PMID- 30712197 OWN - NLM STAT- MEDLINE DCOM- 20190820 LR - 20190820 IS - 1573-7217 (Electronic) IS - 0167-6806 (Linking) VI - 175 IP - 1 DP - 2019 May TI - Impact of the updated 2018 ASCO/CAP guidelines on HER2 FISH testing in invasive breast cancer: a retrospective study of HER2 fish results of 2233 cases. PG - 51-57 LID - 10.1007/s10549-019-05148-5 [doi] AB - OBJECTIVES: Human epidermal growth factor receptor 2 (HER2, ERBB2) is a valuable prognostic and predictive biomarker in breast cancer. Accurate assessment of HER2 status is essential in selecting the patients with invasive breast cancer who will likely response to HER2-targeted therapies. Some major modifications in the diagnostic recommendation for fluorescence in situ hybridization (FISH) have been made in the updated 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologist (CAP) guideline. According to the revised guideline, concomitant IHC assays are required to arrive at the most accurate HER2 status designation after HER2 FISH equivocal results; however, little is known about its influence on the clinical practice of pathologist. The purpose of this study was to evaluate the impact of the revised 2018 ASCO/CAP guidelines on the HER2 status designation. METHODS: We retrospectively reviewed the HER2 FISH testing results from 2233 cases of invasive breast cancer between January 2014 and December 2017. Concomitant immunohistochemistry (IHC) were performed on the same tissue blocks that were used for the FISH testing. RESULTS: Compared to the 2013 guidelines, the HER2 status in 183 (8.2%) cases were re-defined when reassessed by the 2018 guidelines. Among these 183 cases, 175 equivocal cases according to the 2013 guideline were re-defined as HER2 negative (n = 173) or HER2 positive (n = 2). Eight previously classified as HER2 positive cases were converted to negative in the 2018 scheme, all of which were with HER2 IHC scores of 1+ or 2+. The number of cases in the negative category was 1705 according to the 2018 guidelines as opposed to 1524 by the 2013 guidelines. CONCLUSIONS: The updated 2018 ASCO/CAP guidelines eliminated the FISH equivocal category, which can be attributed to reflex HER2 IHC, and partly ease the dilemma for clinical practice. Reflex IHC for FISH equivocal cases is of prime importance; furthermore, HER2 FISH results were converted from positivity to negativity based on the concomitant IHC results in a small percentage of cases. In all, implementation of the 2018 ASCO/CAP guidelines provides much clearer instructions and recommendations for the HER2 status designation, and thus reduces the risk of misdiagnosis. FAU - Liu, Zhi-Hua AU - Liu ZH AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, People's Republic of China. FAU - Wang, Kun AU - Wang K AD - Department of Breast Cancer, Cancer Center, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, People's Republic of 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, People's Republic of 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, People's Republic of 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, People's Republic of China. FAU - Long, Xiao-Yu AU - Long XY AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, People's Republic of China. FAU - Ge, Yan AU - Ge Y AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, People's Republic of 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, People's Republic of 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, People's Republic of China. FAU - Liu, Yan-Hui AU - Liu YH AD - Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, 106 Zhongshan Er Lu, Guangzhou, 510080, People's Republic of China. 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, People's Republic of China. xfpraider@163.com. LA - eng PT - Journal Article DEP - 20190202 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) MH - Breast Neoplasms/*diagnosis/*genetics/metabolism MH - Female MH - Humans MH - Immunohistochemistry MH - *In Situ Hybridization, Fluorescence MH - Neoplasm Invasiveness MH - Neoplasm Staging MH - Practice Guidelines as Topic MH - Receptor, ErbB-2/*genetics/metabolism MH - Retrospective Studies OTO - NOTNLM OT - ASCO/CAP guidelines OT - Breast cancer OT - Fluorescence in situ hybridization OT - HER2 OT - Immunohistochemistry EDAT- 2019/02/04 06:00 MHDA- 2019/08/21 06:00 CRDT- 2019/02/04 06:00 PHST- 2018/11/04 00:00 [received] PHST- 2019/01/22 00:00 [accepted] PHST- 2019/02/04 06:00 [pubmed] PHST- 2019/08/21 06:00 [medline] PHST- 2019/02/04 06:00 [entrez] AID - 10.1007/s10549-019-05148-5 [pii] AID - 10.1007/s10549-019-05148-5 [doi] PST - ppublish SO - Breast Cancer Res Treat. 2019 May;175(1):51-57. doi: 10.1007/s10549-019-05148-5. Epub 2019 Feb 2.