title: Oral lichen planus and malignant transformation: a longitudinal cohort study.
abstract: OBJECTIVE
  Oral lichen planus (OLP) is associated with risk for developing oral squamous cell carcinoma (OSCC). We performed a 7-year prospective study to assess the incidence of malignant transformation of OLP among adults.
  
  
  METHODS
  Three hundred twenty-seven OLP patients, 229 women (70.0%) and 98 men (30.0%), were observed during the follow-up period.
  
  
  RESULTS
  During a mean follow-up of 81.7 months, 8 of 327 patients developed an OSCC in OLP areas (0.36%/y), yielding the high overall standardized incidence ratio of 17.7 (95% confidence interval [CI] 8.8-35.3). The standardized incidence ratio for OSCC was significantly higher in women [27.0 (95% CI 11.2-64.8)] than in men [11.2 (95% CI 3.6-34.9)]. Six OSCCs were well differentiated (75%) and 2 moderately differentiated (25%). Three subjects (37.5%) developed recurrences within 2 years (mean 16.1 ± 3.5 months). Disease-free survival rate after 69.8 months was 97.3%.
  
  
  CONCLUSIONS
  OLP was associated with a significant increase in the risk for OSCC. Close surveillance may help to reduce the morbidity of OSCC arising from OLP at 24 months.
authors.affiliation: Unit of Oral Pathology and Medicine, Department of Reconstructive and Diagnostic Surgical Sciences, University of Milan, Milan, Italy. gpbombeccari@libero.it
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Bombeccari
authors.forename: Gianpaolo
authors.initials: G
authors.lastname: Guzzi
authors.forename: Mauro
authors.initials: M
authors.lastname: Tettamanti
authors.forename: Aldo Bruno
authors.initials: AB
authors.lastname: Giannì
authors.forename: Alessandro
authors.initials: A
authors.lastname: Baj
authors.forename: Francesco
authors.initials: F
authors.lastname: Pallotti
authors.forename: Francesco
authors.initials: F
authors.lastname: Spadari
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology*; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007558:Italy / Q000453:epidemiology; D017676:Lichen Planus, Oral / Q000401:mortality / Q000473:pathology*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000401:mortality / Q000473:pathology*; D009364:Neoplasm Recurrence, Local; D011230:Precancerous Conditions / Q000473:pathology*; D011446:Prospective Studies