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:
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, and hands.
Skin cancer may form in basal cells or squamous cells. Basal cell carcinoma and squamous cell carcinoma are the most common types of skin cancer. They are also called nonmelanoma skin cancer. Actinic keratosis is a skin condition that sometimes becomes squamous cell carcinoma.
Melanoma is less common than basal cell carcinoma or squamous cell carcinoma. It is more likely to invade nearby tissues and spread to other parts of the body.
Anything that increases a person's chance of getting a disease is called a risk factor. Not every person with one or more of these risk factors will develop skin cancer, and it will develop in people who don't have any known risk factors. Talk with your doctor if you think you may be at risk.
Risk factors for basal cell carcinoma and squamous cell carcinoma of the skin include the following:
Older age is the main risk factor for most cancers. The chance of getting cancer increases as you get older.
Not all changes in the skin are a sign of basal cell carcinoma, squamous cell carcinoma of the skin, or actinic keratosis. Check with your doctor if you notice any changes in your skin.
Signs of basal cell carcinoma and squamous cell carcinoma of the skin include the following:
Basal cell carcinoma and squamous cell carcinoma of the skin occur most often in areas of the skin exposed to the sun, such as the nose, ears, lower lip, or top of the hands.
Signs of actinic keratosis include the following:
Actinic keratosis occurs most commonly on the face or the top of the hands.
In addition to asking about your personal and family health history and doing a physical exam, your doctor may perform the following tests and procedures:
Basal cell carcinoma
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 raised bump that looks smooth and pearly. A less common type looks like a scar or it is flat and firm and may be skin-colored, yellow, or waxy. 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
Squamous cell carcinoma occurs on areas of the skin that have been damaged by 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 sunburned or exposed to chemicals or radiation. Often this cancer looks like a firm red bump. The tumor may feel scaly, bleed, or form a crust. Squamous cell tumors may spread to nearby lymph nodes. Squamous cell carcinoma that has not spread can usually be cured.
Actinic keratosis is a skin condition that is not cancer, but sometimes changes into squamous cell carcinoma. One or more lesions may occur in areas that have been exposed to the sun, such as the face, the back of the hands, and the lower lip. It looks like rough, red, pink, or brown scaly patches on the skin that may be flat or raised, or as a cracked and peeling lower lip that is not helped by lip balm or petroleum jelly. Actinic keratosis may disappear without treatment.
Different types of treatment are available for patients with basal cell carcinoma, squamous cell carcinoma of the skin, 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 basal cell carcinoma, squamous cell carcinoma of the skin, or actinic keratosis:
Simple excision, Mohs micrographic surgery, curettage and electrodesiccation, and cryosurgery are used to treat basal cell carcinoma and squamous cell carcinoma of the skin. Laser surgery is rarely used to treat basal cell carcinoma. Simple excision, shave excision, curettage and desiccation, dermabrasion, and laser surgery are used to treat actinic keratosis.
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. External radiation therapy uses a machine outside the body to send radiation toward the area of the body with cancer.
External radiation therapy is used to treat basal cell carcinoma and squamous cell carcinoma of the skin.
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.
Chemotherapy for basal cell carcinoma, squamous cell carcinoma of the skin, and actinic keratosis is usually topical (applied to the skin in a cream or lotion). Topical fluorouracil (5-FU) is used to treat basal cell carcinoma.
Photodynamic therapy (PDT) is a cancer treatment that uses a drug and a certain type of light to kill cancer cells. A drug that is not active until it is exposed to light is injected into a vein or put on the skin. 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.
Immunotherapy 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.
Targeted therapy is a type of treatment that uses drugs or other substances to identify and attack specific cancer cells.
A chemical peel is a procedure used to improve the way certain skin conditions look. A chemical solution is put on the skin to dissolve the top layers of skin cells. Chemical peels may be used to treat actinic keratosis. This type of treatment is also called chemabrasion and chemexfoliation.
Other drug therapy
Retinoids (drugs related to vitamin A) are sometimes used to treat squamous cell carcinoma of the skin. Diclofenac and ingenol are topical drugs used to treat actinic keratosis.
For more information, visit Cancer.gov
Source: PDQ® Adult Treatment Editorial Board. PDQ Breast Cancer Treatment. Bethesda, MD: National Cancer Institute. This information should not be used to make decisions about insurance reimbursement.