Each year, there are approximately 13,500 new cases of melanoma.
There are two types of skin cancer: melanoma and non-melanoma, with the latter being the most common cancer in the UK by far. Melanoma tends to occur more in older people; however, it is also seen in a higher percentage of younger people when compared to other cancers. Non-melanoma skin cancer is common in people who spend a lot of time in the sun and get sunburnt regularly.
Due to treatment and cures being more accessible and more successful for non-melanoma, it is often excluded from national cancer statistics.
There are a few different types of melanoma, but they are generally treated in the same way.
Superficial spreading melanoma tends to start growing outwards rather than growing down into the skin. As a result, it is not usually at risk of spreading to other parts of the body until it does begin to grow downwards. This is the most common type of melanoma and is often found in middle-aged people.
Nodular melanoma tends to grow downwards, deeper into the skins, quite quickly if not removed. This type is often signalled by a raised area on the skin in the form of a very dark brownish black, or black, mole and it may bot develop from a pre-existing mole. This form is often found in middle-aged people and in parts of the body only exposed to the sun occasionally, like the chest or back.
Lentigo maligna melanoma develops from very slow growing pigmented areas of the skin called lentigo maligna. The lentigo maligna is flat and grows outwards on the skin, meaning it will gradually get bigger over many years and may change shape. If it becomes melanoma it also starts to grow into the skin and may form lumps. This form of melanoma is most common in elderly people, and appear in areas of the skin that get plenty of sun exposure, such as the face.
Acral lentiginous melanoma is most commonly found on the palms of the hands and soles of the feet, or around the big toenail and may grow under the nails. It’s rare, but is the most common type of melanoma in dark skinned people.
Amelanotic melanoma is rare, but difficult to diagnose as it will usually not have any colour beyond perhaps appearing as pink or red.
There are 2 main types of non-melanoma skin cancer.
The most common type is Basal cell skin cancer (BCC) and it makes up 75% of all non-melanoma skin cancers. They develop mostly in areas of skin exposed to the sun, such as the nose, forehead and cheeks, as well as the back and lower legs. It is most common in middle-aged people. It’s very rare for BCCs to spread to another part of the body to form a secondary cancer and it’s possible to have more than one at any one time. Having had a basal cell skin cancer also increases your risk of getting another.
Roughly 20% of non-melanoma skin cancers are Squamous cell skin cancer (SCC) and they also appear in areas that have been exposed to the sun. Common areas are the head, neck and the back of your hands and forearms. They can also develop in scars or areas of skin that were burned in the past. SCCs don’t often spread and if they do, it’s typically just to deeper layers of the skin. Sometimes, but very unusually they may spread to lymph nodes and other organs to cause secondary cancers.
The most common symptoms of melanoma are moles changing or new ones appearing. Generally, a mole that is more than 6mm may be a risk sign, but it’s not a hard and fast rule. Cancerous moles can be smaller than this and healthy moles can be bigger. With this in mind it’s best to consider looking at changes.
The NHS provides an ABCDE checklist to help tell the difference:
- 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 – most 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
Melanoma can also form on the eye and will typically manifest itself as a dark spot in your vision, generally eye melanoma will be caught during a routine eye exam.
Non-melanoma skin cancer is usually signalled by a lump or discoloured patch on the skin that doesn’t disappear for weeks and slowly progresses over months or years. Cancerous lumps will typically be red and firm while cancerous patches are usually flat and scaly. If you have any skin abnormality such as a lump, ulcer, lesion or skin discolouration that hasn’t healed after four weeks it is good practice to visit your GP. It’s unlikely to be skin cancer, but it’s always best to be sure.
Melanoma, like many skin cancers, is caused by UV light damaging the cells. The main cause of UV light reaching our skin is sunlight. Sun lamps and tanning beds can also increase your risk of developing skin cancer. Repeated sunburns are also a major increase in risk.
If you have lots of moles on your body you’re also at risk of melanoma, especially if they’re large (over 5mm), so it’s important to check them for changes and avoid exposing them to intense sunlight.
Other factors that increase the risk of melanoma are:
- a close relative who's had melanoma skin cancer
- pale skin that doesn't tan easily
- red or blonde hair; blue eyes
- a large number of freckles
- previously damaged your skin through sunburn or radiotherapy treatment
- a condition that suppresses your immune system, such as HIV, or if you take medicines that suppress your immune system
- a previous diagnosis of skin cancer
Non-Melanoma skin cancer is caused in mostly the same way, but some families also have an increased risk of developing it.
It is important to check your moles using the ABCDE system. If you are referred to a specialist by your GP you will most likely go through a ‘dermoscopy’ where your mole will be checked by a specialist using a dermascope. A dermascope is similar to a magnifying glass that can magnify areas up to 10 times so the specialist can get a closer look.
If you mole appears to be harmless you will be discharged with some advice on keeping safe in the sun. If the specialist can’t determine whether it’s harmless or not they will ask you to come back in 3 months for any changes.
If the specialist believes it may be melanoma they will remove the mole. This may be done in the same appointment, or it may be in a later one. To remove the mole the specialist will numb the area around the mole and remove it and a little bit of skin around it, it will then be sent for tests.
You will also have a blood test at some point to measure your vitamin D levels. You may also have a CT scan, PET-CT scan or an MRI if they feel they need more information on the cancer.
If the doctors believe the melanoma may have spread, you will be offered further options to test whether it has, these can include a lymph node ultrasound and biopsy.
Much like with melanoma, non-melanoma skin cancer will most likely be diagnosed with a dermoscopy. Usually there will also be a biopsy, where a surgeon removes the tumour and sends it for tests. It may be that the cancer has not spread, so the biopsy is also the treatment. Much like with melanoma, you may also have a lymph node biopsy if the doctors believe there is a risk the cancer has spread.
You may also have a CT scan or an MRI.
Surgery is the main treatment for melanoma, at stage 1 and 2 the doctors will remove more tissue from the area you had your biopsy for diagnosis, to ensure there are no remaining cancerous cells. If your melanoma has spread to the lymph nodes you may need surgery to remove all the lymph nodes in the area near the melanoma, this is called a lymph node dissection. After this you may also be offered radiotherapy to the area where you had your lymph nodes removed.
For non-melanoma skin cancer surgery is often the only treatment needed. The surgery is usually similar to the biopsies used to diagnose the cancer, a small surgery on the cancer and the skin surrounding it. You may also be offered radiotherapy or chemotherapy. Alternatively, you could be offered immunotherapy, which involves a cream that uses the immune system to attack cancers. You may also be offered Photodynamic therapy, which uses a drug that makes your skin sensitive to light combined with a special type of light focused on the area where the cancer is to destroy the cancer cells.
You can significantly decrease your risk of developing skin cancer by keeping your skin protected from the sun's harmful UV rays. Keeping in the shade between the hours of 10am and 3pm, covering up on holiday with t-shirts and hats and making sure to always wear sun cream with an SPF of 15 or above are all small ways you can protect your skin.
Avoiding tanning beds and sun showers altogether will also dramatically decrease your risk of developing skin cancer.
If you have any concerns about the signs and symptoms of skin cancer, please visit your GP.