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 nonmelanoma skin cancer were diagnosed in 2012 among over 3.3 million people in the United States.
The three main types of skin cancer are
These three types are caused, at least in part, by long-term sun exposure.
Less common types of skin cancer are
Cancer of skin glands
Bowen disease Bowen Disease Bowen disease is an early form of squamous cell carcinoma that is confined to the outer layer of the skin (epidermis) and has not yet invaded the deeper layers. Bowen disease most commonly occurs... read more 
and possibly keratoacanthomas Keratoacanthomas Keratoacanthomas are round, firm, usually pink or flesh-colored growths that have a central crater that is scaly or crusted. Some keratoacanthomas may be a form of squamous cell carcinoma. Keratoacanthomas... read more 
are forms of squamous cell carcinoma. Lymphoma Overview of Lymphoma Lymphomas are cancers of lymphocytes, which reside in the lymphatic system and in blood-forming organs. Lymphomas are cancers of a specific type of white blood cells known as lymphocytes. These... read more 
, 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.
Screening for skin cancer
People should notify their doctor if they notice any unusual or changed skin marks. Routine skin examination is done by doctors or by people examining their own skin, or both.
Prevention of skin cancer
Because many skin cancers seem to be related to UV exposure, doctors recommend a number of measures to limit UV exposure, starting in early childhood.
Avoiding the sun Avoidance Sunburn results from a brief (acute) overexposure to ultraviolet (UV) light. Overexposure to ultraviolet light causes sunburn. Sunburn causes painful reddened skin and sometimes blisters, fever... read more
: For example, seeking shade, minimizing outdoor activities between 10 AM and 4 PM (when the sun’s rays are strongest), and avoiding sunbathing and the use of tanning bedsWearing protective clothing Clothing Sunburn results from a brief (acute) overexposure to ultraviolet (UV) light. Overexposure to ultraviolet light causes sunburn. Sunburn causes painful reddened skin and sometimes blisters, fever... read more
: For example, long-sleeved shirts, pants, and broad-brimmed hatsUsing sunscreen Sunscreens Sunburn results from a brief (acute) overexposure to ultraviolet (UV) light. Overexposure to ultraviolet light causes sunburn. Sunburn causes painful reddened skin and sometimes blisters, fever... read more
: At least sun protection factor (SPF) 30 with UVA and UVB protection used as directed and reapplied every 2 hours and after swimming or sweating but not used to prolong sun exposure
Doctors do not know whether these measures reduce the chances of people developing or dying of melanoma Melanoma Melanoma is a skin cancer that begins in the pigment-producing cells of the skin (melanocytes). Melanomas can begin on normal skin or in existing moles. They may be irregular, flat or raised... read more 
. However, sun protection does decrease the risk of developing basal cell carcinoma Basal Cell Carcinoma Basal cell carcinoma, the most common skin cancer, originates in certain cells of the outer layer of the skin (epidermis). Usually, a small, shiny bump appears on the skin and enlarges slowly... read more 
and squamous cell carcinoma Squamous Cell Carcinoma Squamous cell carcinoma is cancer that begins in the squamous cells of the skin. Thick, scaly growths appear on the skin and do not heal. To diagnose the cancer, doctors do a biopsy. Treatment... read more 
, and using tanning beds, particularly by young people, does seem to increase the risk of melanoma.
Treatment of skin cancer
Doctors treat most skin cancers by removing them surgically. Usually, the scar that is left after surgery depends on the size of the original cancer, which, if caught early, may be small.
Larger or more invasive cancer may require removal of a significant amount of skin, which may have to be replaced with a skin graft or a skin flap.
With a skin graft Skin Tissue transplantation is the removal of various tissues, such as skin cells, corneas, cartilage, or bone, from a body and then inserting that tissue into the same or another person who has... read more , a piece of skin is removed from another area of the person's body, typically where the skin is loose. The piece of skin is sewn onto the area where the cancer was removed.
With a skin flap, doctors transfer skin from an adjacent area to replace the area where the cancer was removed. With a flap, but not with a graft, the transferred skin is not cut completely free, so it still has its own blood supply. Also, a flap is usually thicker than a graft.
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
American Academy of Dermatology: Patient-friendly information about finding, treating, and raising awareness for skin cancers
American Cancer Society: Skin Cancer: Information about different types of skin cancer, including detection, prevention, treatment options, and other resources
The Skin Cancer Foundation: Skin Cancer 101: Information about different types of skin cancer, including detection, prevention, treatment options, and other resources
