Basal cell carcinoma (BCC), a skin cancer

This article focuses solely on the treatments and stages of basal cell carcinoma. For more general details on skin cancer, the risks and prevention, please consult Skin Cancer, an overview

Basal cell carcinoma (BCC) is the most common form of skin cancer and the most frequently occurring form of all cancers. In the U.S. alone, more than 4 million cases are diagnosed each year. BCCs arise from abnormal, uncontrolled growth of basal cells.

Because BCCs grow slowly, most are curable and cause minimal damage when caught and treated early. Understanding BCC causes, risk factors and warning signs can help you detect them early, when they are easiest to treat and cure.

One of three main types of cells in the top layer of the skin, basal cells shed as new ones form. BCC most often occurs when DNA damage from exposure to ultraviolet (UV) radiation from the sun or indoor tanning triggers changes in basal cells in the outermost layer of skin (epidermis), resulting in uncontrolled growth.

What does BCC look like?

BCCs can look like open sores, red patches, pink growths, shiny bumps, scars or growths with slightly elevated, rolled edges and/or a central indentation. At times, BCCs may ooze, crust, itch or bleed. The lesions commonly arise in sun-exposed areas of the body. In patients with darker skin, about half of BCCs are pigmented (meaning brown in color).

The following stages are used for basal cell carcinoma and squamous cell carcinoma of the skin that is on the head or neck but not on the eyelid:

Stage 0 (Carcinoma in situ)

In stage 0, abnormal cells are found in the squamous cell or basal cell layer of the epidermis. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I

In stage I, cancer has formed and the tumor is 2 centimeters or smaller.

Stage II

In stage II, the tumor is larger than 2 centimeters but not larger than 4 centimeters.

Stage III

or

In stage III, one of the following is found:

• the tumor is larger than 4 centimeters, or cancer has spread to tissue covering the nerves below the dermis, or has spread below the subcutaneous tissue, or has spread to the bone and the bone has minor damage. Cancer may have also spread to one lymph node on the same side of the body as the tumor and the node is 3 centimeters or smaller, and cancer has not spread through to the outside covering of the lymph node; or
• the tumor is 4 centimeters or smaller. Cancer has spread to one lymph node on the same side of the body as the tumor and the node is 3 centimeters or smaller.

Stage IV

or

or

In stage IV, one of the following is found:

• the tumor is any size and cancer may have spread to the bone and the bone has minor damage, or to tissue covering the nerves below the dermis, or below the subcutaneous tissue. Cancer has spread to the lymph nodes as follows:
  • one lymph node on the same side of the body as the tumor, the affected node is 3 centimeters or smaller, and cancer has spread through to the outside covering of the lymph node; or
  • one lymph node on the same side of the body as the tumor, the affected node is larger than 3 centimeters but not larger than 6 centimeters, and cancer has not spread through to the outside covering of the lymph node; or
  • more than one lymph node on the same side of the body as the tumor, the affected nodes are 6 centimeters or smaller, and cancer has not spread through to the outside covering of the lymph nodes; or
  • one or more lymph nodes on the opposite side of the body as the tumor or on both sides of the body, the affected nodes are 6 centimeters or smaller, and cancer has not spread through to the outside covering of the lymph nodes.
• the tumor is any size and cancer may have spread to tissue covering the nerves below the dermis, or below the subcutaneous tissue, or to bone marrow or to bone, including the bottom of the skull. Also:
  • cancer has spread to one lymph node that is larger than 6 centimeters and cancer has not spread through to the outside covering of the lymph node; or
  • cancer has spread to one lymph node on the same side of the body as the tumor, the affected node is larger than 3 centimeters, and cancer has spread through to the outside covering of the lymph node; or
  • cancer has spread to one lymph node on the opposite side of the body as the tumor, the affected node is any size, and cancer has spread through to the outside covering of the lymph node; or
  • cancer has spread to more than one lymph node on one or both sides of the body and cancer has spread through to the outside covering of the lymph nodes.
• the tumor is any size and cancer has spread to bone marrow or to bone, including the bottom of the skull, and the bone has been damaged. Cancer may have also spread to the lymph nodes; or
• cancer has spread to other parts of the body, such as the lung.

The following stages are used for basal cell carcinoma and squamous cell carcinoma of the skin on the eyelid:

Stage 0 (Carcinoma in situ)

In stage 0, abnormal cells are found in the epidermis, usually in the basal cell layer. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.

Stage I

In stage I, cancer has formed. Stage I is divided into stages IA and IB.

