PMID- 27543979 OWN - NLM STAT- MEDLINE DCOM- 20170306 LR - 20170817 IS - 1943-7722 (Electronic) IS - 0002-9173 (Linking) VI - 146 IP - 3 DP - 2016 Sep TI - Comparison of HER2 Dual-Color and Fluorescence In Situ Hybridization in Breast Cancer: A Cohort Study Emphasizing Equivocal Cases. PG - 339-45 LID - 10.1093/ajcp/aqw117 [doi] AB - OBJECTIVES: Human epidermal growth factor receptor 2 (HER2; ERBB2 gene) is of prognostic and predictive significance in breast carcinoma. Both fluorescence in situ hybridization (FISH) and dual-color in situ hybridization (DISH) methods are available. DISH and FISH are highly concordant in validation studies, but differences may be more prevalent in the equivocal range. Our goal was to compare FISH and DISH on a cohort enriched for equivocal cases, with respect to HER2 determination. METHODS: The cohort was enriched for equivocal (2+) cases. DISH and FISH were evaluated using standard protocols and the results compared with respect to HER2 status, HER2 copy number, and HER2/chromosome 17 (Chr17) ratio. RESULTS: In total, 109 cases were identified. The agreement rate of DISH with FISH was 74%. The mean +/- SD HER2/Chr17 ratio by DISH was 1.63 +/- 0.08 vs 1.59 +/- 0.26 by FISH (P = .45). The mean +/- SD HER2 copy number by DISH was 4.56 +/- 0.45 vs 4.75 +/- 1.08 by FISH (P = .004). Individual signals were more easily resolved using FISH in cases with higher copy numbers. CONCLUSIONS: In our cohort enriched for equivocal cases, the numerical values of HER2 copy number were significantly lower using DISH, resulting in discordances. Although DISH is a valid method, variations with FISH may be expected in high-equivocal cases and in quality assurance activities. CI - (c) American Society for Clinical Pathology, 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. FAU - Shao, Tiffany AU - Shao T AD - From the Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada. FAU - Wood, Martha AU - Wood M AD - Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada. FAU - Wing, Anthony AU - Wing A AD - Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada. FAU - Hnatovska, Marta AU - Hnatovska M AD - Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada. FAU - Mendes, Maria AU - Mendes M AD - Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada. FAU - Brendan Mullen, J AU - Brendan Mullen J AD - From the Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada. FAU - Chang, Martin C AU - Chang MC AD - From the Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, Toronto, Canada. mchang2@mtsinai.on.ca. LA - eng PT - Comparative Study PT - Journal Article PL - England TA - Am J Clin Pathol JT - American journal of clinical pathology JID - 0370470 RN - EC 2.7.10.1 (ERBB2 protein, human) RN - EC 2.7.10.1 (Receptor, ErbB-2) SB - IM MH - Adult MH - Aged MH - Aged, 80 and over MH - Breast Neoplasms/*diagnosis/genetics/pathology MH - Cohort Studies MH - Female MH - Gene Amplification MH - Humans MH - In Situ Hybridization/*methods MH - In Situ Hybridization, Fluorescence/methods MH - Middle Aged MH - Receptor, ErbB-2/*genetics OTO - NOTNLM OT - Breast cancer OT - DISH OT - FISH OT - HER2 OT - In situ hybridization EDAT- 2016/08/21 06:00 MHDA- 2017/03/07 06:00 CRDT- 2016/08/21 06:00 PHST- 2016/08/21 06:00 [entrez] PHST- 2016/08/21 06:00 [pubmed] PHST- 2017/03/07 06:00 [medline] AID - aqw117 [pii] AID - 10.1093/ajcp/aqw117 [doi] PST - ppublish SO - Am J Clin Pathol. 2016 Sep;146(3):339-45. doi: 10.1093/ajcp/aqw117.