title: Study of oral epithelial atypia among Sudanese tobacco users by exfoliative cytology.
abstract: BACKGROUND
  Prevalence of oral cancer is high in Sudan and the disease is attributed to N-nitrosamine rich oral snuff consumption.
  
  
  METHODS
  As part of the development of a screening procedure for oral cancer and precancer, exfoliative cytology (EFC) was applied to a retrospective cohort to assess the presence and severity of oral epithelial atypia (ET) in 300 subjects (100 toombak dippers; 100 cigarette smokers; 100 non-tobacco users) without prior knowledge of the subjects' tobacco exposure. Five patients with oral squamous cell carcinoma (OSCC) were included as internal controls.
  
  
  RESULTS
  ET was ascertained in 29 subjects and could not be ascertained in the remaining 271. Among the 29 subjects with ET, there were 11 (38%) toombak dippers, 14 (48%) cigarette smokers and 4 (14%) non-tobacco users. Among the 271 subjects without ET, there were 89 (33%) toombak dippers, 86 (32%) cigarette smokers and 96 (35%) non-tobacco users. ET was found in all the 5 control cases with OSCC. For the ET among toombak dippers and cigarette smokers, adjusted OR and the 95% CI were found to be 3 (0.91-9.7) and 4 (1.2-12.3), respectively.
  
  
  CONCLUSIONS
  In view of these findings, we propose the use of EFC for detection and assessment of oral ET.
authors.affiliation: Toombak and Smoking Research Centre, P.O. Box 102, Khartoum, Sudan.
authors.forename: Hussain Gad-Elkarim
authors.initials: HG
authors.lastname: Ahmed
authors.forename: Ali Mohammed
authors.initials: AM
authors.lastname: Idris
authors.forename: Salah Osman
authors.initials: SO
authors.lastname: Ibrahim
mesh_terms: D000328:Adult; D003581:Cytodiagnosis / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D009061:Mouth Mucosa / Q000473:pathology*; D009062:Mouth Neoplasms / Q000175:diagnosis / Q000209:etiology / Q000473:pathology*; D011230:Precancerous Conditions / Q000175:diagnosis / Q000209:etiology / Q000473:pathology*; D012907:Smoking / Q000009:adverse effects*; D013397:Sudan; D014030:Tobacco, Smokeless / Q000009:adverse effects*