Chivukula M, Bhargava R, Brufsky A, et al.. Clinical importance of HER2 immunohistologic heterogeneous expression in core-needle biopsies vs resection specimens for equivocal (immunohistochemical score 2+) cases

Department of Pathology, Magee Women's Hospital of UPMC, Pittsburgh, PA 115213, USA.
Modern Pathology (Impact Factor: 6.19). 05/2008; 21(4):363-8. DOI: 10.1038/modpathol.3801021
Source: PubMed


HER2 oncoprotein is overexpressed in 15-20% of breast carcinomas and is associated with poor outcome. The 2+ group is considered equivocal, since gene amplification is observed in some but not others. The aim of our study is to ascertain if there is clinical significance to heterogeneity of HER2 immunohistologic expression in breast core-needle biopsies vs surgical resection specimens. A total of 37 invasive breast carcinomas diagnosed on core-needle biopsies and scored 2+ by HER2 immunohistochemical assay were selected from our files. The results were obtained on these selected cases, of which 19 cases were nonamplified and 18 cases were amplified. The follow-up resection specimens were reviewed and two additional tumor blocks were selected in each case for HER2 immunostaining. The 74 tissue blocks were examined for HER2 using antibody clone CB11 on the Benchmark XT and scored as negative (score 0 or 1+), weakly positive (2+) or strongly positive (3+). Results within the amplified group, 56% (11/18) showed significant areas with 3+ score in both blocks, 28% (5/18) remained as 2+, 11% (2/18) showed score 0-1+. In the nonamplified group, 42% (8/19) had score 0-1+, 37% (7/19) remained as 2+, 0% (0/19) had score 3+. Five (5) cases showed heterogeneous staining in both the groups. In the amplified group, 56% of cases showed strong 3+ in both the blocks of which half of these cases had areas of 2+. Fluorescence in situ hybridization was performed on a representative resection specimen block. In the amplified group 72% (13/18) cases were amplified, 22% (4/18) were nonamplified. In the nonamplified group, no amplification is detected in a great majority of cases 89% (17/19). HER2 immunohistochemistry on core-needle biopsies is usually predictive of tumor HER2 status. However, performing fluorescence in situ hybridization on core-needle biopsies almost completely resolves the issue of heterogeneous expression of HER2.

