Detection of Her-2/neu oncogene in breast carcinoma by chromogenic in situ hybridization in cytologic specimens

Determination of Her-2/neu oncogene amplification is important in the current treatment of breast carcinoma. In addition to fluorescence in situ hybridization (FISH) and immunohistochemical stain (HercepTest), chromogenic in situ hybridization (CISH) has been shown to be a sensitive and specific method to determine the Her-2/neu status of surgical specimens. The effectiveness of CISH in detecting the Her-2/neu oncogene in cytologic specimens has not been well documented. Twenty-five cases of fine needle aspirate smears and touch imprints from infiltrating ductal carcinomas were examined. Both CISH and FISH were performed on each case using a digoxigenin-labeled Her-2 DNA probe for CISH (Zymed) and both Her-2 and chromosome 17 probes for FISH (Vysis). Sixty tumor cells were evaluated in each case. The scoring system and interpretation of CISH were as follows: (1) no amplification (<5 brown dots/nucleus), (2) amplification (>10 brown dots/nucleus), and (3) low-level amplification (5-9 brown dots/nucleus). Of the 25 cases analyzed, 23 (3 amplified and 20 nonamplified) showed similar results for both methods. Two cases were discordant. In these cases, low-level amplification was suggested by CISH but nonamplification by FISH. One of the cases can be explained by polysomy for chromosome 17 by FISH. In conclusion, our preliminary data suggest that CISH is a useful technique to determine Her-2/neu oncogene status in cytologic specimens. In a case of low-level amplification, a CISH chromosome 17 probe should be used, or FISH is recommended for confirmation.     

Evaluation of HER2 gene amplification in invasive breast cancer using a dual‐color chromogenic in situ hybridization (dual CISH)

Fluorescence in situ hybridization (FISH) assay is considered the ‘gold standard’ for evaluation of HER2/neu (HER2) gene status, however, it is difficult to recognize morphologic features of tumors using fluorescence microscopy. Thus, chromogenic in situ hybridization (CISH) has been proposed as an alternative method to evaluate HER2 gene amplification. Here, we examined the dual color CISH (dual CISH) method which provides information regarding the copy number of the HER2 gene and chromosome 17 centromere from a single slide. We examined 40 cases of invasive ductal carcinomas of the breast that were resected surgically. HER2 gene status was assessed with FISH (Abbott) and dual CISH (Dako). HER2 gene amplification status was classified according to the guidelines of the American Society of Clinical Oncology and College of American Pathologists (ASCO/CAP). Comparison of the cut‐off values for HER2/chromosome 17 centromere copy number ratio obtained by dual CISH and FISH showed that there was almost perfect agreement between two methods (Kappa coefficient 0.96). The results of the two commercial products were almost consistent for evaluation of HER2 gene counts on the sections. The current study proved that dual CISH is comparable with FISH for evaluating HER2 gene status.     

Dual-colour chromogenic in-situ hybridization is a potential alternative to fluorescence in-situ hybridization in HER2 testing

Hwang C‐C, Pintye M, Chang L‐C, Chen H‐Y, Yeh K‐Y, Chein H‐P, Lee N & Chen J‐R
(2011) Histopathology 59 , 984–992 Dual‐colour chromogenic in‐situ hybridization is a potential alternative to fluorescence in‐situ hybridization in HER2 testing Aim: Dual‐colour chromogenic in‐situ hybridization (dc‐CISH) is an emerging methodology for characterizing genomic alterations. This study was aimed at evaluating the performance of a dc‐CISH kit (ZytoVision) in determining human epidermal growth factor receptor 2 (HER2) status in breast cancer. Methods and results: Two hundred and twenty‐eight invasive breast carcinomas arranged in tissue microarrays were analysed in parallel with dc‐CISH, fluorescence in‐situ hybridization (FISH), and immunohistochemistry. Of 227 tumours with available FISH and dc‐CISH results, HER2 amplification and non‐amplification were detected in 49 (21.6%) and 178 (78.4%) tumours, respectively, by both assays. The concordance between dc‐CISH and FISH results showed 100% agreement (κ‐coefficient = 1.00). Immunohistochemically, 162 (71%), 25 (11.0%) and 41 (18%) tumours were scored 0/1+, 2+, and 3+, respectively. The corresponding results with both FISH and dc‐CISH demonstrated HER2 amplification in two (3.2%), nine (36%) and 38 (93%) tumours, respectively. Complete consensus among these three methods was observed in 197 cases, representing 98% of all 3+ and 0/1+ tumours (κ‐coefficient = 0.92). Confirmatory testing of 25 2+ tumours showed complete consensus between FISH and dc‐CISH. Conclusions: dc‐CISH is a promising alternative to FISH in HER2 testing, and the single‐institute incidence of HER2 amplification in breast cancer in Taiwan is 21.2%.     

