Long‐term follow‐up of metil aminolevulinate (MAL)‐PDT in difficult‐to‐treat cutaneous Bowen’s disease

Abstract

Bowen's disease (BD) is a form of intraepidermal squamous cell carcinoma, which is clinically characterized by gradually enlarging, well-demarcated erythematous plaques with irregular borders and surface crusting or scaling, affecting primarily the elderly. BD often presents with lesions difficult to treat with standard therapy as surgery, cryosurgery, or 5-fluorouracil (5-FU) for the risk of significantly poor cosmetic outcome, failure rate, and adverse events, related mainly to the age of the patients. Topical PDT with methyl aminolevulinate (MAL) represents a valid and approved therapy for BD lesions in many cases, especially for lesions located at poor healing sites or for large patches of disease, due to its high efficacy coupled with good tolerability and tissue-sparing attitude. In this study, we sought to investigate the efficacy, safety, and cosmetic outcome of MAL-PDT in a series of patients with BD lesions which were challenging to treat for clinical, surgical, and patient-related reasons, such as size of the lesion, difficult surgical approach for anatomical sites, or age of patients and request of the best cosmetic result. We also performed a long-term follow-up to assess recurrence rates and eventual late-onset adverse events.

Effectiveness of photodynamic therapy in Bowen's disease: a retrospective observational study in 423 lesions

“…Once again, PDT proved to be an attractive option for BD in terms of cosmetic outcome. The majority of the lesions (78.0%) healed with no long‐term adverse events observed during FU, which is in concordance with previous studies …”

“…This may reflect the wishes from female patients of obtaining better cosmesis in this area. The head and neck stands out as the most common area for PDT in both men and women, which is not in concordance with other studies in which the extremities were the most commonly treated sites . Nevertheless, body site did not seem to influence the effect of PDT in contrast to the study made by Truchelo et al …”

“…In the case of larger lesions where surgery may cause significant morbidity and/or BD located on poor healing sites such as the lower legs, PDT is a commonly used treatment with good cosmetic and functional results. 3,[7][8][9][10] Conventional PDT involves two steps. A photosensitizing drug, 5-aminolevulinic acid (ALA) or methyl aminolevulinate (MAL), is applied on the lesion, followed by illumination with red light at 635 nm.…”

BritishAssociation ofDermatologists' guidelines for the management of squamous cell carcinomain situ(Bowen's disease) 2014

“…68 Complete clinical clearance rates of 88-100% are reported 3 months after one cycle of MAL-PDT, with 68-89% of treated lesions remaining clear over follow-up periods of 17-50 months. 40,[70][71][72][73] A multicentre, randomized study compared MAL-PDT with cryotherapy or 5-FU in 225 patients with 275 SCCs in situ.…”

Squamous Cell Carcinoma Following Photodynamic Therapy for Cutaneous Bowen’s Disease in a Series of 105 Patients

“…The light energy absorbed by the photoactive porphyrin is transferred to oxygen, generating ROS. Two MAL PDT sessions 8 days apart are recommended for the treatment of BD.The effectiveness (complete clearance) of PDT for the treatment of BD is approximately 80%, with recurrences in 10-20% of cases (8,11,13). Side-effects are essentially local erythema, oedema, warmth, burning, tingling and painful sensations (13,14).…”