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Skin cancer (melanoma)

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What is skin cancer (melanoma)?

Melanoma is a rare and serious type of cancer that begins in the skin and 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 most often the back, legs, arms and face are affected.

In most cases, melanomas have an irregular shape and more than one 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.

Whys does melanoma happen?

Melanoma happens when some cells in the skin begin to develop abnormally. It is not known exactly why this happens, although it is thought that exposure to ultraviolet (UV) light from natural or artificial sources may be partly responsible.

A number of factors can increase your chances of developing melanoma, such as having:

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

Read more about the causes of melanoma.


See your doctor if you notice any change to your moles. Your doctor can often diagnose melanoma after an examination, although they will usually refer you to a specialist in skin conditions (dermatologist) or a specialist plastic surgeon 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 what is known as a sentinel node biopsy to check if melanoma has spread elsewhere in your body.

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. However, you may need follow-up care to prevent melanoma recurring.

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.

Who is affected

Melanoma is relatively rare, but it is becoming more common.

Melanoma is one of the most common cancers in people aged 15-34 and is also responsible for most skin cancer deaths. More than 2,000 people die every year in the UK due to melanoma.

Recurrent melanoma

If you have had melanoma in the past, there is a chance it may return. This risk is increased if your previous 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 yourself for any tumours on your skin.

Can melanoma be prevented?

Melanoma is not always preventable, but you can reduce your chances of developing the condition by avoiding overexposure 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 an early diagnosis and increase your chances of successful treatment.

Read more about preventing melanoma.

Melanoma symptoms

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

Normal moles are usually a single colour, round or oval in shape and not larger than 6mm (1/4 inch) in diameter. Melanomas are more likely to have an irregular shape, be more than one colour, and are often larger than 6mm (1/4 inch) in diameter. A melanoma may also be itchy and may bleed.

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

  • A stands for asymmetrical – melanomas have two very different halves and are an irregular shape.
  • B stands for border – unlike a normal mole, melanomas have a notched or ragged border.
  • C stands for colours – melanomas will be a mix of two or more colours.
  • D stands for diameter – unlike most moles, melanomas are larger than 6mm (1/4 inch) in diameter.
  • E stands for enlargement or evolution – a mole that changes characteristics and size over time is more likely to be a melanoma.

Melanomas can appear anywhere on your body, but the back, legs, arms and face are the most common locations. Sometimes, they may develop underneath a nail.

If you are concerned about one of your moles, see your doctor as soon as possible.

Want to know more?

  • Cancer Research UK: Melanoma symptoms.

Melanoma causes

The exact cause of melanoma is not known, although most cases are closely linked to the effects of ultraviolet (UV) light on the skin.

What is cancer?

The body is made up of millions of different types of cells. Cancer happens when some cells multiply in an abnormal way. When cancer affects organs and solid tissues, it causes a growth called a tumour to form. Cancer can occur in any part of the body.

It is not clear why cells sometimes multiply abnormally.

How does cancer spread?

Left untreated, cancer can quickly grow and spread, either in the skin or the blood, or to other parts of the body. This usually happens through the lymphatic system.

The lymphatic system is a series of glands that spread throughout your body and link together in a similar way to the blood circulation system. The lymph glands produce many of the cells needed by your immune system.

If the cancer reaches your lymphatic system, it can spread to any other part of your body, including your bones, blood and organs.


In most cases, it is thought melanomas are caused by exposure to sunlight. Sunlight contains UV light that can affect the skin.

There are two main types of UV – ultraviolet A (UVA) and ultraviolet B (UVB). Both UVA and UVB damage skin over time, making it more likely for skin cancers (including melanomas) to develop.

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

However, not all melanomas are linked with exposure to UV light and they can appear on areas of skin that are rarely exposed.

Increased risk

Factors that increase your risk of developing melanoma include:

  • pale skin that tends to burn and not tan easily
  • a family member who has had melanoma
  • red or blonde hair
  • blue eyes
  • age
  • a large number of moles
  • a large number of freckles
  • a condition that suppresses your immune system, such as HIV
  • medicines that suppress your immune system (immunosuppressants), commonly used after organ transplants

All of the above risk factors make your skin more sensitive to the effects of the sun.

Want to know more?

  • Cancer Research UK: Skin cancer risks and causes.

Diagnosing melanoma

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

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


If your doctor decides a suspicious looking mole could be the result of melanoma, you will be referred to a skin specialist (dermatologist) or specialist plastic surgeon for further testing.

The dermatologist or plastic surgeon may do a biopsy. This is a small operation where a suspect mole is removed from your skin to be studied under a microscope. This shows whether the mole is cancerous.

