title: Patients with oral cancer developing from pre-existing oral leukoplakia: do they do better than those with de novo oral cancer?
abstract: BACKGROUND
  It has been suggested that patients with squamous cell carcinomas derived from oral leukoplakia have a better prognosis than patients with carcinomas that are not associated with oral leukoplakia.
  
  
  OBJECTIVE
  To study the mortality rate of 19 patients with a squamous cell carcinoma derived from pre-existing oral leukoplakia.
  
  
  METHODS
  The mortality rate of 19 patients with a proven oral squamous cell carcinoma derived from a pre-existing oral leukoplakia was compared with that of a similar size group of patients with oral carcinoma without a pre-existing oral leukoplakia, being matched for gender, age, smoking habits, use of alcohol, oral subsite and histopathologic grade. Treatment in all patients was primarily by surgical excision. The mortality rates up to 5 years have been computed according to the Kaplan-Meier method.
  
  
  RESULTS
  No significant difference of the mortality rates up to 5 years of follow-up was observed between the two groups of patients.
  
  
  CONCLUSIONS
  Patients with oral cancer developing from pre-existing oral leukoplakia do not do better than those with de novo oral cancer.
authors.affiliation: Department of Oral and Maxillofacial Surgery/Pathology, VUmc/ACTA, Amsterdam, The Netherlands.
authors.forename: Manon
authors.initials: M
authors.lastname: Weijers
authors.forename: Ivo
authors.initials: I
authors.lastname: Ten Hove
authors.forename: Remy H B
authors.initials: RH
authors.lastname: Allard
authors.forename: Dick P D
authors.initials: DP
authors.lastname: Bezemer
authors.forename: Isaäc
authors.initials: I
authors.lastname: van der Waal
mesh_terms: D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000473:pathology; D002471:Cell Transformation, Neoplastic; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007972:Leukoplakia, Oral / Q000473:pathology*; D008137:Longitudinal Studies; D008297:Male; D009062:Mouth Neoplasms / Q000401:mortality* / Q000473:pathology