PMID- 31388934 OWN - NLM STAT- MEDLINE DCOM- 20200226 LR - 20221207 IS - 1573-7217 (Electronic) IS - 0167-6806 (Print) IS - 0167-6806 (Linking) VI - 178 IP - 2 DP - 2019 Nov TI - HER2 double-equivocal breast cancer in Chinese patients: a high concordance of HER2 status between different blocks from the same tumor. PG - 275-281 LID - 10.1007/s10549-019-05387-6 [doi] AB - PURPOSE: Human epidermal growth factor receptor 2 (HER2) status is both an independent prognostic factor and a predictive factor for the efficacy of targeted therapy for breast cancer, so it is critical to accurately detect HER2 protein expression and/or gene amplification. According to the recommendations of the 2013 American Society of Clinical Oncology and College of American Pathologists (ASCO/CAP) guidelines for HER2 breast cancer testing, an additional test should be pursued on a different block from the same tumor as one of the options for patients with immunohistochemistry (IHC) 2+ and a HER2/CEP17 ratio of < 2.0 with an average HER2 signals per tumor cell of >/= 4.0 and < 6.0 by reflex test using dual-probe fluorescence in situ hybridization (FISH) (double-equivocal HER2). Our aim in this study is to explore the consistency of HER2 status between the two blocks. METHODS: We retrospectively analyzed 5685 primary invasive breast cancers between April 2015 and January 2019 from Peking Union Medical College Hospital. For cases with double-equivocal HER2 revealed in initial blocks, HER2 gene status was evaluated by FISH in a different block from the same tumor. The FISH score was interpreted according to the 2013 ASCO/CAP guidelines for HER2 testing. RESULTS: In our cohort of 5685 specimens, the overall HER2 IHC3+, 2+, 1+ and 0 cases were 20.5%, 31.8%, 28.3%, and 19.5%, respectively. Then, 13.7%, 66.3%, and 20.0% of HER2 amplification, non-amplification, and equivocation rates were found, respectively, in IHC2+ patients (n = 1777) by reflex FISH assay. For specimens with double-equivocal HER2 (n = 333), HER2 status was assessed in another block from the same tumor by FISH and then the frequency of HER2 positive, negative, and equivocation was estimated at 5.7%, 22.5%, and 71.8%, respectively. Because double-equivocal HER2 cases are classified in the HER2 negative category by the 2018 ASCO/CAP HER2 testing guidelines, only 1.3% (19/1511) of HER2 positive patients were determined through additional HER2 testing in another block from the HER2 negative population. CONCLUSIONS: HER2 status in different blocks from the same tumor in primary invasive breast cancer was highly concordant. Our data supported the recommendation of the 2018 ASCO/CAP HER2 testing guidelines in breast cancer to remove the suggestion for additional HER2 testing using another block contained in the previous version. FAU - Liu, Yuanyuan AU - Liu Y AD - Molecular Pathology Research Center, Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. FAU - Wu, Shafei AU - Wu S AD - Molecular Pathology Research Center, Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. FAU - Shi, Xiaohua AU - Shi X AD - Molecular Pathology Research Center, Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. FAU - Luo, Yufeng AU - Luo Y AD - Molecular Pathology Research Center, Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. FAU - Pang, Junyi AU - Pang J AD - Molecular Pathology Research Center, Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. FAU - Wang, Changjun AU - Wang C AD - Department of Breast Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. FAU - Mao, Feng AU - Mao F AD - Department of Breast Surgery, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. FAU - Liang, Zhiyong AU - Liang Z AD - Molecular Pathology Research Center, Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. FAU - Zeng, Xuan AU - Zeng X AUID- ORCID: 0000-0002-8711-753X AD - Molecular Pathology Research Center, Department of Pathology, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China. zengxuan88@yahoo.com. LA - eng GR - 2017YFC1309004/National Key Research and Development Program of China/ GR - 2016-I2M-1-002/Chinese Academy of Medical Sciences (CAMS) Initiative for Innovative Medicine/ GR - 2017-I2M-1-005/Chinese Academy of Medical Sciences (CAMS) Initiative for Innovative Medicine/ GR - 2015KJRK1L01/National Human and Population Scientific Data Sharing Platform/ GR - 2016ZX310176-2/Pathology Research Center of the Chinese Academy of Medical Sciences/ PT - Journal Article DEP - 20190806 PL - Netherlands TA - Breast Cancer Res Treat JT - Breast cancer research and treatment JID - 8111104 RN - EC 2.7.10.1 (ERBB2 protein, human) RN - EC 2.7.10.1 (Receptor, ErbB-2) SB - IM MH - Asian People MH - Breast Neoplasms/*epidemiology/genetics/*metabolism/pathology MH - China/epidemiology MH - Female MH - Gene Amplification MH - Gene Expression MH - Humans MH - Immunohistochemistry MH - In Situ Hybridization, Fluorescence MH - Neoplasms MH - Receptor, ErbB-2/genetics/*metabolism PMC - PMC6797640 OTO - NOTNLM OT - Breast cancer OT - Equivocal OT - FISH OT - HER2 OT - IHC COIS- All authors declare that they have no conflicts of interest. EDAT- 2019/08/08 06:00 MHDA- 2020/02/27 06:00 PMCR- 2019/08/06 CRDT- 2019/08/08 06:00 PHST- 2019/07/26 00:00 [received] PHST- 2019/07/30 00:00 [accepted] PHST- 2019/08/08 06:00 [pubmed] PHST- 2020/02/27 06:00 [medline] PHST- 2019/08/08 06:00 [entrez] PHST- 2019/08/06 00:00 [pmc-release] AID - 10.1007/s10549-019-05387-6 [pii] AID - 5387 [pii] AID - 10.1007/s10549-019-05387-6 [doi] PST - ppublish SO - Breast Cancer Res Treat. 2019 Nov;178(2):275-281. doi: 10.1007/s10549-019-05387-6. Epub 2019 Aug 6.