What Is Skin Cancer?

Overview

Skin cancer, the abnormal growth of skin cells in the outer layer of the skin or epidermis, is one of the most prevalent cancers in the UK. It can be categorised into two main types: melanoma and non-melanoma.¹

Non melanoma

147,000 new cases of non-melanoma skin cancer (NMSC) are reported each year in the UK. Non-melanoma skin cancer originates in the upper layers of the skin, and the treatment is usually successful due to a low risk of it spreading to other areas of the body. Basal and squamous cell carcinomas are two common types of NMSC.

Melanoma

Melanomas are a much rarer class of skin cancer. However, they are by far the most aggressive form of skin cancer. It originates in the melanocytes, the lowest layer of the epidermis, which are responsible for producing the pigment melanin. From here it is capable of spreading to other organs in the body.

Causes of skin cancer

Over 90% of skin cancer cases are caused by overexposure to the carcinogen ultraviolet radiation (UVR) which is present in sunlight.^1,2 UVR consists of ultraviolet A (UVA) and ultraviolet B rays (UVB). UVA can penetrate further into the skin and induce more profound skin damage than UVB rays. UVB damage can cause sunburn in the short term. UVR participates in the development of skin cancer (both malignant melanoma and NMSC) by producing DNA damage, gene mutations, etc. This results in the uncontrolled replication of skin cells and, thus, the development of a mass of cancer cells.³

Although most skin cancers are linked to UVR exposure, there are other risk factors: 

• Skin type: skin cancer is more common in pale individuals. This is because they have less melanin (the protective layer in the skin)
• Previous history of skin cancer: If you have previously had skin cancer, it is more likely to return. If your doctors believe there is a high chance of the skin cancer reoccurring, they will most likely schedule regular check-ups
• Family history of skin cancer: If one of the parents had squamous cell skin cancer (SCC) it increases the child's risk of developing SCC. Individuals with a family history of melanoma have an increased risk of basal cell skin cancer (BCC)
• Moles or freckles: The more moles or freckles you have, the more likely you will develop melanoma
• Gender: People assigned males at birth (AMAB) have a slightly higher risk of developing NMSC because they are more likely to work outdoors⁴
• Use of immunosuppressant drugs or a medical condition that suppresses your immune system
• Using sunbeds

Signs and symptoms of skin cancer

How skin cancer presents can vary significantly between individuals, with some symptoms being more difficult to notice. The British Skin Foundation recommends that you check your skin about once a month for moles that have appeared or changed.

Melanomas 

For melanomas, the NHS suggests using the ABCDE system to differentiate between a melanoma and a non-cancerous mole.

• Asymmetrical- two halves of the melanoma differ and are irregular in their shape
• Border- melanomas generally present with a notched or irregular edge
• Colour- melanomas do not usually consist of just one colour, and commonly observed shades are brown, pink, and black
• Diameter- most melanomas exceed 6mm in diameter
• Enlargement/ elevation- Changing moles are more likely to be melanoma

Although melanomas can appear anywhere on the body, they are uncommon in areas protected from the sun, such as the scalp.

In people assigned females at birth (AFAB), it is more common for melanomas to appear on the legs. Whereas in AMABs, the most commonly affected area is the back.⁵

Non melanoma

Non-melanoma skin cancer commonly develops on skin exposed to the sun, such as the face, hands, shoulders, upper chest, and back.

According to Cancer Research UK, the symptoms consist of a skin sore, or area of the skin that:

• Does not heal within four weeks
• Looks unusual
• Hurts, itches, bleeds, crusts, or scabs for more than four weeks

The cancerous lumps can be red and firm and occasionally develop into ulcers. On the other hand, cancerous patches are generally flat and scaly.

Although it is most likely not skin cancer, if you experience a skin abnormality, it is best to have it checked out by your GP. They will be able to examine the skin abnormality and refer you to a specialist if they are concerned.  

Management and treatment for skin cancer

The primary treatment for both melanoma and NMSC is surgical. It consists of removing the cancerous cells.

However, there are other treatment options available such as:

• Chemotherapy
• Biological therapy
• Photodynamic therapy
• Radiation therapy

The treatment you will receive for your skin cancer depends on the type, size, stage, and location and is best discussed with your doctor. Treatment for NMSC is usually successful, with the NHS reporting that at least 90% of cases are successfully cured. The success rate is high because, unlike most other types of cancer, the risk of it spreading is comparatively low. Meanwhile, if melanoma is identified early, treatment is usually successful; however, if diagnosed at an advanced stage, treatment is primarily used to reduce the spread of cancer.

FAQs

How is skin cancer diagnosed?

If you go to the GP with a skin abnormality such as a lump, ulcer, or skin discolouration, the GP will check your skin for signs of skin cancer. If they are concerned or unsure, they will refer you to a dermatologist or a specialist plastic surgeon. Alternatively, they may take photographs and email them to a specialist. Once the specialist has examined your suspected skin cancer, they may perform a biopsy to confirm a diagnosis of skin cancer.

If you receive a skin cancer diagnosis, you might required to undergo surgery to remove surrounding skin that may contain cancerous cells.

How can I prevent skin cancer?

To reduce your risk of skin cancer, you should avoid overexposure to UV radiation. You can protect yourself from UV damage by:

• Wearing high-factor suncream
• Wearing sensible clothing in the sun
• Reducing the duration that you spend in the sun
• Regularly checking your skin can lead to an early diagnosis, increasing your chances of successful treatment
• Avoid sunbeds

Who are at risks of skin cancer?

People with frequent exposure to UV radiation, pale skin, a large number of moles, immunodeficiency conditions, or under immunosuppressant drugs, family history, or previous history of skin cancer are at a greater risk of skin cancer.

How common is skin cancer?

Skin cancer is becoming progressively common in the UK. According to Cancer Research UK, 1 in 36 AMABs and 1 in 47 AFABs in the UK will be diagnosed with melanoma during their lifetime. There are around 16,700 newly diagnosed melanoma patients and 156,000 newly diagnosed NMSC patients in the UK every year. 

When should I see a doctor?

You should see a GP if you are concerned about any skin abnormality that hasn’t healed after four weeks. If in doubt, it is always best to get it examined.

Summary

Skin cancer is the abnormal growth of skin cells in the outer layer of the skin, the epidermis. Risk factors for skin cancer include exposure to UV radiation, pale skin, a large number of moles, immunosuppressant drugs, and a family history, or previous history of skin cancer. Early detection of skin cancer is critical to successful treatment; therefore, if you are concerned about a skin abnormality, book an appointment with your GP as soon as possible.