Skin cancer (melanoma)

Melanoma is a type of skin cancer that can spread to other organs in the body.

The most common sign of melanoma is the appearance of a new mole or a change in an existing mole. This can happen anywhere on the body, but the back, legs, arms and face are most commonly affected.

In most cases, melanomas have an irregular shape and more than 1 colour. They may also be larger than normal moles and can sometimes be itchy or bleed.

An 'ABCDE checklist' has been developed for people to tell the difference between a normal mole and a melanoma. 

Read more about the symptoms of melanoma.

These pages mainly cover a type of melanoma known as superficial spreading melanoma, which accounts for around 70% of all melanomas in the UK.

Nodular melanoma

Nodular melanoma is a fast-developing type of melanoma, most common in middle-aged people. It may not develop from an existing mole and can appear in areas of skin that aren't regularly exposed to the sun.

Lentigo maligna melanoma

Lentigo maligna melanoma is most common in elderly people and those who have spent a lot of time outdoors. It is common on the face and tends to grow slowly over a number of years.

Acral lentiginous melanoma 

Acral lentiginous melanoma is a rare type of melanoma that usually appears on the palms of the hands and the soles or big toenails of the feet. This is the most common type of melanoma in people with dark skin.

Cancer Research UK has more information about the different types of melanoma.

Why does melanoma happen?

Melanoma happens when some cells in the skin begin to develop abnormally. It's thought that exposure to ultraviolet (UV) light from natural or artificial sources may be partly responsible.

Certain things can increase your chances of developing melanoma, such as having:

• lots of moles or freckles
• pale skin that burns easily
• red or blonde hair
• a family member who has had melanoma

Read more about the causes of melanoma.

Diagnosing melanoma

Speak to your GP if you notice any change to your moles. Your GP will refer you to a specialist clinic or hospital if they think you have melanoma.

In most cases, a suspicious mole will be surgically removed and studied to see if it is cancerous. This is known as a biopsy.

You may also have a test to check if the melanoma has spread elsewhere in your body. This is known as a sentinel node biopsy.

Read more about diagnosing melanoma.

How is melanoma treated?

The main treatment for melanoma is surgery, although your treatment will depend on your circumstances.

If melanoma is diagnosed and treated at an early stage, surgery is usually successful.

If melanoma isn't diagnosed until an advanced stage, treatment is mainly used to slow the spread of the cancer and reduce symptoms. This usually involves medicines, such as chemotherapy.

Read more about treating melanoma.

Once you have had melanoma, there is a chance it may return. This risk is increased if your cancer was widespread and severe.

If your cancer team feels there is a significant risk of your melanoma returning, you will probably need regular check-ups to monitor your health. You will also be taught how to examine your skin and lymph nodes to help detect melanoma if it returns.

Who is affected

Melanoma is the 5th most common cancer in the UK.

More than a quarter of cases are diagnosed in people under 50, which is unusual compared to most other types of cancer. It's also becoming more common in the UK over time, thought to be caused by increased exposure to UV light from the sun and sunbeds.

Can melanoma be prevented?

Melanoma is not always preventable, but you can reduce your chances of developing it by limiting your exposure to UV light.

You can help protect yourself from sun damage by using sunscreen and dressing sensibly in the sun. Sunbeds and sunlamps should also be avoided.

Regularly checking your moles and freckles can help lead to early diagnosis and increase your chances of successful treatment.

The first sign of a melanoma is often a new mole or a change in the appearance of an existing mole.

Normal moles are usually round or oval, with a smooth edge, and no bigger than 6mm (1/4 inch) in diameter.

Speak to your GP as soon as possible if you notice changes in a mole, freckle or patch of skin, especially if the changes happen over a few weeks or months.

Signs to look out for include a mole that is:

• getting bigger
• changing shape
• changing colour
• bleeding or becoming crusty
• itchy or painful

A helpful way to tell the difference between a normal mole and a melanoma is the ABCDE checklist:

• Asymmetrical – melanomas have 2 very different halves and are an irregular shape
• Border – melanomas have a notched or ragged border
• Colours – melanomas will be a mix of 2 or more colours
• Diameter – melanomas are larger than 6mm (1/4 inch) in diameter.
• Enlargement or elevation – a mole that changes size over time is more likely to be a melanoma

Melanomas can appear anywhere on your body, but they most commonly appear on the back, legs, arms and face. They may sometimes develop underneath a nail.

In rare cases, melanoma can develop in the eye. Noticing a dark spot or changes in vision can be signs, although it is more likely to be diagnosed during a routine eye examination.

Read further information:

• Cancer Research UK: Melanoma symptoms

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 3 types of UV light:

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

UVC is filtered out by the Earth's atmosphere, but 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 skin cancer.

Artificial sources of 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, increases the risk of melanoma in people of all ages.

