title: High growth rate of benign thyroid nodules bearing RET/PTC rearrangements.
abstract: BACKGROUND
  Benign thyroid nodules display a broad range of behaviors from a stationary size to a progressive growth. The RET/PTC oncogene has been documented in a fraction of benign thyroid nodules, besides papillary thyroid carcinomas, and it might therefore influence their growth.
  
  
  OBJECTIVE
  The aim of the present work was to evaluate whether RET/PTC in benign thyroid nodules associates with a different nodular growth rate.
  
  
  METHODS
  In this prospective multicentric study, 125 subjects with benign nodules were included. RET rearrangements were analyzed in cytology samples; clinical and ultrasonographic nodule characteristics were assessed at the start and at the end of the study.
  
  
  RESULTS
  RET/PTC was present in 19 nodules. The difference between the mean baseline nodular volume of the RET/PTC- and RET/PTC+ nodules was not significant. After 36 months of follow-up, the RET/PTC+ group (n = 16) reached a volume higher than the RET/PTC- group (n = 90) (5.04 ± 2.67 vs. 3.04 ± 2.26 ml; P = 0.0028). We calculated the monthly change of nodule volumes as a percentage of baseline. After a mean follow-up of 36.6 months, the monthly volume increase of nodules bearing a RET rearrangement was 4.3-fold that of nodules with wild-type RET (1.83 ± 1.2 vs. 0.43 ± 1.0% of baseline volume; P < 0.0001).
  
  
  CONCLUSIONS
  Benign thyroid nodules bearing RET rearrangements grow more rapidly than those with wild-type RET. Searching for RET rearrangements in benign thyroid nodules might be useful to the clinician in choosing the more appropriate and timely therapeutic option.
authors.affiliation: Department of Endocrinologia ed Oncologia Molecolare e Clinica, Università di Napoli Federico II, Via S. Pansini, 5, 80131 Naples, Italy.
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Sapio
authors.forename: Anna
authors.initials: A
authors.lastname: Guerra
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Marotta
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Campanile
authors.forename: Raffaele
authors.initials: R
authors.lastname: Formisano
authors.forename: Maurilio
authors.initials: M
authors.lastname: Deandrea
authors.forename: Manuela
authors.initials: M
authors.lastname: Motta
authors.forename: Paolo Piero
authors.initials: PP
authors.lastname: Limone
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Fenzi
authors.forename: Guido
authors.initials: G
authors.lastname: Rossi
authors.forename: Mario
authors.initials: M
authors.lastname: Vitale
mesh_terms: D000328:Adult; D000368:Aged; D015139:Blotting, Southern; D005260:Female; D015321:Gene Rearrangement; D006801:Humans; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D011446:Prospective Studies; D051096:Proto-Oncogene Proteins c-ret / Q000235:genetics*; D016606:Thyroid Nodule / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology; D014463:Ultrasonography
chemical_list: D015514:Oncogene Proteins, Fusion; D051096:Proto-Oncogene Proteins c-ret; C099282:RET protein, human