INTRODUCTION
Basal cell carcinoma (BCC) is the most common form of skin cancer in North America.1,2 Although there is a 5-year survival rate of 100% and metastasis is rare (incidence of 0.0028%-0.55%), BCCs cause significant morbidity as well as a burden on healthcare services.2-4 High cure rates with low chances of recurrence are seen with early detection and treatment.2,3 There are 2 categories of treatment for BCC: surgical and non-surgical. Surgical options include electrodessication and curettage (ED&C), cryosurgery, surgical excision, and Mohs micrographic surgery (MMS).1-3 Non-surgical options include photodynamic therapy (PDT), radiation therapy, and topical therapies such as imiquimod or fluorouracil creams.1-3 The goal of treating BCCs is to achieve a complete removal of the lesion while preserving cosmesis.5
The treatment standards in Canada consist of surgical excision or ED&C for low-risk BCC and MMS for high-risk BCC.1 Similarly, surgical excision and MMS are the treatment standards in the United States (US).6-8 Topical PDT provides a high level of cosmesis difficult to accomplish with surgical techniques.3 PDT relies on a photosensitizer, such as methyl aminolevulinate (MAL) that promotes cell death without affecting the surrounding tissue.9 MAL-PDT is marketed as Metvix® (Galderma & Photocure ASA), which contains 16.8% MAL and is indicated for treatment of both BCC and actinic keratosis.9 Canadian and American guidelines suggest the use of PDT for low-risk superficial BCCs.1,6
MAL-PDT is well tolerated, with the most common side effects being local reactions consisting of stinging pain, burning, pruritus, erythema, and edema that typically resolve on the day of treatment.1,10 A systematic review evaluating treatment options found the average recurrence rate of MAL-PDT to be 17.8% (95% CI: 9.1-31.8) for primary BCC.11 Another review found that MAL-PDT achieved a complete remission in 91% of superficial BCCs.12 The average 5-year overall cure rate for MAL-PDT is 87% for primary superficial lesions.3 Although a slightly higher recurrence rate is seen, MAL-PDT treatment is preferred over surgery due to a significantly better cosmetic outcome.12 Weston and Fitzgerald revealed that patients place the most importance on risk of scarring and cosmetic outcome, whereas lesion response had no significant impact when deciding between MAL-PDT or surgical treatment.13
