The information on this page was reviewed and approved by
Maurie Markman, MD, President, Medicine & Science at CTCA.
This page was updated on March 1, 2021.
Skin cancer is the most common type of cancer in the United States. Each year, about 3.5 million cases of skin cancer are diagnosed. Most skin cancers are non-melanoma, and if caught early, may be treated by a dermatologist in an outpatient procedure. Melanoma comprises only about 1 percent of all skin cancers, but it is responsible for more than 90 percent of skin cancer deaths.
Skin cancer occurs when the body does not repair damage to the DNA inside skin cells, allowing the cells to divide and grow uncontrollably. Skin cell damage may be caused by a variety of factors, including genetics and skin type. Most cases of skin cancer result from overexposure to ultraviolet (UV) light produced by the sun. Skin cancer may appear as a dark spot, lesion, a wound that does not heal or a bump on the skin.
The primary risk factor for melanoma and non-melanoma skin cancers is exposure to ultraviolet (UV) light, including sunlight and tanning beds, with the risk growing with the amount of exposure.
Besides sun exposure, common skin cancer risk factors include:
Caucasians are at greater risk of developing skin cancer than people with darker skin. The risk of skin cancer is also higher for individuals with blond or red hair, blue or green eyes, or fair skin that burns or freckles easily.
Skin cancer risks increase as you age, likely due to accumulated UV radiation from sun exposure.
People who live in areas with bright, year-round sun exposure, or those who spend a lot of time outdoors without sun protection or sunscreen, are at greater risk. Early exposure, particularly for people who had frequent sunburns during childhood, also increases skin cancer risks. Skin cancers may also be found in younger individuals who spend a lot of time in the sun. Doctors often recommend a broad spectrum sunblock with a sun protection factor (SPF) of 30 or higher and protective clothing as forms of skin cancer prevention.
Men are twice as likely to develop basal cell carcinomas and three times more likely to develop squamous cell carcinomas than women.
Common types of skin cancer include:
Because many skin cancers develop where they can be seen, there is a good chance of early detection. Regular examination of the skin is critical in looking for any new or unusual growths or changes in existing moles.
It is important to examine more than the legs, trunk, arms, face and neck. You should also check for signs of skin cancer between the toes, underneath the nails and on palms of the hands, soles of the feet, genitals and even the eyes.
Individuals should pay attention for warning signs of skin cancer, including:
Diagnosing skin cancer usually begins with a visual examination. The Skin Cancer Foundation and the American Cancer Society recommend monthly self-examinations and annual doctor visits to screen for potential skin cancer. If you are being seen by a primary care physician, you may be referred to a dermatologist who can perform more specialized tests and make a diagnosis.
A dermatologist may use a special microscope or magnifying lens to examine the suspicious spot more closely, a process called dermatoscopy. In many cases, the skin cancer is removed in the dermatologist's office.
Tests used to diagnose skin cancer include:
Most cases of skin cancer may be treated in a dermatologist's office or with outpatient surgery. If a dermatologist determines the skin cancer is melanoma or Merkel cell carcinoma, more aggressive treatment may be required.
The most common treatment options for skin cancer include:
Just ask Alexa. Find voice-activated answers to 800+ questions on 40+ cancer types.
Learn How