The Assessment of HER2 Gene Status by Fluorescence In Situ Hybridization in Invasive Breast Carcinomas With Equivocal HER2 Immunostaining: Experience From a Single Institution

2018 ◽  
Vol 26 (7) ◽  
pp. 593-599 ◽  
Author(s):  
Boubacar Efared ◽  
Ibrahim S. Sidibé ◽  
Sana Gamrani ◽  
Ihsane El Otmani ◽  
Fatimazahra Erregad ◽  
...  

Background. A subset of breast carcinomas harbors overexpression of the human epidermal growth factor receptor 2 (HER2). Fluorescence in situ hybridization (FISH) should be performed in breast carcinomas with equivocal HER2 immunostaining (immunohistochemistry [IHC] HER2 2+). The aim of our study is to investigate clinicopathologic factors associated with HER2 status in breast invasive carcinomas with IHC HER2 2+ through FISH analysis. Methods. This is a retrospective study including the FISH analysis of 111 patients with invasive breast carcinomas with equivocal HER2 immunostaining. Results. The mean age was 49.51 ± 10.48 years, and invasive breast carcinoma of no special type was the most histological type in our study (96.4%). Most patients had tumors positive for hormones receptors (88.2% positive for estrogen receptor and 81.4% for progesterone receptor). On FISH, the HER2 amplification rate was 22.5%. There was no significant association of HER2 status with any clinicopathologic factors ( P > .05). Conclusions. Our study shows that there are no reliable clinicopathologic factors to predict the HER2 status in breast tumors with equivocal HER2 immunostaining, supporting the necessary usage of FISH in such circumstances.

2006 ◽  
Vol 28 (4) ◽  
pp. 151-159
Author(s):  
Elna Moerland ◽  
Rens L. H. P. M. van Hezik ◽  
Toine C. J. M. van der Aa ◽  
Mike W. P. M. van Beek ◽  
Adriaan J. C. van den Brule

In this study the detection of HER2 gene amplification was evaluated using Fluorescence In Situ Hybridization (FISH; PathVysion) in comparison with Multiplex Ligation-dependent Probe Amplification (MLPA), a PCR based technique. These two methods were evaluated on a series of 46 formalin fixed paraffin embedded breast carcinomas, previously tested for protein overexpression by HercepTest (grouped into Hercep 1+, 2+ and 3+). HER2 gene amplification (ratio ≥ 2.0) by FISH was found in 9/10, 10/30 and 0/6 in IHC 3+, 2+ and 1+/0 cases, respectively. Digitalized automated spot counting performed with recently developed CW4000 CytoFISH software was 100% concordant with manual FISH scoring. Using MLPA 18/46 samples showed a clear HER2 amplification. Comparing MLPA and IHC showed the same results as for FISH and IHC. All but one FISH positive cases (18/19) were confirmed by MLPA for the presence of the gene amplification. The overall concordance of detection of Her2 gene amplification by FISH and MLPA was 98% (45/46). Furthermore, both the level of amplification and equivocal results correlated well between both methods. In conclusion, MLPA is a reliable and reproducible technique and can be used as an either alternative or additional test to determine HER2 status in breast carcinomas.


2006 ◽  
Vol 130 (10) ◽  
pp. 1440-1445 ◽  
Author(s):  
Patrick L. Fitzgibbons ◽  
Douglas A. Murphy ◽  
David M. Dorfman ◽  
Patrick C. Roche ◽  
Raymond R. Tubbs

