Molecular Staging Using Qualitative RT-PCR Analysis Detecting Thyreoglobulin mRNA in the Peripheral Blood of Patients with Differentiated Thyroid Cancer After Therapy

Abstract

Background: The prognostic significance of molecular staging using thyroglobulin (Tg)-based RT-PCR analysis in the peripheral blood of patients with differentiated thyroid cancer (DTC) was investigated. Herein, the specificity of molecular staging in DTC patients after thyroidectomy and ¹³¹I ablation therapy was analysed, using different specific cDNA primers in qualitative nested and classical RT-PCR protocols. Patients and Methods: Ninty-five patients receiving TSH suppressive therapy were included, of whom 51 were disease-free and 44 presented residual/recurrent or metastatic disease as evidenced by biochemical and/or ¹³¹I whole-body scan. Results: Our analysis detected RT-PCR products suggestive of the presence of Tg mRNA in all the blood samples tested, including healthy controls. A splice variant (350 bp) of Tg transcript (missing exon 3) was detected by nested RT-PCR in 34% of blood samples, however, without correlation to disease status. Conclusion: Qualitative Tg-based molecular staging in the peripheral blood of patients with DTC shows poor specificity in assessing DTC disease status.