Basal cell carcinoma is the most common form of skin cancer. It arises from cells residing in the deepest layer of the epidermis and develops more readily when a person is exposed to UV radiation. These cancers tend to be slow-growing and rarely spread (metastasize).
Symptoms of basal cell carcinomas
Basal cell carcinomas can present in many different ways such as:
Raised pink or pearly bump
Pigmented bumps that look like moles with a pearly edge
A sore that continuously heals and re-opens
A flat scaly scar with a waxy appearance and poorly defined edges
A flat pink or red lesion with very little flakiness or scale
Basal cell carcinomas are easily treated in their early stages. The larger the tumor has grown, however, the more extensive the treatment needed. Although this cancer seldom spreads, or metastasizes, to vital organs, it can damage surrounding tissue. Therefore, when a basal cell carcinoma arises near a vital organ, such as the eye, early detection is extremely important.
When small skin cancers are removed, the scars are usually cosmetically acceptable. If the tumors are very large, a skin graft or flap may be used to repair the wound in order to achieve the best cosmetic result and facilitate healing.
Causes of basal cell carcinoma
Almost all basal cell cancers occur on parts of the body excessively exposed to the sun — especially the face, ears, neck, scalp, shoulders, chest and back. On rare occasions, however, tumors develop on unexposed areas.
Who’s at risk?
Anyone with a history of sun exposure can develop a basal cell carcinoma. Exposure to ultraviolet (UV) light is the risk factor most closely linked to this cancer. However, other factors (such as ionizing radiation, chronic arsenic ingestion, and immune suppression, family history, skin type, and genetic syndromes) also potentially contribute to carcinogenesis. People who are at highest risk have fair skin, blond or red hair, and blue, green, or grey eyes. Those most often affected are older people, but as the number of new cases has increased sharply each year in the last few decades, the average age of patients has steadily decreased.
This type of skin cancer is rarely seen in children, but occasionally a teenager is affected. More and more people in their twenties and thirties are presenting with basal cell carcinoma.
A diagnosis of basal cell carcinoma is confirmed with a biopsy. In this procedure, the skin is first numbed with local anesthesia. A piece of tissue is then removed and sent to our pathologists. If tumor cells are present, treatment is required. Fortunately, there are several effective methods for eradicating basal cell carcinoma. The choice of treatment is based on the type, size, location, and depth of penetration of the tumor, the patient’s age and general health, and the likely cosmetic outcome of specific treatments. Treatment can almost always be performed on an outpatient basis. Any pain or discomfort during the procedure is minimal, and pain afterwards is rare.
Mohs Micrographic Surgery
Using local anesthesia, we remove the tumor along with a very thin layer of tissue around it. The layer is immediately checked under a microscope thoroughly. If tumor is still present in the depths or peripheries of this surrounding tissue, the procedure is repeated until the last layer examined under the microscope is tumor-free. This technique saves the greatest amount of healthy tissue and has the highest cure rate, generally 98 percent or better. It is frequently used for tumors that have recurred, are poorly demarcated, or are in critical areas around the eyes, nose, lips, and ears. We don’t currently offer this treatment at the Dermatological Center for Skin Health but can refer you to others who do if necessary.
After numbing the area with local anesthesia, we use a scalpel to remove the entire growth along with a surrounding border of normal skin as a safety margin. The skin around the surgical site is then closed with a number of stitches, and the excised tissue is sent to our laboratory for microscopic examination to verify that all the malignant cells have been removed. The effectiveness of the technique does not match that of Mohs Micrographic Surgery, but produces cure rates are around 90 percent.
Curettage and Electrodesiccation
Using local anesthesia, we scrape off the cancerous growth with a curette (a sharp, ring-shaped instrument). The heat produced by an electrocautery needle destroys any residual tumor and controls bleeding. This technique may be repeated twice or more to ensure that all cancer cells are eliminated. It can produce cure rates approaching those of surgical excision, but may not be as useful for aggressive basal cell carcinomas or those in high-risk or difficult sites.
X–ray beams are directed at the tumor, with no need for cutting or anesthesia. Total destruction generally requires several treatments per week for a few weeks. Radiation may be used for tumors that are hard to manage surgically and for elderly patients or others who are in poor health. No anesthesia is necessary. The Dermatological Center for Skin Health has an advanced radiology department to handle your radiation therapy.
With this treatment, tumor tissue is destroyed by freezing with liquid nitrogen, without the need for cutting or anesthesia. The procedure may be repeated at the same session to ensure total destruction of malignant cells. The growth becomes crusted and scabbed, and usually falls off within a week or so. Cryosurgery may be preferred in patients with bleeding disorders or who cannot tolerate other procedures.
Photodynamic Therapy (PDT)
PDT can be useful when patients have multiple basal cell carcinomas at one time. A photosensitizing agent, which will be taken up by the abnormal cells, is applied to the tumors at the physician’s office. The patient returns the next day and the medicated areas are activated by a strong light. This treatment selectively destroys basal cells while causing minimal damage to surrounding normal tissue. We don’t currently offer this treatment at the Dermatological Center for Skin Health but can refer you to others who do if necessary.
Imiquimod is FDA-approved only for superficial basal cell carcinomas, with cure rates generally between 80 and 90 percent. The 5% cream is rubbed gently into the tumor five times a week for up to six weeks or longer. It is the first in a new class of drugs that work by stimulating the immune system. 5-Fluorouracil (5-FU) is a topical chemotherapy drug also has been FDA-approved for superficial basal cells, with similar cure rates to imiquimod. The 5% liquid or ointment is gently rubbed into the tumor twice a day for three to six weeks.
New medicines for Advanced Basal Cell Carcinoma
In extraordinarily rare cases of metastatic or locally advanced basal cell carcinoma, it can become dangerous, sometimes even life-threatening. Erivedge (vismodegib), the first medicine ever for advanced basal cell carcinoma, is an oral drug approved by the FDA in early 2012 only for very limited circumstances where surgery is not possible or contraindicated.