Analysis of circulating tumor DNA does not improve the clinical management of patients with locally advanced and metastatic papillary thyroid carcinoma

Background: Circulating cell-free tumor DNA (ctDNA) in plasma is a promising noninvasive instrument for cancer monitoring. Detection of BRAFV600Eon ctDNA of patients with papillary thyroid carcinoma (PTC) may represent an indicator of tumor aggressiveness and progression. Methods: Eighty-three plasma samples were collected from 70 patients with thyroid nodules undergoing surgery and from 13 patients with PTC causing distant metastases. A total of 59 PTCs from both groups were evaluated for BRAF mutation on tumor tissue and on ctDNA from plasma samples by real-time polymerase chain reaction (PCR) and digital PCR. Results: Of 59 PTCs, 22 were BRAFV600Emutated (37.3%). The corresponding ctDNA was negative by using both techniques. Conclusion: Although highly sensitive techniques were used, in our study, circulating BRAFV600Ealleles were never detected in the plasma of patients with PTC; therefore, our results raise the question about the clinical usefulness of BRAFV600Eanalysis on ctDNA of patients with PTC.