Abstract Context.—Correct assessment of human epidermal growth factor receptor 2 (HER2) status is essential in managing patients with invasive breast carcinoma, but few data are available on the accuracy of laboratories performing HER2 testing by immunohistochemistry (IHC). Objective.—To review the results of the 2004 and 2005 College of American Pathologists HER2 Immunohistochemistry Tissue Microarray Survey. Design.—The HER2 survey is designed for laboratories performing immunohistochemical staining and interpretation for HER2. The survey uses tissue microarrays, each consisting of ten 3-mm tissue cores obtained from different invasive breast carcinomas. All cases are also analyzed by fluorescence in situ hybridization. Participants receive 8 tissue microarrays (80 cases) with instructions to perform immunostaining for HER2 using the laboratory's standard procedures. The laboratory interprets the stained slides and returns results to the College of American Pathologists for analysis. In 2004 and 2005, a core was considered “graded” when at least 90% of laboratories agreed on the result—negative (0, 1+) versus positive (2+, 3+). This interlaboratory comparison survey included 102 laboratories in 2004 and 141 laboratories in 2005. Results.—Of the 160 cases in both surveys, 111 (69%) achieved 90% consensus (graded). All 43 graded cores scored as IHC-positive were fluorescence in situ hybridization-positive, whereas all but 3 of the 68 IHC-negative graded cores were fluorescence in situ hybridization-negative. Ninety-seven (95%) of 102 laboratories in 2004 and 129 (91%) of 141 laboratories in 2005 correctly scored at least 90% of the graded cores. Conclusion.—Performance among laboratories performing HER2 IHC in this tissue microarray–based survey was excellent. Cores found to be IHC-positive or IHC-negative by participant consensus can be used as validated benchmarks for interlaboratory comparison, allowing laboratories to assess their performance and determine if improvements are needed.


2013 ◽  
Vol 138 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Kurt A. Schalper ◽  
Sudha Kumar ◽  
Pei Hui ◽  
David L. Rimm ◽  
Peter Gershkovich

Context.—In 2007 the American Society of Clinical Oncology/College of American Pathologists made new recommendations for HER2 testing and redefined HER2 positivity. Objective.—To analyze results from simultaneous HER2 testing with immunohistochemistry and fluorescence in situ hybridization (FISH) in 2590 invasive breast carcinomas between 2002 and 2010, using 2 scoring systems. Design.—Cases from between 2002 and 2006 were scored by using original US Food and Drug Administration criteria (N = 1138) and those from between 2007 and 2010 were evaluated according to American Society of Clinical Oncology/College of American Pathologists criteria (N = 1452). Concordance between testing methods and clinicopathologic associations were determined. Results.—Overall concordance between immunohistochemistry/FISH in the 9-year period was 96.2% (κ = 0.82), and positive concordance was lower. After 2007, the proportion of HER2/neu-positive and HER2/neu-negative cases was not significantly changed when using immunohistochemistry (10.5% versus 8.9%, P = .22 and 69.4% versus 63%, P = .13, respectively), but the number of equivocal cases was higher (19.9% versus 28%, P < .001). While the proportion of negative cases by FISH remained unchanged after 2007 (86.5% versus 88.2%, P = .76), the number of positive cases was lower (13.4% versus 9.2%, P < .001). In addition, 38 cases (2.6%) were FISH equivocal, 16 of which were also equivocal by immunohistochemistry. Overall, immunohistochemistry/FISH concordance was 95.9% between 2002 and 2006 (κ = 0.82) and 96.4% after 2007 (κ = 0.82). However, an approximately 13% lower positive assay concordance was noted in the last period. Conclusions.—Application of American Society of Clinical Oncology/College of American Pathologists recommendations is associated with comparable overall immunohistochemistry/FISH concordance, reduced positive concordance, and increased equivocal results.


2020 ◽  
Vol 8 (3) ◽  
pp. 139-146
Author(s):  
Maryam Moradi Chaleshtori ◽  
◽  
Zohreh Hojati ◽  
Ali Jazaeri ◽  
Hossein Teimori ◽  
...  

Background: HER2 status testing in breast cancer is crucial for the detection of eligible patients for trastuzumab therapy. In this study, the relative copy number of HER2 gene, in patients with breast cancer, was determined by fluorescence in situ hybridization (FISH) and the results were compared with those of immunohistochemistry (IHC) to obtain the concordance rate between these two methods. Material and Methods: HER2 status of 31 invasive breast cancer samples was compared using IHC and FISH techniques. The ratio of HER2/CEP17 was used to determine the amplification of the HER2 gene. If the ratio of HER2/CEP17 is greater than 2.2, HER2 gene amplification has occurred in the cancer cells. Then, a comparative analysis is performed to estimate the concordance rate between FISH and IHC results. Results: The gene amplification of HER2 was observed in 26% of cases by FISH. The IHC and FISH results showed 100%, 36.36%, and 85.71% concordance rates for cases with IHC scores of 3+, 2+, and 0/+1, respectively. The overall concordance between the two methods was 80%. Based on statistical analysis, HER2 status showed a considerable correlation with tumor grade (P= 0.02). No correlation was observed between HER2 gene status and the size and type of tumor, characteristics of lymph node, and patients’ age. Conclusion: The data suggested that IHC results are reliable for HER2 status testing in cases with IHC scores 0/+1 and 3+. However, in patients with an IHC score of +2, it is necessary to perform a complimentary test to evaluate HER2 status to avoid haphazard treatment with trastuzumab in negative cases and identifying positive cases for suitable treatment.


