title: Suprabasal expression of Ki-67 as a marker for the severity of oral epithelial dysplasia and oral squamous cell carcinoma.
abstract: BACKGROUND
  Transition of the normal oral epithelium to dysplasia and to malignancy is featured by increased cell proliferation. To evaluate the hypothesis of distributional disturbances in proliferating and stem cells in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC).
  
  
  OBJECTIVE
  To evaluate layer wise expression of Ki-67 in oral epithelial dysplasia and in OSCC.
  
  
  METHODS
  Thirty histologically confirmed cases of oral epithelial dysplasia, fifteen cases of OSCC and five cases of normal buccal mucosa were immunohistochemically examined and nuclear expression of Ki-67 was counted according to basal, parabasal, and suprabasal layers in epithelial dysplasia and number of positive cells per 100 cells in OSCC as labeling index (LI).
  
  
  RESULTS
  Suprabasal expression of Ki-67 increased according to the severity of epithelial dysplasia and the difference was statistically significant (P < 0.001). The mean Ki-67LI was 12.78 for low risk lesions, 28.68 for high risk lesions, 39.45 for OSCC and 13.6 for normal buccal mucosa.
  
  
  CONCLUSIONS
  The results of the present study demonstrate the use of proliferative marker Ki-67 in assessing the severity of epithelial dysplasia. Suprabasal expression of Ki-67 provides an objective criteria for determining the severity of epithelial dysplasia and histological grading of OSCC.
authors.affiliation: Department of Oral Pathology and Microbiology, Saraswati Dental College and Hospital, Lucknow, Uttar Pradesh, India.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Dwivedi
authors.forename: Shaleen
authors.initials: S
authors.lastname: Chandra
authors.forename: Bina
authors.initials: B
authors.lastname: Kashyap
authors.forename: Vineet
authors.initials: V
authors.lastname: Raj
authors.forename: Akhil
authors.initials: A
authors.lastname: Agarwal
keywords: Ki-67; oral epithelial dysplasia; oral squamous cell carcinoma