The Skin Cancer Foundation Journal

MAY 2012

The 2012 edition of The Skin Cancer Foundation Journal features medically reviewed, reader-friendly articles such as tanning, the increasing incidence of skin cancer diagnoses among young women, & the prevalence of melanoma among white males over 50.

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HEALTH High power, monochromatic lasers emitting light within the visible range (400-800 nanometers, or billionths of a meter) of the light spectrum are the most commonly used light sources. Lasers work quickly, minimizing therapeutic exposure time.3 The intensity of light at each wavelength of a light source should ideally be in the area of the spectrum at which the photosensitizer is best absorbed and optimally reaches the depth of the target (cancer) cells in the skin. For lesions on the outermost layer of the skin, blue light (417 nm) is preferred. For lesions occurring in or extend- ing into the dermis (the layer of skin beneath the epidermis), more deeply penetrating red light (570 to 670 nm) is used. ALA is best activated by blue light lasers, while red light lasers most effectively activate MAL. FDA-APPROVED INDICATIONS While PDT has been used to treat a wide range of skin diseases, it is currently FDA-approved only for the treatment of AKs. The approved protocol involves applying ALA to individual AKs, then exposing the lesions to blue light 14-18 hours later. However, most physicians expose the treated skin to blue light one to three hours later, which substantially re- duces patient discomfort but produces comparable results. Additionally, ALA is typically applied to the entire skin area affected by multiple AKs or dif- fuse actinic damage. MAL is also currently FDA- approved to treat non-growing AKs on the face and scalp in people who are immunocompromised and therefore particularly vulnerable to skin can- cers. The procedure involves a three hour application of MAL followed by red light illumination. One to two photodynamic sessions with ALA or MAL typically achieves cure rates of 70-90 percent or more, comparable to those achieved with therapies such as cryosurgery.3 Additionally, PDT provides a superior cosmetic result and requires less downtime than topical treatments such as 5-fluorouracil or imiquimod. PDT can also be used to treat subclinical precancerous lesions 64 (those which are invisible to the naked eye).4 OFF-LABEL INDICATIONS PDT has several off-label, or unofficial, applications.4 successful in treating superficial squa- mous cell carcinomas (SCC)5 It has been particularly , including Bowen's Disease (now considered an early, non-invasive form of SCC), though it is not recommended for invasive SCCs, given its limited depth of penetration. Topical MAL or ALA can be used to treat basal cell carci- noma (BCC), particularly superficial BCCs. Topical MAL is also used to treat nodular BCCs, although cure rates are not as high as with surgical excision. PDT has also been used widely for the treatment of acne6,7 and signs of skin aging such as wrinkled, rough skin.8 (It promotes the growth of proteins, including collagen, which can lead to more youthful skin.) The US Department of Health & Human Services' Agency for Healthcare Research and Quality currently gives the use of PDT for "photorejuvenation" a grade of B, indicating fair evidence to support this use. SIDE EFFECTS PDT is minimally invasive and generally very well tolerated. The most common adverse effects are immediate redness, itching, burning, and mild to moderate pain, followed by delayed crusting of the skin.9,10 Phototoxic reactions are greatly minimized by the avoidance of both natural and artificial light (especially UV light) for approximately 48 hours following treatment. THE FUTURE More research will likely reveal new photosensitizers and light sources that will enhance the treatment of an increasing number of skin diseases and offer a better molecular under- standing of their basis. Photodynamic therapy is an evolving and exciting treatment option for dermatologists and patients. PDT TREATMENT OF A SUPERFICIAL BASAL CELL CARCINOMA A) Prior to photodynamic therapy using oral 5-aminolevulinic acid (ALA) plus red light, B) three months post-treatment, and C) clinical resolution of the lesion at 6 months. JESSE M. LEWIN, MD, is a dermatology resi- dent in the Ronald O. Perelman Department of Dermatology at New York University Langone Medical Center. He attended New York University School of Medicine, where he was president of the Alpha Omega Alpha Honor Society. He has published several articles in the field of dermatology. JULIE K. KAREN, MD, is a Clinical Assistant Professor of Dermatology at the New York University Langone Medical Center. She is a Mohs surgeon and practices at the Laser & Skin Surgery Center of NY. She has published numerous articles and chapters in the field of dermatology and dermatologic surgery. ELIZABETH K. HALE, MD, is Clinical Associate Professor of Dermatology at the New York University Langone Medical Center. She is a Mohs surgeon and a member of the American College of Mohs Surgery. Dr. Hale practices at the Laser & Skin Surgery Center of NY, and lectures extensively on the prevention and treatment of skin cancer. She is a Vice President of The Skin Cancer Foundation. References available on p.97. SK IN CANCER FOUNDAT ION JOURNA L

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