Summary

Key Points

• Skin cancer is a disease in which malignant (cancer) cells form in the tissues of the skin.
• There are different types of cancer that start in the skin.
• Skin color and being exposed to sunlight can increase the risk of nonmelanoma skin cancer and actinic keratosis.
• Nonmelanoma skin cancer and actinic keratosis often appear as a change in the skin.
• Tests or procedures that examine the skin are used to detect (find) and diagnose nonmelanoma skin cancer and actinic keratosis.
• Certain factors affect prognosis (chance of recovery) and treatment options.

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). Skin cancer begins in the epidermis, which is made up of three 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: Cells that make melanin and are found in the lower part of the epidermis. Melanin is the pigment that gives skin its natural color. When skin is exposed to the sun, melanocytes make more pigment and cause 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 different 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. Nonmelanoma skin cancers rarely spread to other parts of the body. Melanoma is the rarest form of skin cancer. It is more likely to invade nearby tissues and spread to other parts of the body. Actinic keratosis is a skin condition that sometimes becomes squamous cell carcinoma.

This summary is about nonmelanoma skin cancer and actinic keratosis. See the following PDQ summaries for information on melanoma and other kinds of cancer that affect the skin:

• Melanoma Treatment
• Mycosis Fungoides and the Sézary Syndrome Treatment
• Kaposi Sarcoma Treatment
• Merkel Cell Carcinoma Treatment
• Unusual Cancers of Childhood Treatment
• Genetics of Skin Cancer

Risk Factors

Skin color and being exposed to sunlight can increase the risk of nonmelanoma skin cancer and actinic keratosis.

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. Talk with your doctor if you think you may be at risk. 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.
• Having certain changes in the genes that are linked to skin cancer.
• Being exposed to arsenic.
• Risk factors for actinic keratosis 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.

Screening and Detection

Tests or procedures that examine the skin are used to detect (find) and diagnose nonmelanoma skin cancer and actinic keratosis.

The following procedures may be used:

• Skin exam: A doctor or nurse checks the skin for bumps or spots that look abnormal in color, size, shape, or texture.
• Skin biopsy: All or part of the abnormal-looking growth is cut from the skin and viewed under a microscope by a pathologist to check for signs of cancer. There are four 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.
  • Incisional biopsy: A scalpel is used to remove part of a growth.
  • Excisional biopsy: A scalpel is used to remove the entire growth.

Signs and Symptoms

Nonmelanoma skin cancer and actinic keratosis often appear as a change in the skin.

Not all changes in the skin are a sign of nonmelanoma skin cancer or actinic keratosis. Check with your doctor if you notice any changes in your skin.

Signs of nonmelanoma skin cancer include the following:

• A sore that does not heal.
• Areas of the skin that are:
• Raised, smooth, shiny, and look pearly.
• Firm and look like a scar, and may be white, yellow, or waxy.
• Raised, and red or reddish-brown.
• Scaly, bleeding or crusty.
• Signs of actinic keratosis include the following:
• A rough, red, pink, or brown, raised, scaly patch on the skin that may be flat or raised.
• Cracking or peeling of the lower lip that is not helped by lip balm or petroleum jelly.

Treatment Options

There are different types of treatment for patients with nonmelanoma skin cancer and actinic keratosis.

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.

Five types of standard treatment are used:

Surgery

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 abnormal tissue, 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

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 radiation therapy 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

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 squamous cell carcinoma of the skin.

See Drugs Approved for Basal Cell Carcinoma for more information.

Photodynamic therapy

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.

Biologic therapy

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.

Interferon and imiquimod are biologic agents used to treat skin cancer. Interferon (by injection) may be used to treat squamous cell carcinoma of the skin. Topical imiquimod therapy (a cream applied to the skin) may be used to treat some small basal cell carcinomas.

See Drugs Approved for Basal Cell Carcinoma for more information.

New types of treatment are being tested in clinical trials.

Information about clinical trials is available from the NCI website.

Patients may want to think about taking part in a clinical trial.

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.

Patients can enter clinical trials before, during, or after starting their cancer treatment.

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.

Follow-up tests may be needed.

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.

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.

Basal cell carcinoma and squamous cell carcinoma are likely to recur (come back), usually within 5 years, or new tumors may form. Talk to your doctor about how often you should have your skin checked for signs of cancer.