Chromogenic in situ Hybridization is a Reliable Alternative to Fluorescence in situ Hybridization for Diagnostic Testing of 1p and 19q Loss in Paraffin‐Embedded Gliomas

Recent studies imply the importance of rapid and reliable diagnostic assessment of 1p/19q status in oligodendroglial tumors. To date, fluorescence in situ hybridization (FISH) is the most commonly applied technique. FISH, however, has several technical shortcomings that are suboptimal for diagnostic applications: results must be viewed in a fluorescence microscope, results are usually evaluated by a single investigator only, and signal fading excludes physical archiving. Also, in gliomas, the distinction of diffusely infiltrating tumor cells from reactively altered normal tissue may be challenging in fluorescence microscopy. Dual‐color chromogenic in situ hybridization (CISH) has started to replace FISH in some diagnostic tests performed in pathology. Here, we present the first single institute experience with a side‐by‐side analysis of 1p/19q FISH and CISH in a series of 42 consecutive gliomas. FISH and CISH produced identical results for 1p and 19q in 93% of cases (n = 39/42). Discrepant results were reevaluated by repeated FISH and a polymerase chain reaction (PCR)‐based microsatellite marker analysis for loss of heterozygosity. Reevaluation confirmed CISH data in all three cases. We conclude that CISH is a reliable alternative in 1p/19q testing in paraffin‐embedded tissues likely to be more sensitive to detect 1p/19q status than FISH analysis.     

Chromogenic in situ hybridization (CISH) to detect HER2 gene amplification in breast and gastric cancer: Comparison with immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH)

The chromogenic in situ hybridization (CISH) assay, designed to detect the amplification of the HER2 gene in formalin‐fixed, paraffin‐embedded (FFPE) breast cancer (BC) and gastric cancer (GC) tissue specimens, was evaluated in 125 FFPE BC cases and 198 FFPE GC cases for which the HER2 status had been predetermined using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). In the 125 BC cases and the 198 gastric cases, we found a very good concordance (98.4% and 99.0%, respectively) between CISH and FISH. In particular, we evaluated the polysomy cases, as these cases often have ambiguous treatment options in clinical practice. The polysomy of chromosome 17 was defined as the presence of three or more CEP17 signals in at least 10% of the tumor cells. In the 50 BC cases and 54 GC cases displaying chromosome 17 polysomy, the concordance between FISH and CISH was 98.0% and 98.1%, respectively. These results indicate that CISH could provide an accurate and practical alternative to FISH for the clinical diagnosis of HER2 gene amplification in FFPE BC and FFPE GC samples.     

Chromosomal changes in prostate cancer: a fluorescence in situ hybridization study

The incidence of prostate cancer (PC) is increasing steadily with the aging population in Singapore. As the pattern of chromosomal aberrations in Asian men with PC is poorly understood, we investigated the numerical aberrations for chromosomes 7, 8, 11, and 17 by fluorescence in situ hybridization (FISH). FISH was performed on standard sections and tissue microarrays of 54 PC and 33 benign prostatic hyperplasia (BPH) specimens. Among the 54 PC specimens, FISH detected 44 cases as aneusomy and two as disomy and was unsuccessful for eight cases. Cytogenetic alterations of two or more chromosomes per tumor were detected in 33/46 (72%) PCs. The most frequent alteration was aneusomy of chromosome 8 detected in 34/46 (74%) cases followed by numerical aberrations in chromosome 7 (61%). Gain of 8q24, loss of chromosome 7, and gain of 11q13 were associated with higher Gleason score and were statistically significant. Gain of chromosome 7 was more common in locally advanced disease, while gain of chromosome 11q13 and chromosome 7 was more common in metastatic disease.     

