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Assessment of HER2 using the 2018 ASCO/CAP guideline update for invasive breast cancer: a critical look at cases classified as HER2 2+ by immunohistochemistry. Virchows Arch 2021; 479:23-31. [PMID: 33527151 DOI: 10.1007/s00428-021-03034-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 01/08/2021] [Accepted: 01/13/2021] [Indexed: 12/14/2022]
Abstract
In 2018, the American Society of Clinical Oncology/College of American Pathologists revised the criteria for HER2 immunohistochemistry (IHC) equivocal (2+) classification in their updated guideline. We reviewed invasive breast cancer specimens originally classified as equivocal (2+) under the 2018 guideline that underwent HER2 fluorescence in situ hybridization (FISH) testing from August 2018 to August 2019 at our Canadian reference hospital to investigate cases with ambiguous staining patterns between the 1+ and 2+ definitions. Demographics, pathologic features, and pre-analytic conditions were recorded. The H&E and corresponding HER2 IHC slides were reviewed to confirm tumor type and grade, and classify as HER2 indeterminate, 0, 1+, 2+, or "Intermediate" (staining features between the 1+ and 2+ classifications). FISH testing was performed on 289 cases and 273 met inclusion criteria. The FISH-amplified rate was 12.1%. Upon IHC review, 44.7% (122/273) of cases were reclassified as Intermediate. These cases had incomplete staining with moderate intensity (43/122, 35.3%) and/or <10% complete weak or moderate staining (102/122, 83.6%). Intermediate cases had a significantly lower frequency of amplified FISH results than 2+ cases (p < 0.0001), with only four (3.3%) FISH positive and two (1.6%) FISH heterogeneous. Our study highlights the ambiguity in the current guideline for classifying some HER2 IHC patterns. As the rate of gene amplification in these cases was low (4.9%), we recommend adhering to the 2018 HER2 2+ criteria for reflex FISH testing. However, cases with <10% moderate complete staining and certain heterogeneous patterns warrant special consideration. Further descriptive clarification of 1+ criteria is needed.
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A Scoring Method for Immunohistochemical Staining on Ki67. Appl Immunohistochem Mol Morphol 2020; 29:e20-e28. [PMID: 32287078 DOI: 10.1097/pai.0000000000000853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 02/29/2020] [Indexed: 11/26/2022]
Abstract
An accurate interpretation of immunohistochemistry (IHC) staining results is crucial for precise disease diagnosis. In this study, we present a novel scoring method for interpreting and reporting of IHC staining assay results for the nuclear-type molecule. On the basis of the histologic characteristics, the samples were subdivided into 3 basic structural units and tissue subtypes including covered, mosaic, and mesenchymal subtypes. A cut-off of moderate-positive (2+) cells and 10% as the differential expression were applied to stratify the results into 11 grade scoring system (0 to X level). The observer can directly identify and count the number and percentage of positive cells from IHC staining data. Furthermore, Ki67 staining results in 88 carcinoma specimens were re-evaluated to determine the ease, reliability, reproducibility, and variance among different observers. The results indicated the consistency ratio of 68.0% for the mosaic subtype and 80% for the mesenchymal subtype, and 68.2% for the covered subtype by 5 experienced pathologists independently. Using 10% as the cut-off threshold, the consistency ratio of 92.5%, 96.8%, and 92.9% was noted for mosaic, mesenchymal, and covered subtypes, respectively. Besides, the correlation of counts revealed excellent agreement among the 5 independent pathologists. Overall, the proposed IHC scoring method is a novel, simple, reliable, and reproducible grading system for accurate interpretation of IHC staining data. Furthermore, the presented practical grading approach has the potential to improve the clinical evaluation of the IHC staining data for personalized therapy.
