Xiangyan Zhang1, Lili Wang1, Jigang Wang1, Han Zhao1, Jie Wu1, Shuhong Liu2, Lu Zhang3, Yujun Li1, Xiaoming Xing4. 1. Department of Pathology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China. 2. Department of Pneumology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China. 3. Prenatal Diagnosis Center, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China. 4. Department of Pathology, The Affiliated Hospital of Qingdao University, 16 Jiangsu Road, Qingdao 266003, China. Electronic address: edithxing@126.com.
Abstract
AIMS: To investigate whether immunohistochemistry (IHC) could be used to screen BRAF mutation status in formalin-fixed paraffin-embedded (FFPE) colorectal carcinoma (CRC) and papillary thyroid carcinoma (PTC) samples. METHODS: Eight surgical resected samples, including 2 CRCs with mutated BRAF V600E, 2 PTCs with mutated BRAF V600E, 2 CRCs with wild-type BRAF and 2 PTCs with wild-type BRAF, were selected to explore the optimized IHC conditions for BRAF V600E (VE1) immunostaining using BenchmarkXT automated immunostainer VENTANA Medical System. BRAF V600E status was tested by optimized IHC and ARMS-PCR methods in 255 samples (123 CRCs and 132 PTCs). Sanger sequencing was performed to validate the BRAF V600E status if discordant results were found between optimized IHC and ARMS-PCR methods. RESULTS: Antigen retrieval time in 32 min and 64 min showed satisfactory intensity and homogeneity of BRAF V600E staining in CRC and PTC samples, respectively. The concordance between IHC and ARMS/Sanger sequencing was 99.2% (122/123) in CRCs and 96.2% (127/132) in PTCs. In CRCs, the sensitivity of IHC staining for BRAF V600E was 100% (3/3) and the specificity was 99.1% (119/120). In PTCs, the sensitivity was 100% (106/106) and specificity was 80.8% (21/26). The overall concordance across all cases was 97.6% (249/255). CONCLUSION: The appropriate antigen retrieval protocol is critical for accurate analysis of BRAF V600E status by Benchmark XT automated immunostainer. IHC is a suitable method to screen BRAF V600E mutation in FFPE samples of CRCs and PTCs.
AIMS: To investigate whether immunohistochemistry (IHC) could be used to screen BRAF mutation status in formalin-fixed paraffin-embedded (FFPE) colorectal carcinoma (CRC) and papillary thyroid carcinoma (PTC) samples. METHODS: Eight surgical resected samples, including 2 CRCs with mutated BRAFV600E, 2 PTCs with mutated BRAFV600E, 2 CRCs with wild-type BRAF and 2 PTCs with wild-type BRAF, were selected to explore the optimized IHC conditions for BRAFV600E (VE1) immunostaining using BenchmarkXT automated immunostainer VENTANA Medical System. BRAFV600E status was tested by optimized IHC and ARMS-PCR methods in 255 samples (123 CRCs and 132 PTCs). Sanger sequencing was performed to validate the BRAFV600E status if discordant results were found between optimized IHC and ARMS-PCR methods. RESULTS: Antigen retrieval time in 32 min and 64 min showed satisfactory intensity and homogeneity of BRAFV600E staining in CRC and PTC samples, respectively. The concordance between IHC and ARMS/Sanger sequencing was 99.2% (122/123) in CRCs and 96.2% (127/132) in PTCs. In CRCs, the sensitivity of IHC staining for BRAFV600E was 100% (3/3) and the specificity was 99.1% (119/120). In PTCs, the sensitivity was 100% (106/106) and specificity was 80.8% (21/26). The overall concordance across all cases was 97.6% (249/255). CONCLUSION: The appropriate antigen retrieval protocol is critical for accurate analysis of BRAFV600E status by Benchmark XT automated immunostainer. IHC is a suitable method to screen BRAFV600E mutation in FFPE samples of CRCs and PTCs.
Authors: Scott Kopetz; Katherine A Guthrie; Van K Morris; Heinz-Josef Lenz; Anthony M Magliocco; Dipen Maru; Yibing Yan; Richard Lanman; Ganiraju Manyam; David S Hong; Alexey Sorokin; Chloe E Atreya; Luis A Diaz; Carmen Allegra; Kanwal P Raghav; Stephen E Wang; Christopher H Lieu; Shannon L McDonough; Philip A Philip; Howard S Hochster Journal: J Clin Oncol Date: 2020-12-23 Impact factor: 50.717