What is Melanoma Cancer?

Over the past four decades, the incidence of melanoma has been increasing at a faster pace than any other cancer in the fair-skinned populations in Europe, North America and Oceania according to a report from the Lancet.

Worldwide, melanoma is the 20th most common cancer. There were an estimated 287,723 new cases (1.6% of all cancers) and 60,712 deaths (0.6% of all cancer deaths) from melanoma in 2018, and a five-year prevalence of 965,623 cases.

In Europe, melanoma is the 6th most common cancer. There were an estimated 144,209 new cases (3.4% of all cancers) and 27,147 deaths (1.4% of all cancer deaths) from melanoma in 2018, and a five-year prevalence of 494,111 cases.

In females in the UK, melanoma skin cancer is the 5th most common cancer, with around 8,400 new cases every year (2016–2018). In males in the UK, melanoma skin cancer is the 6th most common cancer, with around 8,400 new cases every year (2016–2018).

Each year more than a quarter (29%) of all new melanoma skin cancer cases in the UK are diagnosed in people aged 75 and over and incidence rates for melanoma skin cancer in the UK are highest in people aged 85 to 89. (Source Cancer Research UK)

What is melanoma cancer?

Melanoma is the most serious type of skin cancer and can spread to other organs in the body.

There are four main types of melanoma skin cancer:

• Superficial spreading melanomas – These are the most common type of melanoma in the UK. They are more common in people with pale skin and freckles, and much less common in people with darker skin. They initially tend to grow outwards rather than downwards, so they do not pose a problem. But if they grow downwards into the deeper layers of skin, they can spread to other parts of the body. You should see a GP if you have a mole that is getting bigger, particularly if it has an irregular edge.
• Nodular melanomas – These are a faster-developing type of melanoma that can quickly grow downwards into the deeper layers of skin if not removed. Nodular melanomas usually appear as a changing lump on the skin that might be black to red in colour. They often grow on previously normal skin and most commonly grow on the head and neck, chest or back.
• Lentigo maligna melanomas – These most commonly affect older people. They are slow growing lesions that appear in areas of skin that get a lot of sun exposure, such as the face or upper body. Because they grow slowly they can take years to develop. To start with, lentigo maligna melanomas are flat and develop sideways in the surface layers of the skin. They look like a freckle, but they are usually larger, darker and stand out more than a normal freckle. They can gradually get bigger and may change shape. At a later stage, they may grow downwards into the deeper layers of the skin and can form lumps (nodules).
• Acral lentiginous melanomas – These are a rare type of melanoma that usually grow on the palms of the hands and soles of the feet. They can also sometimes develop around a nail, most commonly the thumbnail or big toenail. Acral lentiginous melanomas are the most common type of melanoma in people with dark skin, but they can happen in people with any skin colour.

What are the signs and symptoms of melanoma cancer?

Unusual moles, sores, lumps, blemishes, markings or changes in the way an area of the skin looks or feels may be a sign of melanoma or another type of skin cancer, or a warning that it might occur.

A normal mole is usually an evenly coloured brown, tan or black spot on the skin. It can be either flat or raised. It can be round or oval. Moles are generally less than 6 millimetres. Some moles can be present at birth, but most appear during childhood or young adulthood. Once a mole has developed, it will usually stay the same size, shape and colour for many years. Some moles may eventually fade away. New moles that appear later in life should be checked by a doctor.

The most important warning sign of melanoma is a new spot on the skin or a spot that is changing in size, shape or colour. Another important sign is a spot that looks different from all of the other spots on your skin.

The ABCDE is a guide to the usual signs of melanoma:

A is for Asymmetry – One half of a mole or birthmark does not match the other.

B is for Border – The edges are irregular, ragged, notched or blurred.

C is for Colour – The colour is not the same all over and may include different shades of brown or black, or sometimes with patches of pink, red, white or blue.

D is for Diameter – The spot is larger than 6 millimetres across (about ¼ inch), although melanomas can sometimes be smaller than this.

E is for Evolving – The mole is changing in size, shape or colour.

Other warning signs of melanoma are:

• A sore that doesn’t heal.
• Spread of pigment from the border of a spot into the surrounding skin.
• Redness or a new swelling beyond the border of the mole.
• Change in sensation, such as itchiness, tenderness or pain.
• Change in the surface of a mole, for example scaly, oozing, bleeding, or the appearance of a lump or bump.