Dual-colour chromogenic in situ hybridization for testing of HER-2 oncogene amplification in archival breast tumours

Chromogenic in situ hybridization (CISH), which uses an enzymatic reaction to detect the hybridized DNA probe, is a new alternative to fluorescence in situ hybridization (FISH) for the assessment of HER-2 oncogene amplification status in breast cancer. The main advantage of CISH over FISH is the use of bright-field microscopy, which is rapid and allows the histopathological evaluation of tumour tissue sections. The main disadvantage of CISH has been the use of a single probe, thereby making it necessary to hybridize the control probe (chromosome 17 centromere) on an adjacent tissue section. The present paper presents an efficient protocol for dual-colour CISH (dc-CISH) based on the co-hybridization of probes to the HER-2 oncogene and chromosome 17 centromere. The probes were detected sequentially with antibodies to digoxigenin and biotin and with secondary antibody polymers labelled with horseradish peroxidase and alkaline phosphatase. The peroxidase reaction was visualized with tetramethyl benzidine (green reaction product) and the alkaline phosphatase reaction with New Fuchsin (red reaction product). The accuracy of the method was verified by comparing the results for four cell lines and 40 tumour samples with those obtained using FISH (Vysis Inc.). The results of FISH and dc-CISH showed high concordance (91%, Kappa coefficient = 0.82). It is concluded that dual-colour CISH, which is a new alternative to FISH enables the assessment of copy number ratio (HER-2/17 centromere) in conjunction with proper histopathological evaluation and the ease of bright-field microscopy.     

Chromogenic and fluorescent in situ hybridization in breast cancer

Fluorescent (FISH) and chromogenic (CISH) in situ hybridization have recently become part of the diagnostic armamentarium of breast pathologists. HER2 gene testing by FISH and/or CISH has become an integral part of the diagnostic workup for patients with breast cancer. In this era of high throughput technologies, these techniques have proven instrumental for the validation of results from microarray-based comparative genomic hybridization and for the identification of novel oncogenes and tumor suppressor genes. Furthermore, FISH and CISH applied to tissue microarrays have expedited the characterization of genomic changes associated with specific breast cancer molecular subtypes and the identification of novel prognostic and predictive markers. In this review, we provide in this review a critical assessment of CISH and FISH and the impact of the analysis of amplification of specific oncogenes (eg, HER2, EGFR, MYC, CCND1, and FGFR1) and deletion of tumor suppressor genes (eg, BRCA1 and BRCA2) on our understanding of breast cancer.     

Determination of HER2 amplification in primary breast cancer using dual‐colour chromogenic in situ hybridization is comparable to fluorescence in situ hybridization: a European multicentre study involving 168 specimens

