Photodynamic therapy reduces present and future burden of basal cell nevus syndrome

June 1, 2008

Outcomes in a small case series indicate photodynamic therapy using topical and intralesional aminolevulinic acid (ALA) is a safe and effective strategy for managing patients with basal cell nevus syndrome. The noninvasive modality has many benefits compared with conventional strategies.

Key Points

National report - Photodynamic therapy (PDT) using topical and intralesional amino levulinic acid (ALA) appears to be a useful, noninvasive alternative for the management of patients with basal cell nevus syndrome (BCNS), according to dermatologists at Boston University.

Daniel B. Wasserman, M.D., and colleagues describe outcomes of five patients with BCNS treated off-label with ALA-PDT.

The treatment was safe and effective in clearing most basal cell carcinomas (BCCs), as well as any existing actinic keratoses, but it also had a benefit for reducing the number of subsequently appearing new lesions during follow-up extending up to five years.

"Patients with BCNS can develop dozens, if not hundreds, of basal cell carcinomas over their lifetime in areas that are cosmetically sensitive and/or prone to scarring after surgery. Repeated surgery to remove these tumors is associated with significant morbidity, and sun avoidance and sunscreen use is minimally effective in preventing the development of new lesions. Frustrated patients may fail to return for routine surveillance," Dr. Wasserman tells Dermatology Times.

"ALA-PDT is not approved for the treatment of BCNS, and we and others are still trying to tease out optimal protocols for its use. However, based on its efficacy and multiple advantages compared with conventional BCC therapy, ALA-PDT appears to have a valuable role for treating and preventing skin cancers in patients with BCNS," he says.

Dr. Wasserman is a resident in the department of dermatology, Boston University School of Medicine, and will be beginning a fellowship in Laser and Photomedicine at Massachusetts General Hospital, Harvard Medical School, Boston, in July 2008.

Barbara Gilchrest, M.D., professor and chairman, department of dermatology, Boston University School of Medicine, was Dr. Wasserman's senior collaborator in the reported research.

All of the patients included in the series had presented to their dermatologist with a high tumor burden and were referred to Boston University to explore possible nonsurgical alternatives.

ALA-PDT was performed repeatedly on the face, chest, back or other area where BCCs were present, after a full informed consent discussion in which the off-label nature of the treatment was explained.

Patients with more than one anatomic site of involvement often were treated in serial visits.

With the aim of deriving a field effect and a benefit of treating microscopic cancers that were not yet clinically apparent, the protocol involved topical application of 20 percent ALA solution (Levulan Kerastick, DUSA Pharmaceuticals) to the entire skin of the face or other anatomic site where BCCs were present.

In addition, in some instances, larger, nodular BCCs were injected with a 1:1 mixture of the ALA solution with 1 percent lidocaine containing epinephrine.

Following a one- to two-hour incubation period, light treatment was performed with 10 J/cm2 blue light (Blu-U, DUSA Pharmaceuticals).

The PDT was well-tolerated. Although all patients developed moderate phototoxicity, the erythema and edema peaked after 24 hours and resolved within a week.

Most existing BCCs cleared, but any that remained after an approximate one to three months of follow-up were excised.

"The treatment was not 100 percent effective in clearing existing lesions or preventing new ones. However, it certainly reduced the tumor burden of what is a very difficult disease," Dr. Wasserman says.

The treated lesions healed without scarring or pigmentary changes, and the PDT was also associated with improvement in diffuse photodamage and in the appearance of facial scars.

Disclosure: DUSA Pharmaceuticals provided the supplies for the study, but neither Dr. Wasserman nor Dr. Gilchrest have any financial interest in that company. Dr. Gilchrest does serve as a consultant to DUSA.