A small fraction of melanomas can start in places other than the skin, such as under a fingernail or toenail, inside the mouth, or even in the coloured part of the eye, the iris, so it is important to arrange to see your doctor for any new or changing spots in these areas as well.

What causes melanoma cancer?

It is generally believed that melanoma cancer occurs as a result of complex interaction between environmental, genetic and individual host factors. Melanoma is caused by skin cells that begin to develop abnormally.

Exposure to ultraviolet (UV) light from the sun is thought to cause most melanomas, but there is evidence to suggest that some may result from sunbed exposure. Ultraviolet (UV) light can damage the DNA in skin cells.

The main source of UV light is sunlight, which contains three types of UV light:

• Ultraviolet A (UVA).
• Ultraviolet B (UVB).
• Ultraviolet C (UVC).

UVC is most dangerous to the skin but is filtered out by the Earth’s atmosphere. UVA and UVB damage pale skin over time, making it more likely for skin cancers to develop. UVB is thought to be the main cause of skin cancer overall, but it is not yet known whether UVA also plays a role in causing melanoma cancer.

What are the risk factors of melanoma cancer?

Melanoma skin cancer incidence is related to age, with the highest incidence rates being in older people.

Factors that may increase the risk of melanoma can include:

• Fair skin – Having less pigment (melanin) in your skin means you have less protection from damaging UV radiation. If you have blond(e) or red hair, light-coloured eyes, and freckle or sunburn easily, you are more likely to develop melanoma than someone with a darker complexion. But melanoma can develop in people with darker complexions, including Black and Asian people.
• A history of sunburn – One or more severe, blistering sunburns can increase your risk of melanoma. Excessive exposure to UV radiation, which comes from the sun and from tanning lights and beds, can increase the risk of skin cancer, including melanoma. People living closer to the Earth’s equator, where the sun’s rays are more direct, experience higher amounts of UV radiation than do those living further north or south. In addition, if you live at a high elevation, you are exposed to more UV radiation.
• Having many moles or unusual moles – Having more than 50 ordinary moles on your body indicates an increased risk of melanoma. Also, having an unusual type of mole increases the risk of melanoma. Known medically as dysplastic nevi, these tend to be larger than normal moles and have irregular borders and a mixture of colours.
• A family history of melanoma – If a close relative, such as a parent, child or sibling, has had melanoma, you have a greater chance of developing melanoma, too.
• Weakened immune system – People with weakened immune systems have an increased risk of melanoma and other skin cancers. Your immune system may be impaired if you take medicine to suppress the immune system, such as after an organ transplant, or if you have a disease that impairs the immune system, such as HIV AIDS.

Can melanoma cancer be prevented?

There is no sure way to prevent melanoma skin cancer, although Cancer Research UK state that 86% of melanoma skin cancer cases in the UK are preventable.

Whilst not entirely preventable, there are however things you can do that might lower your risk of melanoma. The most important way to lower your risk of melanoma is to protect yourself from exposure to UV rays. Practise sun safety when you are outdoors whether for pleasure or when you are working. Simply staying in the shade is one of the best ways to limit your UV exposure.

If you are going to be in the sun:

• Slip on a shirt or protective clothing.
• Put on a hat.
• Use high factor sunscreen, even on cloudy days, and reapply regularly, more often if you are swimming or perspiring. When buying sunscreen, the label should have a sun protection factor (SPF) of at least 30 to protect against UVB and at least 4-star UVA protection.
• Use wraparound sunglasses to protect the eyes and sensitive skin around them.

Children need special attention since they tend to spend more time outdoors and can burn more easily. Parents and other caregivers should protect children from excess sun exposure by using the points above. Children need to be taught about the dangers of too much sun exposure as they become more independent.

Over recent years, skin cancer has become much more common in the UK. This is thought to be the result of increased exposure to intense sunlight while on holiday abroad. Make sure that you never burn, and spend time in the shade when the sun is strongest. In the UK, this is between 11am and 3pm from March to October. When holidaying abroad, check these times for the locality you are in.

Avoid using tanning beds and sunlamps. Tanning lamps give off UV rays, which can cause long-term skin damage and can contribute to skin cancer. Tanning bed use has been linked with an increased risk of melanoma, especially if it is started before a person is 30.

What are the stages of melanoma cancer?

