title: Loss of heterozygosity studies in squamous cell carcinomas of the head and neck.
abstract: BACKGROUND
  Loss of heterozygosity (LOH) studies have been pivotal in identifying tumor suppressor genes involved in the pathogenesis of a number of cancers. In squamous cell carcinomas of the head and neck region (SCCHN), LOH studies using the Southern blot technique are scarce.
  
  
  METHODS
  SCCHNs were obtained immediately after surgical resection from 78 patients. Histologic confirmation was made by frozen section and tumors with less than 50% malignant cells were excluded. DNA was digested with restriction enzymes, and after Southern blotting the membranes were hybridized with radio-labeled probes. Chromosome arms analyzed included 1p, 3p, 4p, Sq, 8p, lOp, 11p, 11q, 13q, 17p, 17q, 18q, 21q, and 22q.
  
  
  RESULTS
  The average rate LOH was 25% per chromosome arm. Significantly higher rates of LOH were observed for chromosome arms 5q (56%) and 17p (45%). Other investigators have reported high rates of LOH for the H- ras-1 locus, and chromosome arms 11p, 11q, and 13q. However, these results were not confirmed in this study. For patients with stage 1 or 2 tumors, the overall LOH rate was 13%, and for patients with stage 3 or 4 disease the rate was 23%. This difference was statistically significant (p < 0.025).
  
  
  CONCLUSIONS
  tumors progress to higher stages, they appear to accumulate an increasing number of genetic abnormalities. Chromosome arms 5q and 17p contain tumor suppressor genes which are likely to be involved in the pathogenesis of SCCHN:
authors.affiliation: Medical Oncology Department, Royal Perth Hospital, Western Australia.
authors.forename: D T
authors.initials: DT
authors.lastname: Ransom
authors.forename: J H
authors.initials: JH
authors.lastname: Leonard
authors.forename: J H
authors.initials: JH
authors.lastname: Kearsley
authors.forename: G R
authors.initials: GR
authors.lastname: Turbett
authors.forename: K
authors.initials: K
authors.lastname: Heel
authors.forename: V
authors.initials: V
authors.lastname: Sosars
authors.forename: N K
authors.initials: NK
authors.lastname: Hayward
authors.forename: J F
authors.initials: JF
authors.lastname: Bishop
mesh_terms: D000328:Adult; D000368:Aged; D015139:Blotting, Southern; D002294:Carcinoma, Squamous Cell / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D046508:Culture Techniques; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D006258:Head and Neck Neoplasms / Q000209:etiology / Q000235:genetics* / Q000473:pathology; D006579:Heterozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D012680:Sensitivity and Specificity
chemical_list: D004273:DNA, Neoplasm