title: Clinical predictors of oral leukoplakia recurrence following CO₂ laser vaporization.
abstract: OBJECTIVE
  The objective of this study was to determine whether risk of early leukoplakia recurrence (within 3 months) following carbon dioxide (CO2) laser removal varies by clinical characteristics including lesion size, site and accessibility of margins.
  
  
  METHODS
  A retrospective cohort study included patients with oral leukoplakia who had their first CO2 laser surgery for removal of oral leukoplakia between 2005 and 2010 at the UCSF oral medicine clinic. Twenty-six patients with 32 separate lesions met the eligibility criteria after a clinic database search was followed by review of clinical notes and biopsy reports from existing patient charts. Data analysis included computation of summary statistics, and logistic regression analyses to evaluate recurrence of leukoplakia by clinical characteristics of the lesions.
  
  
  RESULTS
  Patient data and the characteristics of lesions were evaluated as possible predictors of early recurrence following laser removal; these included age, sex, duration, size, appearance and histopathology of the lesion. The only one that reached statistical significance was poor accessibility of the margins of the lesion (vs. good accessibility, OR = 24.57 (95% CI: 1.59-16.68), p = 0.016); the probability for trend for good, questionable, and poor accessibility was 0.0028. This finding remained significant after controlling for age, sex, duration and size of lesion. Four out of five lesions with poor accessibility showed recurrence at 3 months. Of these, three involved the gingiva and one the lateral tongue.
  
  
  CONCLUSIONS
  This study has identified poor accessibility of the lesion margins as a predictor for early recurrence of leukoplakia following laser removal. Other variables evaluated did not reach statistical significance, possibly due to lack of power.
authors.affiliation: Oral Medicine, 100 West El Camino Real, Suite 76, Mountain View, CA 94040, USA. Electronic address: nitacwu@gmail.com.
authors.forename: Nita
authors.initials: N
authors.lastname: Chainani-Wu
authors.affiliation: General Dentistry, Mountain View, CA, USA. Electronic address: dustinchrislee@gmail.com.
authors.forename: Dustin
authors.initials: D
authors.lastname: Lee
authors.affiliation: NCIRE, Northern California Institute for Research and Education, 4150 Clement Street, 151 NC, San Francisco, CA 94121-1545, USA. Electronic address: erin.madden@ncire.org.
authors.forename: Erin
authors.initials: E
authors.lastname: Madden
authors.affiliation: National Dental Center, Singapore. Electronic address: sqxchel@gmail.com.
authors.forename: Chelsia
authors.initials: C
authors.lastname: Sim
authors.affiliation: San Mateo, CA, USA. Electronic address: kornelia_collins@yahoo.com.
authors.forename: Kornelia
authors.initials: K
authors.lastname: Collins
authors.affiliation: University of California, San Francisco, USA.
authors.forename: Sol
authors.initials: S
authors.lastname: Silverman
mesh_terms: D000328:Adult; D005260:Female; D005887:Gingival Neoplasms / Q000473:pathology / Q000601:surgery; D006801:Humans; D054020:Lasers, Gas / Q000627:therapeutic use*; D007972:Leukoplakia, Oral / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014062:Tongue Neoplasms / Q000473:pathology / Q000601:surgery
keywords: Carbon dioxide laser; Oral cancer; Oral dysplasia; Oral leukoplakia; Recurrence; Surgical treatment