Author(s):  
Christina H. Wei ◽  
Lino Garcia ◽  
Joyce Murata-Collins ◽  
Daniel Schmolze ◽  
Sophia Apple

Context.— The global impact of the new 2018 American Society of Clinical Oncology/College of American Pathologists human epidermal growth factor receptor 2 (HER2) practice guideline update on the overall HER2 status designation, compared with the prior 2013 iteration, is unknown. Objectives.— To report the quantitative impact of the new guideline on HER2 status distribution. Design.— The analysis comprised a retrospective cohort of patients from the author's institution, combined with other peer-reviewed publications that assessed the impact of the 2018 guideline in relation to the 2013 guideline. Results.— Our study revealed that the new guideline led to an average 9% reclassification rate for the overall HER2 status, with a net gain in overall HER2 negative designation. This is largely due to reclassification of the equivocal (Group 4) groups. Unexpectedly, infrequent but consistent discordance between Group 1/5 and fluorescence in situ hybridization results are observed across studies (1.8%; 73 of 3965 cases where fluorescence in situ hybridization and immunohistochemistry are both reported). Conclusions.— Early clinical recognition of these resultant changes, including emerging issues of tumor heterogeneity, and potential discordance between immunohistochemistry to fluorescence in situ hybridization, is important for accurate clinical assessment of individual HER2 test results.


2020 ◽  
Vol 144 (9) ◽  
pp. 1097-1107 ◽  
Author(s):  
Anqi Li ◽  
Qianming Bai ◽  
Hui Kong ◽  
Shuling Zhou ◽  
Hong Lv ◽  
...  

Context.— The updated American Society of Clinical Oncology/College of American Pathologists guideline for human epidermal growth factor receptor 2 (HER2) testing in breast cancer requires pathologists to re-evaluate HER2 status. Objective.— To define HER2 status of breast cancer using immunohistochemistry and fluorescence in situ hybridization. Design.— Diagnostic reports of invasive breast cancers made between 2014 and 2018 with HER2 immunohistochemistry and fluorescence in situ hybridization results were retrieved. HER2 status was re-defined using the updated recommendations. Results.— Of 2514 tumors, 89.7% (2254 of 2514) suggested for fluorescence in situ hybridization assay were HER2 immunohistochemistry 2+. Approximately 8.9% (225 of 2514) and 1.4% (35 of 2514) of tumors were of immunohistochemistry 0/1+ and 3+, respectively. Based on the average HER2 copy number and HER2:CEP17 ratio, tumors were assigned into 5 groups, including 13.1% (330 of 2514) group 1 tumors, 2.1% (52 of 2514) group 2 tumors, 1.1% (27 of 2514) group 3 tumors, 7.0% (175 of 2514) group 4 tumors, and 76.8% (1930 of 2514) group 5 tumors. In combination with immunohistochemistry, all tumors in group 2 and group 4 changed HER2 status, from positive and equivocal into negative, respectively, while group 3 tumors remained positive. Comparative analyses of clinicopathologic features of tumors in different groups revealed that group 2 and 4 tumors displayed worse clinicopathologic features than those of group 5, while group 3 tumors shared similar clinicopathologic features to those of group 1. Conclusions.— Following the updated guideline, HER2 status is clearly designated. Significant differences regarding clinical features were observed between tumors in different groups but they share the same HER2 status, suggesting further validation of the accuracy of this diagnostic approach is warranted.


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