In the second part of our interview with Mr Per Hall, Clinical Advisor for Skin Cancer at Check4Cancer and Consultant Plastic Surgeon, looks in more detail at the different types of skin cancer and provides clarity on the treatment options available.
What are the different types of skin cancer?
There are three common types of skin cancer which can all look different and behave in different ways. All are more common on parts of the skin exposed to the sun.
The most common form of skin cancer is Basal Cell Carcinoma which is a very slow growing mark. It can present as anything from a flat pinky-red patch, to a shiny dome shaped bump. These might bleed, crust or ooze. Basal Cell Carcinomas can look different on different skin types and will frequently be pigmented, or coloured, in darker skins.
The second most common is Squamous Cell Carcinoma. These can also appear as red sores, scaly patches or thickened almost wart-like lesions which crust and bleed. They have a small tendency to spread, usually to the lymph glands, but when treated early on this is unlikely. Patients who are immunosuppressed for any reason are much more prone to this type of skin cancer.
The least common, but most concerning type of skin cancer is melanoma. This is a malignant mole which might arise in a pre-existing mole or as a new lesion. The most common sub-variant of melanoma (60-70%)1 is called a Superficial Spreading Melanoma. These are perhaps the easiest to recognise as they have an irregular shape and outline, variations in colours and are often asymmetrical. If this type of cancer began in a pre-existing mole, the signs to look out for are a mole changing in size, shape or colour.
Less common (15-30%)1 is Nodular Melanoma which usually appears as a blue-black bump but can occasionally be a newly appeared dome-shaped pink or red bump. This type is harder to recognise early and therefore tends to be spotted at a later stage.
The Lentigo Maligna Melanoma (5-15%)1 variant is most commonly seen on the sun-exposed faces or hands of more elderly patients. These are large and irregularly shaped brown patches on the face, ears or arms, developing areas of blue-black within them. They mimic ‘age spots’ commonly seen on pale skinned people but it is important to recognise the differences between them. This melanoma remains in the top layers of the skin for a long time and can therefore often be picked up while still in its pre-malignant form (Lentigo Maligna).
For pale skinned people, the least common type of melanoma occurs on the palms, soles of the feet and under nails, but these are some of the most common sites of melanoma for darker skinned people. This is referred to as an Acral or Acral Lentiginous Melanoma and often spreads, appearing as black, brown or varied colours.
What are the rates of survival depending on the stage the cancer is found?
Basal Cell Carcinomas (BCCs) are almost always entirely curable usually with surgery, but in certain cases requiring radiotherapy. BCCs recur on the skin, but they never spread anywhere else in the body. The average risk of recurrence at the same site following removal is around 4% in 5 years.
Squamous Cell Carcinomas (SCCs) can also usually be cured by surgical removal. However, a small number which are more aggressive can come back and may even spread to the lymph glands. If this happens then treatments including a combination of surgery, radiotherapy and sometimes chemotherapy, can be offered.
Melanoma survival can largely be predicted from the thickness in the skin of the original melanoma. The thinner and closer to the top portion of the skin, the better the outcome. The 5-year survival can be estimated from the table below:
| Melanoma skin thickness | 5-year survival rate |
| Melanoma in situ | 100% |
| Melanoma <0.75mm | 97.9% |
|
Melanoma >0.75mm-1.5mm |
90.7% |
|
Melanoma >1.5-3.0mm |
75.4% |
|
Melanoma >3.0mm thick |
55.0% |
The ‘stage’ of melanoma takes into account the original thickness of the melanoma and whether or not it has spread to the lymph glands or beyond them to the body in general. The further the spread, the worse the probable outcome.
What are the treatment options?
For most skin cancers, surgery is the preferred option although some BCCs and SCCs at awkward sites can be treated with radiotherapy. The treatment for melanoma is surgery in the first instance. We may then wish to go onto ‘staging investigations’ which can include a technique known as “Sentinel Lymph Node Biopsy” to find out if there are any microscopic melanoma cells that have already spread to lymph glands.
Sentinel lymph node biopsy is a surgical procedure involving the injection of a tracer which is used to identify the specific lymph gland that drains the skin which has the melanoma sitting in it. If this gland is free of cancer, then the melanoma is unlikely to have spread. Approximately 20% of sentinel lymph nodes are found to be positive in the groups most at risk. Patients whose cancer is found to have progressed to a later stage are usually managed by multidisciplinary teams and will undergo treatments designed to reduce the risk of melanoma recurring. These treatments often focus on enhancing the body’s immune response to the condition.
Who can people talk to if they are concerned or want more information?
GPs or skin cancer specialists can provide information and support. Macmillan nurses are also often trained in the management of skin cancer, particularly melanoma.
In your experience, how has treatment changed in recent years and how do you see it developing in the future?
When I first became interested in melanoma about 30 years ago, the incidence was 8 people in 100,000. Now it's 25 people in 100,000, so the incidence doubles approximately every 10 years. That being said, we are much better at recognising it early thanks to educational campaigns. These have brought down the delay for people seeking treatment to the point that the vast majority are coming forward with thin and curable lesions.
The advent of Sentinel Lymph Node biopsy has helped us identify people whose disease has progressed further than initially thought and allow us to provide the required treatment.
Now, with the ability to characterise the genetic make-up of melanoma and grow cells in the laboratory, we are beginning to see targeted, bespoke treatments for tumours. Blanket chemotherapy treatments had disappointing results, whereas now we are seeing much more encouraging results with these targeted approaches. Tumour cells are very clever at changing their DNA, so we need to be prepared to switch treatments in a similar way to changing antibiotics when a bug becomes resistant.
References
1 https://www.cancerresearchuk.org/about-cancer/melanoma/stages-types/types">https://www.cancerresearchuk.org/about-cancer/melanoma/stages-types/types
Mr Per Hall | Clinical Advisor for Skin Cancer at Check4Canncer
Mr Per Hall has been a consultant plastic surgeon in Cambridge since 1995. He has been a pioneer in the early detection of skin cancer using computer imaging for over 20 years. Mr Hall and his team have had a major input in the development of SIAscopy, producing the most clinical papers on the subject. He continues to collaborate in studies aiming to help identify suspicious skin lesions at the earliest opportunity and continues to work with computer scientists on ways to improve diagnosis including the use of artificial intelligence. Mr Hall is also committed to the reconstructive surgical needs of children in developing countries and regularly trains surgeons in cleft lip and palate surgery in Ethiopia to facilitate this. Mr Hall oversees the Check4Cancer SkinCheck service.
