Skin cancer is the malignant (cancer) cells found in the epidermis, an outer layer of the skin, which acts as the body’s major barrier against an inhospitable environment.
The epidermis is made up of different types of cells. Skin cancers are classified by the types of epidermal cells involved:
- Basal cell carcinoma develops from abnormal growth of the cells in the lowest layers of the epidermis and is the most common type of skin cancer, accounting for 75% to 80% of cases.
- Squamous cell carcinoma involves changes in the squamous cells, found in the middle layer of the epidermis. SCC accounts for 16% to 20% of skin cancer cases and occurs twice as often in men than in women.
- Melanoma develops from melanocytes, the cells that produce the skin’s color. Melanoma is treatable when it is detected in early stages.
Skin cancers are sometimes classified as either melanoma or non-melanoma. Basal cell carcinoma and squamous cell carcinoma are the most common non-melanoma skin cancers. Depending on the type, they can be fast or slow growing, but they are rarely spread to other parts of the body. If they are detected early, most can be treated successfully. Melanoma is less common, but, it is a more serious type of skin cancer because it tends to spread (metastasize) quickly throughout the body. It is the leading cause of death from skin disease.
What Causes Skin Cancer?
Skin cancer occurs when the DNA of healthy skin cells are damaged. Much of the damage to DNA in skin cells results from excessive exposure to light from sunlight, tanning booths or tanning lamps. This is considered as the main cause of all skin cancers. The other causes of skin cancer include:
- Being Caucasians
- Being ages over 40
- Having a family history of skin cancer, particularly melanoma
- Long-term exposure to chemicals such as arsenic, tar coal and oil
- Exposure to radiation from other cancer treatments
- Weakened immune system
- Infection by certain types of human papilloma virus
- Having certain types of moles
Skin cancer can develop in anyone, not only people with these risk factors. Young people, even those with dark skin, hair, and eyes – can develop skin cancer.