Basal cells are small, round skin cells normally found in the upper part of your skin (called the epidermis). When these cells become cancerous, they grow out of control, and typically turn into small skin tumors that sometimes destroy skin and nearby tissues. This can be especially devastating if a basal cell cancer develops on the face, where it can cause disfigurement, and can interfere with the function of the eyelids, nose and mouth. Basal cell tumors rarely spread (metastasize) or cause death, but they can grow large over time, causing damage around and under them.

Like the two other common forms of skin cancer -- squamous cell carcinoma and malignant melanoma -- basal cell cancer often develop because of repeated, long-term exposure to the sun. That's why basal cell cancer is most common in people who spend a great deal of time in the sun, especially if they have light skin and blue eyes. Less often, basal cell cancer may be caused by exposure to arsenic or certain industrial pollutants. Older people who received X-ray treatment for acne as teenagers are at higher risk of developing basal cell cancer.

Basal cell cancer is the most common form of skin cancer diagnosed in the United States. More than 750,000 people are treated for it every year. Although about 90% of basal cell cancers are found on some part of the face, this cancer can grow on any part of the body, especially on unprotected portions of the body exposed to sunlight.

A basal cell skin cancer usually appears as a tiny, painless bump with a pink, pearly surface. As the cancer slowly grows, the center of the bump may become sore and develop into a crater that bleeds, crusts or forms a scab. Although it is commonly located on the face, particularly the nose, basal cell cancer can develop on the ears, back, neck and other skin surfaces frequently exposed to the sun.

A rare type of basal cell cancer called a morpheaform basal cell carcinoma may look like a small scar.

Your doctor will examine your skin and do a biopsy, which involves removing skin so it can be examined in a laboratory. In some cases, the doctor will cut or shave away a small piece of abnormal skin to serve as the biopsy sample. In other cases, the doctor will remove the entire abnormal area and send it to the laboratory for examination.

Once a basal cell cancer develops on the skin, it usually grows slowly. It can become very large, especially if it is on your lower back, the back of your shoulder or some other area that you do not usually see in the mirror.

Because the risk of developing basal cell cancer is increased by unprotected exposure to sunlight, you can help to reduce this risk in several ways:

• Apply sunscreen with a sun protection factor (SPF) of 15 or higher before you go outdoors.
• Limit your time outdoors when the sun is at its peak (in most parts of the continental United States, from about 10 a.m. to 3 p.m.).
• Wear sunglasses with ultraviolet light protection.
• Wear long pants, a shirt with long sleeves and a hat with a wide brim.
• Be aware that some drugs may increase your skin's risk of damage from the sun. These include certain antibiotics, and drugs used to treat psychiatric illness, high blood pressure, heart failure, acne and allergies. If you take prescription medications and spend significant time outdoors, ask your doctor if you need to take extra precautions to avoid sun exposure.
• Be aware that some skin care products can make your skin more vulnerable to damage from sunlight. These include products containing alpha-hydroxy acids.

If a basal cell cancer develops on your skin, detecting the problem early may limit damage. Examine your skin thoroughly every one to two months. Use a mirror to check your skin on less visible areas, such as your back, shoulders, upper arms, buttocks and the soles of your feet. Have a yearly skin exam by your physician.

Treatments for basal cell cancer include:

• Curettage and electrodesiccation. A sharp instrument is used to scrape away visible cancer, and then an electric probe is used to kill remaining microscopic cancer cells.
• Excision. Visible cancer and some healthy tissue is cut away, then the skin is stitched closed.
• Cryosurgery. Cancerous cells are frozen with liquid nitrogen.
• Laser therapy. The cancer is destroyed with a laser beam.
• Radiation. High energy rays are used to destroy the cancer.
• Moh's micrographic surgery. The tumor is shaved away in thin layers. Each layer is checked under a microscope to see if it contains cells. This procedure preserves as much healthy skin as possible while making sure that all of the cancer is removed. This is the most common treatment for basal cell cancers on the eyelids, nose and fingers.

Less common or experimental therapies include:

• Topical fluorouracil, an anticancer drug applied directly to the skin
• Topical imiquimod cream (Aldara) for very superficial basal cell skin cancers
• Chemotherapy injected directly into the tumor
• Photodynamic therapy, which kills cancer with chemicals and light

Determining the right treatment depends on many factors, including the size and location of the cancer, whether it has returned after previous treatment, age and general health. Once treatment is finished and the cancer is gone, the doctor will schedule regular follow up skin examinations. Thirty-six percent of patients who have been treated for one basal cell cancer develop a second basal cell cancer within the next five years.

Call your doctor or a dermatologist (a doctor who specializes in skin problems) if you notice a pearly nodule on your skin, a new skin growth, or a skin ulcer that does not heal.

The outlook is usually excellent. Overall, about 95 percent of basal cell cancers are cured if they are treated early.

National Cancer Institute (NCI)
NCI Public Inquiries Office
6116 Executive Blvd.
Bethesda, MD 20892-8322
Phone: 301-435-3848
Toll-Free: 1-800-422-6237
E-Mail: cancergovstaff@mail.nih.gov
http://www.nci.nih.gov/

American Cancer Society (ACS)
Toll-Free: 1-800-227-2345
TTY: 1-866-228-4327
http://www.cancer.org/

American Academy of Dermatology
P.O. Box 4014
Schaumburg, IL 60168-4014
Phone: 847-240-1280
Toll-Free: 1-866-503-7546
Fax: 847-240-1859
http://www.aad.org/

The Skin Cancer Foundation
149 Madison Ave.
Suite 901
New York, NY 10016
Phone: 212-725-5176
http://www.skincancer.org/