Skin Cancer Prevention (PDQ®)

As a National Cancer Institute (NCI)-designated Comprehensive Cancer Center, a core part of our mission is to educate patients and the community about cancer. The following summary is trusted information from the NCI.

What is prevention?

Cancer prevention is action taken to lower the chance of getting cancer. By preventing cancer, the number of new cases of cancer in a group or population is lowered. Hopefully, this will lower the number of deaths caused by cancer.

To prevent new cancers from starting, scientists look at risk factors and protective factors. Anything that increases your chance of developing cancer is called a cancer risk factor; anything that decreases your chance of developing cancer is called a cancer protective factor.

Some risk factors for cancer can be avoided, but many cannot. For example, both smoking and inheriting certain genes are risk factors for some types of cancer, but only smoking can be avoided. Regular exercise and a healthy diet may be protective factors for some types of cancer. Avoiding risk factors and increasing protective factors may lower your risk but it does not mean that you will not get cancer.

Different ways to prevent cancer are being studied, including:

  • Changing lifestyle or eating habits.
  • Avoiding things known to cause cancer.
  • Taking medicines to treat a precancerous condition or to keep cancer from starting.

General Information About Skin Cancer

The skin is the body's largest organ. It protects against heat, sunlight, injury, and infection. Skin also helps control body temperature and stores water, fat, and vitamin D. The skin has several layers, but the two main layers are the epidermis (upper or outer layer) and the dermis (lower or inner layer).

The epidermis is made up of 3 kinds of cells:

  • Squamous cells are the thin, flat cells that make up most of the epidermis.
  • Basal cells are the round cells under the squamous cells.
  • Melanocytes are found throughout the lower part of the epidermis. They make melanin, the pigment that gives skin its natural color. When skin is exposed to the sun, melanocytes make more pigment, causing the skin to tan, or darken.

The dermis contains blood and lymph vessels, hair follicles, and glands.

Anatomy of the skin, showing the epidermis, dermis, and subcutaneous tissue. Melanocytes are in the layer of basal cells at the deepest part of the epidermis.

See the following PDQ summaries for more information about skin cancer:

The most common types of skin cancer are squamous cell carcinoma, which forms in the squamous cells and basal cell carcinoma, which forms in the basal cells. Squamous cell carcinoma and basal cell carcinoma are also called nonmelanoma skin cancers. Melanoma, which forms in the melanocytes, is a less common type of skin cancer.

Skin cancer can occur anywhere on the body, but it is most common in skin that is often exposed to sunlight, such as the face, neck, hands, and arms.

The number of new cases of nonmelanoma skin cancer appears to be increasing every year. The number of new cases of melanoma has stayed about the same since the 1990s. Basal cell carcinoma and squamous cell carcinoma are the most common types of skin cancer in the United States. These nonmelanoma skin cancers can usually be cured. Melanoma is more likely to spread to nearby tissues and other parts of the body and can be harder to cure. Finding and treating melanoma skin cancer early may help prevent death from melanoma.

Skin Cancer Prevention

Avoiding cancer risk factors such as smoking, being overweight, and lack of exercise may help prevent certain cancers. Increasing protective factors such as quitting smoking, eating a healthy diet, and exercising may also help prevent some cancers. Talk to your doctor or other health care professional about how you might lower your risk of cancer.

Studies suggest that being exposed to ultraviolet (UV) radiation and the sensitivity of a person's skin to UV radiation are risk factors for skin cancer. UV radiation is the name for the invisible rays that are part of the energy that comes from the sun. Sunlamps and tanning beds also give off UV radiation.

Risk factors for nonmelanoma and melanoma cancers are not the same:

  • Nonmelanoma skin cancer
    • Being exposed to natural sunlight or artificial sunlight (such as from tanning beds) over long periods of time.
    • Having a fair complexion, which includes the following:
      • Fair skin that freckles and burns easily, does not tan, or tans poorly.
      • Blue or green or other light-colored eyes.
      • Red or blond hair.
    • Having actinic keratosis.
    • Past treatment with radiation.
    • Having a weakened immune system.
    • Being male.
  • Melanoma skin cancer
    • Having a fair complexion, which includes the following:
      • Fair skin that freckles and burns easily, does not tan, or tans poorly.
      • Blue or green or other light-colored eyes.
      • Red or blond hair.
    • Being exposed to natural sunlight or artificial sunlight (such as from tanning beds) over long periods of time.
    • Having a history of many blistering sunburns as a child.
    • Having several large or many small moles.
    • Having a family history of unusual moles (atypical nevus syndrome).
    • Having a family or personal history of melanoma.
    • Being white and male.

It is not known if nonmelanoma skin cancer risk is decreased by staying out of the sun, using sunscreens, or wearing long sleeve shirts, long pants, sun hats, and sunglasses when outdoors.

Sunscreen may help decrease the amount of UV radiation to the skin. One study found that wearing sunscreen can help prevent actinic keratoses, scaly patches of skin that may become squamous cell carcinoma. However, the use of sunscreen has not been proven to lower the risk of melanoma skin cancer.

Although protecting the skin and eyes from the sun has not been proven to lower the chance of getting skin cancer, skin experts suggest the following:

  • Use sunscreen that protects against UV radiation.
  • Do not stay out in the sun for long periods of time, especially when the sun is at its strongest.
  • Wear long sleeve shirts, long pants, sun hats, and sunglasses, when outdoors.

Cancer prevention clinical trials are used to study ways to lower the risk of developing certain types of cancer. Some cancer prevention trials are conducted with healthy people who have not had cancer but who have an increased risk for cancer. Other prevention trials are conducted with people who have had cancer and are trying to prevent another cancer of the same type or to lower their chance of developing a new type of cancer. Other trials are done with healthy volunteers who are not known to have any risk factors for cancer.

The purpose of some cancer prevention clinical trials is to find out whether actions people take can prevent cancer. These may include eating fruits and vegetables, exercising, quitting smoking, or taking certain medicines, vitamins, minerals, or food supplements.

Clinical trials are taking place in many parts of the country. Information about clinical trials can be found in the Clinical Trials section of the NCI Web site. Check for clinical trials in NCI's PDQ Cancer Clinical Trials Registry for nonmelanoma skin cancer prevention trials and melanoma prevention trials that are now accepting patients.



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