Chromogenic In Situ Hybridization to Detect HER‐2/ neu Gene Amplification in Histological and ThinPrep ® ‐Processed Breast Cancer Fine‐Needle Aspirates: A Sensitive and Practical Method in the Trastuzumab Era

The Global Landscape on the Access to Cancer Medicines for Breast Cancer: The ONCOLLEGE Experience

There is a growing global debate over barriers affecting the timely access to innovative anticancer therapies. Access to medicines is often traced back to the issue of costs: however, more commonly, the distance between valuable innovative treatments and the actual treatment of patients is far beyond the mere problem of financial barriers. A comprehensive approach to understand, assess to medicines should be pursued, to dissect the determinants and formulate solutions for all patients. In this chapter, we discuss drivers of access to innovation for patients with breast cancer, based on a case study of access to HER2-diagnositcs and therapeutics yielding a global landscape analysis, based on the efforts and expertise of the global collaborative group "ONCOLLEGE".

Chromogenic in Situ Hybridization Technique versus Immunohistochemistry in Assessment of HER2/neu Status in 448 Iraqi Patients with Invasive Breast Carcinoma

BACKGROUND

The rapidly growing knowledge regarding factors controlling tumour growth, with the new modalities of therapy acting on the biological activity of the tumours draw the attention of most cancer researches nowadays and represent a major focus for clinical oncology practice. For the detection of HER2/neu protein overexpression and gene amplification, immunohistochemistry (IHC) and in-situ hybridisation (ISH) is the recommended techniques, respectively, with high concordance between the two techniques. The current United Kingdom recommendations for HER2/neu testing are either for a two-tier system using IHC with reflex ISH testing in equivocal positive cases, or a one-tier ISH strategy.

AIM

To compare the results of HER2/neu gene status in patients with breast carcinoma obtained by chromogenic in situ hybridisation with those obtained by immunohistochemistry, and to compare these results with hormonal receptors expression by immunohistochemistry and with age of patients.

METHODS

Immunohistochemistry technique was used for evaluation of status of estrogen receptors (ER) and progesterone receptors (PR) and HER2/neu protein expression in 448 Iraqi patients with invasive breast carcinoma with different grades and histological types and then chromogenic in situ hybridization (CISH) technique was applied for all scores of HER2/neu to detect the gene status and compare the results in all negative, equivocal and positive cases by immunohistochemistry (IHC). The cases were referred from different centres, and IHC and CISH techniques were done in central public health laboratory in Baghdad over 28 months, from July 2013 to November 2015. A comparison of the results was made to find the relationship between HER2/neu and hormone receptors status and other clinical parameters like patients age.

RESULTS

The mean age of the study cases was 49.08 years, ranging from 24 to 83 years. Of the 448 cases of breast carcinoma, 44 (9.8%) cases were of score 0 by IHC, none of them (0%) showed HER2/neu gene amplification by CISH. 71(15.8%) cases were of score 1 by IHC, 15 (21.12%) of them showed HER2/neu gene amplification by CISH, all were of low amplification. There were 306 (68.3%) cases of score 2 by IHC, of which 102 (33.33%) cases showed HER2/neu gene amplification by CISH, with 79 (25.81%) of them with low amplification and 23 (7.51%) cases with high amplification, while only one case (0.32%) remained in equivocal category. In score 3, all the 27 (6.0%) cases showed gene amplification with 12 (44.44%) cases with low amplification and 15 (55.55) cases with high amplification with overall percentage of gene amplification in score 3 of 100%. There was a significant inverse relationship between hormone receptors (ER and PR) status and HER2/neu gene amplification. No significant relationship was found between the patient's age and HER2/neu gene amplification.

CONCLUSION

Although immunohistochemistry is a widely used, less expensive and reliable test, we strongly advice performance of chromogenic in situ hybridization in assessment of HER2/neu gene status in all cases diagnosed with breast carcinoma as significant number of cases that were reported as negative by immunohistochemistry showed positive amplification by chromogenic in situ hybridization and can get benefit from anti-HER2 targeted treatments.

Advances in HER2 testing

HER2-positive breast cancer is a particularly aggressive type of breast cancer. Indication of HER2 positivity is essential for its treatment. In addition to a few FDA-approved methods such as immunohistochemical (IHC) detection of HER2 protein expression and in situ hybridization (ISH) assessment of HER2 gene amplification, several novel methods have been developed for HER2 testing in recent years. This chapter provides an overview of HER2 testing with emphasis on those new methods.

