title: 9-cis-retinoic acid treatment increases serum concentrations of alpha-tocopherol in former smokers.
abstract: OBJECTIVE
  Low serum concentrations of antioxidants may be associated with an increased risk of cancer. Based on the accumulated evidence, we hypothesized that retinoids would elevate serum alpha-tocopherol. This study was designed to determine whether 9-cis-retinoic acid (9-cis-RA), the most common chemopreventive agent, could alter serum alpha-tocopherol in former smokers. Because hyperlipidemia is a known side effect of retinoids, we also evaluated the association between serum alpha-tocopherol and lipids in the same population.
  
  
  METHODS
  Subjects who had stopped smoking at least 12 months before the study were randomly assigned to receive oral 9-cis-RA or placebo daily for 3 months. Clinical information and blood samples were obtained monthly; serum alpha-tocopherol concentrations were measured by high-performance liquid chromatography and lipid levels by enzymatic assays before treatment and every month during the treatment.
  
  
  RESULTS
  Of the 149 subjects in the study, 113 completed 3 months of treatment and provided samples for evaluation of serum alpha-tocopherol. Serum alpha-tocopherol levels in the 9-cis-RA group (n = 52) were higher after treatment (r = 0.445, P < 0.01) than before. The incidences of grade > or =2 hypertriglyceridemia and hypercholesterolemia were higher in the 9-cis-RA group than in the placebo group (P = 0.0005 and P = 0.01, respectively), but there were no serious complications related to hyperlipidemia.
  
  
  CONCLUSIONS
  Treatment of former smokers with 9-cis-RA significantly increased their serum alpha-tocopherol levels, and this could be a benefit. In addition, serum alpha-tocopherol could serve as a biomarker for 9-cis-RA treatment.
authors.affiliation: Department of Thoracic/Head and Neck Medical Oncology, University of Texas M.D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030, USA.
authors.forename: Ji-Youn
authors.initials: JY
authors.lastname: Han
authors.forename: Diane D
authors.initials: DD
authors.lastname: Liu
authors.forename: J Jack
authors.initials: JJ
authors.lastname: Lee
authors.forename: Jonathan
authors.initials: J
authors.lastname: Kurie
authors.forename: Reuben
authors.initials: R
authors.lastname: Lotan
authors.forename: Waun K
authors.initials: WK
authors.lastname: Hong
authors.forename: Ho-Young
authors.initials: HY
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000077556:Alitretinoin; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D001980:Bronchi / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002784:Cholesterol / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010919:Placebos; D012907:Smoking / Q000097:blood*; D016896:Treatment Outcome; D014212:Tretinoin / Q000627:therapeutic use*; D014280:Triglycerides / Q000097:blood; D024502:alpha-Tocopherol / Q000097:blood*
chemical_list: D000970:Antineoplastic Agents; D010919:Placebos; D014280:Triglycerides; D000077556:Alitretinoin; D014212:Tretinoin; D002784:Cholesterol; D024502:alpha-Tocopherol