[Thyroglobulin RT-PCR method for detection of lymph node metastases during the course of differentiated thyroid cancers].
In patients with a suspicion of recurrence of differentiated thyroid cancer with metastases to lymph nodes, detection of thyroglobulin (Tg) mRNA in fine needle biopsy material may support the interpretation of classic cytological examination in cases where it fails to detect lymph node involvement early enough.


OBJECTIVE
Prospective study of thyroglobulin mRNA detection in neck lymph nodes in patients with suspected differentiated thyroid cancer (DTC) metastases.


METHODS
70 nodes from 60 patients with suspected DTC recurrence were investigated. Patients with suspicion of lymph node metastases of other types of cancer were included as a control group. Thyroglobulin RT-PCR was conducted in residual material left after preparation of cytological smears from fine needle biopsy specimens. Primers spanning exons 3-5 were used with 39 cycles of PCR. RNA isolation control and cDNA amplification were carried out using GADPH starters.


RESULTS
Classical cytology confirmed nodal involvement in 22 of DTC patients, RT-PCR Tg was positive in 20 of them (91%). Among 48 patients with a suspicion of DTC recurrence and negative cytology, Tg mRNA was found twice. One positive RT-PCR result was confirmed by repeated cytology conducted 4-6 months later and followed by surgery. No positive result of RT-PCR was obtained with other head and neck malignancies. The overall specificity was estimated with 98%.


CONCLUSIONS
RT-PCR Tg shows sufficient specificity to be applied in further studies estimating its usefulness in fine needle biopsy for early detection of lymph node metastases in differentiated thyroid cancer.
Gubała
E
E
Zakładu Medycyny Nuklearnej i Endokrynologii Onkologicznej, Centrum Onkologii-Instytut im. M. Skłodowskiej-Curie w Gliwicach.
Handkiewicz-Junak
D
D
Zeman
M
M
Chmielik
E
E
Wiench
M
M
Jarzab
B
B
D001707:Biopsy, Needle / Q000379:methods; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D009333:Neck; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013954:Thyroglobulin / Q000235:genetics / Q000302:isolation & purification*; D013964:Thyroid Neoplasms / Q000097:blood* / Q000175:diagnosis*
D012333:RNA, Messenger; D013954:Thyroglobulin