title: Prognostic impact of fibrosarcomatous transformation in dermatofibrosarcoma protuberans: a cohort study.
abstract: BACKGROUND
  Dermatofibrosarcoma protuberans (DFSP) is a rare, low-grade cutaneous malignancy that sometimes transforms into a high-grade fibrosarcomatous variant (DFSP-FS). Limited data compare clinical features and biological behavior of these 2 entities.
  
  
  OBJECTIVE
  We sought to compare clinical features and biological behavior of DFSP and DFSP-FS.
  
  
  METHODS
  This was a retrospective cohort study of ambulatory patients with DFSP or DFSP-FS treated between January 1955 and March 2012 in the dermatology department of a tertiary care academic medical center.
  
  
  RESULTS
  Of 188 patients, 171 (91%) had DFSP and 17 (9%) had DFSP-FS. Recurrence-free survival differed significantly between the groups over time (P = .002). The 1-year and 5-year recurrence-free survival was 94% and 86%, respectively, for DFSP, vs 86% and 42%, respectively, for DFSP-FS. Metastatic disease occurred in no patients with DFSP and in 18% (3 of 17) with DFSP-FS (P < .001). There were no statistically significant differences in age at diagnosis, sex, race, symptomatology, maximum tumor size, muscle/bone invasion, or duration of tumor before diagnosis.
  
  
  CONCLUSIONS
  The retrospective nature of study was a limitation.
  
  
  CONCLUSIONS
  DFSP-FS exhibits more aggressive behavior than DFSP, with lower recurrence-free survival and greater metastatic potential. Their similar clinical presentation mandates histopathological differentiation for prognosis.
authors.affiliation: Feinberg School of Medicine, Northwestern University, Chicago, Illinois.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Hoesly
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Garrett C
authors.initials: GC
authors.lastname: Lowe
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Lohse
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Jerry D
authors.initials: JD
authors.lastname: Brewer
authors.affiliation: Department of Dermatology, Mayo Clinic, Rochester, Minnesota. Electronic address: lehman.julia@mayo.edu.
authors.forename: Julia S
authors.initials: JS
authors.lastname: Lehman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002471:Cell Transformation, Neoplastic; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018223:Dermatofibrosarcoma / Q000473:pathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000473:pathology*; D055815:Young Adult
keywords: cutaneous signs of disease; dermatofibrosarcoma protuberans; fibrosarcoma; oncogenesis; pathology; surgery