Jong-Kyu Kim1, Chan Yong Seong2, In Eui Bae3, Jin Wook Yi2, Hyeong Won Yu3, Su-Jin Kim2, Jae-Kyung Won4, Young Jun Chai5, June Young Choi3, Kyu Eun Lee6. 1. Department of General Surgery, Ewha Womans University College of Medicine and Graduate School of Medicine, 1071, Anyangcheon-ro, Yangcheon-gu, Seoul, 03760, Korea. 2. Department of Surgery, Seoul National University Hospital and College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Korea. 3. Department of Surgery, Seoul National University College of Medicine, Seoul National University Bundang Hospital, 82 Gumo-ro 173beon-gil, Bundang-gu, Seongnam, 13620, Korea. 4. Department of Pathology, Seoul National University Hospital and College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Korea. jkyung.won@gmail.com. 5. Department of Surgery, Seoul National University Boramae Medical Center, 20 Boramaep-ro 5-gil, Dongjak-gu, Seoul, 07061, Korea. 6. Department of Surgery, Seoul National University Hospital and College of Medicine, 101 Daehak-ro, Jongno-gu, Seoul, 03080, Korea. kyueunlee@snu.ac.kr.
Abstract
BACKGROUND: BRAFV600E mutation is the most common somatic variant in papillary thyroid carcinoma (PTC) and is associated with aggressive prognostic factors. The conventional detection method for BRAF mutations is polymerase chain reaction followed by Sanger sequencing. Recently, an immunohistochemistry (IHC) method using a BRAFV600E-specific antibody (VE1) has been developed and widely adopted in the clinics; however, there is a lack of evidence regarding the comparability of the IHC and Sanger sequencing methods. METHODS: Our institution began using the BRAFV600E IHC test in January 2013. We retrospectively analyzed 697 samples that were tested using both the IHC and sequencing methods, and evaluated their concordance. RESULTS: BRAF mutation was detected in 90.0% (627/697) of samples using IHC and 83.4% (581/697) of samples using direct sequencing. The diagnostic parameters of IHC compared with Sanger sequencing were as follows: 100% sensitivity (581/581), 60.3% specificity (70/116), 92.7% positive predictive value (581/627), and 100% negative predictive value (70/70). No false negative results were recorded using IHC. The overall concordance rate between the two methods was 93.4% (651/697). Discordant results were found in 46 samples (6.6%), 29 of which were from cases with small tumors (< 6 mm), 8 were from cases with low tumor cellularity, and 9 were specimens yielding low-quality DNA. CONCLUSIONS: IHC using the VE1 antibody is a reliable and highly sensitive method for detecting the BRAFV600E mutation in classic PTC.
BACKGROUND:BRAFV600E mutation is the most common somatic variant in papillary thyroid carcinoma (PTC) and is associated with aggressive prognostic factors. The conventional detection method for BRAF mutations is polymerase chain reaction followed by Sanger sequencing. Recently, an immunohistochemistry (IHC) method using a BRAFV600E-specific antibody (VE1) has been developed and widely adopted in the clinics; however, there is a lack of evidence regarding the comparability of the IHC and Sanger sequencing methods. METHODS: Our institution began using the BRAFV600E IHC test in January 2013. We retrospectively analyzed 697 samples that were tested using both the IHC and sequencing methods, and evaluated their concordance. RESULTS:BRAF mutation was detected in 90.0% (627/697) of samples using IHC and 83.4% (581/697) of samples using direct sequencing. The diagnostic parameters of IHC compared with Sanger sequencing were as follows: 100% sensitivity (581/581), 60.3% specificity (70/116), 92.7% positive predictive value (581/627), and 100% negative predictive value (70/70). No false negative results were recorded using IHC. The overall concordance rate between the two methods was 93.4% (651/697). Discordant results were found in 46 samples (6.6%), 29 of which were from cases with small tumors (< 6 mm), 8 were from cases with low tumor cellularity, and 9 were specimens yielding low-quality DNA. CONCLUSIONS: IHC using the VE1 antibody is a reliable and highly sensitive method for detecting the BRAFV600E mutation in classic PTC.
Authors: Fresia Pareja; Michael S Toss; Felipe C Geyer; Edaise M da Silva; Mahsa Vahdatinia; Ana Paula M Sebastiao; Pier Selenica; Austin Szatrowski; Marcia Edelweiss; Hannah Y Wen; Raluca Mihai; Zsuzsanna Varga; Maria P Foschini; Brian P Rubin; Ian O Ellis; Sarat Chandarlapaty; Achim A Jungbluth; Edi Brogi; Britta Weigelt; Jorge S Reis-Filho; Emad A Rakha Journal: Histopathology Date: 2020-05 Impact factor: 5.087