Basal Cell Carcinoma

What is basal cell carcinoma?

Basal cell carcinoma (BCC) is the most common form of skin cancer. In the vast majority of cases, it is caused by chronic exposure to harmful solar radiation and therefore occurs most frequently on sun-exposed areas of the body. BCCs are more common in men, with a male to female ratio of approximately 2:1. People with fair skin, light hair, blue, green, or grey eyes are at the highest risk of developing this skin cancer. In a few instances, there are other contributing factors such as immunosuppression (a weakened immune system), family history of skin cancer, burns, and exposure to arsenic and radiation.

BCCs are slow-growing tumors characterized by the progressive invasion of adjacent tissues. These tumors are rarely lethal, and their potential to metastasize is below 0.1%. Usually, the only BCCs that metastasize are the ones that are neglected and not treated.

Presentation:
Basal cell carcinoma may have several different appearances on your skin. The nodular BCC initially presents as a bump or nodule with blood vessels on its surface. As the lesion progresses, it may form a non-healing sore. The superficial BCC appears as a pink, scaly patch. Pigmented BCCs may appear as the nodular or superficial variant, but with various amounts of brown or black pigment. The sclerosing (morpheaform) BCC presents as a pink or whitish hard area on the skin that is similar to a scar. This variant has the most aggressive growth pattern out of all basal cell carcinomas. It is therefore the hardest to treat. Fortunately, sclerosing basal cell carcinomas represent only about 5% of all BCCs. The head and neck areas are the most frequent locations of BCCs, but they can be found anywhere on the skin.

Nevoid basal cell carcinoma syndrome (Gorlin syndrome).
Nevoid basal cell carcinoma syndrome (also known as basal cell nevus syndrome and Gorlin syndrome) is a rare genetic condition characterized by multiple abnormalities. It is caused by mutations in the patched gene located on chromosome 9. The most common clinical manifestations of nevoid basal cell carcinoma syndrome (NBCCS) include small indentations or pits on palms and soles(seen in 87% of patients), multiple basal cell carcinomas (seen in 80% of Caucasians, and 38% of African-Americans), cavities in jaws(74%), and “coarse face”(54%). Multiple additional abnormalities have also been described. X-rays of various bones, spine and skull also show abnormal features.

The management of multiple basal cell carcinomas in NBCCS patients presents a significant challenge. Multiple surgical procedures performed with the use of traditional excision, as well as
Mohs micrographic surgery techniques are often a source of discomfort, pain, and disfigurement for patients affected with NBCCS. CO2 laser resurfacing as well as imiqumod cream may be used in the treatment of this condition.

Treatment:
The diagnosis of BCC needs to be confirmed by a skin biopsy. Treatment options for this type of skin cancer include excision, Mohs micrographic surgery, curettage and electrodessication, radiation therapy, cryosurgery, and the use of imiquimod cream.

In Mohs micrographic surgery, the excision of a lesion is followed by immediate analysis of the excised piece of skin. The surgeon checks if the tumor is still present on the specimen margins. Once the surgeon determines that all BCC has been cleared, the skin is stitched together. Mohs surgery is usually reserved for BCCs on the face, tumors of morpheaform subtype, and recurrent lesions. The purpose of Mohs surgery is to remove the smallest amount of tissue possible. It is highly accurate with cure rates up to 99%. This technique is very expensive, and therefore cannot be used in every basal cell carcinoma case. Mohs surgery may take from several hours to a whole day to complete.

Conventional excision
is used in the treatment of BCCs that don’t meet any of the above mentioned criteria. The lesion is excised with a small amount of normal tissue around it to ensure adequate removal. The excision usually takes less than an hour to accomplish. Cure rates are reported to be around 90%.

Curettage and electrodessication is a technique of scraping the area followed by burning it with electric current. The procedure takes about 5-10 minutes with cure rates similar to conventional excision (about 90%).

Cryosurgery and radiotherapy are uncommonly used techniques. Cryotherapy is effective, but requires prolonged healing. Radiation therapy is usually reserved for elderly patients in whom surgery is contraindicated, or for very large, inoperable tumors. It is painless, but requires multiple visits. Both methods result in cure rates above 90%.

Imiquimod cream is a new non-surgical treatment for basal cell carcinomas. The cream stimulates the patient’s own immune system to attack basal cell carcinomas. While imiquimod cream causes a lot of irritation during use, it ultimately results in minimal scarring. The efficacy rates for imiquimod are reported to be around 80%.

References
Doctoroff A, Oberlender AS, Purcell SM. Full face carbon dioxide resurfacing in the management of a patient with the nevoid basal cell carcinoma syndrome. Dermatol Surg, 2003;29(12):1236-1240

Alexander Doctoroff, D.O., F.A.O.C.D.
Assistant Chief of Dermatology,
Veterans Administration Medical Center
East Orange, New Jersey

Assistant Clinical Professor of Medicine,
University of Medicine and Dentistry of New Jersey

www.metropolitanderm.com