Research Papers:
Immunohistochemistry cannot replace DNA analysis for evaluation of BRAF V600E mutations in papillary thyroid carcinoma
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Abstract
Monika Szymonek1, Artur Kowalik2, Janusz Kopczyński3, Danuta Gąsior-Perczak1, Iwona Pałyga1, Agnieszka Walczyk1, Klaudia Gadawska-Juszczyk1, Agnieszka Płusa3, Ryszard Mężyk4, Magdalena Chrapek5, Stanisław Góźdź6,7 and Aldona Kowalska1,7
1Endocrinology Clinic, Holycross Cancer Center, Kielce, Poland
2Department of Molecular Diagnostics, Holycross Cancer Center, Kielce, Poland
3Department of Surgical Pathology, Holycross Cancer Center, Kielce, Poland
4Cancer Epidemiology, Holycross Cancer Center, Kielce, Poland
5Department of Probability Theory and Statistics Institute of Mathematics, Faculty of Mathematics and Natural Science, Jan Kochanowski University, Kielce, Poland
6Oncology Clinic, Holycross Cancer Center, Kielce, Poland
7The Faculty of Health Sciences, Jan Kochanowski University in Kielce, Poland
Correspondence to:
Monika Szymonek, email: [email protected]
Keywords: BRAF V600E, papillary thyroid cancer, immunohistochemistry, Sanger sequencing, qPCR
Received: May 17, 2017 Accepted: July 25, 2017 Published: August 24, 2017
ABSTRACT
Introduction: The BRAF V600E mutation is the most common genetic event occurring in papillary thyroid cancer (PTC). Recently, the possibility of using immunohistochemistry (IHC) to detect the BRAF V600E mutation has been reported.
Materials and methods: In 140 patients with classical PTC, the status of the BRAF V600E mutation was determined by IHC (using two alternative staining protocols, IHC-1 and IHC-2) and molecular biology methods: Sanger sequencing (SEQ) and real-time PCR (qPCR).
Results: The BRAF V600E mutation was detected in 57.1% (80/140) patients by IHC-1 and 62.9% (88/140) patients by IHC-2. The highest correlation in detecting the BRAF V600E mutation was found between IHC-2 and qPCR (94.2%), and between IHC-1 and qPCR (83.9%). Correlations between IHC-1 and SEQ and between IHC-2 and SEQ were 71.5% and 76.2%, respectively. The IHC-2 protocol had higher sensitivity, PPV, and NPV, and Cohen’s kappa than IHC- 1. The presence of BRAF V600E mutation in IHC-2 statistically correlated with age at diagnosis, histopathological stage, and extrathyroidal extension.
Conclusions: The results obtained in this study indicate a lack of concordance between BRAF V600E detection by IHC and molecular methods. The IHC method cannot replace molecular methods for the detection of the BRAF V600E mutation.
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PII: 20451