title: Malignant transformation of oral epithelial dysplasia: clinicopathological risk factors and outcome analysis in a retrospective cohort of 138 cases.
abstract: OBJECTIVE
  To explore the usefulness of a new binary system of grading dysplasia proposed by the World Health Organization and to identify significant risk factors for malignant transformation in a long-term follow-up cohort of patients with oral epithelial dysplasia.
  
  
  RESULTS
  A total of 138 patients with histologically confirmed oral dysplasia between 1978 and 2008 were reviewed retrospectively in our department. The mean follow-up period was 5.1 years. Of these dysplasias, 37 (26.8%) developed into cancer, with a mean duration of 4.6 years. Cox regression analysis revealed that high-grade dysplasia was an independent risk factor for transition, but age, gender, lesion site, diet habit, smoking and alcohol intake were not risk factors. High-grade dysplasia was associated with a 2.78-fold (95% confidence interval 1.44-5.38; P = 0.002) increased risk of transition, as compared with low-grade dysplasia. Consistently, high-grade dysplasia had a significantly higher incidence of malignancy than low-grade dysplasia by Kaplan-Meier analysis (log-rank test, P = 0.001).
  
  
  CONCLUSIONS
  The utilization of high-grade dysplasia as a significant indicator for evaluating malignant transformation risk in patients with potentially malignant lesions is suggested; this may be helpful to guide treatment selection in clinical practice.
authors.affiliation: Department of Oral Mucosal Diseases, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Zhe-Xuan
authors.initials: ZX
authors.lastname: Bao
authors.forename: Lin-Jun
authors.initials: LJ
authors.lastname: Shi
authors.forename: Guo-Yao
authors.initials: GY
authors.lastname: Tang
authors.forename: Zeng-Tong
authors.initials: ZT
authors.lastname: Zhou
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000009:adverse effects; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D015331:Cohort Studies; D004032:Diet / Q000009:adverse effects; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology*; D060787:Neoplasm Grading / Q000379:methods; D011230:Precancerous Conditions / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D016896:Treatment Outcome; D055815:Young Adult