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). Skin cancer begins in the epidermis, which is made up of 3 kinds of cells:
Squamous cells: Thin, flat cells that form the top layer of the epidermis.
Basal cells: Round cells under the squamous cells.
Melanocytes: Found in the lower part of the epidermis, these cells 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 darken.
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. There are several types of cancer that start in the skin. The most common types are basal cell carcinoma and squamous cell carcinoma, which are nonmelanoma skin cancers. Actinic keratosis is a skin condition that sometimes develops into squamous cell carcinoma.
This summary refers to the treatment of nonmelanoma skin cancer and actinic keratosis. Nonmelanoma skin cancers rarely spread to other parts of the body. Melanoma, the rarest form of skin cancer, is more likely to invade nearby tissues and spread to other parts of the body. See the following PDQ summaries for information on melanoma and other kinds of skin cancer:
Mycosis Fungoides and the Sézary Syndrome Treatment
Kaposi Sarcoma Treatment
Merkel Cell Carinoma Treatment
Anything that increases your chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn’t mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors for basal cell carcinoma and squamous cell carcinoma include the following:
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.
Risk factors for actinic keratosis include the following:
Red or blond hair.
Not all changes in the skin are a sign of nonmelanoma skin cancer or actinic keratosis, but a doctor should be consulted if changes in the skin are seen.
Possible signs of nonmelanoma skin cancer include the following:
A sore that does not heal.
Areas of the skin that are:
Small, raised, smooth, shiny, and waxy.
Small, raised, and red or reddish-brown.
Flat, rough, red or brown, and scaly.
Scaly, bleeding, or crusty.
Similar to a scar and firm.
Possible signs of actinic keratosis include the following:
A rough, red, pink, or brown, raised, scaly patch on the skin.
Cracking or peeling of the lower lip that is not helped by lip balm or petroleum jelly.
The following procedures may be used:
Skin examination: A doctor or nurse checks the skin for bumps or spots that look abnormal in color, size, shape, or texture.
Biopsy: All or part of the abnormal-looking growth is cut from the skin and viewed under a microscope by a pathologist to see if cancer cells are present. There are 3 main types of skin biopsies:
Shave biopsy: A sterile razor blade is used to “shave-off” the abnormal-looking growth.
Punch biopsy: A special instrument called a punch or a trephine is used to remove a circle of tissue from the abnormal-looking growth.
Excisional biopsy: A scalpel is used to remove the entire growth.
The prognosis (chance of recovery) depends mostly on the stage of the cancer and the type of treatment used to remove the cancer.
Treatment options depend on the following:
The stage of the cancer (whether it has spread deeper into the skin or to other places in the body).
The type of cancer.
The size and location of the tumor.
The patient’s general health.
The process used to find out if cancer has spread within the skin or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. A biopsy is often the only test needed to determine the stage of nonmelanoma skin cancer. Lymph nodes may be examined in cases of squamous cell carcinoma to see if cancer has spread to them.
The three ways that cancer spreads in the body are:
Through tissue. Cancer invades the surrounding normal tissue.
Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.
When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.
The following are high-risk features for nonmelanoma skin cancer:
The tumor is thicker than 2 millimeters.
The tumor is described as Clark level IV (has spread into the lower layer of the dermis) or Clark level V (has spread into the layer of fat below the skin).
The tumor has grown and spread along nerve pathways.
The tumor began on an ear or on a lip that has hair on it.
The tumor has cells that look very different from normal cells under a microscope.
In stage 0, abnormalcells are found in the squamous cell or basal cell layer of the epidermis (topmost layer of the skin). These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.
In stage I, cancer has formed. The tumor is not larger than 2 centimeters at its widest point and may have one high-risk feature.
In stage II, the tumor is either:
larger than 2 centimeters at its widest point; or
any size and has two or more high-risk features.
In stage III:
The tumor has spread to the jaw, eye socket, or side of the skull. Cancer may have spread to one lymph node on the same side of the body as the tumor. The lymph node is not larger than 3 centimeters.
Cancer has spread to one lymph node on the same side of the body as the tumor. The lymph node is not larger than 3 centimeters and one of the following is true:
the tumor is not larger than 2 centimeters at its widest point and may have one high-risk feature; or
the tumor is larger than 2 centimeters at its widest point; or
the tumor is any size and has two or more high-risk features.
