Apart from some very rare skin cancers such as lymphomas and sarcomas of the skin, the vast majority of the more common types of skin cancer we see, can be divided into two distinct groups of: non-melanoma and melanoma skin cancer.
Non-melanoma skin cancer is the most common type of skin cancer and it includes two types: Basal Cell Carcinoma (BCC) and Squamous Cell Carcinoma (SCC). BCC is two to three times more common and has a much better prognosis than SCC, which can be more serious. However both BCC and SCC skin cancer are wholly treatable. Non-melanoma skin cancer is most common in older people.
The National Cancer Registry Ireland (NCRI) reports that in Ireland between 1994 and 2011 an annual average of over 6,300 cases of non-melanoma skin cancer were diagnosed per year, approximately 68 per cent of which were BCC and 30 per cent SCC. Despite the large number of cases diagnosed per year, since 1994 fewer than 50 people per year on average have died from this cancer.
Melanoma skin cancer is a much more serious form of the disease. Data from the NCRI shows that every year in Ireland, approximately 850 new cases of melanoma skin cancer are diagnosed and there are 150 melanoma-related deaths.
According to the NCRI more than 60 per cent of patients are female and melanoma is the third most common cancer diagnosed in the 15-44 year age group. However the highest death rates from melanoma are seen in men over the age of 50
RISK FACTORS
While like most cancers your risk of developing skin cancer increases with age, your overall risk of developing the disease even as a young adult, depends on a number of factors such as your skin type (determined by how your skin behaves when you go out in the sun without protection).
Fair skin that burns easily, red hair, a lot of moles, and skin that shows signs of excess sun exposure in the past, such as freckling, all increase your risk of developing skin cancer. Other risk factors include a personal history of the disease; if you have had skin cancer in the past you are much more likely to get it a second or third time.
Less than 10 per cent of melanoma has a genetic component and there are a number of very rare syndromes that can predispose you to developing BCC. People whose immune systems are suppressed, such as those who are taking immunosuppressant medication following an organ transplant, are also at an increased risk of developing skin cancer.
The sun is carcinogenic as are sunbeds and skin cancer is associated with exposure to both. SCC is associated with more chronic sun exposure so for example if you are outdoors a lot with work or hobbies, whereas BCC is associated with high dose intermittent sun exposure that you can get from going on a two week sun holiday a couple of times a year. BCC and most types of melanoma are also associated with having had blistering sunburn as a child and the use of sunbeds. In fact the use of sunbeds under the age of 35 is an independent risk factor for melanoma and would be highly discouraged.
SIGNS AND SYMPTOMS OF THE DISEASE
Melanoma: approximately a third of all melanoma occurs in a pre-existing mole and the rest occur as a new mole or pigmented lesion, so it is important to regularly check your skin for changes.
A handy tip for checking moles is to remember the ABCDE guide.
A -is a mole becoming asymmetrical?
B - is the border becoming irregular?
C- the colour, has it changed?
D- is for diameter, is it increasing in size?
E- is evolution, where these changes are occurring reasonably quickly.
There is also another thing to look out for known as the ugly duckling sign. Do you have one mole that stands out from all the others and looks a bit funny? All these symptoms should be assessed.
Non-melanoma: in relation to non-melanoma skin cancer, you should look out for a broken area of skin that doesn't heal after two months as this could be BCC. It may present as a translucent or pearly patch of skin with visible blood vessels and often there is an ulcer or a break in the skin in the centre of the tumour. SCC tends to present as a wart or lump that grows very quickly and can be tender. The majority of non-melanoma skin cancer occurs on sun exposed sites such as the face.
There are also some pre-cancerous changes that can occur on the skin that need to be checked out but are usually nothing to worry about and can be treated very easily. These include well or ill-defined areas of scaly skin that is a bit red.
TREATMENT
Melanoma
Thankfully if you present early with melanoma where the tumour is thin or less than 1 mm with no other adverse features, surgery is the only treatment you will need. Survival in these cases is at about 95 per cent, again underlining the importance of getting any skin changes checked early.
Melanoma can affect you in three ways. It can return locally in the scar of the original melanoma, a risk which is reduced by taking away the appropriate amount of normal tissue from around the scar; it can spread to the lymph nodes, which is more likely with thicker tumours; and it can spread to the internal organs, again more likely with thicker melanomas.
All melanoma cases are discussed at regular multi-disciplinary team meetings, which are attended by the specialists involved in the care of melanoma patients. There include the dermatologists, surgeons, medical oncologists, radiation oncologists, pathologists and radiologists.
Melanoma management is determined by the thickness of the original melanoma. Patients with thicker tumours may be offered a surgical procedure called a sentinel lymph node biopsy which can provide prognostic information to check if the cancer has spread. If lymph nodes are affected by melanoma, surgical removal of these lymph nodes may be offered to the patient.
There are a number of new and emerging drug treatments available now for patients with melanoma which has spread to the lymph nodes and for those where it has metastasised (spread to other organs in the body). These are used as add on or adjuvant therapies to surgery and they can prolong survival in some, but sadly not in all patients.
It is also important to remember that if you have had one melanoma you have got a one in 12 chance of developing a second entirely separate one, so regular self-examination is essential.
Non melanoma
The majority of BCC will be treated surgically by simply removing the tumour with the appropriate surgical margins. BCC is generally cured after surgical excision. There is a subset of patients with high risk tumours that may benefit from a type of surgery called mohs micrographic surgery. This is where the tumour is removed with a very narrow margin by the Mohs surgeon The tumour is then examined immediately under a microscope by the Mohs surgeon to determine if more skin needs to be removed and this can be done immediately without any further delay. Removal of tumours by Mohs micrographic surgical technique offers a cure rate of about 99 per cent.
There are also a number of non-surgical treatment options for certain type of BCC such as topical creams or photodynamic (light) therapy.
The majority of SCCs are treated surgically by excision with appropriate surgical margins and some patients with high risk SCCs may benefit from Mohs micrographic surgery.
It is important to note that there really is no such thing as a safe amount of sun exposure. It is therefore important to never use a sunbed, never let your children get sunburnt. Remember to cover up and if you can see your skin through your clothes the sun can too. Wear a hat that adequately covers your ears and avoid the peak mid-day sun. Sun protection creams with an SPF of at least 30 and UVA protection should be applied to exposed skin and remember to reapply it on a regular basis.
Anyone who is concerned about any changes on their skin should contact their GP who may need to refer them to a dermatologist. Presenting early can save lives. Seeing late presentations of melanoma is upsetting because you know if you catch it early enough you can make a big difference.
RESOURCES
Irish Cancer Society cancer.ie
[ British association of dermatologists patient information leafletsOpens in new window ]
Dr Aoife Lally, consultant dermatologist St Vincent’s University Hospital, Dublin.