[Indications for surgery of thyroid cancer based on bioptate molecular examination].
BACKGROUND
In differentiated thyroid cancer (DTC) the differentiation between reactive and metastatic lymph nodes is difficult at the early stages of metastasis. The aim of the study was to assess the results of fine needle aspiration (FNA) samples examination by the use of RT-PCR for Tg mRNA. The special attention was directed to the evaluation of specificity of TgRNA estimation.


METHODS
The group consisted of 193 DTC patients with suspicion of lymph node recurrence and at least one positive RT-PCR result. Thyroglobulin RT-PCR was conducted in residual material left after preparation of cytological smears from FNA specimens. Primer spanning exons 3-5 were used with 39 cycles of PCR. RNA isolation control and cDNA amplification were carried out using GAPDH starters. 308 lymph node biopsies were included.


RESULTS
246 positive results for Tg RNA were observed in the analyzed group, 71.1% confirmed by FNA. Among other 71 results, in which cytological examination did not correspond unequivocally to molecular findings, in 34 metastases were confirmed both by cytological and clinical examination. There were 11 patients operated due to the positive serial molecular examination only. In 10 (91%) of them DTC metastases were confirmed. So, the positive predictive value of the molecular result ranged between 75-89% and the negative one was 100%.


CONCLUSIONS
In DTC patients RT-PCR Tg mRNA is helpful in qualification of suspicious lymph nodes to surgery in DTC patients. At the negative cytological finding, the positive molecular result constitutes an indication for early surgery.
Gubała
Elzbieta
E
Department of Nuclear Medicine and Endocrine Oncology, Comprehensive Cancer Center and M. Sklodowska-Curie Memorial Institute of Oncology, Gliwice Branch, Gliwice.
Olczyk
Tomasz
T
Pawlaczek
Agnieszka
A
Handkiewicz-Junak
Daria
D
Roskosz
Józef
J
Krajewska
Jolanta
J
Zeman
Marcin
M
Chmielik
Ewa
E
Kukulska
Aleksandra
A
Czarniecka
Agnieszka
A
Włoch
Jan
J
D000231:Adenocarcinoma, Papillary / Q000473:pathology* / Q000556:secondary / Q000601:surgery*; D014408:Biomarkers, Tumor / Q000032:analysis*; D044963:Biopsy, Fine-Needle / Q000379:methods; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000601:surgery*
D014408:Biomarkers, Tumor; D012333:RNA, Messenger