The stage of a melanoma tells you how deeply it has grown into the skin, and how far it has spread. Doctors use different systems to stage melanoma. These include the TNM system or number staging system, or they might use the Clark or Breslow scale to describe how deeply the melanoma has grown into the skin.

TNM Staging

Tumour (T) describes the thickness of the melanoma. There are six main stages of tumour thickness in melanoma – Tis to T4.

• Tis, or melanoma in situ, is the very earliest stage of a skin cancer. “In situ” means that the cancer cells have not had the opportunity to spread to anywhere else in the body, they remain in the top layer of the skin (the epidermis) and are all contained in the area in which they began to develop. They have not started to spread or grow into deeper layers of the skin and have not become invasive. Some doctors call melanoma in situ a pre-cancer.
• T0 means no melanoma cells can be seen where the melanoma started (primary site).
• T1 means the melanoma is 1 mm thick or less. It is split into T1a and T1b.
• T1a means the melanoma is less than 0.8 mm thick and the skin over the tumour does not look broken under the microscope (not ulcerated).
• T1b means either the melanoma is less than 0.8 mm thick but is ulcerated or the melanoma is between 0.8 mm and 1.0 mm and may or may not be ulcerated.
• T2 means the melanoma is between 1 mm and 2 mm thick.
• T3 means the melanoma is between 2 mm and 4 mm thick.
• T4 means the melanoma is more than 4 mm thick.
• T2 and T4 melanoma is further divided into a and b depending on whether it is ulcerated or not; a means without ulceration, b means with ulceration.

Node (N) stage describes whether cancer cells are in the nearby lymph nodes.

There are four main stages in melanoma:

• N0 means there are no melanoma cells in the nearby lymph nodes.
• N1 means there are melanoma cells in one lymph node or there are in-transit, satellite or microsatellite metastases.
• N2 means there are melanoma cells in 2 or 3 lymph nodes or there are melanoma cells in one lymph node and there are also in-transit, satellite or microsatellite metastases.
• N3 means there are melanoma cells in 4 or more lymph nodes or there are melanoma cells in 2 or 3 lymph nodes and there are in-transit, satellite or microsatellite metastases or there are melanoma cells in any number of lymph nodes and they have stuck to each other (matted lymph nodes).

Metastasis (M) describes whether the cancer has spread to a different part of the body.

There are two stages of metastasis – M0 and M1:

• M0 means the cancer hasn’t spread to another part of the body.
• M1 means the cancer has spread to another part of the body.

M1 can be further divided depending on which parts of the body the cancer has spread to and whether there are raised levels of a chemical in the blood called lactate dehydrogenase (LDH).

The Clark scale – this is a way of measuring how deeply the melanoma has grown into the skin and which levels of the skin are affected.

The Clark scale has five levels:

• Level 1 is also called melanoma in situ – The melanoma cells are only in the outer layer of the skin (the epidermis).
• Level 2 means there are melanoma cells in the layer directly under the epidermis – This is known as the papillary dermis (superficial dermis).
• Level 3 means the melanoma cells are touching the next layer down, known as the reticular dermis (deep dermis).
• Level 4 means the melanoma has spread into the reticular dermis.
• Level 5 means the melanoma has grown into the layer of fat under the skin (subcutaneous fat).

Breslow thickness – This is the measurement of the depth of the melanoma from the surface of your skin down through to the deepest point of the tumour. It is measured in millimetres (mm) with a small ruler, called a micrometre. A pathologist uses the special ruler with a microscope when looking at your tissue sample in the laboratory. Doctors use the Breslow depth in the TNM staging system.

Can melanoma cancer be detected early?

According to Cancer Research UK, when diagnosed at its earliest stage, all (100%) people with melanoma skin cancer will survive their disease for one year or more.

Unlike cancers that develop inside the body, skin cancers form on the outside and are usually visible. That is why skin examination, both at home and with a GP or dermatologist, is especially vital. Learning what to look for on your own skin gives you the power to detect cancer early when it is easiest to cure, before it can become dangerous, disfiguring or deadly.

Learn about the warning signs of skin cancer and know what to look for during a self-examination. If you spot anything that just doesn’t look right, get it checked by your GP as soon as possible. Early diagnosis and, if necessary, early treatment is also less invasive, often just surgery under local anaesthetic.

How is melanoma cancer diagnosed?

