title: Oral cancer development in patients with leukoplakia--clinicopathological factors affecting outcome.
abstract: BACKGROUND
  Oral leukoplakia (OL) is the best-known potentially malignant disorder. The objective of the current study was to evaluate the clinicopathological factors predictive of outcome in a large cohort of patients with OL, and report our experience in the early detection of malignant events.
  
  
  METHODS
  A total of 320 patients with biopsy-proven OL were retrospectively reviewed from the study institution who had a mean follow-up of 5.1 years. Data on patient and lesion at initial diagnosis and patient underwent sequential biopsies were reviewed. Multiple biopsies indicates > = 3 times sequential biopsies. Oral cancer-free survival rate (OCFS) was determined by the Kaplan-Meier method and significant factors were identified by Cox regression analysis.
  
  
  RESULTS
  The 3-year and 5-year OCFS was 86.6% and 82.0%, respectively. A new binary system of grading oral dysplasia was performed and Kaplan-Meier analysis indicated that high-grade dysplasia had significantly higher malignant incidence than low-grade dysplasia (5-year OCFS, 90.5% vs 59.0%; P<0.001), especially during the first 2-3 years of follow-up. Multivariate analysis revealed that the 4 factors including patient aged >60 years, lesion located at lateral/ventral tongue, non-homogenous lesion, high-grade dysplasia were independent significant indicators for OL malignant transformation. In addition, significant positive correlation between the multiple biopsies and these 4 factors and malignant outcome was established.
  
  
  CONCLUSIONS
  Elderly patients with OL located at lateral/ventral tongue and who had non-homogenous lesion with high-grade dysplasia correlated much higher risk of transformation. This high-risk subpopulation was suggested to undergo sequential biopsies and histologic examination contributing to early detection of malignant event.
authors.affiliation: Shanghai Key Laboratory of Stomatology, Department of Oral Maxillofacial-Head and Neck Oncology, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Lin-Jun
authors.initials: LJ
authors.lastname: Shi
authors.forename: Lan
authors.initials: L
authors.lastname: Wu
authors.forename: Jin-Qiu
authors.initials: JQ
authors.lastname: Feng
authors.forename: Xi
authors.initials: X
authors.lastname: Yang
authors.forename: Jiang
authors.initials: J
authors.lastname: Li
authors.forename: Zeng-Tong
authors.initials: ZT
authors.lastname: Zhou
authors.forename: Chen-Ping
authors.initials: CP
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D007972:Leukoplakia, Oral / Q000150:complications / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000209:etiology; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors