title: Increased allelic loss in toluidine blue-positive oral premalignant lesions.
abstract: OBJECTIVE
  Recent studies have shown that a loss of chromosome regions (loss of heterozygosity [LOH]) containing known or presumptive tumor suppressor genes is predictive of the cancer risk of oral premalignant lesions. This preliminary study investigated whether the dye toluidine blue (TB) preferentially stains oral premalignant lesions with LOH. This stain has been used by clinicians to delineate dysplasia/carcinoma in the oral cavity.
  
  
  METHODS
  The study included 32 patients with oral lesions who underwent biopsy after the assessment of TB dye retention. A total of 39 biopsy specimens were examined (14 hyperplastic, 25 dysplastic). Fourteen of the biopsy specimens were TB-negative. The specimens were analyzed for LOH at 10 microsatellite loci on 3 chromosome arms (3p, 9p, and 17p), and the LOH results of TB-positive samples were compared with those that were negative for the tissue staining.
  
  
  RESULTS
  TB-positive samples had a higher frequency of loss than TB-negative cases for loci on 3p (P = .013) and 17p (P = .049). In addition, more TB-positive cases showed a loss of multiple arms (>2 arms, P = .015), a pattern that has been associated with markedly increased cancer risk.
  
  
  CONCLUSIONS
  The study results suggest that TB staining may help identify oral premalignant lesions with increased LOH and increased cancer risk.
authors.affiliation: University of British Columbia, Vancouver, Canada. joelepstein@bccancer.bc.ca
authors.forename: Joel B
authors.initials: JB
authors.lastname: Epstein
authors.forename: Lewei
authors.initials: L
authors.lastname: Zhang
authors.forename: Catherine
authors.initials: C
authors.lastname: Poh
authors.forename: Hisae
authors.initials: H
authors.lastname: Nakamura
authors.forename: Ken
authors.initials: K
authors.lastname: Berean
authors.forename: Miriam
authors.initials: M
authors.lastname: Rosin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D016009:Chi-Square Distribution; D002872:Chromosome Deletion; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics; D002899:Chromosomes, Human, Pair 9 / Q000235:genetics; D004396:Coloring Agents; D005260:Female; D016147:Genes, Tumor Suppressor; D006801:Humans; D006965:Hyperplasia / Q000175:diagnosis / Q000235:genetics; D019656:Loss of Heterozygosity; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D011230:Precancerous Conditions / Q000175:diagnosis* / Q000235:genetics*; D012307:Risk Factors; D014048:Tolonium Chloride
chemical_list: D004396:Coloring Agents; D014048:Tolonium Chloride