García‐Caballero T, Grabau D, Green A R, Gregory J, Schad A, Kohlwes E, Ellis I O, Watts S & Mollerup J
(2010) Histopathology 56, 472–480
Determination of HER2 amplification in primary breast cancer using dual‐colour chromogenic in situ hybridization is comparable to fluorescence in situ hybridization: a European multicentre study involving 168 specimens Aims: Fluorescence in situ hybridization (FISH) can be used to reveal several genomic imbalances relevant to proper cancer diagnosis and to the correct treatment regime. However, FISH requires expensive and advanced fluorescence microscopes in addition to expertise in fluorescence microscopy. To determine whether a newly developed dual‐colour chromogenic in situ hybridization (CISH) method is a suitable alternative to FISH, we analysed the human epidermal growth factor receptor 2 gene (HER2) amplification level of 168 breast cancer specimens using dual‐colour CISH and FISH and compared the results. Methods and results: We found 100% agreement between HER2 status determined by FISH and dual‐colour CISH. Furthermore, we observed that the time used to score slides was significantly reduced by 28% in dual‐colour CISH compared with the FISH protocol. Concordance between HER2 protein status and dual‐colour CISH or FISH was equally good with an overall agreement of 96.8%. Correlation between the HER2/centromere 17 gene ratios obtained with dual‐colour CISH and FISH was highly significant with an overall correlation coefficient (ρ) of 0.96. Conclusions: We conclude that dual‐colour CISH and bright field microscopy are excellent alternatives to FISH when analysing the HER2 status of primary breast cancer.     

Detection of numerical and structural alterations and fusion of chromosomes 16 and 1 in low-grade papillary breast carcinoma by fluorescence in situ hybridization.

Intracystic papillary breast tumors, including intraductal papilloma and low-grade intracystic papillary carcinoma, constitute a group for which differential diagnosis is frequently difficult. We examined the status of chromosomes 16 and 1 by multicolor fluorescence in situ hybridization (FISH) analyses and the DNA ploidy patterns by flow cytometry in 26 intracystic papillary tumors. Alterations of chromosomes 16 and 1 were detected by FISH in 93 and 85%, respectively, of 14 low-grade papillary carcinomas, and the latter alterations always concurred with the former. Two-color FISH using probes for the D1Z1 (1q12) and D16Z2 (16cen) loci or the D1Z1 and D16Z3 (16q11) loci showed that fusion of chromosomes 16 and 1, mostly with breakpoints distal to 16q11.2 and proximal to 1q12, occurred in 77% of the papillary carcinomas. DNA aneuploidy was detected in 6% of these carcinomas. No papilloma showed these chromosome alterations or DNA aneuploidy. Chromosome 16 and 1 fusions appeared to occur frequently in diploid breast carcinomas and to be involved in the acquisition of a malignant phenotype by duct epithelial cells. We suggest that two-color FISH methods for detecting 1;16 fusions might be applicable as supportive methods for the differential diagnosis of intracystic papillary breast tumors.     

髓母细胞瘤比较基因组杂交分析及ERBB-2异常表达的意义

目的研究髓母细胞瘤全基因组的遗传学异常,探讨癌基因的异常表达在髓母细胞瘤发病机制中的作用以及与预后的关系。方法应用比较基因组杂交（comparative genomic hybridization,CGH）技术检测14例髓母细胞瘤全基因组的遗传学改变;同时,在扩大系列的29例髓母细胞瘤中,应用荧光原位杂交（fluorescence in situ hybridization,FISH）和免疫组化染色分别检测ERBB-2在基因水平和蛋白水平的表达。结果（1）CGH结果显示,在所有14例髓母细胞瘤标本中,每一条染色体臂上都检测到了染色体的失衡（获得或丢失）,最常见的染色体异常为17q（85．7％）和7q（35．7％）的获得,以及8p（50％）、16q（28．6％）和17p（35．7％）的丢失;（2）FISH检测中,44．5％（13／29例）的肿瘤细胞有ERBB-2基因的异常表达;（3）免疫组化结果显示,37．9％（11／29例）的病例有抗体c-erbB-2的阳性表达;（4）在预后较差的16例患者中,56％（9／16例）的病例有ERBB-2的过度表达。结论CGH研究发现了髓母细胞瘤全基因组的染色体失衡。在染色体17q特异性位点上ERBB-2基因的异常改变很可能在髓母细胞瘤的发病机制中起着重要的作用,其过度表达与患者的预后密切相关。     

Interphase cytogenetics of gastric carcinoma: Fluorescence in situ hybridization (FISH) applied to cells obtained from formalin-fixed paraffin-embedded tissues

