High frequency of level II-V lymph node involvement in RET/PTC positive papillary thyroid carcinoma.
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.
Wang
Y L
YL
Department of Head & Neck Surgery, Cancer Hospital, Fudan University, Shanghai, China.
Zhang
R M
RM
Luo
Z W
ZW
Wu
Y
Y
Du
X
X
Wang
Z Y
ZY
Zhu
Y X
YX
Li
D S
DS
Ji
Q H
QH
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*
D015514:Oncogene Proteins, Fusion; D011505:Protein-Tyrosine Kinases; C093573:ret-PTC fusion oncoproteins, human