Effectiveness of photodynamic therapy in Bowen's disease: an observational and descriptive study in 51 lesions.

Introduction: Bowen disease (BD) or squamous cell carcinoma (SCC) in situ affects both skin and mucous membranes and has the potential to progress to invasive SCC. Photodynamic therapy (PDT) has been approved recently for the treatment of BD. Some studies have demonstrated its efficacy and good cosmetic outcome.

Objective: To assess the efficacy of PDT in the treatment of BD.

Patients And Methods: We carried out an observational, retrospective and descriptive study. A total of 47 patients with 51 lesions of BD were included. All the lesions were confirmed with previous cutaneous biopsy. All patients were treated with the standard protocol. Topical methyl-aminolaevulinic acid was occluded during 3 h and followed by illumination with red-light (630 nm, 38 J/cm2, 7.5 min). Clinical and fluorescence photographs images were taken before each session. All patients received two sessions one week apart. Clinical response was classified in partial or complete response. Fluorescence response was classified in negative, intermediate or intense. The follow-up period and the adverse events observed including pain were also collected.

Results: A total of 20 men and 27 women with a mean age of 75.57 years old were treated with PDT. Lesions were most frequently located in the lower limbs. Globally, 76.09% of the lesions achieved complete response after 2 sessions with a medium follow-up of 16.61 months. Fluorescence of the lesions disappeared when clinical response was achieved, but not always. The most common adverse effect was an immediate burning sensation. All lesions showed an excellent cosmetic result.

Conclusion: Photodynamic therapy is an effective treatment for BD in terms of both clinical remission and cosmetic results, with good tolerance and minimal adverse effects.