Comparative Performance of Breast Cancer Human Epidermal Growth Factor Receptor 2 Fluorescence In Situ Hybridization and Brightfield In Situ Hybridization on College of American Pathologists Proficiency Tests

CONTEXT.—

Fluorescence in situ hybridization (FISH) and brightfield in situ hybridization (ISH) are 2 clinically approved laboratory methods for detecting ERBB2 (HER2) amplification in breast cancer.

OBJECTIVE.—

To compare the performance of FISH and brightfield ISH on proficiency testing administered by the College of American Pathologists Laboratory Accreditation Program.

DESIGN.—

Retrospective review was performed on 70 tissue core samples in 7 separate proficiency testing surveys conducted between 2009 and 2013.

RESULTS.—

The samples included 13 consensus-amplified tissue cores, 53 consensus-nonamplified cores, and 4 cores that did not reach consensus for FISH and/or brightfield ISH. There were 2552 individual responses for FISH and 1871 individual responses for brightfield ISH. Consensus response rates were comparable for FISH (2474 of 2524; 98.0%) and brightfield ISH (2135 of 2189; 97.5%). The FISH analysis yielded an average HER2 copy number per cell that was significantly higher (by 2.86; P = .02) compared with brightfield ISH for amplified cores. For nonamplified cores, FISH yielded slightly, but not significantly, higher (by 0.17; P = .10) HER2 copy numbers per cell. There was no significant difference in the average HER2 to control ratio for either consensus-amplified or consensus-nonamplified cores. Participants reported "unable to analyze" more frequently for brightfield ISH (244 of 2453; 9.9%) than they did for FISH (160 of 2684; 6.0%).

CONCLUSIONS.—

Our study indicates a high concordance rate in proficiency testing surveys, with some significant differences noted in the technical performance of these assays. In borderline cases, updated American Society of Clinical Oncology/College of American Pathologists cutoff thresholds that place greater emphasis on HER2 copy number per cell could accentuate those differences between FISH and brightfield ISH.

Comparison of HER2 status determination methods in HER2 (2+) patients: Manual fluorescent in situ hybridization (FISH) vs. dual silver enhanced in situ hybridization (SISH)

HER2 amplification has been demonstrated in 15-25% of invasive breast carcinomas and can be assessed using immunohistochemical and in situ hybridization methods. Here, we compared the accuracy of dual SISH to manual FISH in HER2 (2+) breast carcinoma and evaluated the feasibility of dual SISH method in routine practice. Sixty HER2 (2+) consecutive tumor samples diagnosed between January 2009 and February 2013 were selected. Demographic, histological and immunohistochemical features and FISH results were recruited from patient records and compared to dual SISH results. Nine (15%) of the 60 tumor samples were excluded from statistical analysis due to lack of interpretable SISH signals. HER2 staining percentages by immunohistochemistry differed between 20 and 80%. HER2 amplification was shown in 7 (13.7%) and 8 (15.7%) patients by FISH and SISH, respectively. Very good agreement was observed between FISH and SISH methods (kappa value: 0.92). Significant correlation was found between HER2 staining percentage and FISH positivity, in contrast to SISH positivity (p=0.012 vs. p=0.069). Our results are consistent with previously reported literature, indicating SISH can be used to determine HER2 status. However, preanalytical and analytical problems may cause inadequate or uncountable signals, making interpretation impossible for the pathologist and highlighting the importance of standardization and quality control programs.

The diagnostic and prognostic role of liquid-based cytology: are we ready to monitor therapy and resistance?

Here, we evaluate the diagnostic and prognostic role of liquid-based cytology (LBC) in different body lesions, including thyroid, lung, effusions and malignant breast lesions. LBC has gained consensus after being applied to both non-gynecologic and fine-needle aspiration cytology. Although some remain sceptical regarding the diagnostic efficacy of LBC, mainly when used alone, in recent years, good results have been obtained as long as it showed a high diagnostic accuracy. Here, we discuss the additional possibility of storing material for the application of ancillary techniques (immunocytochemistry-molecular analysis) with several diagnostic and prognostic advantages, which may pave the way for the challenging evaluation of both monitoring responses to treatment and resistance to targeted therapies in thyroid, lung, breast carcinoma or malignant effusions. Furthermore, it provides the use of several molecular spots as specific targets for personalized therapy.

HER 2 immunohistochemistry for breast cancer cell blocks can be used in the same way as that used for histological specimens

Background

Human epidermal growth factor receptor 2 (HER2) testing of samples from recurrent or metastatic breast cancer is recommended by the 2013 update of the American Society of Clinical Oncology/College of American Pathologists guidelines. Although cytological analysis can be applied to several types of metastatic lesions, the practical method for HER2 testing of cytological specimens is yet to be resolved. We conducted immunohistochemical (IHC) staining for HER2 in breast cancer cell blocks (CBs) and compared the results with those from the corresponding histological specimens. In cases of discrepancy between the two types of specimen, the bright‐field HER2 dual in situ hybridization (DISH) assay was performed.

