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
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
Paget disease of the nipple or extramammary Paget (usually near the anus)
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.
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: 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 beds
Wearing protective clothing: For example, long-sleeved shirts, pants, and broad-brimmed hats
Using sunscreen: 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. However, sun protection does decrease the risk of developing basal cell carcinoma and squamous cell carcinoma, and using tanning beds, particularly by young people, does seem to increase the risk of melanoma.
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, 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.