Skin Cancer Causes
With incidents of skin cancer on the rise, many people are becoming concerned about precisely what causes the condition to occur in the first place. Unfortunately, the medical community is still not clear on exactly what causes skin cancer to develop. What is clear, however, is that overexposure to ultra violet (UV) rays can put you at significantly increased risk.
How Does Skin Cancer Develop?
Our skin consists of three separate layers: the epidermis (uppermost layer), the dermis, and the subcutis. The epidermis is a thin, protective layer of skin that our bodies are continually shedding. It also houses the squamous cells (which lie just beneath the surface), basal cells (located at the bottom of the epidermis), and other cells called melanocytes.
These latter cells produce melanin, the substance that gives our skin its natural pigmentation. When our skin is exposed to the sun, the melanocytes produce more melanin to protect the deeper layers of the skin, in turn causing the skin to appear darker. In other words, tanned skin is a result of excess production of melanin.
When your skin and DNA are healthy, they are able to produce all of these cells in an orderly fashion – normally by pushing older cells towards the surface so as to make room for healthy new ones. However, if your DNA becomes damaged (by sun exposure, for example), it will no longer be able to regulate this process. As a result, new cells may begin to grow uncontrollably and eventually form a mass of cancerous cells.
Ultraviolet Rays and Skin Cancer
The majority of DNA damage is the result of overexposure to UV rays, which can come from natural sunlight as well as the artificial variety (i.e. tanning beds). More specifically, UVA and UVB rays are what lead to skin damage.
Previously, scientists thought UVB rays were the only ones that led to skin cancer. And while these rays are harmful to the skin’s DNA – causing sunburn as well as many basal cell and squamous cell cancers – that does not mean UVA rays are not equally as damaging. In fact, these rays actually penetrate the skin more deeply, leading to a weakened immune system, which in turn increases a person’s risk of developing skin cancer – particularly malignant melanoma.
Because tanning beds emit high levels of UVA rays, they can actually be even more dangerous than natural sunlight for your skin. The fact that you generally spend less time on a tanning bed than you would under the sun doesn’t make a difference either. In fact, the occasional, intense exposure of tanning beds actually makes them more dangerous. That is because any intense exposure does damage to the melanocytes. If they are then subjected to further exposure they will not be able to repair the DNA, making them more likely to become malignant (cancerous).
Of course, sun exposure is not the only factor contributing to your risk of skin cancer; genetics is also important, as is exposure to certain toxic chemicals that form part of radiation treatments.