What is a Basal Cell Carcinoma?
Basal Cell Carcinoma (also called BCC or 'rodent ulcer') is an extremely common form of skin cancer. It is estimated that over 100,000 new cases occur in the UK every year, and the incidence is increasing. BCCs tend to grow slowly, and whilst metastasis (spreading to other organs) is extremely rare, BCCs do cause problems as they grow into nearby structures such as the nose or eyelid. They also tend to start to bleed as they grow larger, which can be a nuisance or, in some cases, potentially dangerous. They usually do not cause pain but can itch, and if they grow in a hair-bearing area (such as scalp or eyelid) then they can cause the hair to fall out. If left untreated, BCCs can be very troublesome, leading to profuse bleeding issues, destruction of features such as the nose, or even blindness in the case of eyelid tumours. Rarely, they can invade deeper structures such as bone and may even cause death (but this is rare).
There are a number of causes that have been linked to basal cell carcinoma, but the major factor seems to be ultraviolet light (UVB), in the form of sunlight. Other causes of basal cell carcinoma include genetic, or other causes such as pre-existing growths. Overall, though, it seems that no one cause is enough to cause a basal cell carcinoma, and it is likely that a combination of factors leads to them forming.
Sunlight has been strongly linked to the formation of basal cell carcinoma, as well as other forms of skin cancer. In the case of basal cell carcinoma, it seems to be mostly linked to a long-term effect, due to sun exposure from many years before; it is common to see people with a basal cell carcinoma that only really had their excess exposure 20 or 30 years before. This can have been from sunbathing, but may also have been from everyday exposure (a common example is people who served in the forces and were sent for a few years to hot countries). Unfortunately, it used to be thought many years ago that sunlight was 'good for you', so people often strived for a 'healthy tan' - it's only later that we are seeing the damage caused by this sun exposure in the form of a basal cell carcinoma. Dark tans are also unfortunately seen amongst many cultures as being desirable, and the incidence of skin cancer amongst younger age groups is rising accordingly.
Whilst sunbathing is an obvious way to get too much sun, there are many other ways which are often overlooked. Many jobs involve outside work, which include trades such as building. Also, hobbies such as gardening, golf and fishing will lead to long hours in the sun, which can eventually lead to the formation of a basal cell carcinoma.
Probably the best known genetic causes of basal cell carcinoma are Gorlin's syndrome and Xeroderma Pigmentosum (XP).
Gorlin's syndrome is a genetic condition that affects approximately 1 in 30,000 people. It is caused by a mutation in the PTCH1 gene, which usually makes a protein called 'patched-1'. Gorlin's syndrome can cause features such as fibromas (benign growths) in the heart and ovaries, small pits on the palms, and a prominent forehead. It can also cause numerous basal cell carcinomas, which may start appearing at a relatively early age (before 30 years old). Some patients with Gorlin's syndrome may find that they don't form many basal cell carcinomas, but others can literally have hundreds growing through their lifetime. Surgery or other treatments such as curettage are still the usual treatment for the basal cell carcinomas, although newer treatments such as the drug 'Vismodegib' are proving to have a promising role in Gorlin's syndrome.
Xeroderma Pigmentosum (XP) affects approximately 1 in a million people, and causes extreme sensitivity to sunlight. XP is caused by gene mutations that lead to problems in repairing damaged DNA. DNA can be damaged by sunlight, and in XP exposure to sunlight can cause dry skin (Xeroderma) and skin pigmentation (Pigmentosum). XP also greatly increases the risk of forming skin cancers, including basal cell carcinoma, which can form in childhood.
A number of other factors have been associated with basal cell carcinoma, including diet, tobacco, soot and previous burns. Immunosuppession is also an important cause of basal cell carcinoma, and can affect people with HIV or those taking medication for organ transplants or forms of arthritis.
What are the symptoms of Basal Cell Carcinoma?
The symptoms can vary, depending on the size, location and type of basal cell carcinoma. They usually start with no symptoms at all, and are thought of as 'a spot that comes and goes'. In time they can start to itch, and eventually can crust (scab) and bleed. Classically, people notice them as they bleed when drying with a towel.
Where do Basal Cell Carcinomas occur?
Due to being more prone to develop as a response to UV light, BCCs tend to occur on sun-exposed areas such as the face, legs and arms. They can, though, occur pretty much anywhere on the skin.
How can Basal Cell Carcinoma be treated?
Please click on one of the links below for more information on BCC treatment:
This information is provided for general knowledge only and does not replace information provided by healthcare professionals. If you have any concerns of any skin growth, you should consult a medical professional urgently.