title: Effects of topical tretinoin on dysplastic nevi.
abstract: OBJECTIVE
  As potential precursors of melanoma and markers of increased melanoma risk, dysplastic nevi are suitable targets of strategies for melanoma chemoprevention. We report the results of a pilot study of topical retinoic acid in patients with dysplastic nevi.
  
  
  METHODS
  Five male patients with dysplastic nevi applied tretinoin to half of the back for 6 months. Baseline photographs of dysplastic nevi were compared with posttreatment photographs and assessed for morphologic change. At study completion, each subject had four nevi excised from the treated side and four from the untreated side of the back. Biopsies were histologically evaluated for the presence of dysplasia.
  
  
  RESULTS
  All patients developed signs of irritation as a result of treatment. One patient was not compliant with treatment due to skin irritation. The four compliant patients showed significant decreases in the clinical atypia of treated lesions, with concomitant fading and even disappearance of many treated nevi. Histologically, only four of 16 treated nevi met histologic criteria for dysplasia, in comparison to 13 of 16 untreated nevi.
  
  
  CONCLUSIONS
  These results suggest that there is concomitant clinical and histologic improvement in a significant percentage of dysplastic nevi treated with topical tretinoin. However, the utility of topical tretinoin for chemoprevention of melanoma is limited by difficulty of application and associated inflammation. While new strategies in chemoprevention of melanoma are explored, sun protection and assiduous avoidance of sunburn must remain the mainstay of melanoma prevention.
authors.affiliation: Pigmented Lesion Group, University of Pennsylvania Cancer Center.
authors.forename: A C
authors.initials: AC
authors.lastname: Halpern
authors.forename: L M
authors.initials: LM
authors.lastname: Schuchter
authors.forename: D E
authors.initials: DE
authors.lastname: Elder
authors.forename: D
authors.initials: D
authors.lastname: Guerry
authors.forename: R
authors.initials: R
authors.lastname: Elenitsas
authors.forename: B
authors.initials: B
authors.lastname: Trock
authors.forename: I
authors.initials: I
authors.lastname: Matozzo
mesh_terms: D000287:Administration, Topical; D000328:Adult; D016588:Anticarcinogenic Agents / Q000627:therapeutic use*; D002454:Cell Differentiation; D004416:Dysplastic Nevus Syndrome / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008545:Melanoma / Q000517:prevention & control; D010865:Pilot Projects; D014212:Tretinoin / Q000008:administration & dosage / Q000627:therapeutic use*
chemical_list: D016588:Anticarcinogenic Agents; D014212:Tretinoin