What is Squamous Cell Cancer?

Squamous cell carcinoma (SCC) is an uncontrolled growth of abnormal cells arising in the squamous cells, which compose most of the skin’s upper layers (the epidermis). SCCs often look like scaly red patches, open sores, elevated growths with a central depression, or warts; they may crust or bleed. They can become disfiguring and sometimes deadly if allowed to grow. An estimated 700,000 cases of SCC are diagnosed each year in the US, and between 3,900 and 8,800 people died from the disease in the US in 2012. Incidence of the disease has increased up to 200 percent in the past three decades in the US.

SCC is mainly caused by cumulative ultraviolet (UV) exposure over the course of a lifetime; daily year-round exposure to the sun’s UV light, intense exposure in the summer months, and the UV produced by tanning beds all add to the damage that can lead to SCC.

SCCs may occur on all areas of the body including the mucous membranes and genitals, but are most common in areas frequently exposed to the sun, such as the rim of the ear, lower lip, face, balding scalp, neck, hands, arms and legs. Often the skin in these areas reveals telltale signs of sun damage, including wrinkles, pigment changes, freckles, “age spots,” loss of elasticity, and broken blood vessels.

What to look for?

Squamous cell carcinomas typically appear as persistent, thick, rough, scaly patches that can bleed if bumped, scratched or scraped. They often look like warts and sometimes appear as open sores with a raised border and a crusted surface.

In addition to the signs of SCC shown here, any change in a preexisting skin growth, such as an open sore that fails to heal, or the development of a new growth, should prompt an immediate visit to a physician.

Treatment Options

Squamous cell carcinomas detected at an early stage and removed promptly are almost always curable and cause minimal damage. However, left untreated, they eventually penetrate the underlying tissues and can become disfiguring. A small percentage even metastasize to local lymph nodes, distant tissues, and organs and can become fatal. Therefore, any suspicious growth should be seen by a physician without delay. A tissue sample (biopsy) will be examined under a microscope to arrive at a diagnosis. If tumor cells are present, treatment is required.

Fortunately, there are several effective ways to eradicate squamous cell carcinoma. The choice of treatment is based on the tumor’s type, size, location, and depth of penetration, as well as the patient’s age and general health.

Treatment can almost always be performed on an outpatient basis. A local anesthetic is used during most surgical procedures. Pain or discomfort is usually minimal, and there is rarely much pain afterwards.

• Excision: The physician uses a scalpel to remove the entire growth, along with a surrounding border of apparently normal skin as a safety margin. The wound around the surgical site is then closed with sutures (stitches). The excised tissue specimen is then sent to the laboratory for microscopic examination to verify that all cancerous cells have been removed. A repeat excision may be necessary on a subsequent occasion if evidence of skin cancer is found in the specimen. The accepted cure rate for primary tumors with this technique is about 92 percent. This rate drops to 77 percent for recurrent squamous cell carcinomas.
• Cryotherapy: The physician destroys the tumor tissue by freezing it with liquid nitrogen, using a cotton-tipped applicator or spray device. There is no cutting or bleeding, and no anesthesia is required. The procedure may be repeated several times at the same session to help ensure destruction of all malignant cells. The growth becomes crusted and scabbed, and usually falls off within weeks. Redness, swelling, blistering and crusting can occur following treatment, and in dark-skinned patients, some pigment may be lost. Inexpensive and easy to administer, cryosurgery may be the treatment of choice for patients with bleeding disorders or intolerance to anesthesia. However, it has a lower overall cure rate than the surgical methods. Depending on the physician’s expertise, the 5-year cure rate can be quite high with selected, generally superficial squamous cell carcinoma; but cryosurgery is not often used today for invasive SCC because deeper portions of the tumor may be missed and because scar tissue at the cryotherapy site might obscure a recurrence.
• Topical: 5-fluorouracil (5-FU) and imiquimod, both FDA-approved for treatment of actinic keratoses and superficial basal cell carcinomas, are also being tested for the treatment of some superficial squamous cell carcinomas. Successful treatment of Bowen’s disease, a noninvasive SCC, has been reported. However, invasive SCC should not be treated with 5-FU. Some trials have shown that imiquimod may be effective with certain invasive SCCs, but it is not yet FDA-approved for this purpose. Imiquimod stimulates the immune system to produce interferon, a chemical that attacks cancerous and precancerous cells, while 5-FU is a topical form of chemotherapy that has a direct toxic effect on cancerous cells.

Because most treatment options involve cutting, some scarring from the tumor removal should be expected. This is most often cosmetically acceptable with small cancers, but removal of a larger tumor often requires reconstructive surgery, involving a skin graft or flap to cover the defect. .

Squamous cell carcinomas usually remain confined to the epidermis (the top skin layer) for some time. However, the larger these tumors grow, the more extensive the treatment needed. They eventually penetrate the underlying tissues, which can lead to major disfigurement, sometimes even the loss of a nose, eye or ear. A small percentage spread (metastasize) to distant tissues and organs. When this happens, squamous cell carcinomas frequently can be life-threatening.

Metastases most often arise on sites of chronic inflammatory skin conditions and on the ear, nose, lip, and mucosal regions, including the mouth, nostrils, genitals, anus, and the lining of the internal organs.