title: A long-term follow-up study on the natural course of oral leukoplakia in a Swedish population-based sample.
abstract: OBJECTIVE
  To assess the natural course of screening-detected oral leukoplakia (OL) among non-consulting individuals.
  
  
  METHODS
  A cohort of 555 individuals with OL, confirmed in 1973-1974 during a population-based survey, were followed through January 2002 via record linkages with nationwide and essentially complete registers. A sample of 104 drawn from the 297 surviving cohort members who still were living in the area in 1993-1995 was invited to a re-examination. Sixty-seven of them attended.
  
  
  RESULTS
  At the time of re-examination OL had disappeared in 29 (43%) individuals. There was a statistically significant association between cessation of/no smoking habits in 1993-1995 and the disappearance of OL. Never/previous daily smokers were thus over-represented among individuals whose OL had disappeared compared to those with persisting OL [n = 23 (82%) vs. n = 18 (47%), P < 0.01]. Eighteen (78%) of the twenty three non-smokers with disappearing OL had quit after the initial examination. One man and two women developed oral cancer during follow-up while 0.7 and 0.07, respectively, were expected.
  
  
  CONCLUSIONS
  Smoking cessation was associated with an increased disappearance of OL. Hence, at least one-fourth had lesions that could be classified as tobacco-related. Small observed and expected numbers prohibited firm conclusions about a possible excess risk of developing oral cancer.
authors.affiliation: Institute of Odontology, Karolinska Institutet, Stockholm, Sweden. ann.roosaar@ki.se
authors.forename: A
authors.initials: A
authors.lastname: Roosaar
authors.forename: L
authors.initials: L
authors.lastname: Yin
authors.forename: A L V
authors.initials: AL
authors.lastname: Johansson
authors.forename: G
authors.initials: G
authors.lastname: Sandborgh-Englund
authors.forename: O
authors.initials: O
authors.lastname: Nyrén
authors.forename: T
authors.initials: T
authors.lastname: Axéll
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007972:Leukoplakia, Oral / Q000453:epidemiology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000209:etiology; D012907:Smoking / Q000009:adverse effects; D013548:Sweden / Q000453:epidemiology