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Yang L, Zhang Z, Li J, Chen M, Yang J, Fu J, Bu H, Tang S, Liu Y, Li H, Li X, Xu F, Teng X, Yang Y, Ma Y, Guo S, Wang J, Guo D. 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. J Cancer 2018; 9:2327-2333. [PMID: 30026828 PMCID: PMC6036724 DOI: 10.7150/jca.25586] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2018] [Accepted: 04/18/2018] [Indexed: 02/05/2023] Open
Abstract
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 ≤ 10% of cells with intense, complete and circumferential membrane staining or 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.
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Affiliation(s)
- Libo Yang
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.,Laboratory of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Zhang Zhang
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Jiayuan Li
- Department of Epidemiology and Biostatistics, West China School of Public Health, Sichuan University, Chengdu, Sichuan Province, China
| | - Min Chen
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Jieliang Yang
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Jing Fu
- Department of Pathology, Sichuan Academy of Medical Sciences & Sichuan Provincial People' s Hospital, Chengdu, Sichuan Province, China
| | - Hong Bu
- Department of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China.,Laboratory of Pathology, West China Hospital, Sichuan University, Chengdu, Sichuan Province, China
| | - Shaoxian Tang
- Department of Pathology, Shanghai Cancer Center, Fudan University, Shanghai, China
| | - Yueping Liu
- Department of Pathology, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei Province, China
| | - Huixiang Li
- Department of Pathology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
| | - Xiaomei Li
- Department of Pathology, Harbin Medical University Cancer Hospital, Harbin, Heilongjiang Province, China
| | - Fangping Xu
- Department of Pathology and Laboratory Medicine, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong Province, China
| | - Xiaodong Teng
- Department of Pathology, First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yinghong Yang
- Department of Pathology, Fujian Medical University Union Hospital, Fuzhou, Fujian Province, China
| | - Yun Ma
- Department of Pathology, Affiliated Tumor Hospital, Guangxi Medical University, Nanning, Guangxi Province, China
| | - Shuangping Guo
- Department of Pathology, Xijing Hospital, the Air Force Military Medical University, Xi'an, Shanxi Province, China
| | - Jinfen Wang
- Department of Pathology, Shanxi Cancer Hospital, Taiyuan, Shanxi Province, China
| | - Deyu Guo
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University, Chongqing, China
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Jia Y, Chen L, Jia Q, Dou X, Xu N, Liao DJ. The well-accepted notion that gene amplification contributes to increased expression still remains, after all these years, a reasonable but unproven assumption. J Carcinog 2016; 15:3. [PMID: 27298590 PMCID: PMC4895059 DOI: 10.4103/1477-3163.182809] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 04/25/2016] [Indexed: 02/06/2023] Open
Abstract
“Gene amplification causes overexpression” is a longstanding and well-accepted concept in cancer genetics. However, raking the whole literature, we find only statistical analyses showing a positive correlation between gene copy number and expression level, but do not find convincing experimental corroboration for this notion, for most of the amplified oncogenes in cancers. Since an association does not need to be an actual causal relation, in our opinion, this widespread notion still remains a reasonable but unproven assumption awaiting experimental verification.
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Affiliation(s)
- Yuping Jia
- Animal Facilities, Shandong Academy of Pharmaceutical Sciences, Ji'nan, Shandong 250101, USA
| | - Lichan Chen
- Hormel Institute, University of Minnesota, Austin, MN 55912, USA
| | - Qingwen Jia
- Animal Facilities, Shandong Academy of Pharmaceutical Sciences, Ji'nan, Shandong 250101, USA
| | - Xixi Dou
- Animal Facilities, Shandong Academy of Pharmaceutical Sciences, Ji'nan, Shandong 250101, USA
| | - Ningzhi Xu
- Laboratory of Cell and Molecular Biology, Cancer Institute, Chinese Academy of Medical Science, Beijing 100021, China
| | - Dezhong Joshua Liao
- Department of Pathology, Guizhou Medical University Hospital, Guizhou, Guiyang 550004, P.R. China
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