Karen Klickmann(847) 240-1735[email protected]
Jennifer Gale(847) 240-1730[email protected]
Julie Bremer(847) 240-1743[email protected]EMBARGOED UNTIL OCTOBER 17, 2001
ACTINIC KERATOSES: NEW TREATMENT OPTIONS FOR THIS ADVANCED WARNING SIGN OF SKIN CANCER
NEW YORK (October 17, 2001) -- When it comes to skin cancer, the next best thing to prevention is early diagnosis and cure. For one of the most common types of skin cancer, squamous cell carcinoma, a skin growth called actinic keratosis can be the earliest sign of skin cancer. If diagnosed before they become skin cancers, actinic keratoses (AKs) can be removed using one of several new therapies and treatments. And the latest technology is also allowing dermatologists to develop preventative treatments that can help patients avoid AKs in the future.
Speaking today at the American Academy of Dermatology's Derm Update 2001, dermatologist David J. Leffell, MD, Professor of Dermatology and Surgery, Department of Dermatology, Yale University School of Medicine, New Haven, Connecticut, discussed the new treatments available for actinic keratoses and the potentially powerful preventative therapies of the future.
"In the past, AKs were most commonly seen in people over the age of 60," said Dr. Leffell. "However, changes in lifestyle and in the environment are responsible for the increased incidence of AKs in individuals even as young as 30. It's important for everyone to be aware of the significance of these lesions and that dermatologists have even more advanced treatment options to remove and prevent them."
Actinic keratoses are small, scaly spots that develop on parts of the body that have been exposed to the sun. Commonly known as "sunspots," actinic keratoses can have a variety of appearances. The earliest form may look like nothing more than a flat, red spot. As the lesion grows larger, it may become scaly and even thickened, much like a wart. The vast majority of AKs develop on the face and the back of the hands.
AKs develop as a result of sun exposure. Ultraviolet B (UVB) radiation from the sun strikes the skin and causes mutations in surface skin cells that can cause malfunctions in certain genes. One of these genes, p53, is a tumor suppressor gene that prevents abnormal, cancer-prone cells from dividing and growing into skin cancer. When the sun causes mutations in the skin, the p53 gene becomes damaged and therefore can no longer prevent cancer-prone cells from dividing.
"Several studies have shown that the use of a broad-spectrum sunscreen with an SPF of 15 or higher, prevents these damaging mutations that can lead to AKs," said Dr. Leffell. "Further studies have demonstrated that even skin which has been sun-exposed but does not have actinic keratoses yet, may still have the cancer-causing mutations that can lead to them. This proves that even if you avoid the sun as an adult, much of the damage has already accumulated from the sun exposure you experienced as a child."
Traditional treatment methods can treat one or two lesions at a time. However, many patients have dozens of lesions or even have the cancer causing mutations under their skin that have not yet developed into AKs. A new method of treatment for multiple AKs, especially those on the face and scalp, is photodynamic therapy. This therapy involves the topical application of aminolevulinic acid (ALA), a natural chemical in the body used to process heme, a red blood cell component. Once applied, the application targets the AKs and is absorbed by the affected area. After 16 hours a non-laser blue light is shined on the skin activating the solution and killing the cancerous cells.
Patients usually experience some local discomfort during photodynamic therapy. Over the next few days, the lesions crust over, then heal.
Another traditional, long-standing approach to the management of multiple AKs is the application of 5-fluorouracil, a topical chemotherapy cream. The cream is applied twice daily to affected areas until any pre-cancerous lesions become red and crusted. At that point, the treatment is stopped and healing begins.
Other treatment methods focus on destroying the abnormal cells in actinic keratoses. The traditional treatment involves freezing AKs with liquid nitrogen because both pre-cancerous and cancerous cells are more sensitive to cold than normal cells. AKs usually regress following this treatment.
Since the discovery of how mutations in the skin form actinic keratoses, many promising new treatments are in development that seek to reverse the mutation. T4 Endonuclease is a viral DNA-repair enzyme that can be used in a lotion to penetrate the skin and bind to the mutations in AKs. Once these mutations are cut off, regular cellular activity can begin repairing and healing the AKs. The drug is now in phase III clinical trials in the United States under the direction of the Food and Drug Administration (FDA).
A recent study of T4 Endonuclease was used on patients prone to excessive skin cancers. Patients in the study demonstrated a 68 percent decrease in the number of AKs and a 30 percent decrease in the number of basal cell cancers, a form of skin cancer that usually appears as a small, fleshy bump or nodule on the head, neck or hands.
Another promising area of treatment is the use of a class of drugs which modify the immune system of the skin and stimulate the body's own rejection of the pre-cancerous cells of AKs. One such drug, imiquimod, is currently only approved by the FDA for the treatment of genital warts. However, several studies performed outside the United States, have proven that imiquimod can be used to treat AKs, although the precise treatment regimen remains to be determined.
"Although it is not known for certain what percent of actinic keratoses transform into skin cancer, it is best to be carefully monitored by a dermatologist and have any lesions properly checked," said Dr. Leffell. "For the first time in several years there are now a range of options for treating, and perhaps preventing, AKs."
The American Academy of Dermatology, founded in 1938, is the largest, most influential, and most representative of all dermatologic associations. With a membership of over 13,000 dermatologists worldwide, the Academy is committed to: advancing the diagnosis and medical, surgical, and cosmetic treatment of the skin, hair and nails; advocating high standards in clinical practice, education, and research in dermatology; supporting and enhancing patient care for a lifetime of healthier skin. For more information, contact the AAD at 1-888-462-DERM or www.aad.org.
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