title: Loss of heterozygosity of tumor suppressor genes (p16, Rb, E-cadherin, p53) in hypopharynx squamous cell carcinoma.
abstract: OBJECTIVE
  Microsatellite alterations, especially those that cause loss of heterozygosity (LOH), have recently been postulated as a novel mechanism of carcinogenesis and a useful prognostic factor in many kinds of malignant tumors. However, few studies have focused on a specific site, hypopharynx. The aim of this study was to evaluate the relationship between LOH and hypopharyngeal squamous cell carcinoma (HPSCC).
  
  
  METHODS
  Laboratory-based study.
  
  
  METHODS
  Integrated health care system.
  
  
  METHODS
  Matched normal and cancerous tissues from 30 patients with HPSCC were examined for LOH in 4 tumor suppressor genes (TSGs) (p16, Rb, E-cadherin, and p53) at loci 9p21, 13q21, 6q22, and 17p13, respectively, using microsatellite markers amplified by polymerase chain reaction. The results for each loci were compared with clinicopathological features.
  
  
  RESULTS
  Among the 30 cases, 26 (86.7%) exhibited LOH, with the most common alteration being LOH at p53 (52.6%). Significantly higher rates of LOH detection were seen in Rb, p53, and the LOH-high group (cases where 2 or more loci with LOH were found) in cases of lymph node metastasis. Compared with stage I and II carcinoma, tumors of stages III and IV had significantly higher frequencies of LOH in Rb, p53, and the LOH-high group. However, the presence of LOH was not significantly correlated with survival.
  
  
  CONCLUSIONS
  These results suggest that LOH in TSGs such as Rb and p53 may contribute to the development and progression of HPSCC. The presence of LOH in the primary tumor may also be predictive of lymph node metastasis.
authors.affiliation: Department of Otorhinolaryngology--Head & Neck Surgery, Sungkyunkwan University School of Medicine, Kangbuk Samsung Hospital, Seoul, Korea.
authors.forename: Sang-Hyuk
authors.initials: SH
authors.lastname: Sang-Hyuk Lee
authors.forename: Nam-Hoon
authors.initials: NH
authors.lastname: Lee
authors.forename: Sung-Min
authors.initials: SM
authors.lastname: Jin
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Rho
authors.forename: Sung-Jin
authors.initials: SJ
authors.lastname: Jo
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015820:Cadherins / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D005260:Female; D016161:Genes, Retinoblastoma / Q000235:genetics*; D016153:Genes, Suppressor; D019942:Genes, p16; D016158:Genes, p53 / Q000235:genetics*; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D007013:Hypopharynx / Q000473:pathology; D053208:Kaplan-Meier Estimate; D019656:Loss of Heterozygosity / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016133:Polymerase Chain Reaction; D011379:Prognosis
chemical_list: D015820:Cadherins