Most skin cancers occur on sun-exposed areas of skin, and there is a lot of scientific evidence to support ultraviolet (UV) radiation as a causative factor in most types of skin cancer. Family history is also important, particularly in melanoma. The lighter your skin type, the more susceptible you are to UV damage and to skin cancer. You have a higher risk of developing skin cancer, and should be particularly careful about sun exposure, if you have any of these factors:
- Long-term sun exposure
- Fair skin (typically blonde or red hair with freckles) and lighter eye color
- Place of residence (increased risk in southern climates)
- Presence of moles, particularly if there are irregular edges, uneven coloring, or an increase in the size of the mole
- Family history of skin cancer, particularly melanoma
- Use of indoor tanning devices
- Severe sunburns as a child
- Non-healing ulcers or nodules in the skin
- History of organ transplant or other immune system suppression
What Are the Different Types of Skin Cancer?
There are several types of cancer that originate in the skin. The most common types are basal cell carcinoma and squamous cell carcinoma. These types are classified as non-melanoma skin cancer. Melanoma is the third type of skin cancer. It is less common than basal cell or squamous cell cancers, but potentially much more serious. Other types of skin cancer are rare.
Basal cell carcinoma is the most common type of skin cancer (70 percent of all skin cancers). It typically appears as a small raised bump that has a pearly appearance. It is most commonly seen on areas of the skin that have received excessive sun exposure. These cancers may spread to the skin surrounding them, but rarely spread to other parts of the body.
Squamous cell carcinoma (20 percent of all skin cancers) is also seen on the areas of the body that have been exposed to excessive sun (nose, lower lip, hands, and forehead). Often this cancer appears as a firm red bump or ulceration of the skin that does not heal. Squamous cell carcinomas can spread to lymph nodes in the area.
Melanoma is a skin cancer (malignancy) that arises from the melanocytes in the skin. This makes up five percent of skin cancers. Melanocytes are the cells that give color to our skin. These cancers typically arise as pigmented (colored) lesions in the skin with an irregular shape, irregular border, and multiple colors. It is the most harmful of all the skin cancers, because it can spread to lymph nodes or other sites in the body. Fortunately, most melanomas have a very high cure rate when identified and treated early.