title: Facial basal cell carcinomas recurring after photodynamic therapy: a retrospective analysis of histological subtypes.
abstract: BACKGROUND
  Photodynamic therapy (PDT) is an established treatment for basal cell carcinomas (BCCs). Although recurrences are sometime observed, their histological patterns have never been specifically studied or compared with the one of the initial tumor.
  
  
  OBJECTIVE
  To compare the histopathological aggressiveness of BCCs recurring after PDT with that of the primary tumors.
  
  
  METHODS
  The study population included 12 patients with 16 post PDT recurrent BCCs. Outcome measures were proportion of histologically aggressive subtypes in BCC recurrences vs. primary tumor.
  
  
  RESULTS
  62.5% of recurrent BCCs displayed a transition from a non-aggressive to an aggressive subtype.
  
  
  CONCLUSIONS
  Post PDT recurrences appear to display an increased histological aggressiveness, although the latter may reflect the natural course of tumor progression. Despite the presence of potential biases, our study raises the possibility that PDT favors the selection of more aggressive tumor cells. Better systematic large-scale follow-up studies are required to assess the exact frequency and histological types of BCC recurrences after PDT.
authors: Department of Dermatology, Inselspital, Berne University Hospital, Berne, Switzerland.
authors: Sabine
authors: S
authors: Fiechter
authors: André
authors: A
authors: Skaria
authors: Helga
authors: H
authors: Nievergelt
authors: Romain
authors: R
authors: Anex
authors: Luca
authors: L
authors: Borradori
authors: Laurent
authors: L
authors: Parmentier
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002280:Basal Cell Carcinoma / Q000188:drug therapy* / Q000473:pathology; D005145:Face; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015580:Mohs Surgery / Q000379:methods; D009364:Neoplasm Recurrence, Local / Q000209:etiology*; D010778:Photochemotherapy / Q000009:adverse effects*; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000473:pathology; D013997:Time Factors; D016896:Treatment Outcome