title: Effect of carbon dioxide laser resurfacing on epidermal p53 immunostaining in photodamaged skin.
abstract: OBJECTIVE
  To quantitatively examine changes in p53 tumor suppressor gene immunostaining after carbon dioxide (CO(2)) laser resurfacing of photodamaged skin to assess the potential value of this treatment in reducing the risk of progression to cutaneous carcinoma.
  
  
  METHODS
  Serial in vivo immunohistochemical analyses after laser therapy.
  
  
  METHODS
  Academic referral center, Department of Dermatology, University of Michigan, Ann Arbor.
  
  
  METHODS
  Volunteer sample of 11 adults, 51 to 76 years old, with clinically evident photodamage of the forearms.
  
  
  METHODS
  Focal CO(2) laser resurfacing of photodamaged forearms and serial biopsies at baseline, 3 weeks, and 6 months after treatment.
  
  
  METHODS
  Because keratinocytes with mutations in p53 or altered p53 expression stain via immunohistochemical techniques, image analysis of immunohistochemically stained sections was used to quantify p53 expression.
  
  
  RESULTS
  Positive immunostaining for p53 in the interfollicular epidermis was noted in 8 of 11 subjects at baseline, with an average staining density of 250 cells/mm(2). Average staining decreased to 3 cells/mm(2) 3 weeks after treatment. This decrease was sustained at 5 cells/mm(2) 6 months after resurfacing.
  
  
  CONCLUSIONS
  There was a consistent decrease in p53 immunostaining in the interfollicular epidermis lasting for at least 6 moths after CO(2) laser resurfacing of photodamaged skin. Since p53 mutation or overexpression is observed in a majority of cases of cutaneous carcinoma, the posttreatment repopulation of the epidermis with p53-negative keratinocytes should theoretically decrease the risk of malignant progression. Further study of laser resurfacing as a prophylactic procedure in patients at high risk for skin cancer development appears warranted.
authors.affiliation: Department of Dermatology, University of Michigan Medical School, Ann Arbor, USA. jorringe@umich.edu
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Orringer
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Johnson
authors.forename: Sewon
authors.initials: S
authors.lastname: Kang
authors.forename: Darius J
authors.initials: DJ
authors.lastname: Karimipour
authors.forename: Craig
authors.initials: C
authors.lastname: Hammerberg
authors.forename: Ted
authors.initials: T
authors.lastname: Hamilton
authors.forename: John J
authors.initials: JJ
authors.lastname: Voorhees
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Fisher
mesh_terms: D000287:Administration, Topical; D000368:Aged; D001707:Biopsy, Needle; D002245:Carbon Dioxide / Q000627:therapeutic use; D004817:Epidermis / Q000473:pathology* / Q000528:radiation effects; D005260:Female; D005500:Follow-Up Studies; D016158:Genes, p53 / Q000235:genetics*; D006801:Humans; D007150:Immunohistochemistry; D028022:Low-Level Light Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009154:Mutation; D011446:Prospective Studies; D015361:Rhytidoplasty / Q000295:instrumentation / Q000379:methods*; D018570:Risk Assessment; D016037:Single-Blind Method; D015595:Skin Aging; D016896:Treatment Outcome; D014212:Tretinoin / Q000627:therapeutic use*
chemical_list: D002245:Carbon Dioxide; D014212:Tretinoin