Treating Cancer, Keratosis, And Acne

A therapy traditionally used on esophageal cancer and lung cancer is causing a buzz in dermatology circles as a way to treat precancerous skin lesions, sun damage and acne.
Called photodynamic therapy, or PDT, it is gaining popularity with claims that it's more convenient and less painful, and that it brings fewer side effects than conventional treatments.
The Food and Drug Administration has approved PDT only for the treatment of certain tumors and actinic keratoses, which are scaly or crusty bumps that form on the skin surface from too much sun. But now the procedure also is being widely used for sun damage and acne on an "off-label" basis.
"There are exciting new and improved cosmetic indications," says Dr. Ron Berne, an Elmwood Park, Ill. dermatologist who began using PDT on his patients in March.
He explained that PDT can improve sun damage such as blotchy complexion, fine lines and telangiectasia, which are dilated superficial blood vessels such as are found with rosacea. The procedure improves the entire area treated, creating a more uniform color, texture and tone, rather than just spot treating with liquid nitrogen or other techniques.
The procedure involves applying a topical solution called 5-aminolevulinic acid (Levulan Kerastick) directly to the skin, then activating it with a light source for a specific time. The solution is absorbed by the abnormal keratin in precancerous or sun-damaged cells or oil glands, depending on what is being targeted.
A variety of light sources may be used, from lasers and intense pulsed light to blue light, which refers to the light wavelength. Therapy can be repeated several times at the same site if necessary.
PDT also can dramatically improve mild to moderate inflammatory acne when used in combination with other treatments, Berne says, eliminating the need for oral antibiotics or the controversial drug Accutane. The Levulan is absorbed into the oil glands, significantly reducing them.
Accutane has a much higher risk of side effects, such as birth defects and liver problems, according to Berne.
Kim Nguyen, 32, of Chicago, Ill., is allergic to many antibiotics and benzyl peroxide, so she is limited in her choices of acne treatment. She has had two PDT treatments.
"I can see a reduction in the acne and scars, and the redness is less intense," she says.
She has two more treatments scheduled, and her health insurance has covered a portion of the cost.
A PDT treatment typically ranges from $250 to $350.
In general, patients must avoid all sunlight and even brightly lit rooms for 36 hours or risk getting a severe burn due to heightened skin sensitivity to light.
"Plan a day and a half inside in the shadows," Berne says.
Even with that drawback, Berne prefers PDT as a treatment for actinic keratoses.
The standard treatment uses liquid nitrogen to freeze off the lesions. But doctors can't treat more than a couple at a time, so return office visits are required, according to Berne.
"For multiple actinic keratoses, conventional therapy can be painful and inconvenient," he added.
PDT targets only abnormal cells, so all lesions can be treated at one time, or repeated if necessary, according to Berne.
The use of PDT in dermatology, however, isn't universally hailed, says Dr. Gregg Menaker, director of dermatologic surgery at Evanston Northwestern Healthcare and assistant professor of dermatology at the Feinberg School of Medicine at Northwestern University, Evanston, Ill.
While director of the dermatologic surgery unit at Massachusetts General Hospital (Boston), "I saw a steady parade of people from our lab to my surgical unit for lesions that didn't go away with PDT," he says.
In patients with multiple actinic keratoses, not every lesion may be an actinic keratosis, he explains. The lesion could be a squamous cell, a common skin cancer. "There are other treatments that are faster, cheaper and more effective," he says.
As for using PDT for acne, Menaker says, "Our standard acne therapies are going to end up being the preferred way to treat acne. Acne patients are mostly kids who are in school and don't want to come to the dermatologist. From a scheduling standpoint it's difficult. And there is no long-term data to support its use."
But PDT is in use at the Texas Dermatology Research Institute, where Dr. William Abramovits, a professor of dermatology at Baylor University Medical Center in Dallas employs it to treat actinic keratoses, acne and other skin diseases.
He says, however, that because low-energy light may not be able to penetrate deep enough into thick lesions, PDT may fail to destroy squamous cell cancers or thick actinic keratoses.
"Many centers, particularly in Europe, are exploring the potential of newer sensitizers, and light of wavelengths that will penetrate deep enough to destroy thicker lesions," Abramovits says. "The results are very promising."