title: Loss of heterozygosity in 73 human thyroid tumors.
abstract: OBJECTIVE
  The aim of the study was to establish the LOH frequency of selected polymorphic markers in different histological types of thyroid tumors: 18 colloid goiters (CG), five follicular adenomas (FA), nine follicular carcinomas (FTC), 40 papillary carcinomas (PTC), and one anaplastic carcinoma (ATC). For PTC, tumors negative for RET/PTC rearrangements were preferred.
  
  
  METHODS
  LOH studies were performed using 14 highly polymorphic markers previously described as frequently lost in thyroid tumors.
  
  
  RESULTS
  In 20 cases (27%) the loss of at least one marker was found. No difference between the frequency of the LOH in FTC and PTC tumors was revealed (33% v. 33%). No differences between histopathological subtypes of PTC in LOH were found. Papillary thyroid carcinomas showed a tendency to higher LOH frequency from patients older than 45 years of age compared to younger ones (9/23 v. 4/17) although it was not statistically significant.
  
  
  CONCLUSIONS
  We conclude that papillary thyroid cancers, particularly those diagnosed in patients older than 45 years of age, do exhibit LOH at least with the same frequency as follicular cancers. This increased number of LOH events may contribute to the clinical aggressiveness of cancer in older patients.
authors.affiliation: Department of Biology and Genetics, Medical University of Gdansk, Gdansk, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Wozniak
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Wiench
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Olejniczak
authors.forename: Jan
authors.initials: J
authors.lastname: Wloch
authors.forename: Andrzej
authors.initials: A
authors.lastname: Lachinski
authors.forename: Dariusz
authors.initials: D
authors.lastname: Lange
authors.forename: Tomasz
authors.initials: T
authors.lastname: Olczyk
authors.forename: Barbara
authors.initials: B
authors.lastname: Jarzab
authors.forename: Janusz
authors.initials: J
authors.lastname: Limon
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology; D002291:Carcinoma, Papillary / Q000235:genetics / Q000473:pathology; D002875:Chromosomes / Q000235:genetics; D005819:Genetic Markers; D006801:Humans; D019656:Loss of Heterozygosity / Q000235:genetics*; D018895:Microsatellite Repeats; D008875:Middle Aged; D011505:Protein-Tyrosine Kinases / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology
chemical_list: D005819:Genetic Markers; D012333:RNA, Messenger; D011505:Protein-Tyrosine Kinases