Blue light therapy for basal cell carcinoma has benefits, drawbacks

May 1, 2011

Results of a recent study to determine the effectiveness of noncoherent blue light in the intralesional photodynamic therapy (PDT) of basal cell carcinoma (BCC) found the treatment to be beneficial for a certain subgroup of patients.

Key Points

New York - Results of a recent study to determine the effectiveness of noncoherent blue light in the intralesional photodynamic therapy (PDT) of basal cell carcinoma (BCC) found the treatment to be beneficial for a certain subgroup of patients.

According to Roy G. Geronemus, M.D., one of the study investigators, the intralesional injection of a photosensitizing agent in combination with PDT is particularly geared to the patient that is prone to numerous nonmelanoma skin cancers (NMSC) or those who are poor candidates for surgery. Dr. Geronemus is director of Laser & Skin Surgery of New York, where the study took place.

The study

Researchers hypothesized that intralesional injection of photosensitizing agents may enhance PDT efficacy by increasing depth of activity around localized tumors. Their purpose was to determine the effectiveness of noncoherent blue light in the intralesional PDT of BCC.

The team conducted a prospective, IRB-approved study of 20 BCCs at Laser & Skin Surgery of New York. High-risk skin cancer patients were not included.

Each BCC was injected with 20 percent aminolevulinic acid, incubated for one hour and then exposed to non-coherent blue light for 1,000 seconds (10 J/cm2 ). If clearance was not attained at eight weeks, a second treatment was performed.

Clinical evaluations were performed at the time of each treatment and repeated at 16 weeks, one year and two years after PDT. These follow-up visits included subjective patient assessments as well as punch biopsies of the areas that had been treated.

Study results

All 20 of the BCCs were evaluated at 16 weeks, showing recurrences at two sites' histology. Of the 18 sites that were still negative at 16 weeks, 13 were evaluated again at one year, when an additional four sites showed recurrence. Seven patients returned for two-year exams and showed recurrence at one site.

Although the remaining one and two-year follow-ups may show increasing recurrence rates, the overall recurrence rate in the two-year study time period is 35 percent (seven of the 20 sites), to date. No adverse or unusual events were noted.

"These findings might result in the dermatologist looking at this form of treatment over surgery in a subset of patients with superficial BC and some squamous cell carcinomas, realizing that the success rate might not be as high," Dr. Geronemus says. "Mohs surgery is still the gold standard."

Although the intralesional PDT treatment is not as effective as surgery, the procedure leaves no scars and is well-tolerated, with the best results appearing to be in an area of greatest concern for many patients, which is below the knee.

"For those patients who don't require Mohs surgery or are not candidates for Mohs surgery, this treatment provides another therapeutic option," Dr. Geronemus says. "It's a noninvasive, easily applied, cosmetically acceptable treatment of BCC. In addition, it has minimal downtime and minimal discomfort.

"In some cases, the treatment may be appropriate for patients who are concerned about having scars in cosmetic areas beyond the face," he says.

Disclosures: Dr. Geronemus received research support from DUSA.