The interphase cytogenetics in formalin-fixed and paraffin-embedded gastric cancer tissues were examined by fluorescence in sku hybridization (FISH) with α-satellite DNA probes. Two gastric carcinoma cell lines, TMK-1 and MKN-28, were first analyzed cytogenetically. Of 25 TMK-1 cell karyotypes, chromosome 7 showed trisomy and chromosome 17 showed disomy in 18 cells. Most MKN-28 cells showed disomy of both chromosomes 7 and 17. Suspensions of singly isolated TMK-1 and MKN-7 cells were obtained from the cultured cells, and from paraffinembedded tissue specimens fixed with formalin for 0, 1, 3 and 5 days obtained from xenotrans-planted tumors in nude mice. The numbers of chromosomes 7 and 17 analyzed with the karyotypic preparations coincided well with those determined by FISH, even in the paraffin-embedded specimens. The number of tumor cells showing no signals, however, increased in the specimens after 5 days formalin fixation. In 10 surgically removed gastric carcinomas, the predominant signal number for chromosomes 7 and 17 in the cells of paraffinembedded tissues was two (disomy), except in one papillary carcinoma, which was trisomic for chromosome 7. Large subpopulations (more than 20%) showing trisomy were found in four cases for chromosome 7 and in five cases for chromosome 17. A higher frequency of trisomy was found in well differentiated than in poorly differentiated carcinomas. These findings suggest that the FISH technique is a useful tool for detecting chromosomal aberrations in gastric adenocarcinoma cells, even in paraffinembedded specimens, as long as the tissues are fixed with formalin for an appropriate time.     

Numerical aberrations of chromosomes 1 and 7 in renal cell carcinomas as detected by interphase cytogenetics

Alcohol-fixed single cell suspensions of 37 renal cell carcinomas (RCCs) were assessed by both flow cytometry (FCM) and the fluorescence in situ hybridization (FISH) technique, using chromosome 1- and chromosome 7-specific centromere DNA probes. DNA diploidy or near-diploidy was observed in 30 of the 37 RCCs and only 12 of these (near-)diploid tumours were disomic for both chromosomes 1 and 7. Numerical aberrations of chromosome 1 and/or chromosome 7 were present in 18 of the 30 (near-)diploid RCCs and five of these cases showed monosomy for chromosome 1 in more than 50 per cent of the tumour cells. A double target FISH, with a centromeric and a telomeric specific probe for 1p36, excluded misinterpretation on the basis of clustering of 1q12, and suggested a complete loss of chromosome 1. All these five (near-)diploid RCCs with monosomy for chromosome 1 were eosinophilic chromophilic cell carcinomas, according to the Thoenes classification of RCC. This observation is of special interest, because it was recently concluded from cytogenetic studies that the diagnosis of chromophilic renal cell carcinoma must be considered as obsolete. Monosomy for chromosome 1 seems to be a non-random numerical aberration of (near-)diploid eosinophilic chromophilic cell carcinomas, and a gain of one or more chromosomes 1 appeared to be a common phenomenon in RCCs, especially in the DNA aneuploid tumours. As these chromosomal abnormalities were not found in the earlier classical cytogenetic studies, we conclude that in situ hybridization techniques are required in addition to chromosome banding techniques to obtain a complete characterization of the chromosome imbalances in RCCs.     

LOSS OF CHROMOSOME 9 IN TISSUE SECTIONS OF TRANSITIONAL CELL CARCINOMAS AS DETECTED BY INTERPHASE CYTOGENETICS. A COMPARISON WITH RFLP ANALYSIS

