Basal cell carcinoma (BCC) is both the most common type of skin cancer and the most common type of cancer overall. Roughly 80 percent of skin cancers are basal cell carcinomas. They develop in the basal cell layer that is the lowest layer of the epidermis.
What Causes Basal Cell Carcinoma?
The most common cause of basal carcinoma is prolonged exposure to the sun. Most carcinomas, in fact, develop on parts of the body that are routinely exposed to the sun like the face or hands.
The sun produces three types of ultraviolet rays: UVA, UV, and UVC. The last is wholly blocked by the Earth’s ozone layer and thus doesn’t reach the surface of the Earth, while the other two types make it through. UVB causes most sunburns, and UVA causes most of the signs of the aging in the skin.
How Do Ultraviolet Rays Cause Skin Cancer?
Ultraviolet rays can damage the DNA or genetic material in people’s skin cells. A sunburn, in fact, indicates that such damage is already taking place. The damaged DNA causes the cells to mutate.
As with a normal burn, the body has ways of trying to repair the damage. If skin cells are hopelessly damaged by a normal burn or a sunburn, the body gets rid of them. During the process, the skin blisters and peels off.
Unfortunately, the body’s repair mechanisms are not perfect, and some mutated cells can get left behind. After years of exposure to the sun, the mutant cells accumulate and eventually grow out of control, causing cancer.
Sunburn, however, does not have to involve blisters or peeling skin. If a person’s skin has turned pink or red after being in the sun, they have a sunburn. Even worse, the damage to the skin cells starts developing even before someone shows signs of sunburn.
Are There Other Factors That Increase the Likelihood of Developing BCC?
Yes. Using tanning beds or sun lamps will increase the chances of developing BCC. Such devices produce the same types of UV rays as the sun does. Ultraviolet rays produced by a tanning bed are therefore just as bad as those produced by the sun.
People with fair skin are more susceptible to skin cancer of any type simply because it takes less time for the sun to damage their skin cells. People who burn easily and/or have freckles are particularly vulnerable to basal cell carcinoma.
Basal cell carcinoma is twice as common in men as it is in women, and the chances of developing it increase as a person ages.
Other factors that increase the chances of developing BCC include the following:
- Certain chronic skin disorders
- Psoriasis treatments that involve the use of ultraviolet rays
- Prolonged exposure to certain chemicals including arsenic, paraffin and coal tar
- Radiation treatments
- Certain genetic disorders like Gorlin syndrome or xeroderma pigmentosum
Many of the above risk factors increase a person’s sensitivity to ultraviolet rays. Xeroderma pigmentosum (XP) is a rare genetic disorder characterized by extreme sensitivity to UV rays; even just a few minutes’ exposure to the sun can cause a severe sunburn.
