biopsy on a lymph node. This is called a fine-needle aspiration (FNA).

During FNA, cells are removed using a needle and syringe so they can be examined.

Finding cancerous cells in a nearby lymph node would suggest the squamous cell carcinoma has started to spread to other parts of your body.

Staging skin cancer

Staging is used to describe how far a tumour has spread. The stage of the cancer will help determine your recommended treatment.

For non-melanoma skin cancer, this only applies to squamous cell carcinoma, as there's no staging system for basal cell carcinoma.

Find out what cancer stages and grades mean

Page last reviewed: 6 January 2020
Next review due: 6 January 2023

Treatment - Skin cancer (non-melanoma)

Surgery is the main treatment for non-melanoma skin cancer, although it may depend on your individual circumstances.

Non-surgical treatments, such as freezing (cryotherapy), anti-cancer creams, photodynamic therapy (PDT), radiotherapy and electrochemotherapy, are also used in certain circumstances. 

Overall, treatment is successful for at least 9 out of 10 people with non-melanoma skin cancer.

If you have skin cancer, your specialist care team may include a dermatologist, a plastic surgeon, a radiotherapy and chemotherapy specialist (an oncologist), a pathologist (a specialist in diseased tissue) and a specialist nurse.

If you have non-melanoma skin cancer, you may see several (or all) of these specialists as part of your treatment.

When deciding which treatment is best for you, doctors will consider:

  • the type of cancer you have
  • the stage of the cancer (its size and how far it's spread)
  • your general health

Your cancer team will recommend what they think is the best treatment option, but the final decision will be yours.

Before visiting hospital to discuss your treatment options, you may find it useful to write a list of questions you'd like to ask.

For example, you may want to find out what the advantages and disadvantages are of particular treatments.

Surgical excision

Surgical excision is an operation to cut out the cancer along with surrounding healthy tissue to ensure the cancer is completely removed.

Surgical excision may be done in combination with a skin graft, which involves removing a patch of healthy skin, usually from a part of the body where any scarring cannot be seen, such as your neck, abdomen or upper thigh. It's then connected (grafted) to the affected area.

In most cases, surgery is enough to cure non-melanoma skin cancer.

Mohs micrographic surgery

Mohs micrographic surgery (MMS) is a specialist form of surgery used to treat non-melanoma skin cancers when:

  • it's felt there's a high risk of the cancer spreading or returning
  • the cancer is in an area where it would be important to remove as little skin as possible, such as the nose or close to the eyes

MMS involves surgical excision of the tumour and a small area of surrounding skin.

The edges are immediately checked under a microscope to make sure all the tumour has been completely removed.

If it has not, further surgery is done, usually on the same day. This minimises the removal of healthy tissue and reduces scarring while ensuring that the tumour has been completely removed.

Curettage and electrocautery

Curettage and electrocautery is a similar technique to surgical excision, but it's only suitable in cases where the cancer is quite small.

The surgeon will use a small spoon-shaped or circular blade to scrape off the cancer before burning (cauterising) the skin to remove any remaining cancer cells and seal the wound.

The procedure may need to be repeated 2 or 3 times to ensure the cancer is completely removed.

Cryotherapy

Cryotherapy uses cold treatment to destroy the cancer. It's sometimes used for non-melanoma skin cancers that are at an early stage.

Liquid nitrogen is used to freeze the cancer, and this causes the area to form a scab.

After about a month, the scab containing the cancer will fall off your skin. Cryotherapy may leave a small white scar on your skin.

Anti-cancer creams

Anti-cancer creams are also used for certain types of non-melanoma skin cancers, but are only recommended when the tumour is contained within the top layer of the skin, such as early basal cell carcinoma and Bowen's disease.

There are 2 main types of anti-cancer creams:

  • chemotherapy creams – these contain a medicine called 5-fluorouracil
  • immune stimulating creams – these contain a medicine called imiquimod

For non-melanoma skin cancer, chemotherapy creams containing 5-fluorouracil are used.

The cream is applied to the affected area for several weeks.

As only the surface of the skin is affected, you will not experience the side effects associated with other forms of chemotherapy, such as being sick or hair loss. However, your skin may feel sore for several weeks afterwards.

Immune stimulating creams containing imiquimod is used to treat basal cell carcinomas with a diameter of less than 2cm. It's also used to treat actinic keratoses and Bowen's disease.

Imiquimod encourages your immune system to attack the cancer in the skin and is used over several weeks.

Common side effects of 5-fluorouracil cream and imiquimod include redness, flaking or peeling skin and itchiness. Less common and more serious side effects include blistering or skin ulceration.

Photodynamic therapy (PDT)

Photodynamic therapy (PDT) is used to treat basal cell carcinoma, Bowen's disease and actinic keratoses. It involves using a cream that makes the skin highly sensitive to light.

After the cream has been applied, a strong light source is shone on to the affected area of your skin, which kills the cancer.

PDT may cause a burning sensation and may leave scarring, although there is usually less scarring than with surgery.

Radiotherapy

Radiotherapy involves using low doses of radiation to destroy the cancer. The level of radiation involved is safe. However, your skin may feel sore for a few weeks after radiotherapy.

Radiotherapy is sometimes used to treat basal cell and squamous cell carcinomas if:

  • surgery would not be suitable
  • the cancer covers a large area
  • the area is difficult to operate on

Radiotherapy is sometimes used after surgical excision to try to prevent the cancer coming back. This is called adjuvant radiotherapy.

Electrochemotherapy

Electrochemotherapy is a possible treatment for non-melanoma skin cancer.

It may be considered if:

  • surgery is not suitable or has not worked
  • radiotherapy and chemotherapy have not worked

The procedure involves giving chemotherapy into the tumour or sometimes directly into a vein (intravenously). Short, powerful pulses of electricity are then directed to the tumour using electrodes.

The electrical pulses allow the medicine to enter the tumour cells more effectively and cause more damage to the tumour.

The procedure is usually done using general anaesthetic, where you're unconscious, but some people may be able to have local anaesthetic, where you're conscious but the area being treated is numbed.

Depending on how many tumours need to be treated, the procedure can take up to an hour to complete.

The main side effect is pain where the electrode was used, which can last for a few days and may require painkillers.

It takes around 6 weeks for results to appear and the procedure usually needs to be repeated.

Your specialist can give you more detailed information about electrochemotherapy.

Page last reviewed: 6 January 2020
Next review due: 6 January 2023