Interphase cytogenetics by in situ hybridization (ISH) using a panel of centromere-associated DNA probes for chromosomes 1, 7, 9, 10, 11, 16, 17, and 18 was performed on 5 μm thick frozen tissue sections of transitional cell carcinomas (TCCs) of the urinary bladder. By this approach, chromosome ploidy, numerical chromosome aberrations, imbalance between chromosomes, and heterogeneity of aberrations within individual tumours were determined. In 15 of 24 TCCs, loss or underrepresentation of chromosome 9, compared with the ISH copy numbers of at least five other chromosomes, was demonstrated. Independently, RFLP analysis were performed on the same cases to detect loss of heterozygosity (LOH) of chromosome loci 9q34, 11p15, 16q22–24, 17p13, and 18q21. LOH was found in 9 of 19 informative cases for chromosome locus 9q34. Comparison of the ISH and RFLP results showed no correlation between numerical aberration and LOH for the loci on chromosomes 11, 16, 17, and 18. However, numerical loss of chromosome 9 was found in 89 per cent (eight of nine cases) with LOH for 9q34. Conversely, LOH at 9q34 was observed in only 67 per cent (eight of 12 cases) with underrepresentation of chromosome 9. Moreover, in 60 per cent of the non-informative cases (three of five cases), underrepresentation for chromosome 9 was observed. These results indicate that the heterochromatin probe for chromosome 9 can be reliably used in TCC tissue sections for the detection of chromosomal loss. In aneuploid TCCs, this DNA probe can be used for the detection of chromosomal underrepresentation only in combination with other centromere-associated DNA probes.     

用荧光原位杂交技术检测乳腺癌细胞系第6号染色体长臂缺失

目的 研究１０例乳腺癌细胞系的６号染色体第臂缺失。方法 运用荧光原位杂交（ｆｌｕｏｒｅｓｃｅｎｃｅ ｉｎ ｓｉｔｕ ｈｙｂｒｉｄｉｚａｔｉｏｎ,ＦＩＳＨ）技术,并采用３７个分布于６ｑ１２－６ｑ２７的ＹＡＣ探针和６号染色体着丝粒特异性探针,检测了１０例乳腺癌细胞系的６号染色体长臂。结果 在５例细胞系中发现６ｑ１２－６ｑ２７的大段缺失,１例发现有６ｑ２５－ｑ２７的小段缺失。在含有多个细胞亚群的两侧细胞     

人白介素-2基因在原代培养骨骼肌细胞中的表达研究

目的 对以人白介素－２在原代培养骨骼肌细胞中的表达作为肿瘤基因治疗模式进行新的探索;方法 将人白介素－２ｃＤＮＡ片段与ＣＭＶ启动子及ＲＳＶ启动子重组,通过Ｌｉｐｏｆｅｃｔｉｎ介导将得到真核表达载体ｐＣＭＶ－ＩＬ２和ｐＲＳＶ－ＩＬ２转入原代培养的骨骼肌细胞,并用免疫组织化学方法观察白介素－２的表达;结果 ｐＣＭＶ－ＩＬ２和ｐＲＳＶ－ＩＬ２经酶切鉴定正确,免疫组织化学观察到约有１０％左右细胞表达了白介     

Comparative genomic hybridization of ductal carcinoma in situ of the breast—evidence of multiple genetic pathways

There is strong evidence that ductal carcinoma in situ (DCIS) represents a precursor lesion of invasive breast cancer. In order to analyse specific chromosomal alterations of DCIS, 38 paraffin-embedded specimens of DCIS and six associated invasive carcinomas were examined by means of comparative genomic hybridization (CGH). Losses of 16q material were seen almost exclusively in well- and intermediately-differentiated DCIS. These two subgroups differed in the average number of genetic imbalances, 2·5 and 5·5 respectively. Additionally, a higher frequency of gains of 1q and losses of 11q material was seen in intermediately-differentiated in contrast to well-differentiated DCIS. Poorly-differentiated DCIS displayed a higher frequency of amplifications (17q12, 11q13) and a higher average rate of genetic imbalances (7·1). Analysis of adjacent invasive breast carcinoma revealed a genetic pattern almost identical to the one seen in the DCIS counterpart. These data characterize DCIS as a genetically far-advanced, heterogeneous lesion and as a direct precursor of invasive breast cancer. Copyright © 1999 John Wiley & Sons, Ltd.     