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    • "Another important point is the fact that 2+ cases are considered to be the most heterogeneous category, explaining the discordance between core biopsies and surgical specimens [42] and the technique cannot be repeated on surgical specimens in the neoadjuvant setting. These discrepancies are observed more frequently around the cut-off used to define positivity [40]. "
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    ABSTRACT: Until now, FISH has been the gold standard technique to identify HER2 amplification status in ambiguous cases of breast cancer. Alternative techniques have been developed to increase the capacities of investigating HER2 amplification status. The aims of this multicenter study in a large series of breast cancer patients were to prospectively compare the level of performance of CISH, SISH, and qPCR alternative techniques on paraffin-embedded core biopsies with "gold standard FISH" for evaluation of HER2 amplification status. This study was performed on 840 cases scored by immunohistochemistry (IHC): 0=317 (38%), 1+=183 (22%), 2+=109 (13%), 3+=231 (27%). Each of the 15 French centers participating in the study analyzed 56 breast carcinoma cases diagnosed on fixed paraffin-embedded core biopsies. HER2 amplification status was determined by commercially available FISH used as the reference technique with determination of the HER2/CEN17 ratio or HER2 copy number status. The alternative techniques performed on the same cases were commercially available SISH or CISH and a common qPCR method especially designed for the study including a set of 10 primer pairs: 2 for HER2 (exons 8 and 26), 5 to evaluate chromosome 17 polysomy TAOK1, UTP6, MRM1, MKS1, SSTR2 and 3 for diploidy control TSN, LAP3 and ADAMTS16. The concordance between IHC and FISH was 96% to 95% based on the HER2/CEN17 ratio (n=766) or HER2 copy number (n=840), respectively. The concordance of the alternative techniques with FISH was excellent: 97% and 98% for SISH (498 and 587 cases), 98% and 75% for CISH (108 and 204 cases) and 95% and 93% (699 and 773 cases) for qPCR based on the HER2/CEN17 ratio or HER2 copy number, respectively. Similarly, sensitivity ranged from 99% to 95% for SISH, 100% to 99% for CISH and 89% to 80% for qPCR. The concordance with FISH (ratio) in the 2+ cases was 89% for SISH, 100% for CISH and 93% for qPCR. These alternative techniques showed an excellent concordance with FISH in core biopsies allowing their use in routine clinical practice. This newly designed qPCR on paraffin-embedded core biopsies deserves special attention, as it is reliable, easy to perform and less expensive than ISH tests.
    Full-text · Article · Jul 2013 · BMC Cancer
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    • "But the pathological findings inside the tumor are often heterogeneous. For example, the expression of human epidermal growth factor receptor 2 (HER2) is often heterogeneous in breast cancer tissues [1]. This means that the degree of HER2 expression can be differently diagnosed according to the biopsy site even in the same tumor. "
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    ABSTRACT: We aimed to clearly visualize heterogeneous distribution of hypoxia-inducible factor 1α (HIF) activity in tumor tissues in vivo. We synthesized of (125)I-IPOS, a (125)I labeled chimeric protein probe, that would visualize HIF activity. The biodistribution of (125)I-IPOS in FM3A tumor-bearing mice was evaluated. Then, the intratumoral localization of this probe was observed by autoradiography, and it was compared with histopathological findings. The distribution of (125)I-IPOS in tumors was imaged by a small animal SPECT/CT scanner. The obtained in vivo SPECT-CT fusion images were compared with ex vivo images of excised tumors. Fusion imaging with MRI was also examined. (125)I-IPOS well accumulated in FM3A tumors. The intratumoral distribution of (125)I-IPOS by autoradiography was quite heterogeneous, and it partially overlapped with that of pimonidazole. High-resolution SPECT-CT fusion images successfully demonstrated the heterogeneity of (125)I-IPOS distribution inside tumors. SPECT-MRI fusion images could give more detailed information about the intratumoral distribution of (125)I-IPOS. High-resolution SPECT images successfully demonstrated heterogeneous intratumoral distribution of (125)I-IPOS. SPECT-CT fusion images, more favorably SPECT-MRI fusion images, would be useful to understand the features of heterogeneous intratumoral expression of HIF activity in vivo.
    Full-text · Article · Jun 2012 · BioMed Research International
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    • "Therefore, HER2 testing using IHC for CNB specimens appeared to be valid for a majority of primary breast cancers. The present results were similar to the very first studies done by Chivukula et al. that stated as CNB a better sample [25]. "
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    ABSTRACT: Accurate evaluation of human epidermal growth factor receptor type-2 (HER2) status based on core needle biopsy (CNB) specimens is mandatory for identification of patients with primary breast cancer who will benefit from primary systemic therapy with trastuzumab. The aim of the present study was to validate the application of HER2 testing with CNB specimens from primary breast cancers in terms of interobserver reproducibility and comparison with surgically resected specimens. A total of 100 pairs of archival formalin-fixed paraffin-embedded CNB and surgically resected specimens of invasive breast carcinomas were cut into sections. All 100 paired sections were subjected to HER2 testing by immunohistochemistry (IHC) and 27 paired sections were subjected to that by fluorescence in situ hybridization (FISH), the results being evaluated by three and two observers, respectively. Interobserver agreement levels in terms of judgment and the concordance of consensus scores between CNB samples and the corresponding surgically resected specimens were estimated as the percentage agreement and κ statistic. In CNB specimens, the percentage interobserver agreement of HER2 scoring by IHC was 76% (κ = 0.71) for 3 × 3 categories (0-1+ versus 2+ versus 3+) and 90% (κ = 0.80) for 2 × 2 categories (0-2+ versus 3+). These levels were close to the corresponding ones for the surgically resected specimens: 80% (κ = 0.77) for 3 × 3 categories and 92% (κ = 0.88) for 2 × 2 categories. Concordance of consensus for HER2 scores determined by IHC between CNB and the corresponding surgical specimens was 87% (κ = 0.77) for 3 × 3 categories, and 94% (κ = 0.83) for 2 × 2 categories. Among the 13 tumors showing discordance in the mean IHC scores between the CNB and surgical specimens, the results of consensus for FISH results were concordant in 11. The rate of successful FISH analysis and the FISH positivity rate in cases with a HER2 IHC score of 2+ differed among specimens processed at different institutions. It is mandatory to study HER2 on breast cancers, and either CNB or surgical specimen can be used.
    Full-text · Article · Oct 2010 · BMC Cancer
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