title: Effectiveness of photodynamic therapy for mammary and extra-mammary Paget's disease: a state of the science review.
abstract: BACKGROUND
  Paget's disease is a rare skin disorder occurring in the breast (mammary) or in the groin, genital, peri-anal and axillary regions (extra-mammary). Typical treatment involves surgical excision, which in the case of extra-mammary Paget's disease, can lead to significant morbidity. Photodynamic therapy (PDT) which uses a topical or intravenous photosensitizing agent that is activated by a light source to ablate abnormal tissue, offers a minimally invasive alternative. The purpose of this study was to assess the effectiveness of photodynamic therapy in the treatment of Paget's disease.
  
  
  METHODS
  Following Cochrane guidelines, a comprehensive systematic review of all clinical studies and reports examining the use of PDT for mammary and extra-mammary Paget's disease was conducted. Study quality was assessed using the Oxford Levels of Evidence Scale.
  
  
  RESULTS
  21 retrospective and 2 prospective non-comparative studies were identified and included in the review: 9 case reports with 1-2 patients and 14 case series with 1-16 patients. These reports totalled 99 patients with 133 extra-mammary Paget's lesions and 3 patients (with 3 lesions) with mammary Paget's disease. Follow-up periods were typically one year or less, with 77/133 extra-mammary lesions exhibiting complete response to PDT. One recurrent mammary skin lesion and two mammary lesions treated concomitantly with surgery also exhibited complete responses.
  
  
  CONCLUSIONS
  Evidence of the effectiveness of PDT for Paget's disease is promising, but limited. This may, in part, be explained by the rarity of the condition, making controlled comparative clinical trials challenging.
authors.affiliation: Department of Public Health Sciences, University of Alberta, Research Transition Facility, Edmonton, Canada. alexan@ualberta.ca
authors.forename: Alexa A
authors.initials: AA
authors.lastname: Nardelli
authors.forename: Tania
authors.initials: T
authors.lastname: Stafinski
authors.forename: Devidas
authors.initials: D
authors.lastname: Menon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000188:drug therapy*; D004954:Esthetics; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010145:Paget Disease, Extramammary / Q000188:drug therapy*; D010144:Paget's Disease, Mammary / Q000188:drug therapy*; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011446:Prospective Studies; D012189:Retrospective Studies; D016896:Treatment Outcome; D014565:Urogenital Neoplasms / Q000188:drug therapy
chemical_list: D017319:Photosensitizing Agents