Photodynamic therapy for the treatment of extramammary Paget's disease

Abstract

Surgical and ablative treatment modalities for extramammary Paget's disease (EMPD) have high recurrence rates and can be associated with significant morbidity. To evaluate photodynamic therapy (PDT) for the treatment of EMPD. We conducted a retrospective review of notes and histology of five men with anogenital, groin and axillary EMPD treated with PDT at Roswell Park Cancer Institute between 20 April 1995 and 1 February 2001. Sixteen EMPD lesions were treated with topical aminolaevulinic acid (ALA)-PDT. Eleven of these lesions had failed previous Mohs micrographic surgery, excision or laser ablation. When evaluated 6 months after one treatment with ALA-PDT, eight of 16 (50%) sites achieved a complete clinical response (CR); six of eight CRs were in lesions that had failed prior conventional therapies. Three of the eight CRs (37.5%) recurred at 9, 10 and 10 months. One patient who was partially responsive to topical ALA-PDT subsequently received systemic Photofrin(R)-PDT, with a complete clinical and histological response at 1 year. Functional and cosmetic outcome was excellent in all patients. PDT is an effective treatment for EMPD. Recurrence rates are high with topical ALA-PDT, but comparable with standard therapies. Topical ALA-PDT causes little scarring and is preferred for superficial disease and mucosal surfaces. Systemic Photofrin(R)-PDT may be better suited for bulky disease. While further studies are indicated, PDT is well tolerated and appears to be a useful therapy for EMPD.