The Skinny on Nonmelanoma Skin Cancer

Nonmelanoma skin cancer is not just the most common form of skin cancer—it's the most common form of cancer, period. In the United States alone, 800,000 new cases of basal cell carcinoma occur every year. And as the population ages, the number can only rise: 80% of basal cell carcinoma cases develop in people over the age of 50. Squamous cell carcinoma is the second most common form of nonmelanoma skin cancer, with 200,000 new cases per year. And like basal cell carcinoma, it's an age-specific disease: The majority of squamous cell carcinoma cases also occur in people over 50.

Fortunately, basal cell carcinoma is slow spreading and usually doesn't metastasize throughout the body, although if it's left untreated it can be disfiguring because it can spread into and destroy underlying muscle, cartilage, and bone tissue. While squamous cell carcinoma is more aggressive, it is still relatively slow growing and treatable. Even better news: There are several effective treatment options.

Looks Matter

There are several types of basal and squamous cell carcinoma, each with unique, identifiable characteristics. Basal cell carcinomas usually appear on areas of skin that exposed to the sun, such as the scalp, ears, neck, chest, hands, back, and legs. The face is particularly vulnerable, with 85% of basal cell carcinomas developing there. Over 25% of basal cell carcinomas appear on the nose.

The most common type of basal cell carcinoma is nodular basal cell carcinoma. It appears as a translucent, pearly white or pink bump, within tiny blood vessels are visible. These carcinomas often develop ulcers, which crust over but never fully heal.

The ABCs of Skin Cancer Detection

The best weapon against any type of skin cancer is a familiarity with your skin. The American Cancer Society recommends a once-a-month skin exam to check for new blemishes and for changes in old birthmarks or moles.

For your self exam, you'll need a full-length mirror, a hand-held mirror, and a chair. It can help to have another person at hand to examine hard-to-see spots. Examine your face, chest, arms, and belly in the full-length mirror. Turn around to look over your buttocks and upper back. Sit down in the chair and look at the front of your legs and feet. Using the hand-held mirror, examine the back of your legs and the soles of your feet.

Changes in the existing moles can be a sign of melanoma. See your dermatologist if you notice any of the following changes:
· Asymmetry - a mole is lopsided, with halves that don't match in size
· Border - the edges of a mole look blurred or jagged
· Color - a mole that has gotten lighter or darker since the last checkup or a mole that is more than one color
· Diameter - a mole that is larger than a pencil eraser (about 1/4 inch or 6 mm)
· Elevation - a mole that has an uneven surface or is raised above the skin

Less common types of basal cell carcinomas include superficial basal cell carcinomas—multiple shiny pink or red lesions that may look like eczema or psoriasis. These usually develop on the trunk or shoulders. Sclerosing basal cell carcinoma looks like a thick waxy scar and is pale white or yellow.

Like basal cell carcinoma, squamous cell carcinoma tends to appear on areas of the skin that have been exposed to the sun, such as the head, neck, shoulders, and back. Squamous cell carcinomas also can develop in areas where the skin has been damaged, such as scars or burns.

The skin condition known as actinic keratosis can be a precursor to squamous cell carcinoma. Actinic keratosis begin as sandpapery, dry skin lesions that may be slightly raised. Later they become hard and wart-like. They can be pink, red, gray, or brown or might match the color of the surrounding skin. Approximately 1% of actinic keratosis develop into squamous cell carcinoma.

The appearance of squamous cell carcinoma includes wart-like growths, scaly patches, and open sores—all of which are scabbed over yet do not heal and may intermittently bleed. Although a lesion that bleeds is suspicious, you should not wait until bleeding starts to have the lesion examined.

While it's relatively rare for squamous cell carcinoma to metastasize, if it happens the consequences are grave: 95% of localized squamous cell carcinoma are cured—after metastasis, the cure rate plummets to 30%.

Surgical Treatment

Treatment options vary by the location and aggressiveness of the tumor. Tumors in certain areas of the body—such as the face, head, and neck—are more likely to recur and to invade muscle tissue and bone and therefore require more aggressive treatment.

Curettage with electrodesiccation. This type of surgery is usually indicated for smaller tumors in body areas where invasive tumors are unlikely, such as the shoulders, legs, and torso. During curettage, the tumor is scraped away. An electrocautery needle is then applied to kill remaining cancer cells. This process is generally done three times at a single sitting. Curettage with electrodesiccation preserves the lower layer of skin, reducing the risk of scarring.

