What is skin cancer?
Skin cancer occurs when damage to skin cells causes them to mutate and become cancerous. These cells may then begin to rapidly reproduce and form tumours or growths. The majority of skin cell damage is caused by ultraviolet radiation, which is absorbed from sunlight as well as from artificial sources of light such as tanning beds.
There are 3 main types of skin cell in the top layer of skin, otherwise known as the epidermis: basal cells, squamous cells and melanocytes. Each set of cells plays a role in maintaining healthy skin and allowing the epidermis to function properly, and this means that skin cancer is categorized differently according to which type of cell it develops in.
Basal cell carcinoma
Basal cells are located in the lower section of the epidermis and work to constantly reproduce in order to replenish the squamous cells in the layer above. Approximately 80% of all skin cancers begin in the basal cells. The biggest primary cause of basal cell carcinoma is overexposure to sunlight, meaning that it tends to develop on areas of skin which are uncovered such as the head, neck and face. It can grow elsewhere on the body, however.
A basal cell carcinoma usually emerges as a sore, a shiny bump, red patch, scar or lesion on the surface of the skin. The cancerous cells found within a basal cell carcinoma very rarely spread beyond the area where the original growth develops, but it still needs to be treated nonetheless. Early diagnosis almost always results in successful treatment. Basal cell carcinomas develop slowly and will usually not become visible for a number of years after the initial exposure.
Squamous cell carcinoma
The other most common form of skin cancer is known as squamous cell carcinoma, which accounts for just under 20% of cases. Squamous cells are found in the upper layer of the epidermis and break away from the skin when scratched or disturbed. Much like basal cell carcinomas, cancer in the squamous cells is caused by exposure to sun and ultraviolet light.
Squamous cells carcinomas appear slightly different, however. They often look like sores or warts which bleed and crust, and they may seem scaly or ridged.
A melanoma is the rarest but most dangerous form of skin cancer. It forms in the melanocytes, where a pigment called melanin is produced. This pigment is what gives skin a darker tanned appearance. Melanin also acts to block some of more damaging rays from penetrating through to the skin’s deeper layers.
If you have low levels of the melanin pigment you are at greatest risk of overexposure to the sun or ultraviolet light. Around 1 in 4 melanomas develop in moles or other such darker areas on the surface of the skin. The majority of melanomas in men are found on the back or chest area, whilst women usually develop melanomas on the legs. In rare cases a melanoma might be found on the palms, mouth, genitals or rectum area.
Although melanomas are rare they do carry a high risk of spreading the cancer to other parts of the body
What are the symptoms of skin cancer?
There a number of signs to look out for, and they vary depending on whether the cancer is a melanoma or non-melanoma. Likewise, both squamous cell carcinomas and basal cell carcinomas display different symptoms.
The main symptoms of squamous cell carcinomas include:
- A pink/red lump
- Hard to the touch
- May form ulcers
On the other hand, basal cell carcinomas may result in:
- Small and shiny pink/red lump
- Scaly and patchy appearance
- Crusting or scabbing
All of the symptoms of non-melanoma skin cancers could easily be caused by a skin condition or an allergy, but you should seek medical attention if the symptoms persist for more than 4 weeks without improvement and can’t be explained by anything else.
The majority of melanomas begin with changes to a mole. You should see a doctor as soon as possible if you notice a mole is:
- Changing colour, usually getting darker
- Growing in size
- Changing shape
- Itching and irritable
- Red or inflamed
- Bleeding and scabbing/crusting
- Different shades of black or brown
How is skin cancer diagnosed?
The most important stage of the process is knowing your own body well and being able to notice any early signs that something is not right. The chances of treating skin cancer successfully are much higher when it is diagnosed at an early stage, and the best way of doing this is regular self-examination of the skin.
As soon as you notice anything abnormal you should seek medical advice. Your doctor will ask you about your symptoms, your family history and your lifestyle to assess whether you may be at risk of skin cancer. If there is any suspicion that skin cancer could be present you will be sent to a specialist.
It is not always immediately apparent, even for a dermatology specialist, whether the condition is cancerous or non-cancerous. They will assess the skin closely with a dermatoscope, and sometimes the diagnosis is fairly clear on appearance alone.
If the dermatologist is unsure, however, they will most likely conduct a skin biopsy. This involves taking a skin sample which is sent to a laboratory for further analysis.
There are 3 different skin biopsy methods:
- Incisional biopsy: A piece of skin is removed using a surgical knife. The area will need to be stitched up.
- Shave biopsy: A thin layer is shaved from the top of the skin
- Punch biopsy: A small area of skin is removed and leaves a circular patch
You won’t find out the results of the biopsy for at least a week, and sometimes it can take up to 21 days for conclusive results to come back.
How is skin cancer treated?
Once you have discovered the results of your biopsy and it has been confirmed that you have skin cancer, the next stages in the treatment process will vary depending on which type and stage it is. However, whether it be squamous cell, basal cell or melanoma, the cancer is almost always removed surgically.
