Version: 1
The number of new cases of skin cancer has been increasing for several years. The three different types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and malignant melanoma. Photodynamic therapy (PDT) is a new method for treating extended preliminary stages of squamous cell carcinoma, ie, actinic keratosis, and superficial forms of basal cell carcinoma. In PDT, an ointment containing delta aminolevulinic acid (ALA) is applied to the skin. This agent is allowed to work for 4 to 6 hours, whereafter the skin area is illuminated by either a laser or an incoherent (red) light source. An estimated 4000 patients per year comprise the primary target group for this treatment method.
The clinical studies of PDT carried out to date within the field of dermatology are comprised of two randomized controlled studies and several non-controlled treatment studies.
In the controlled studies, 128 patients were randomized to PDT and cryosurgery respectively. Both methods were found to be similar as regards the degree of recovery. The healing time after PDT was significantly shorter and the cosmetic results were better than with cryosurgery. Patients reported no differences between the two methods as regards pain and discomfort during treatment.
There is moderate* scientific evidence on the medical effects of PDT in treating skin malignancies. However, no studies adequately describe the cost-effectiveness of the method.
The current findings suggest that PDT is a promising method. Nevertheless, there is a need for further studies with longer followup times that address patient benefits, risks, and costs.
*This assessment by SBU Alert uses a 4-point scale to grade the quality and evidence of the scientific documentation. The grades indicate: (1) good, (2) moderate, (3) poor, or (4) no scientific evidence on the subject.
This summary is based on a report prepared at SBU in collaboration with Prof. Olle Larkö, Sahlgrenska University Hospital, Göteborg and has been reviewed by Assoc. Prof. Katarina Svanberg, Lund University Hospital.
The complete report is available in Swedish only.
Alert is a joint effort by the Swedish Council on Technology Assessment in Health Care (SBU), the Medical Products Agency, the National Board of Health and Welfare, and the Federation of Swedish County Councils.