Moles

You are at an increased risk of melanoma if you have lots of moles on your body, especially if they are large (over 5mm) or unusually shaped.

Having just 1 unusually shaped or very large mole increases your risk of melanoma by 60%.

For this reason, it's important to monitor moles for changes and avoid exposing them to the sun.

Family history

Research suggests that if you have 2 or more close relatives who have had non-melanoma skin cancer, your chances of developing the condition may be increased.

Increased risk

Certain things are believed to increase your chances of developing all types of skin cancer, including:

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

Read further information:

• Cancer Research UK: Melanoma risks and causes.

A diagnosis of melanoma will usually begin with an examination of your skin. Your GP will refer you to a specialist if they suspect melanoma.

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

As melanoma is a relatively rare condition, many GPs will only see a case every few years. It's important to monitor your moles and return to your GP if you notice any changes. Taking photos to document any changes will help with diagnosis.

Seeing a specialist

In 2015, the National Institute for Health and Care Excellence (NICE) published guidelines to help GPs recognise the signs and symptoms of malignant melanoma and refer people for the right tests faster. To find out if you should be referred for further tests for suspected malignant melanoma, read the NICE 2015 guidelines on Suspected Cancer: Recognition and Referral.

You will be referred to a dermatology clinic or hospital for further testing if melanoma is suspected. You should see a specialist within 2 weeks of seeing your GP.

The dermatologist or plastic surgeon will examine the mole and the rest of your skin. They may also remove the mole and send it for testing (biopsy) to check whether the mole is cancerous. A biopsy is usually carried out under local anaesthetic, meaning the area around the mole will be numbed and you won't feel any pain.

If cancer is confirmed, you will usually need a further operation, most often carried out by a plastic surgeon, to remove a wider area of skin.

Further tests

Further tests will be carried out if there is a concern the cancer has spread into other organs, bones or your bloodstream.

Sentinel lymph node biopsy

If melanoma spreads, it will usually begin spreading through channels in the skin (called lymphatics) to the nearest group of glands (called lymph nodes). Lymph nodes are part of the body’s immune system, helping to remove unwanted bacteria and particles from the body.

Sentinel lymph node biopsy is a test to determine whether microscopic amounts of melanoma (less than would show up on any X-ray or scan) might have spread to the lymph nodes. It is usually carried out by a specialist plastic surgeon, while you are under general anaesthetic.

A combination of blue dye and a weak radioactive chemical is injected around your scar. This is usually done just before the wider area of skin is removed. The solution follows the same channels in the skin as any melanoma.

The first lymph node this reaches is known as the 'sentinel' lymph node. The surgeon can locate and remove the sentinel node, leaving the others intact. The node is then examined for microscopic specks of melanoma (this process can take several weeks).

If the sentinel lymph node is clear of melanoma, it's extremely unlikely that any other lymph nodes are affected. This can be reassuring because if melanoma spreads to the lymph nodes, it's more likely to spread elsewhere.

If the sentinel lymph node contains melanoma, there is a risk that other lymph nodes in the same group will contain melanoma.

Your surgeon should discuss the pros and cons of having a sentinel lymph node biopsy before you agree to the procedure. Sentinel lymph node biopsy does not cure melanoma, but is used to investigate the outlook of your condition.

An operation to remove the remaining lymph nodes in the group may be recommended. This is known as a completion lymph node dissection or completion lymphadenectomy.

Other tests you may have include:

• a computerised tomography (CT) scan
• a magnetic resonance imaging (MRI) scan
• a positron emission tomography (PET) scan
• blood tests

Read further information:

• Cancer Research UK: Melanoma tests
• Cancer Research UK: Further tests for melanoma

Melanoma stages

Health professionals use a staging system to describe how far melanoma has grown into the skin (the thickness) and whether it has spread. The type of treatment you receive will depend on what stage the melanoma has reached.

The melanoma stages can be described as:

• stage 0 – the melanoma is on the surface of the skin
• stage 1A – the melanoma is less than 1mm thick
• stage 1B – the melanoma is 1 to 2mm thick, or the melanoma is less than 1mm thick and the surface of the skin is broken (ulcerated) or its cells are dividing faster than usual (mitotic activity)
• stage 2A – the melanoma is 2 to 4mm thick, or the melanoma is 1 to 2mm thick and is ulcerated
• stage 2B – the melanoma is thicker than 4mm, or the melanoma is 2 to 4mm thick and ulcerated
• stage 2C – the melanoma is thicker than 4mm and ulcerated
• stage 3A – the melanoma has spread into 1 to 3 nearby lymph nodes, but they are not enlarged; the melanoma is not ulcerated and has not spread further
• stage 3B – the melanoma is ulcerated and has spread into 1 to 3 nearby lymph nodes but they are not enlarged, or the melanoma is not ulcerated and has spread into 1 to 3 nearby lymph nodes and they are enlarged, or the melanoma has spread to small areas of skin or lymphatic channels, but not to nearby lymph nodes
• stage 3C – the melanoma is ulcerated and has spread into 1 to 3 nearby lymph nodes and they are enlarged, or the melanoma has spread into 4 or more lymph nodes nearby
• stage 4 – the melanoma cells have spread to other areas of the body, such as the lungs, brain or other parts of the skin