In stage IV, one of the following is true:
The tumor is any size and may have spread to the jaw, eye socket, or side of the skull. Cancer has spread to one lymph node on the same side of the body as the tumor and the affected node is larger than 3 centimeters but not larger than 6 centimeters, or cancer has spread to more than one lymph node on one or both sides of the body and the affected nodes are not larger than 6 centimeters; or
The tumor is any size and may have spread to the jaw, eye socket, skull, spine, or ribs. Cancer has spread to one lymph node that is larger than 6 centimeters; or
The tumor is any size and has spread to the base of the skull, spine, or ribs. Cancer may have spread to the lymph nodes; or
Cancer has spread to distant parts of the body.
Basal cell carcinoma is the most common type of skin cancer. It usually occurs on areas of the skin that have been in the sun, most often the nose. Often this cancer appears as a small raised bump that has a smooth, pearly appearance. Another type looks like a scar and is flat and firm to the touch. Basal cell carcinoma may spread to tissues around the cancer, but it usually does not spread to other parts of the body.
Squamous cell carcinoma occurs on areas of the skin that have been in the sun, such as the ears, lower lip, and the back of the hands. Squamous cell carcinoma may also appear on areas of the skin that have been burned or exposed to chemicals or radiation. Often this cancer appears as a firm red bump. Sometimes the tumor may feel scaly or bleed or develop a crust. Squamous cell tumors may spread to nearby lymph nodes.
Actinic keratosis is a skin condition that is not cancer, but sometimes changes into squamous cell carcinoma. It usually occurs in areas that have been exposed to the sun, such as the face, the back of the hands, and the lower lip. It appears as rough, red, pink, or brown, raised, scaly patches on the skin, or cracking or peeling of the lower lip that is not helped by lip balm or petroleum jelly.
Different types of treatment are available for patients with nonmelanoma skin cancer and actinic keratosis. Some treatments are standard (the currently used treatment), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to help improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
One or more of the following surgical procedures may be used to treat nonmelanoma skin cancer or actinic keratosis:
Mohs micrographic surgery: The tumor is cut from the skin in thin layers. During surgery, the edges of the tumor and each layer of tumor removed are viewed through a microscope to check for cancer cells. Layers continue to be removed until no more cancer cells are seen. This type of surgery removes as little normal tissue as possible and is often used to remove skin cancer on the face.
Simple excision: The tumor is cut from the skin along with some of the normal skin around it.
Shave excision: The abnormal area is shaved off the surface of the skin with a small blade.
Electrodesiccation and curettage: The tumor is cut from the skin with a curette (a sharp, spoon-shaped tool). A needle-shaped electrode is then used to treat the area with an electric current that stops the bleeding and destroys cancer cells that remain around the edge of the wound. The process may be repeated one to three times during the surgery to remove all of the cancer.
Cryosurgery: A treatment that uses an instrument to freeze and destroy abnormaltissue, such as carcinoma in situ. This type of treatment is also called cryotherapy.
Laser surgery: A surgical procedure that uses a laser beam (a narrow beam of intense light) as a knife to make bloodless cuts in tissue or to remove a surface lesion such as a tumor.
Dermabrasion: Removal of the top layer of skin using a rotating wheel or small particles to rub away skin cells.
Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiationtherapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the cerebrospinal fluid, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). Chemotherapy for nonmelanoma skin cancer and actinic keratosis is usually topical (applied to the skin in a cream or lotion). The way the chemotherapy is given depends on the condition being treated.
Retinoids (drugs related to vitamin A) are sometimes used to treat or prevent nonmelanoma skin cancer. The retinoids may be taken by mouth or applied to the skin. The use of retinoids is being studied in clinical trials for treatment of squamous cell carcinoma.
Photodynamic therapy (PDT) is a cancer treatment that uses a drug and a certain type of laser light to kill cancer cells. A drug that is not active until it is exposed to light is injected into a vein. The drug collects more in cancer cells than in normal cells. For skin cancer, laser light is shined onto the skin and the drug becomes active and kills the cancer cells. Photodynamic therapy causes little damage to healthy tissue.
