High-Resolution Melting Is a Sensitive, Cost-Effective, Time-Saving Technique for BRAF V600E Detection in Thyroid FNAB Washing Liquid: A Prospective Cohort Study.
OBJECTIVE
The diagnostic accuracy of thyroid fine needle aspiration biopsy (FNAB) can be improved by the combination of cytological and molecular analysis. In this study, washing liquids of FNAB (wFNAB) were tested for the BRAF V600E mutation, using the sensitive and cost-effective technique called high-resolution melting (HRM). The aim was to demonstrate the feasibility of BRAF analysis in wFNAB and its diagnostic utility, combined with cytology.


METHODS
Prospective cohort study.


METHODS
481 patients, corresponding to 648 FNAB samples, were subjected to both cytological (on cells smeared onto a glass slide) and molecular analysis (on fluids obtained washing the FNAB needle with 1 ml of saline) of the same aspiration. BRAF V600E analysis was performed by HRM after methodological validation for application to wFNAB (technique sensitivity: 5.4%).


RESULTS
The cytological results of the FNAB were: 136 (21%) nondiagnostic (THY1); 415 (64%) benign (THY2); 80 (12.4%) indeterminate (THY3); 9 (1.4%) suspicious for malignancy (THY4); 8 (1.2%) diagnostic of malignancy (THY5). The BRAF V600E mutation was found in 5 THY2, 2 THY3, 6 THY4 and 6 THY5 samples. Papillary carcinoma diagnosis was histologically confirmed in all BRAF+ thyroidectomized patients. BRAF combined with cytology improved the diagnostic value compared to cytology alone in a subgroup of 74 operated patients.


CONCLUSIONS
HRM was demonstrated to be a feasible method for BRAF analysis in wFNAB. Thanks to its sensitivity and cost-effectiveness, it might be routinely used on a large scale in clinical practice. In perspective, standby wFNAB samples could be analyzed a posteriori in case of indeterminate cytology and/or suspicious findings on ultrasound.
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Center for Genomic Research, University of Modena and Reggio Emilia, Italy.
Marco
M
Marino
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Azienda USL of Modena, Modena, Italy.
Maria Laura
ML
Monzani
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Azienda USL of Modena, Modena, Italy.
Giulia
G
Brigante
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Azienda USL of Modena, Modena, Italy.
Katia
K
Cioni
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Azienda USL of Modena, Modena, Italy.
Bruno
B
Madeo
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Azienda USL of Modena, Modena, Italy.
Daniele
D
Santi
Department of Diagnostic and Clinical Medicine and Public Health, University of Modena and Reggio Emilia, Italy.
Antonino
A
Maiorana
Department of Diagnostic and Clinical Medicine and Public Health, University of Modena and Reggio Emilia, Italy.
Stefania
S
Bettelli
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Center for Genomic Research, University of Modena and Reggio Emilia, Italy.
Valeria
V
Moriondo
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Center for Genomic Research, University of Modena and Reggio Emilia, Italy.
Elisa
E
Pignatti
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Azienda USL of Modena, Modena, Italy.
Lara
L
Bonacini
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy.
Cesare
C
Carani
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Azienda USL of Modena, Modena, Italy.
Vincenzo
V
Rochira
Unit of Endocrinology, Department of Biomedical, Metabolic and Neural Sciences, Italy ; Center for Genomic Research, University of Modena and Reggio Emilia, Italy ; Azienda USL of Modena, Modena, Italy.
Manuela
M
Simoni
BRAF gene; High-resolution melting; Papillary thyroid cancer; Thyroid; Washing liquids of fine needle aspiration biopsy