title: High serum level of retinol and α-tocopherol affords protection against oral cancer in a multiethnic population.
abstract: BACKGROUND
  A comparative cross-sectional study involving oral cancer patients and healthy individuals was designed to investigate associations between retinol, α-tocopherol and β-carotene with the risk of oral cancer.
  
  
  METHODS
  This study included a total of 240 matched cases and controls where subjects were selected from the Malaysian Oral Cancer Database and Tissue Bank System (MOCDTBS). Retinol, α-tocopherol and β-carotene levels and intake were examined by high-performance liquid chromatography (HPLC) and food frequency questionnaire (FFQ) respectively.
  
  
  RESULTS
  It was found that results from the two methods applied did not correlate, so that further analysis was done using the HPLC method utilising blood serum. Serum levels of retinol and α-tocopherol among cases (0.177±0.081, 1.649±1.670μg/ml) were significantly lower than in controls (0.264±0.137, 3.225±2.054μg/ml) (p<0.005). Although serum level of β-carotene among cases (0.106±0.159 μg/ml) were lower compared to controls (0.134±0.131μg/ml), statistical significance was not observed. Logistic regression analysis showed that high serum level of retinol (OR=0.501, 95% CI=0.254-0.992, p<0.05) and α-tocopherol (OR=0.184, 95% CI=0.091-0.370, p<0.05) was significantly related to lower risk of oral cancer, whereas no relationship was observed between β-carotene and oral cancer risk.
  
  
  CONCLUSIONS
  High serum levels of retinol and α-tocopherol confer protection against oral cancer risk.
authors.affiliation: Oral Cancer Research and Coordinating Centre, Faculty of Dentistry, University Malaya, Kuala Lumpur, Malaysia E-mail : rosnahmz@um.edu.my.
authors.forename: Vimmitra
authors.initials: V
authors.lastname: Athirajan
authors.forename: Ishak Abdul
authors.initials: IA
authors.lastname: Razak
authors.forename: Nalina
authors.initials: N
authors.lastname: Thurairajah
authors.forename: Wan Maria Nabillah
authors.initials: WM
authors.lastname: Ghani
authors.forename: Helen-Ng Lee
authors.initials: HN
authors.lastname: Ching
authors.forename: Yi-Hsin
authors.initials: YH
authors.lastname: Yang
authors.forename: Karen-Ng Lee
authors.initials: KN
authors.lastname: Peng
authors.forename: Zainal Ariff
authors.initials: ZA
authors.lastname: Abdul Rahman
authors.forename: Wan Mahadzir Wan
authors.initials: WM
authors.lastname: Mustafa
authors.forename: Mannil Thomas
authors.initials: MT
authors.lastname: Abraham
authors.forename: Tay Keng
authors.initials: TK
authors.lastname: Kiong
authors.forename: Yuen Kar
authors.initials: YK
authors.lastname: Mun
authors.forename: Norma
authors.initials: N
authors.lastname: Jalil
authors.forename: Rosnah Binti
authors.initials: RB
authors.lastname: Zain
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000097:blood* / Q000208:ethnology* / Q000517:prevention & control; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000097:blood* / Q000208:ethnology* / Q000517:prevention & control; D009367:Neoplasm Staging; D011379:Prognosis; D012307:Risk Factors; D014801:Vitamin A / Q000097:blood*; D014815:Vitamins / Q000378:metabolism*; D055815:Young Adult; D024502:alpha-Tocopherol / Q000097:blood*
chemical_list: D014815:Vitamins; D014801:Vitamin A; D024502:alpha-Tocopherol