SQUAMOUS CELL CARCINOMA - SCC

SCC stands for squamous cell carcinoma. This is a "non-melanoma" skin cancer, not as serious as melanomas, but far more common. It arises in the epidermis, the uppermost layer of the skin, and when detected and treated at an early stage, they are almost invariably cured. Metastasis, meaning a spread beyond the epidermis, is uncommon for SCCs. Nonetheless, it must be recognized as a risk. Although non-melanomas were formerly a disease of older people, they are now on the increase in the young.

Squamous cell carcinoma, the second most common skin cancer after basal cell carcinoma, afflicts more than 100,000 to 200,000 Americans each year. Squamous cell carcinomas also occur on mucous membranes but are most common on skin areas exposed to the sun.

Although squamous cell carcinomas usually remain confined to the epidermis for some time, they eventually penetrate the underlying tissues if not treated. In a small percentage of cases, they spread (metastasize) to distant tissues and organs. When this happens, they can be fatal. Squamous cell carcinomas that metastasize most often arise on sites of chronic inflammatory skin conditions or on the mucous membranes or lips.

What Causes It

Chronic exposure to sunlight causes most cases of squamous cell carcinoma. That is why tumors appear most frequently on sun-exposed parts of the body: the face, neck, bald scalp, hands, shoulders, arms, and back. The rim of the ear and the lower lip are especially vulnerable to the development of these cancers.

Squamous cell carcinomas may also occur where skin has suffered certain kinds of injury: burns, scars, long-standing sores, sites previously exposed to X-rays or certain chemicals (such as arsenic and petroleum by-products). In addition, chronic skin inflammation or medical conditions that suppress the immune system over an extended period of time may encourage development of squamous cell carcinoma.

Occasionally, squamous cell carcinoma arises spontaneously on what appears to be normal, healthy, undamaged skin. Some researchers believe that a tendency to develop this cancer may be inherited.

Who Gets It

Anyone with a substantial history of sun exposure can develop squamous cell carcinoma. But people who have fair skin, light hair, and blue, green, or gray eyes are at highest risk. Those whose occupations require long hours outdoors or who spend extensive leisure time in the sun are in particular jeopardy. Dark-skinned individuals of African descent are far less likely than fair-skinned individuals to develop skin cancer. More than two thirds of the skin cancers that they do develop, however, are squamous cell carcinomas, usually arising on the sites of preexisting inflammatory skin conditions or burn injuries.

Precancerous Conditions

Certain precursor conditions, some of which result from extensive sun damage, are worth noting. They are sometimes associated with the later development of squamous cell carcinoma. They include:

Actinic, or solar, keratosis. Actinic keratoses are rough, scaly, slightly raised growths that range in color from brown to red and may be up to one inch in diameter. They appear most often in older people.

Actinic cheilitis. A type of actinic keratosis occurring on the lips, it causes them to become dry, cracked, scaly, and pale or white. It mainly affects the lower lip, which typically receives more sun exposure than the upper lip.

Leukoplakia. These white patches on the tongue or inside of the mouth have the potential to develop into squamous cell carcinoma.

Bowen's disease. This is now generally considered to be a superficial squamous cell cancer that has not yet spread. It appears as a persistent red-brown, scaly patch which may resemble psoriasis or eczema. If untreated, it may invade deeper structures.

Regardless of appearance, any change in a preexisting skin growth, or the development of a new growth or open sore that fails to heal, should prompt an immediate visit to a physician. If it is a precursor condition, early treatment will prevent it from developing into a squamous cell carcinoma. Often, all that is needed is a simple surgical procedure or application of a topical chemotherapeutic agent.

TYPES OF TREATMENT

After a physician's examination, a biopsy will be performed to confirm the diagnosis of squamous cell carcinoma. This involves removing a piece of the affected tissue and examining it under a microscope. If tumor cells are present, treatment (usually surgery) is required. Fortunately, there are several effective ways to eradicate squamous cell carcinoma. The choice of treatment is based on the type, size, location, and depth of penetration of the tumor, as well as the patient's age and general state of health. Treatment can almost always be performed on an outpatient basis in a physician's office or at a clinic. A local anesthetic is used during most procedures. Pain or discomfort is usually minimal with most techniques, and there is rarely much pain afterwards.

Excisional Surgery

The physician uses a scalpel to remove the entire growth and a surrounding border of what happens to be normal skin as a "safety margin." The incision is then closed with sutures. The removed tissue is sent to the laboratory, where it is examined microscopically to ensure that all the malignant cells have been removed.

Curettage and Electrodesiccation (Electrosurgery)

The physician scrapes the cancerous tissue away from the skin with a sharp, ring-shaped instrument called a curette, then uses an electric needle to burn the scraped area and a margin of normal skin around it. This two-step procedure may be repeated several times, a deeper layer of tissue being scraped and burned each time, until the physician determines that no tumor cells remain.

Cryosurgery

The physician uses liquid nitrogen to destroy tumor tissue by freezing. No cutting is involved in this bloodless procedure, which may be repeated several times at the same visit to ensure total destruction of malignant cells. Easy to administer, cryosurgery is favored for patients with bleeding disorders or intolerance to anesthesia. Redness, swelling, blistering, and crusting can occur following this treatment.

Mohs Micrographic Surgery (microscopically controlled surgery)

The surgeon successively removes very thin layers of the tumor. Each layer is examined immediately under a microscope. Removal and microscopic examination are repeated until the site is tumor-free. Mohs micrographic surgery saves the greatest amount of healthy tissue and reduces the rate of local recurrence. It is most often used on tumors that have recurred and on those in locations that are difficult to treat (for example, the nose, ears, and around the eyes).

Radiation

A radiation therapist directs X-ray beams at the tumor. Total tumor destruction generally requires a series of treatments, usually several times a week for one to four weeks. Radiation therapy is ideal for certain elderly patients or for individuals whose overall health is poor.

Laser Surgery

The laser beam is used either to excise the tumor, much as a scalpel does, or to destroy it by vaporization, in a procedure similar to electrodesiccation. The major advantage of this relatively new surgical technique is that it seals blood vessels as it cuts, making it useful for patients with bleeding disorders.


If you have any questions about Babar K. Rao, MD, FAAD, or any questions about our dermatology or dermatopathology (skin cancer) procedures please feel free to contact Board Certified Dermatologist, Board Certified Dermatopathologist, Babar K. Rao, MD, FAAD at his Manhattan, New York, Newbrunswick, New Jersey, or Fresno, California offices.