Read further information:

• Cancer Research UK: Treating melanoma
• Cancer Research UK: Stages of melanoma
• Macmillan: Melanoma

Stage 1 melanoma

Treating stage 1 melanoma will involve surgically removing the melanoma and a small area of skin around it – this is known as surgical excision.

Surgical excision is usually carried out under local anaesthetic. This means you will be awake but the area around the melanoma will be numbed, so you won't feel pain. In some cases, general anaesthetic is used, which means you will be asleep during the procedure.

If a surgical excision is likely to leave a significant scar, it may be done in combination with a skin graft. A skin graft involves removing a patch of healthy skin, usually taken from a part of your body where scarring cannot be seen, such as your back. It is then connected, or grafted, to the affected area. Skin grafts or flaps are used when the area of skin being removed is too big to close using a direct method.

Once the melanoma has been removed, there is little possibility it will return and no further treatment should be required. You will probably be asked to come for follow-up appointments before being discharged. 

Stage 2 and 3 melanoma

As with stage 1 melanomas, any affected areas of skin will be removed. The remaining skin is either closed directly, or a skin graft or flap may be carried out if necessary.

Sentinel node biopsy

Sentinel node biopsy, which is not a mandatory procedure, will be discussed with you. If you decide to go ahead with the procedure and the results show no spread to nearby lymph nodes, it is unlikely you will have further problems with this melanoma.

If the test confirms melanoma has spread to nearby nodes, your specialist will discuss with you whether further surgery is required. Additional surgery involves removing the remaining nodes, known as a completion lymph node dissection or completion lymphadenectomy.

Lymph nodes

If the melanoma has spread to nearby lymph nodes, you may need further surgery to remove them. Your doctor will have felt a lump in your lymph nodes and the diagnosis of melanoma is usually confirmed using a needle biopsy (fine needle aspiration). Removing the affected nodes requires a procedure called a block dissection, performed under general anaesthetic.

While the surgeon will try to ensure the rest of your lymphatic system can function normally, there is a risk that the removal of lymph nodes will disrupt the lymphatic system, leading to a build-up of fluids in your limbs. This is known as lymphoedema.

Follow-up

Once the melanoma has been removed, you will need follow-up appointments to see how you are recovering and to watch for any sign of the melanoma returning.

You may be offered treatment to try to prevent the melanoma returning. This is called adjuvant treatment. There is not much evidence that adjuvant treatment helps prevent melanoma from coming back, so this is only offered as part of a clinical trial.

Stage 4 melanoma

It may not be possible to cure melanoma if it has:

• been diagnosed at its most advanced stage
• spread to another part of your body (metastasis)
• come back in another part of your body after treatment (recurrent cancer)

Treatment is available and given in the hope that it can slow the cancer's growth, reduce any symptoms you may have and possibly extend your life expectancy.

You may be able to have surgery to remove other melanomas that have occurred away from the original site.

You may also be able to have other treatments to help with symptoms. These include:

• radiotherapy 
• drug treatments

Radiotherapy

Radiotherapy may be used after an operation to remove your lymph nodes, and can also be used to help relieve the symptoms of advanced melanoma.

Radiotherapy uses controlled doses of radiation to kill cancer cells. It is given at the hospital as a series of 10 to 15 minute daily sessions, with a rest period over the weekend.

The side effects of radiotherapy include:

• tiredness
• nausea
• loss of appetite
• hair loss
• sore skin

Many side effects can be prevented or controlled with medicines your doctor can prescribe, so let them know about any that you experience. After treatment has finished, the side effects of radiotherapy should gradually reduce.

Read further information:

• Cancer Research UK: Radiotherapy for melanoma.

Drug treatment

In recent years there have been major advancements in treating melanoma. The medications used to treat melanoma are changing as new formulations are being introduced into clinics.

The medications currently being used include:

• vemurafenib
• ipilimumab
• nivolumab

However, not everyone is suitable for these drugs. Your specialist will discuss an appropriate treatment with you, and many people are entered into clinical trials.

Chemotherapy

Chemotherapy involves using anti-cancer (cytotoxic) drugs to kill the cancer. It is normally used to treat melanoma that has spread to parts of the body and is mainly given to help relieve symptoms of advanced melanoma.