This summary section describes treatments that are being studied in clinical trials. It may not mention every new treatment being studied. Information about clinical trials is available from the NCI Web site.
Biologic therapy is a treatment that uses the patient’s immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body’s natural defenses against cancer. This type of cancer treatment is also called biotherapy or immunotherapy.
For some patients, taking part in a clinical trial may be the best treatment choice. Clinical trials are part of the cancer research process. Clinical trials are done to find out if new cancer treatments are safe and effective or better than the standard treatment.
Many of today's standard treatments for cancer are based on earlier clinical trials. Patients who take part in a clinical trial may receive the standard treatment or be among the first to receive a new treatment.
Patients who take part in clinical trials also help improve the way cancer will be treated in the future. Even when clinical trials do not lead to effective new treatments, they often answer important questions and help move research forward.
Some clinical trials only include patients who have not yet received treatment. Other trials test treatments for patients whose cancer has not gotten better. There are also clinical trials that test new ways to stop cancer from recurring (coming back) or reduce the side effects of cancer treatment.
Clinical trials are taking place in many parts of the country. See the Treatment Options section that follows for links to current treatment clinical trials. These have been retrieved from NCI's listing of clinical trials.
Some of the tests that were done to diagnose the cancer or to find out the stage of the cancer may be repeated. Some tests will be repeated in order to see how well the treatment is working. Decisions about whether to continue, change, or stop treatment may be based on the results of these tests. This is sometimes called re-staging.
Some of the tests will continue to be done from time to time after treatment has ended. The results of these tests can show if your condition has changed or if the cancer has recurred (come back). These tests are sometimes called follow-up tests or check-ups.
A link to a list of current clinical trials is included for each treatment section. For some types or stages of cancer, there may not be any trials listed. Check with your doctor for clinical trials that are not listed here but may be right for you.
Treatment of basal cell carcinoma may include the following:
Mohs micrographic surgery.
Electrodesiccation and curettage.
Topical chemotherapy with fluorouracil.
A clinical trial of biologic therapy.
Follow-up skin exams are important for people with basal cell carcinoma because they are likely to have a new or recurrent tumor within 5 years of the first one. After treatment, the patient should have skin exams every 6 months for 5 years and once a year after that.
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with basal cell carcinoma of the skin. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.
Treatment of squamous cell carcinoma may include the following:
A clinical trial of biologic therapy and retinoids.
Follow-up skin exams are important for people with squamous cell carcinoma. Because squamous cell carcinoma can spread, patients should have skin exams every 3 months for several years after treatment and then every 6 months.
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with squamous cell carcinoma of the skin. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.
Actinic keratosis is not cancer but is treated because it may develop into cancer. Treatment of actinic keratosis may include the following:
Check for U.S. clinical trials from NCI's list of cancer clinical trials that are now accepting patients with actinic keratosis. For more specific results, refine the search by using other search features, such as the location of the trial, the type of treatment, or the name of the drug. General information about clinical trials is available from the NCI Web site.
For more information from the National Cancer Institute about skin cancer, see the following:
Skin Cancer Home Page
What You Need to Know About™ Melanoma and Other Skin Cancers
Skin Cancer Prevention
Skin Cancer Screening
Cryosurgery in Cancer Treatment: Questions and Answers
Lasers in Cancer Treatment: Questions and Answers
Photodynamic Therapy for Cancer: Questions and Answers
For general cancer information and other resources from the National Cancer Institute, see the following:
What You Need to Know About™ Cancer
Understanding Cancer Series: Cancer
Chemotherapy and You: Support for People With Cancer
Radiation Therapy and You: Support for People With Cancer
Coping with Cancer: Supportive and Palliative Care
Information For Survivors/Caregivers/Advocates
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 8:00 a.m. to 8:00 p.m., Eastern Time. A trained Cancer Information Specialist is available to answer your questions.
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The PDQcancer 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.
Images were added and editorial changes were made to this summary.
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 one treatment is better than another. 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. During treatment clinical trials, information is collected about the effects of a new treatment and how well it works. If a clinical trial shows that a new treatment is better than one currently being used, the new treatment may become "standard." Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
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).