A biopsy is usually carried out under local anaesthetic. 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 margin of skin.

Further tests

If there is a concern the cancer could have spread into other organs, bones or your blood stream, further testing will be carried out.

Sentinel lymph node biopsy

If melanoma spreads, it will usually begin spreading in a predictable way through channels in the skin (called lymphatics) to the nearest group of glands (called lymph nodes).

These are the same glands that come up in your neck when you have a cold or sore throat, but they are found everywhere in the body. They are part of the body’s immune system, helping to remove unwanted bacteria and particles from the body.

Microscopic amounts of melanoma can spread through the lymphatics to the lymph nodes. A melanoma on the arm will most often spread to lymph nodes in the armpit, while a melanoma on the leg will most often spread to glands in the groin.

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 already have spread to the lymph nodes. It is usually carried out by a specialist plastic surgeon.

The plastic surgeon injects a combination of blue dye and a weak radioactive chemical around your scar. This will usually be done just before the wider margin of skin is removed. This dye and the radioactivity will follow the same channels in the skin as any melanoma, and the first lymph node that they get to would, logically, be the first lymph node that any cancer would reach – the “sentinel” lymph node.

Using first the radioactivity and then the blue dye, the surgeon can locate and remove the sentinel node (or sometimes nodes), leaving all the others intact. The node is then given to a pathologist who will be asked to examine it to identify or exclude a single microscopic speck of melanoma (this process can take several weeks).

If the sentinel lymph node is clear of melanoma, it is extremely unlikely (although not impossible) that any other lymph nodes are involved. This can be reassuring, since patients whose melanoma has spread to the lymph nodes are much more likely to have their melanoma spread elsewhere.

If the sentinel lymph node contains melanoma, there is around a 20% risk that at least one other lymph node in the same group will contain melanoma. Under these circumstances, you are usually recommended to have a much bigger operation to remove all the remaining lymph nodes in the affected group.

This is recommended because patients whose lymph nodes are affected and left to grow do less well than those whose affected lymph nodes are removed at an early stage. This bigger operation is often called a completion lymph node dissection or completion lymphadenectomy.

Other tests you may have include:

Melanoma treatment

Staging melanoma

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 stages of melanoma 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 1-2mm thick or the melanoma is less than 1mm thick and the surface of the skin is broken (ulcerated)
  • Stage 2A – the melanoma is 2-4mm thick or the melanoma is 1-2mm thick and is ulcerated
  • Stage 2B – the melanoma is thicker than 4mm or the melanoma is 2-4mm thick and ulcerated
  • Stage 2C – the melanoma is thicker than 4mm and ulcerated
  • Stage 3A – the melanoma has spread into one to three 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 one to three nearby lymph nodes but they are not enlarged, or the melanoma is not ulcerated and has spread into one to three 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 one to three nearby lymph nodes and they are enlarged, or the melanoma has spread into four 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

Want to know more?

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 and is usually carried out by a plastic surgeon.

Surgical excision is usually carried out under local anaesthetic. This means that you will be awake, but the area around the melanoma will be numbed and 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.

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 area of skin will be removed and a skin graft carried out if necessary.

If the melanoma has spread to nearby lymph nodes, you may need further surgery to remove them. This is known as a block dissection and is carried out under a 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.

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. Currently, there is not much evidence that adjuvant treatment helps prevent melanoma from coming back. However, ongoing clinical trials are looking into this and you may be asked to join one. These trials investigate whether drug treatment could be used to reduce the risk of the melanoma returning.

Stage 4 melanoma

If melanoma is diagnosed at its most advanced stage, or if the melanoma has spread to another part of your body (metastasis) or has come back in another part of your body after treatment (recurrent cancer), it may not be possible to cure it.

Treatment is available and given in the hope it can slow the growth of the cancer, 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 may be used after an operation to remove your lymph nodes and also 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 10-15 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 you experience. After treatment has finished, the side effects of radiotherapy should gradually reduce.

Want to know more?

Drug treatment


Chemotherapy involves using anti-cancer (cytotoxic) drugs to kill the cancer. Chemotherapy is normally used to treat melanoma that has spread to parts of the body beyond its original site. It 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 could be used. Your specialist can discuss which drugs are best for you.

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 as tablets. You would probably receive chemotherapy sessions once every three to four 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.


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.


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 that it recognises the melanoma and can work against it. Vaccines are usually given as an injection under the skin repeated every few weeks, often over a period of months.