Absence of estrogen receptor alpha (ESR1) gene amplification in a series of breast cancers in Taiwan

Immunohistochemical expression of ERα, encoded by the ESR1 (estrogen receptor 1) gene located at 6q25.1, is the most important determinant of responsiveness to endocrine therapy in breast cancer. The prevalence and significance of ESR1 amplification in breast cancer remain controversial. We set out to assess ESR1 status and its relevance in breast cancer in Taiwan. We tested tissue samples from 311 invasive carcinomas in a tissue microarray for ESR1 status by fluorescent in situ hybridization (FISH) and chromogenic in situ hybridization (CISH). In order to examine its association with ERα and ESR1 status, HER2 status was determined by FISH. Of the carcinomas, 58.8 % (183/311) was ERα positive. None of the carcinomas showed amplification of ESR1 by either method, whereas 24.1 % (75/311) of the carcinomas harbored HER2 amplification. Of the carcinomas, 9.6 % (26/301) showed ESR1 gain (1.3?≤?ratio ESR1/chromosome 6?<?2) by FISH and 10 % (24/299) by CISH. FISH and CISH results showed a good correlation (κ-coefficient?=?0.786). ESR1 gain by FISH and CISH was significantly associated with high-grade (P?=?0.0294 and 0.0417, respectively) but not with ERα expression, HER2 status, or overall survival. ERα positivity was significantly associated with better overall survival (P?=?0.039). HER2 amplification was significantly related with poor overall survival (P?=?0.002). Our data confirm that in breast cancer, HER2 amplification is a frequent genetic aberration and a negative prognostic factor, and show that ESR1 amplification is not a key genetic abnormality in the tumorigenesis of breast cancer in Taiwan.     

显色原位杂交和免疫组织化学检测乳腺癌HER2/neu基因状况和蛋白表达的对照性研究

目的探讨显色原位杂交（CISH）在检测乳腺癌中HER2／neu基因扩增上的作用。方法挑选乳腺浸润性导管癌患者组织石蜡蜡块（回顾性255例,前瞻性271例）,进行免疫组织化学（IHC）、CISH检测。15例回顾性标本送往德国HERA检测中心进行FISH检测。结果（1）回顾性病例中IHC阳性3＋者CISH基因扩增率为91．6％（120／131）,IHC2＋者CISH基因扩增率为56．5％（39／69）,IHC与CISH检测结果符合率为81．2％（207／255）,两者明显相关（P〈0．01）。（2）前瞻性病例中IHC蛋白过表达率31．7％．CISH基因扩增率27．3％。IHC3＋者CISH基因扩增率为91．4％（53／58）,IHC2＋者CISH基因扩增率为46．4％（13／28）,IHC与CISH检测结果符合率为89．7％（243／271）,两者明显相关（P〈0．01）。（3）经德国检测中心荧光原位杂交（FISH）检测的15例中14例和CISH结果完全一致,1例检测失败,而CISH为无扩增。（4）CISH检测基因扩增与雌激素受体（ER）、孕激素受体（PR）表达明显负相关（P值均〈0．01）。结论CISH检测HER2基因扩增结果与IHC检测蛋白过表达及FISH结果高度一致,CISH是检测HER2基因扩增的一项新技术。     

Supernumerary ring chromosome 20 characterized by fluorescence in situ hybridization

We report on a boy with mild dysmorphic features and developmental delay, in whom karyotyping showed an additional minute ring chromosome in 60% of metaphases. Fluorescence in situ hybridization (FISH) with a centromere specific probe demonstrated that the ring chromosome contained the centromeric region of chromosome 20. The ring was highlighted completely using a chromosome 20 painting probe. A cosmid probe for 20p12-13 gave a positive signal and hybridization with an all-telomere probe showed one signal, suggesting a breakpoint in the 20p telomere. The results suggested that only a small part of 20q was involved in this ring. The ring was also detected in 18% of nuclei of a buccal smear. The phenotypic similarities of symptoms in the proband to patients with a (partial) trisomy 20p and the dissimilarities to symptoms in patients with (partial) trisomy 20q were in agreement with the FISH results.