Cryogenic surgery. Another option for patients with small tumors in low-risk areas is cryogenic surgery, which destroys tumor tissue by exposing it to extreme cold.

A Vaccine for Melanoma?

Most tumors are able to evade detection by the immune system or even suppress it, allowing cancer cells to grow and spread without coming under attack. Melanoma, however, is particularly vulnerable to the body's defenses.

Researchers are developing melanoma vaccines to help amplify that natural immune response. The hope is that these vaccines will prevent tumor expansion or even destroy existing cancer cells. Melanoma vaccines are made with proteins that are components of cancer cells or with whole tumor cells. The body, sensitized to these particular parts of the tumor, is able to mount a destructive immune response.

Several clinical trials have examined the effectiveness of melanoma vaccines against stage III and stage IV melanomas. According to Suzanne L. Topalian, M.D., Director of the Translational Melanoma Program at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, "In general, the clinical trials have shown that various vaccine formulations can significantly enhance the body's immune response against melanoma. However, in patients with advanced stage III or stage IV disease, fewer than 3% have shown clinical benefit defined by tumor regression."

Instead of studying the effectiveness of melanoma vaccines against existing tumors, future research may measure their preventive effect. Dr. Topalian says, "Current studies emphasize prophylactic vaccination of patients with a significant risk of recurrent disease following standard therapies. These vaccines are generally nontoxic, but it is unknown at present whether they will offer an advantage in terms of overall or melanoma-free survival."

Excision. For larger, more invasive tumors and tumors in areas with a high risk of recurrence, such as the head and neck, removal of the entire tumor along with a border of healthy skin may be necessary. In these instances, excision is the best option, although it is more likely to leave scarring.

Mohs' micrographic surgery. According to Nanette Liégeois, M.D., Assistant Professor of Medicine at Johns Hopkins, "Mohs' micrographic surgery is the gold standard in surgery for large tumors and tumor in high-risk areas." After removing the visible tumor, a surgeon removes a thin layer of skin and studies it for the appearance and location of any cancer cells. If cancer cell are still present, the surgeon returns to the part of the tumor site where they were spotted and removes more tissue. The process continues until no more cancer cells are found microscopically. Dr. Liégeois explains, "Because it allows surgeons to pinpoint the location of cancer cells, Mohs' micrographic surgery is helpful in removing tumor cells while preserving healthy skin." The procedure has the highest cure rate of all surgical treatments and minimizes scarring, but it is expensive. Most insurers, including Medicare, will cover Mohs' micrographic surgery for high-risk areas of the face or for particularly aggressive subtypes of nonmelanoma skin cancer.

Noninvasive Treatments

Radiation. This is an option for patients who cannot tolerate surgery. And in cases where skin conservation is important, such as near the eyelids or lips, radiation can produce a more attractive outcome than excision or curettage. However, recurrence rates are higher because the procedure is less precise. It also takes several appointments over at least a month.

Topical treatments. When it's very important to preserve appearance or when there are many lesions, topical treatments are helpful. Imiquimod (Aldara) is a topical treatment that stimulates the immune system to fight cancer cells. The treatment can be used alone or in conjunction with surgery to treat tumors on the torso. Imiquimod is expensive and is untested for basal cell carcinoma of the face and neck. It is not used to treat squamous cell carcinoma.

Photodynamic therapy. Already approved by the FDA to treat actinic keratosis, photodynamic therapy soon may be used for superficial nonmelanoma skin cancers. Treatment uses light to target the atypical cells. During the first stage of treatment, aminolevulinic acid (ALA) is applied to the skin to make the tumor more photosensitive. Then the tumor is exposed to a light-emitting diode or laser. Tumor cells are killed while healthy cells are left intact.

Photodynamic therapy is the most cosmetically pleasing treatment choice for nonmelanoma skin cancer, but there are drawbacks. The treatment, while short in duration, is painful, and it only works for superficial tumors (<2 mm thick). Researchers are investigating the efficacy of new photodynamic materials and different wavelengths of light, searching for a combination that is effective for deeper cancer and produces less pain.

Bottom-line Advice

The best advice for anyone at risk for skin cancer: See a dermatologist and make sure that you're properly evaluated. Dr. Liégeois emphasizes that a periodic exam is even more important if you have had any sort of skin cancer diagnosis in the past, as you have a greater than 50% chance of recurrence. And it's never too late to begin applying sunscreen daily.