As more research is needed into vaccines, you would only have them 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. Two types of monoclonal antibody treatments are bevacizumab and ipilimumab.

Bevacizumab is currently licensed as a treatment for advanced bowel cancer. Research is continuing to see if it can reduce the risk of melanoma returning once it has been removed from the skin or lymph nodes. Your doctor can advise you whether you would be eligible to enter the clinical trial exploring this.

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) that 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 melanoma are BRAF and MEK.

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

In December 2012, NICE recommended a signalling inhibitor called vemurafenib as a possible treatment for melanoma that has spread or cannot be surgically removed.

Want to know more?

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 in real people, with patients monitored both for an effect of the drug on the cancer, and for any side effects. Many patients 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.

Want to know more?

Deciding against treatment for Stage 4 melanoma

As many treatments above have unpleasant side effects that can affect your quality of life, you may decide against having treatment, particularly 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 as and when you need it. This is called palliative care.

Want to know more

Preventing melanoma

The best way to prevent all types of skin cancer is to avoid overexposure to the sun.

This is especially important for people who have already been treated for melanoma, as it can help prevent recurrence of the condition.

However, it is not recommended you completely avoid the sun, as it can be a good source of vitamin D, essential for healthy bones. A few minutes in the sun can help maintain healthy levels of vitamin D.

Some simple steps to manage your sun exposure are outlined below.

Avoid the sun when it is at its hottest

The sun is usually at its hottest between 11am and 3pm, but it can also be strong and have potentially damaging effects at other times. Do not spend long periods in the sun during the day and make sure you spend time in the shade and cover up with clothes as well as sunscreen.

Dress sensibly

If you cannot avoid spending long periods of time in the sun – for example, if you have a job that requires you to work outside – wear clothes that provide protection from the sun. This should include a hat to protect your face and scalp and sunglasses to protect your eyes.

Use sunscreen

When buying sunscreen, make sure it is suitable for your skin type and blocks both ultraviolet A (UVA) and ultraviolet B (UVB) radiation. A sun protection factor (SPF) of at least 15 is recommended.

Sunscreen should be applied around 15 minutes before you go into the sun and reapplied every two hours. If you are planning to spend time in the water, use a waterproof sunscreen and reapply regularly.

Take extra care to protect babies and children. Their skin is much more sensitive than adult skin and repeated exposure to sunlight could lead to skin cancer developing in later life. Before going out into the sun, make sure your children are dressed appropriately and are wearing a hat and high protection factor sunscreen.

Avoid burning

If you spend time in the sun, avoid getting sunburnt. Once you are burnt, the damage has already been done to your skin as it has received a dangerous level of radiation. Every time the skin is exposed to radiation, this increases the chance of a cancer occurring, possibly many years in the future.

Tan sensibly

Most health professionals will tell you to avoid sunbathing altogether because even a tan can increase your risk of developing skin cancer. However, if you are determined to get a tan, do it gradually by limiting the amount of time you spend in the sun each day and by wearing sunscreen. When you begin to tan, limit your exposure to the sun to 30 minutes, then gradually increase it by 5 or 10 minutes a day.

Sunbeds and sunlamps

The British Association of Dermatologists is the UK's leading professional body on skincare. They advise against using sunbeds or sunlamps.

Sunbeds and lamps can be more dangerous than natural sunlight because they use a concentrated source of ultraviolet (UV) radiation.

UV radiation can increase your risk of developing melanomas – the most dangerous type of skin cancer. Sunbeds and sunlamps can also cause premature skin ageing.

If you insist on using sunbeds or sunlamps, the Health and Safety Executive (HSE) has issued advice on health risks linked to UV tanning equipment, such as sunbeds, sunlamps and tanning booths. They recommend you do not use UV tanning equipment if:

  • You have fair, sensitive skin that burns easily or tans slowly or poorly.
  • You have a history of sunburn, particularly in childhood.
  • You have lots of freckles or red hair.
  • You have lots of moles.
  • You are taking medicines or using creams that make your skin sensitive to sunlight.
  • You have a medical condition that is made worse by sunlight.
  • You have had skin cancer or someone in your family has had skin cancer.
  • Sunlight has already badly damaged your skin.

The HSE's advice also includes important points to consider before you decide to use a sunbed. For example, if you use a sunbed, the operator should advise you on your skin type and on how many minutes you should use the machine for.

Check your moles

As well as staying safe in the sun, you should regularly check any moles for signs of melanoma. See your doctor if you notice any changes to your moles or freckles as this can help lead to an early diagnosis and improve the chances of successful treatment.

Read more about the signs of melanoma.

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