Overview of skin cancer

[Britney]

Skin cancer is the most common type of cancer. Skin cancer is most common among people who work or play sports outside and among sunbathers. Fair-skinned people are particularly susceptible to developing most forms of skin cancer because they produce less melanin. Melanin, the protective pigment in the outer layer of skin (epidermis), helps protect the skin from ultraviolet (UV) light. However, skin cancer also can develop in dark-skinned people and in people whose skin has not had significant sun exposure. Skin cancers may also develop years after x-ray therapy or exposure to substances that cause cancer (for example, ingestion of arsenic).
Over 5.4 million new cases of skin cancer are diagnosed in over 3.3 million people in the United States each year.
The three main types of skin cancer are

Basal cell carcinoma
Melanoma
Squamous cell carcinoma

These three types are caused, at least in part, by long-term sun exposure.
Less common types of skin cancer are

Atypical fibroxanthomas
Cancer of skin glands
Kaposi sarcoma
Merkel cell carcinoma
Paget disease of the nipple or extramammary Paget (usually near the anus)

Bowen disease and possibly keratoacanthomas are forms of squamous cell carcinoma. Lymphoma, a cancer of white blood cells, can also develop in the skin.
Most skin cancers are curable, especially when treated at an early stage. At first, skin cancers do not cause any symptoms. Therefore, any unusual skin growth that enlarges or lasts for more than a few weeks should be examined by a doctor.