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Table of Contents What is prevention?
General Information About Skin Cancer
Skin Cancer Prevention
Get More Information From NCI
Changes to This Summary (12/19/2008)
Questions or Comments About This Summary
About PDQ
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.
See the following PDQ summaries for more information on skin cancer:
Back to Top General Information About Skin Cancer
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Skin cancer is a disease in which malignant (cancer) cells form
in the tissues of the skin.
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.
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| 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. |
There are several types of 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.
Skin cancer is the most common cancer in the United
States.
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.
Back to Top Skin Cancer Prevention
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Avoiding risk factors and increasing protective factors may help prevent cancer.
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.
Being exposed to ultraviolet radiation is a risk factor that may increase
the risk of skin 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
booths also give off UV radiation.
Risk factors for nonmelanoma and melanoma cancers are not the same:
- Nonmelanoma skin cancer: The total amount
of time the skin is exposed to UV radiation may affect the risk of nonmelanoma skin cancer.
Spending more time in the sun may increase the risk. People may have an increased risk of nonmelanoma skin cancer if their skin burns easily in the sun.
- Melanoma skin cancer: Being exposed to strong UV radiation for short periods (as with sunburns), especially in
childhood and teen years, may increase the risk of melanoma. People
may have an increased risk of melanoma from UV radiation if they burn
easily in the sun or have freckles or a lot of moles.
It is not known if protecting skin from sunlight and other UV radiation decreases the risk of skin cancer.
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 prevent cancer.
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.
New ways to prevent skin cancer are being studied in clinical
trials.
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
skin cancer prevention trials that are now accepting patients.
Back to Top Get More Information From NCI
Call 1-800-4-CANCER
For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 a.m. to 4:30 p.m. Deaf and hard-of-hearing callers with TTY equipment may call 1-800-332-8615. The call is free and a trained Cancer Information Specialist is available to answer your questions.
Chat online
The NCI's LiveHelp® online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 9:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer.
Write to us
For more information from the NCI, please write to this address:
- NCI Public Inquiries Office
- Suite 3036A
- 6116 Executive Boulevard, MSC8322
- Bethesda, MD 20892-8322
Search the NCI Web site
The NCI Web site provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use our “Best Bets” search box in the upper right hand corner of each Web page. The results that are most closely related to your search term will be listed as Best Bets at the top of the list of search results.
There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.
Find Publications
The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615.
Back to Top Changes to This Summary (12/19/2008)
The PDQ cancer information summaries are reviewed regularly
and updated as new information becomes available. This
section describes the latest changes made to this summary as
of the date above.
This summary was completely reformatted. Images and some
content were added.
Back to Top Questions or Comments About This Summary
If you have questions or comments about this summary, please send them to Cancer.gov through the Web site’s Contact Form. We can respond only to email messages written in English.
Back to Top About PDQ
PDQ is a comprehensive cancer database available on NCI's Web site.
PDQ is the National Cancer Institute's (NCI's) comprehensive cancer information database. Most of the information contained in PDQ is available online at NCI's Web site. PDQ is provided as a service of the NCI. The NCI is part of the National Institutes of Health, the federal government's focal point for biomedical research.
PDQ contains cancer information summaries.
The PDQ database contains summaries of the latest published information on cancer prevention, detection, genetics, treatment, supportive care, and complementary and alternative medicine. Most summaries are available in two versions. The health professional versions provide detailed information written in technical language. The patient versions are written in easy-to-understand, nontechnical language. Both versions provide current and accurate cancer information.
The PDQ cancer information summaries are developed by cancer experts and reviewed regularly.
Editorial Boards made up of experts in oncology and related specialties are responsible for writing and maintaining the cancer information summaries. The summaries are reviewed regularly and changes are made as new information becomes available. The date on each summary ("Date Last Modified") indicates the time of the most recent change.
PDQ also contains information on clinical trials.
A clinical trial is a study to answer a scientific question, such as whether a certain drug or nutrient can prevent cancer. Trials are based on past studies and what has been learned in the laboratory. Each trial answers certain scientific questions in order to find new and better ways to help cancer patients and those who are at risk for cancer. During prevention clinical trials, information is collected about the effects of a new prevention method and how well it works. If a clinical trial shows that a new method is better than one currently being used, the new method may become "standard." People who are at high risk for a certain type of cancer may want to think about taking part in a clinical trial.
Listings of clinical trials are included in PDQ and are available online at NCI's Web site. Descriptions of the trials are available in health professional and patient versions. Many cancer doctors who take part in clinical trials are also listed in PDQ. For more information, call the Cancer Information Service 1-800-4-CANCER (1-800-422-6237); TTY at 1-800-332-8615.
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