Melanocytes are pigmented skin cells that are located in the deep layers of the skin (epidermis).…
Basal cell carcinoma
- Basal cell carcinoma is a very common type of skin growth.
- Treatment can take the form of surgery, skin treatments or radiotherapy.
- In nearly all cases, treatment is effective and the growth is safely removed.
- To prevent basal cell carcinoma, protect your skin from UV radiation, including sunlight and tanning beds.
What is basal cell carcinoma?
Basal cell carcinoma (BCC) is a type of skin cancer that originates in the skin's basal cells. These are cells located at the bottom of the skin's outer layer (the epidermis). Basal cell carcinomas are found on the areas of the body that are exposed to the sun. They can invade locally to deeper layers beneath the skin, but rarely spreads to other areas of the body.
The cause of skin cancer, as with other cancers, is due to damage to the DNA in our cells. In skin cancer, this damage is usually caused by exposure to ultraviolet (UV) radiation, which comes from sunlight and is also used in solariums and sunbeds. The lifetime exposure, pattern of exposure and intensity of UV radiation all influence the risk of developing skin cancer.
The DNA damage can cause a cell to reproduce uncontrollably, creating a mass of abnormal cells. In BCC, the skin's basal cells form a growth in the top layers of the skin.
Risk factors for basal cell carcinoma include:
Signs and symptoms
Basal cell carcinomas appear as bumps or sores that slowly increase in size and do not heal after an injury. They typically appear on sun-exposed areas such as the face, head, neck, shoulders and chest, but can also occur on other areas of the body. They tend to be pale, waxy, translucent and pearly, but can also appear pink, brown, black or skin-coloured.
Methods for diagnosis
Your doctor will look at the abnormal skin area, and will refer you to a specialist if they suspect it might be cancerous.
Your doctor will remove a small sample of your growth for analysis. A local anaesthetic is normally used, depending on the size of the sample removed.
There are four main types of skin biopsies:
- Excisional biopsies: removing the entire abnormal area of skin with a surgical knife (scalpel);
- Incisional biopsies: removing part of the abnormal area of skin, together with neighbouring unaffected skin, with a scalpel;
- Punch biopsies: removing a small circle of the whole skin layer, much like a hole puncher removes holes in paper, and;
- Shave biopsies: shaving off only the top layer of skin.
Types of treatment
The growth is surgically removed.
A surgeon will use a device cooled with liquid nitrogen or nitrous oxide to freeze-kill the growth.
Mohs micrographic surgery
The skin is removed in sections and examined for cancer. The process is repeated until all the cancer has been removed from the skin layers. This helps to minimise the area of skin that is removed, while ensuring all the cancer is completely removed.
Electrodessication and curettage
Electrodessication and curettage is a simple surgical technique. A curette, a device that looks like a spoon with a sharp edge, is used to remove the tissue. This is followed by electrodessication, in which a needle electrode delivers an electric current to the tissue to stop any bleeding.
A focused laser beam is used to cut the tissue, stemming the blood flow by simultaneously burning (cauterising) some of the skin.
Focused X-rays are applied to the area where the tumour is located.
Radiotherapy can be used alone, or together with surgery and/or chemotherapy.
Applying anti-cancer drugs (usually 5-Fluorouracil) directly to the skin.
Topical biologic therapy
Applying biologic drugs directly to the skin. These special drugs, such as imiquimod, either act on the immune system to help it fight infection, cancer and other diseases, or attack cancer cells directly.
Photodynamic therapy (PDT)
This treatment has two steps: In the first step, a special medication is applied as a cream to the skin. The medication is designed so that it is absorbed by the cancer cells. In the second step, a special light is shined on the skin. The light activates the medication, which destroys the cells.
PTD does not usually cause scarring. It can be very effective for some types of BCC, but is not recommended for cases of BCC where the cancer cells can be found in the deeper layers of the skin, where light cannot penetrate well.
Treatment side effects
- Inflammation, resulting in ulcers, can result from topical biologic therapy or chemotherapy;
- Scarring and changes to skin colour, and;
- Radiotherapy can cause nausea, vomiting and fatigue.
Advanced cancer spreads to other parts of the body through the bloodstream and lymphatic system (metastasis) affecting the vital function of organs. This is extremely rare for basal cell carcinoma.
In the large majority of cases, basal cell carcinoma is generally easily treated. The earlier a growth is identified and treated, the easier the treatment and the better the chances of success.
BCC can sometimes come back, with another growth appearing in the same area as the first one.
The best way to prevent Basal cell carcinoma (along with all other types of skin cancer) is to avoid UV radiation, which can be done by avoiding sunlight during the times specific to your state, seeking out shade and wearing protective clothing such as hats and long-sleeved shirts with collars to protect the arms and neck. Avoid tanning in the sun or using sun beds.