The National Institute for Health and Care Excellence (NICE) provide guidelines for GP or dermatologist diagnosis and referral. The first sign of melanoma is usually a new mole or an existing one that is growing, changing colour, either becoming lighter or darker, or becoming irregular in some way. When examining melanoma, medical professionals use either a weighted 7‑point checklist called the Glasgow 7‑point checklist or the ABCDE guide.

Weighted Glasgow 7‑point checklist

Major features of the lesions (scoring 2 points each):

• Change in size.
• Irregular shape.
• Irregular colour.

Minor features of the lesions (scoring 1 point each):

• Largest diameter 7 mm or more.
• Inflammation.
• Oozing.
• Change in sensation.

Referring people to a specialist, if they have a suspicious pigmented skin lesion with a weighted 7‑point checklist score of 3 or more.

ABCDE guide (which has been described above).

• Asymmetry.
• Border irregularity.
• Colour variation.
• Diameter over 6 mm.
• Evolving (enlarging/changing).

Your GP will refer you to a dermatology specialist or clinic for further testing if melanoma is suspected. A dermatologist or plastic surgeon will examine the mole and the rest of your skin. They may take a biopsy – remove the mole and send it for testing – to check whether it is cancerous. A biopsy is usually done using local anaesthetic to numb the area around the mole, so you will not feel any pain.

You will have further tests if there is a concern that the cancer has spread into other organs, bones or your blood.

How is melanoma cancer treated?

If cancer is confirmed, your treatment will depend upon:

• The type of cancer you have.
• The stage of the cancer (its size and how far it has spread).
• Your general health.

Treating stage 1 melanoma involves surgery to remove the melanoma and a small area of skin around it. This is to make absolutely sure that no cancerous cells are left behind in the skin. This is known as surgical excision and is most often done by a plastic surgeon.

Surgical excision is usually done using local anaesthetic, which means you will be awake during the procedure, but the area around the melanoma will be numbed, so you will not feel pain. In some cases, general anaesthetic is used, which means you will be unconscious during the procedure.

If a surgical excision is likely to leave a significant scar, it may be done in combination with a skin graft. However, skin flaps are now more commonly used because the scars are usually less noticeable than those resulting from a skin graft.

In most cases, once the melanoma has been removed there’s little possibility of it returning and no further treatment should be needed. Most people, between 80% to 90%, are monitored for 1 to 5 years and are then discharged with no further problems.

If the test results confirm melanoma has spread to nearby nodes, your specialist will discuss with you whether further surgery is required. Additional surgery involves removing the remaining nodes, which is known as a lymph node dissection or completion lymphadenectomy. Removing the affected lymph nodes is done under general anaesthetic. You may have radiotherapy after an operation to remove your lymph nodes.

If melanoma comes back or spreads to other organs it is called stage 4 melanoma. Treatment for stage 4 melanoma is given in the hope that it can slow the cancer’s growth, reduce symptoms, and extend life expectancy.

You may be offered surgery to remove other melanomas that have grown away from the original site. You may also be able to have other treatments to help with your symptoms, such as radiotherapy and medicine. These medicines are often recommended for people with previously treated or untreated advanced melanoma that has spread or cannot be removed using surgery.

Immunotherapy uses medicine to help the body’s immune system find and kill melanoma cells. Chemotherapy is now rarely used to treat melanoma. Targeted treatments and immunotherapy are the preferred treatment options.

After your treatment, you will have regular follow-up appointments to check whether:

• There are signs of the melanoma coming back.
• The melanoma has spread to your lymph nodes or other areas of your body.
• There are signs of any new primary melanomas.

Final thoughts

Hugh Jackman, who is most famous for his roles as Wolverine in X-Men, and Jean Valjean in Les Misérables, had a sixth skin cancer removed from his face. Jackman took to social media to say, “Deb (his wife) told me to get the mark on my nose checked. Boy was she right! I had a basil cell carcinoma. Please do not be foolish like me. Get yourself checked. And use sunscreen”. The Australian has been active on social media informing his followers of the dangers of UV exposure over the years given his personal experience with skin cancer.

This is great advice – anything that does not look or feel right, get it checked with your GP.

Anyone who needs advice or support for melanoma can contact:

• Cancer Research UK – Call 0808 800 4040 (Monday to Friday, 9am to 5pm)
• Macmillan Cancer Support – Call 0808 808 0000 (every day, 8am to 8pm)