PMID- 30026828 OWN - NLM STAT- PubMed-not-MEDLINE LR - 20201001 IS - 1837-9664 (Print) IS - 1837-9664 (Electronic) IS - 1837-9664 (Linking) VI - 9 IP - 13 DP - 2018 TI - A decision tree-based prediction model for fluorescence in situ hybridization HER2 gene status in HER2 immunohistochemistry-2+ breast cancers: a 2538-case multicenter study on consecutive surgical specimens. PG - 2327-2333 LID - 10.7150/jca.25586 [doi] AB - Objective: To investigate the proportion of HER2 gene amplifications and the association between the HER2-IHC-staining pattern and gene status in IHC-2+ breast cancers according to 2013 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines. Methods: We retrospectively analyzed and re-evaluated the IHC-staining pattern of 2538 IHC-2+ surgical specimens of breast cancer from November 2014 to October 2015 in 12 institutions. All cases used for building a prediction model of HER2 gene amplification according to the IHC-staining pattern and were randomly divided into a training set (n = 1914) or validation set (n = 624). Results: The overall HER2 fluorescence in situ hybridization (FISH) amplification, non-amplification and equivocation rates in HER2 IHC-2+ cases were 17.8%, 76.2% and 6.0%, respectively. In the training set, cases that had 85% of cells with complete membrane staining of any staining intensity tended to be HER2 gene amplified (77.0% and 60.5%, respectively). And cases with weak and incomplete membrane staining had the lowest amplification rate of 6.1%. The prediction model was constructed based on IHC-staining pattern in the training set and validated using a validation set. The positive and negative prediction values were 51.6% and 79.2%, respectively, in the validation set. Moreover, the HER2 copy number per cell was much higher in cases with amplification-associated staining patterns (7.84 and 8.75) than in cases with non-amplification-associated staining patterns (2.97 to 4.41, P < 0.05). Conclusions: In HER2 IHC-2+ breast cancers, the staining pattern is associated with the HER2 gene status. This finding is compatible with recommendations of 2013 ASCO/CAP guidelines. FAU - Yang, Libo AU - Yang L AD - Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China. AD - Laboratory of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China. FAU - Zhang, Zhang AU - Zhang Z AD - Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China. FAU - Li, Jiayuan AU - Li J AD - Department of Epidemiology and Biostatistics, West China School of Public Health, Sichuan University, Chengdu, Sichuan Province, China. FAU - Chen, Min AU - Chen M AD - Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China. FAU - Yang, Jieliang AU - Yang J AD - Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China. FAU - Fu, Jing AU - Fu J AD - Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People' s Hospital, Chengdu, Sichuan Province, China. FAU - Bu, Hong AU - Bu H AD - Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China. AD - Laboratory of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China. FAU - Tang, Shaoxian AU - Tang S AD - Department of Pathology, Shanghai Cancer Center, Fudan University, Shanghai, China. FAU - Liu, Yueping AU - Liu Y AD - Department of Pathology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, China. FAU - Li, Huixiang AU - Li H AD - Department of Pathology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China. FAU - Li, Xiaomei AU - Li X AD - Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang Province, China. FAU - Xu, Fangping AU - Xu F AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China. FAU - Teng, Xiaodong AU - Teng X AD - Department of Pathology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China. FAU - Yang, Yinghong AU - Yang Y AD - Department of Pathology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China. FAU - Ma, Yun AU - Ma Y AD - Department of Pathology, Affiliated Tumor Hospital, Guangxi Medical University, Nanning, Guangxi Province, China. FAU - Guo, Shuangping AU - Guo S AD - Department of Pathology, Xijing Hospital, the Air Force Military Medical University, Xi'an, Shanxi Province, China. FAU - Wang, Jinfen AU - Wang J AD - Department of Pathology, Shanxi Cancer Hospital, Taiyuan, Shanxi Province, China. FAU - Guo, Deyu AU - Guo D AD - Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, China. LA - eng PT - Journal Article DEP - 20180606 PL - Australia TA - J Cancer JT - Journal of Cancer JID - 101535920 PMC - PMC6036724 OTO - NOTNLM OT - Breast Cancer OT - Fluorescence in situ hybridization OT - HER2 OT - Immunohistochemistry COIS- Competing Interests: The authors have declared that no competing interest exists. EDAT- 2018/07/22 06:00 MHDA- 2018/07/22 06:01 PMCR- 2018/01/01 CRDT- 2018/07/21 06:00 PHST- 2018/02/17 00:00 [received] PHST- 2018/04/18 00:00 [accepted] PHST- 2018/07/21 06:00 [entrez] PHST- 2018/07/22 06:00 [pubmed] PHST- 2018/07/22 06:01 [medline] PHST- 2018/01/01 00:00 [pmc-release] AID - jcav09p2327 [pii] AID - 10.7150/jca.25586 [doi] PST - epublish SO - J Cancer. 2018 Jun 6;9(13):2327-2333. doi: 10.7150/jca.25586. eCollection 2018.