Several different chemotherapy drugs are used to treat melanoma and are occasionally given in combination. The drugs most commonly used for melanoma are dacarbazine and temozolomide. However, many different types of drugs can be used. Your specialist can discuss with you which drugs are the most suitable.

Chemotherapy is usually given as an outpatient treatment, which means you will not have to stay in hospital overnight. Dacarbazine is given through a drip and temozolomide is given in tablet form. Chemotherapy sessions are usually given once every 3 to 4 weeks, with gaps between treatment intended to give your body and blood time to recover.

The main side effects of chemotherapy are caused by their influence on the rest of the body. Side effects include infection, nausea and vomiting, tiredness and sore mouth. Many side effects can be prevented or controlled with medicines that your doctor can prescribe.

Electrochemotherapy

Electrochemotherapy is a possible treatment for melanoma. It may be considered if:

• surgery isn't suitable or hasn't worked
• radiotherapy and chemotherapy haven't worked

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

These electrical pulses allow the medicine to enter the tumour cells more effectively and cause more damage to the tumour. The procedure is usually carried out using general anaesthetic (where you're asleep) but some people may be able to have local anaesthetic (where you're awake but the area 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 some pain where the electrode was used, which can last for a few days and may require painkillers.

It usually 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 this treatment option.

Read the NICE (2013) guidelines on Electrochemotherapy for metastases in the skin.

Immunotherapy

Immunotherapy uses drugs (often derived from substances that occur naturally in the body) that encourage your body's immune system to work against the melanoma. Two such treatments in regular use for melanoma are interferon-alpha and interleukin-2. Both are given as an injection (into the blood, under the skin, or into lumps of melanoma).

Side effects include flu-like symptoms, such as chills, a high temperature, joint pain and fatigue.

Vaccines

There is ongoing research into producing a vaccine for melanoma, either to treat advanced melanoma or to be used after surgery in patients who have a high risk of the melanoma coming back.

Vaccines are designed to focus the body’s immune system so it recognises the melanoma and can work against it. Vaccines are usually given as an injection under the skin every few weeks, often over a period of months.

As more research is needed into vaccines, they are only given as part of a clinical trial.

Monoclonal antibodies

Our immune systems make antibodies all the time, usually as a way of controlling infections. They are substances that recognise something which doesn’t belong in the body and help to destroy it. Antibodies can be produced in the laboratory and can be made to recognise and lock onto specific targets, either in the cancer or in specific parts of the body.

Antibodies produced in the laboratory are usually called monoclonal antibodies.

Ipilimumab

Ipilimumab is a monoclonal antibody that has been licensed for use in the UK since 2011. It works like an accelerator for the immune system, allowing the body to work against all sorts of conditions, including cancer.

In December 2012, NICE recommended ipilimumab as a possible treatment for people with previously treated advanced melanoma that has spread or cannot be surgically removed.

Signalling inhibitors

Signalling inhibitors are drugs that work by disrupting the messages (signals) a cancer uses to co-ordinate its growth. There are hundreds of these signals, and it is difficult to know which ones need to be blocked. Most of the signals have short, technical names. Two that are of current interest in relation to melanoma are BRAF and MEK.

There are drugs available that can interfere with these signals, but most are currently only widely available as part of clinical trials.

NICE recommends a signalling inhibitor called vemurafenib as a possible treatment for melanoma that has spread or cannot be surgically removed.

Read further information:

• Cancer Research UK: Biological therapy for melanoma.
• Cancer Research UK: Chemotherapy for melanoma.

Clinical trials

All new treatment for cancer (and other diseases) is first given to patients in a clinical trial.

A clinical trial or study is an extremely rigorous way of testing a drug on people. Patients are monitored for any effects of the drug on the cancer, as well as side effects. Many people with melanoma are offered entry into clinical trials, but some people are suspicious of the process.

There are a few key things to know about clinical trials:

• overall, patients in clinical trials do better than those on routine treatment, even when receiving a drug that would be given routinely
• all clinical trials are highly regulated
• all new treatments will first become available through clinical trials
• even where a new drug fails to offer any benefits over existing treatment, the knowledge that we gain from the trial is valuable for future patients

If you are asked to take part in a trial, you will be given an information sheet and, if you want to take part, you will be asked to sign a consent form. You can refuse or withdraw from a clinical trial without it affecting your care.

Read further information:

• Cancer Research UK: Melanoma research.

Deciding against treatment for stage 4 melanoma

Many of the treatments described have unpleasant side effects that can affect your quality of life. You may decide against having treatment if it is unlikely to significantly extend your life expectancy, or if you do not have symptoms causing you pain or discomfort.

This is entirely your decision and your healthcare team will respect it. If you decide not to receive treatment, pain relief and nursing care will be made available when you need it. This is called palliative care.

Read further information:

• Accessing palliative care
• Cancer Research UK: Advanced melanoma (stage 4)