Squamous cell and basal cell carcinoma
Some small basal cell and squamous cell carcinomas can be removed by a dermatologist trained in the procedure without the need for surgery or any additional treatment. If a carcinoma is slightly larger it will need to be removed surgically, and there are a range of different ways this is done.
Complete margin assessment surgery: The tumour is removed alongside small samples of tissues around the edge. The samples are analyzed to see if cancer cells are present, and the process is repeated until no more are present
Curettage: During this procedure, the lump is extracted using a curettage, a surgical instrument which scoops the lesion from the skin. This may be followed by electrodesiccation, which uses electrical currents to destroy any remaining cancer cells.
Laser therapy: The tumour is destroyed by a high-intensity laser beam. It may leave small scar which fades over time.
Cryotherapy: This form of skin cancer treatment uses liquid nitrogen to freeze the cancerous cells. More than one session of cryotherapy may be needed.
Grafting: If the tumour is particularly large, a more complex surgery will be required to remove it. The resultant missing tissue will need to be replaced, and surgeons do this by taking a skin graft from elsewhere on the body to close the wound.
Reconstruction: In the rare cases where skin cancer develops on the face, the surgery may affect appearance and plastic surgery could be necessary.
Radiotherapy may be used to treat squamous cell and basal cell carcinomas if surgery is not suitable. This might be the case if the tumour is particularly large, if it is in an area which is hard to access, or if the patient has existing health issues. Radiotherapy uses high-energy particles to destroy cancer cells, preventing them from reproducing and eventually shrinking the size of the growth. It might also be used if there is evidence that some cancer cells have been left behind after surgery.
If the skin cancer is only on the very top layer of skin, a chemotherapy cream is applied with the aim of killing the cancer cells.
This treatment uses the body’s natural defence mechanism, the immune system, to weaken cancer cells and halt their growth. It stimulates the production of interferon, a chemical which works to destroy cancer cells. Immunotherapy might be used if the skin cancer is in the nose, mouth, head or neck area.
Doctors use four stages to describe how advanced a melanoma is, how far it has spread or how deeply it has grown into the tissue. In very basic terms, stage 1 means the melanoma is in the skin but not spread to lymph nodes, whilst stage 4 means that it has spread to other parts of the body and is already at an advanced stage. The stage of the melanoma will influence which treatment pathway is most appropriate.
Much like with non-melanoma skin cancer, melanoma tumours will almost always be removed surgically. If the melanoma is at an early stage it will be removed using a process called local excision. The surgeon will extract both the tumour and the tissue immediately around it, and the amount of tissue removed depends on how deep the melanoma is beneath the skin and where the melanoma is on the body.
Local excision can performed alongside a sentinel node biopsy, which is used to check whether the cancer has spread into the lymph nodes. If the biopsy discovers that the cancer has indeed spread to the lymph nodes, you may want to consider another surgical procedure to remove them know as lymph node dissection.
Melanoma surgery is generally performed under local anesthetic, but a general anesthetic is used if you choose to also have a sentinel node biopsy. As a large piece of skin is usually removed during a local excision you might also need a skin graft to repair the missing tissue.
There are certain genes found in the human body which mutate, and around 40-50% of all melanoma cases can be linked to change in the BRAF V600 gene. The gene produces proteins which speed up the reproduction of cancer cells. Drugs can be used to stop these mutations, and the two most commonly used in the treatment of melanomas are:
- Vemurafenib (Zelboraf)
- Dabrafenib (Tafinlar)
These drugs come with a number of side effects similar to radiotherapy or chemotherapy, such as nausea, fatigue, diarrhoea and skin rashes. They might also cause issues with kidney and liver function.
Compared to other forms of cancer, melanomas are relatively resistant to chemotherapy and as such it is not used as a primary treatment. Instead, chemotherapy might used as an addition to surgery and radiotherapy, or when the cancer is at an advanced stage.
Radiotherapy treats advanced melanomas, either before or after surgery. Before surgery, radiotherapy shrinks the tumour and makes the surgical procedure more straightforward, and after surgery it reduces the likelihood of the cancer returning. Radiotherapy requires 5 treatment a sessions a week over 1 or 2 months. When radiotherapy is only applied to the skin it does not have any dramatic side-effects other than a mild burn on the surface.
What happens after skin cancer treatment?
It is very important that you have regular follow-up assessments after your skin cancer treatment. You also need to monitor any changes to the skin or moles, both around the area you had treated and elsewhere on the body. If you have been treated for early stage skin cancer you should aim to have a checkup around twice a year for the first year or two, but anyone who has had treatment for a more-advanced melanoma should have quarterly checkups over the course of 5 or so years.
How much does skin cancer treatment cost?
With many different types of skin cancer, each one needing a different range or combination of treatment, getting a clear idea of how much everything will cost can be difficult. Speaking with an experienced care team to discuss which course of treatment is best for you is the only way to build an accurate cost estimate.
Many skin cancer patients choose to travel abroad for their treatment, either for more affordable prices, shorter waiting times or a higher quality of care.