title: High frequency of level II-V lymph node involvement in RET/PTC positive papillary thyroid carcinoma.
abstract: OBJECTIVE
  To investigate the frequency and clinical significance of RET rearrangement in Chinese patients with papillary thyroid carcinoma (PTC) and discuss the role of RET rearrangement in therapeutic decision-making after the performance of level VI lymph node dissection and the 2002 AJCC staging system.
  
  
  METHODS
  RET/PTC-1 and RET/PTC-3 were detected in 126 PTCs using reverse transcription-polymerase chain reaction (RT-PCR) and direct sequencing.
  
  
  RESULTS
  RET rearrangement was detected in 18 cases of PTC. The patient group aged < 20 years had the highest frequency (3/6) of RET rearrangement among the age groups (< 20 years, 20-40 years and > or = 40 years; P=0.03). RET/PTC-1 positive patients were more likely to suffer from Hashimoto's thyroiditis simultaneously (P=0.02) while RET/PTC-3 positive patients had a higher frequency of extrathyroidal extension (P<0.01) and advanced T classification (P<0.01). RET rearrangement (OR=8.70, 95% CI 1.69-44.81), male (OR=3.88, 95% CI 1.41-10.69), age (OR=0.96, 95% CI 0.93-0.99), multifocality (OR=3.54, 95% CI 1.33-9.41) and advanced T classification (OR=7.32, 95% CI 2.91-18.40) were all identified as risk factors of level II-V lymph node involvement in the multivariate analysis.
  
  
  CONCLUSIONS
  The frequency of RET rearrangement in Chinese patients is low and age related. RET/PTC-1 and RET/PTC-3 are associated with different clinical pathological characteristics but not with lymph node involvement. The RET/PTC positive patients should receive more attention to lateral neck in the management of PTC.
authors.affiliation: Department of Head & Neck Surgery, Cancer Hospital, Fudan University, Shanghai, China.
authors.forename: Y L
authors.initials: YL
authors.lastname: Wang
authors.forename: R M
authors.initials: RM
authors.lastname: Zhang
authors.forename: Z W
authors.initials: ZW
authors.lastname: Luo
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.forename: X
authors.initials: X
authors.lastname: Du
authors.forename: Z Y
authors.initials: ZY
authors.lastname: Wang
authors.forename: Y X
authors.initials: YX
authors.lastname: Zhu
authors.forename: D S
authors.initials: DS
authors.lastname: Li
authors.forename: Q H
authors.initials: QH
authors.lastname: Ji
mesh_terms: D000328:Adult; D002291:Carcinoma, Papillary / Q000201:enzymology*; D002681:China; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008297:Male; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000201:enzymology*
chemical_list: D015514:Oncogene Proteins, Fusion; D011505:Protein-Tyrosine Kinases; C093573:ret-PTC fusion oncoproteins, human