PMID- 28861637 OWN - NLM STAT- MEDLINE DCOM- 20180709 LR - 20180709 IS - 1573-7217 (Electronic) IS - 0167-6806 (Linking) VI - 166 IP - 3 DP - 2017 Dec TI - Impact of repeat HER2 testing after initial equivocal HER2 FISH results using 2013 ASCO/CAP guidelines. PG - 757-764 LID - 10.1007/s10549-017-4479-y [doi] AB - PURPOSE: The updated 2013 American Society of Clinical Oncology/College of American Pathologists guideline recommendations for human epidermal growth factor receptor 2 (HER2) testing have made some major changes in HER2 fluorescence in situ hybridization (FISH) interpretation criteria with additional FISH equivocal cases. Repeat HER2 testing is recommended after initial HER2 FISH equivocal results; however, little is known about its impact on final HER2 status. The aim of this study is to investigate whether reflex test clarifies HER2 status, and to characterize clinicopathological features of the newly defined HER2 equivocal group. METHODS: A total of 886 consecutive cases of primary invasive breast cancer conducted with dual-probe HER2 FISH testing between November 2013 and December 2015 were reviewed. HER2 immunohistochemistry (IHC) and FISH testing were performed on a different tissue block or a new specimen after initial HER2 FISH equivocal results. RESULTS: Compared to 2007 guideline, 85 (9.6%) cases changed their category by using 2013 guideline. The major change of the 85 cases is that 57 (6.4%) cases in HER2 FISH-negative category changed to equivocal, and the equivocal category cases increased from 36 to 67. HER2 FISH equivocal was significantly associated with HER2 IHC equivocal (2+) and chromosome 17 polysomy (P < 0.01). Repeat testing by IHC and FISH clarified HER2 status in 33 and 42% of HER2 equivocal cases, respectively. Overall 32 (48%) initial HER2 equivocal cases stayed HER2 equivocal after repeat FISH and or IHC testing. These tumors were ER/PR+, with high KI-67 index. CONCLUSION: New guidelines classify more HER2 FISH equivocal cases. Repeat HER2 testing clarifies HER2 status in about 50% of initial HER2 FISH equivocal cases. In addition, HER2 equivocal cases merit further study as there is limited information about prognosis and optimal treatment strategy for this population. FAU - Xu, Fang-Ping AU - Xu FP AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. FAU - Wang, Kun AU - Wang K AD - Department of Breast Cancer, Cancer Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China. FAU - Xu, Jie AU - Xu J AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. FAU - Chen, Jie AU - Chen J AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. FAU - Zhang, Yi-Fang AU - Zhang YF AD - Department of Breast Cancer, Cancer Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China. FAU - Wu, Hong-Mei AU - Wu HM AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. FAU - Zhang, Ming-Hui AU - Zhang MH AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. FAU - Long, Xiao-Xu AU - Long XX AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. FAU - Luo, Xin-Lan AU - Luo XL AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. FAU - Zhang, Ke-Ping AU - Zhang KP AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. FAU - Lin, Dan-Yi AU - Lin DY AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. FAU - Liu, Yan-Hui AU - Liu YH AUID- ORCID: 0000-0002-9138-1798 AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, China. pfxufo@hotmail.com. LA - eng PT - Journal Article DEP - 20170831 PL - Netherlands TA - Breast Cancer Res Treat JT - Breast cancer research and treatment JID - 8111104 RN - 0 (Biomarkers, Tumor) RN - EC 2.7.10.1 (ERBB2 protein, human) RN - EC 2.7.10.1 (Receptor, ErbB-2) SB - IM CIN - Breast Cancer Res Treat. 2018 Feb;167(3):823. PMID: 29063311 MH - Adult MH - Aged MH - Biomarkers, Tumor/*genetics MH - Breast Neoplasms/*genetics/pathology MH - Chromosome Aberrations MH - Chromosomes, Human, Pair 17/*genetics MH - Female MH - Guidelines as Topic MH - Humans MH - Immunohistochemistry MH - In Situ Hybridization, Fluorescence MH - Middle Aged MH - Receptor, ErbB-2/*genetics OTO - NOTNLM OT - Breast cancer OT - Chromosome 17 polysomy OT - Equivocal OT - Fluorescence in situ hybridization OT - HER2 OT - Immunohistochemistry EDAT- 2017/09/02 06:00 MHDA- 2018/07/10 06:00 CRDT- 2017/09/02 06:00 PHST- 2017/07/04 00:00 [received] PHST- 2017/08/22 00:00 [accepted] PHST- 2017/09/02 06:00 [pubmed] PHST- 2018/07/10 06:00 [medline] PHST- 2017/09/02 06:00 [entrez] AID - 10.1007/s10549-017-4479-y [pii] AID - 10.1007/s10549-017-4479-y [doi] PST - ppublish SO - Breast Cancer Res Treat. 2017 Dec;166(3):757-764. doi: 10.1007/s10549-017-4479-y. Epub 2017 Aug 31.