Papillary Thyroid Cancer Ret Gene Rearrangement Study Of Pdgf-b Expression And Clinicopathologic Stage

Objective:The frequency of RET rearrangements(RET/PTC) in papillary thyroid carcinomas(PTC) varies significantly according to geographic area.This study mainly investigated the prevalence of RET/PTC in Qingdao and the expression of plateletderived growth factor(PDGF) in order to find the relationship between these two factors.Method:Fresh tissues from 48 PTC patients and 30 nodular goiters were examined for RET rearrangements(RET/PTC1 and RET/PTC3) by means of reverse transcriptase-polymerase chain reaction(RT-PCR) analysis,followed by direct-sequence analysis.The expression of PDGF was analyzed by immunohistochemistry.Results:RET/PTC was found only in PTC.There were 23 RET/PTC positive patients in the 48 patients,with the overall frequency of RET/PTC in PTC was 47.92%,The rate of RET/PTC1 was 35.42%and 12.5%in RET/PTC3.No multiple rearrangements was present. The prevalence rate of RET/PTC was lowest among patients age 30-39y,highest among 40-49y(P＜0.01).The clinical tumor stage of RET/PTC3 was higher than RET/PTC1(P＜0.01).The level of PDGF-B expression was followed by the tumor stage (P＜0.01).There was no relationship between RET/PTC and the expression of PDGF-B (P＞0.05).Conclusions:①RET/PTC may be useful as a specific molecular marker for PTC, which was higher differentiation,but not for benign tumor.②It happened in about half of PTC in Qindao,but lower in olders and children without radiation exposure.③The expression of PDGF-B and clinical tumor stage were direct proportion.④There was no obvious relationnship between RET/PTC and the expression of PDGF-B or clinical tumor stage,but RET/PTC3 may be predict vicious result.