• Stage IA: The tumor is 10 millimeters or smaller and may have spread to the edge of the eyelid where the lashes are, to the connective tissue in the eyelid, or to the full thickness of the eyelid.
• Stage IB: The tumor is larger than 10 millimeters but not larger than 20 millimeters and the tumor has not spread to the edge of the eyelid where the lashes are, or to the connective tissue in the eyelid.

Stage II

Stage II is divided into stages IIA and IIB.

• In stage IIA, one of the following is found:
  • the tumor is larger than 10 millimeters but not larger than 20 millimeters and has spread to the edge of the eyelid where the lashes are, to the connective tissue in the eyelid, or to the full thickness of the eyelid; or
  • the tumor is larger than 20 millimeters but not larger than 30 millimeters and may have spread to the edge of the eyelid where the lashes are, to the connective tissue in the eyelid, or to the full thickness of the eyelid.
• In stage IIB, the tumor may be any size and has spread to the eye, eye socket, sinuses, tear ducts, or brain, or to the tissues that support the eye.

Stage III

Stage III is divided into stages IIIA and IIIB.

• Stage IIIA: The tumor may be any size and may have spread to the edge of the eyelid where the lashes are, to the connective tissue in the eyelid, or to the full thickness of the eyelid, or to the eye, eye socket, sinuses, tear ducts, or brain, or to the tissues that support the eye. Cancer has spread to one lymph node on the same side of the body as the tumor and the node is 3 centimeters or smaller.
• Stage IIIB: The tumor may be any size and may have spread to the edge of the eyelid where the lashes are, to the connective tissue in the eyelid, or to the full thickness of the eyelid, or to the eye, eye socket, sinuses, tear ducts, or brain, or to the tissues that support the eye. Cancer has spread to lymph nodes as follows:
  • one lymph node on the same side of the body as the tumor and the node is larger than 3 centimeters; or
  • more than one lymph node on the opposite side of the body as the tumor or on both sides of the body.

Stage IV

In stage IV, the tumor has spread to other parts of the body, such as the lung or liver.

Treatment depends on the type of skin cancer or other skin condition diagnosed:

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.

There are different types of treatment for patients with basal cell carcinoma, squamous cell carcinoma of the skin, and actinic keratosis.

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.

Eight types of standard treatment are used:

Surgery

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: The tumor, along with some of the normal tissue around it, is cut from the skin.
• Mohs micrographic surgery: The tumor is cut from the skin in thin layers. During the procedure, 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. It is often used to remove skin cancer on the face, fingers, or genitals and skin cancer that does not have a clear border.

• Shave excision: The abnormal area is shaved off the surface of the skin with a small blade.
• Curettage and electrodesiccation: 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. This type of treatment is also called electrosurgery.
• 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.

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

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

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

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.

Photodynamic therapy is also used to treat actinic keratoses.

Immunotherapy

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. This type of cancer treatment is also called biotherapy or biologic therapy.

Interferon and imiquimod are immunotherapy drugs 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 basal cell carcinomas.

Targeted therapy

Targeted therapy is a type of treatment that uses drugs or other substances to attack cancer cells. Targeted therapies usually cause less harm to normal cells than chemotherapy or radiation therapy do.

• Signal transduction inhibitors therapy: This treatment block signals that are passed from one molecule to another inside a cell. Blocking these signals may kill cancer cells. Vismodegib and sonidegib are signal transduction inhibitors used to treat basal cell carcinoma.

Chemical peel

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.

New types of treatment are being tested in clinical trials.

Information about clinical trials is available from the NCI website.

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.

If basal cell carcinoma and squamous cell carcinoma recur (come back), it is usually within 5 years of initial treatment. Talk to your doctor about how often you should have your skin checked for signs of cancer.

Treatment of Basal Cell Carcinoma

Treatment of basal cell carcinoma that is localized may include the following:

• Simple excision.
• Mohs micrographic surgery.
• Radiation therapy.
• Curettage and electrodesiccation.
• Cryosurgery.
• Photodynamic therapy.
• Topical chemotherapy.
• Topical immunotherapy (imiquimod).
• Laser surgery (rarely used).

Treatment of basal cell carcinoma that is metastatic or cannot be treated with local therapy may include the following:

• Targeted therapy with a signal transduction inhibitor (vismodegib or sonidegib).
• A clinical trial of a new treatment.

Treatment of recurrent basal cell carcinoma that is not metastatic may include the following:

• Simple excision.
• Mohs micrographic surgery.