Methods

CBs were prepared from 54 surgically excised breast cancers. The cells were fixed in 10% buffered formalin and embedded in paraffin. A Ventana BenchMark ULTRA (Roche Diagnostics) with anti‐HER‐2/neu (4B5) rabbit monoclonal primary antibody and INFORM HER2/neu Dual ISH DNA Probe Cocktail was used for the assays.

Results

Successful results were obtained in 52 of 54 CBs. Forty cases showed agreement between CBs and the histological specimens. No discrepancy was observed between the two types of specimens in cases where HER2 expression was positive. IHC results of CB in 12 discrepant cases were HER2 intermediate or negative. The DISH results of 11 of these cases were negative.

Conclusion

IHC staining of HER2 for breast cancer CBs can be used in the same way as that used for histological specimens, although the number of equivocal cases in CBs is greater than that in histological specimens. Diagn. Cytopathol. 2016;44:274–279. © 2016 The Authors Diagnostic Cytopathology Published by Wiley Periodicals, Inc.

Bright-field HER2 dual in situ hybridization (DISH) assay on breast cancer cell blocks: a comparative study with histological sections

BACKGROUND

HER2 testing for samples from recurrent or metastatic disease is recommended by the 2013 update of the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines and cytological analysis can be applied to several types of metastatic lesions. However, the practical method to assess the HER2 testing of breast cancer cytology specimens has yet to be resolved. Therefore, we conducted the bright-field HER2 dual in situ hybridization (DISH) assay on cell blocks (CBs) prepared from breast cancer cell samples as a validation study before clinical use.

METHODS

CBs were prepared from tumor cell samples collected from 54 surgically excised breast tumors. The cells were fixed in 10 % buffered formalin for 16-28 h, and embedded in paraffin. The INFORM HER2/neu Dual ISH DNA Probe Cocktail was used for the DISH assay on the Ventana BenchMark ULTRA (Roche Diagnostics).

RESULTS

Successful results were obtained in 51 of 54 CB specimens, and the results from the CB specimens were in agreement with those from the histological sections in 48 of the 51 cases (concordance rate, 94 %; kappa, 0.846). The intraclass correlation coefficient (ICC) between the CB and histological specimens in the continuous HER2/CEP17 signal count ratio was 0.89 (95 % CI 0.81-0.93), and the Pearson's CC was 0.91 (95 % CI 0.85-0.94).

CONCLUSION

The HER2 DISH assay, utilizing 10 % buffered formalin-fixed CB, would be a reliable and ideal method to assess the HER2 gene status of breast cancer cytological specimens.

Advantages and disadvantages of technologies for HER2 testing in breast cancer specimens

OBJECTIVES

Human epidermal growth factor receptor 2 (HER2) plays a central role as a prognostic and predictive marker in breast cancer specimens. Reliable HER2 evaluation is central to determine the eligibility of patients with breast cancer to targeted anti-HER2 therapies such as trastuzumab and lapatinib. Presently, several methods exist for the determination of HER2 status at different levels (protein, RNA, and DNA level).

METHODS

In this review, we discuss the main advantages and disadvantages of the techniques developed so far for the evaluation of HER2 status in breast cancer specimens.

RESULTS

Each technique has its own advantages and disadvantages. It is therefore not surprising that no consensus has been reached so far on which technique is the best for the determination of HER2 status.

CONCLUSIONS

Currently, emphasis must be put on standardization of procedures, internal and external quality control assessment, and competency evaluation of already existing methods to ensure accurate, reliable, and clinically meaningful test results. Development of new robust and accurate diagnostic assays should also be encouraged. In addition, large clinical trials are warranted to identify the technique that most reliably predicts a positive response to anti-HER2 drugs.

Liquid-based cytology in fine-needle aspiration of breast lesions: a review

OBJECTIVE

Fine-needle aspiration (FNA) is a safe and cost-effective technique for the diagnosis of breast lesions, especially when correlated with clinical and imaging studies. However, the success of breast FNA is highly dependent on the adequate preparation of cytological conventional smears (CS). The liquid-based cytology (LBC) technique consists of an automated method for preparing thin-layer cytological samples from cell suspensions collected in alcohol-based preservative. LBC is designed to improve CS by avoiding limiting factors such as obscuring material, air-drying and smearing artifacts.

STUDY DESIGN

We performed a review of the published literature about LBC applied to breast FNA.

RESULTS

LBC preparations of breast aspirates demonstrated better cellular preservation, less cell overlapping and elimination of blood and excessive inflammation compared to CS. Conversely, alterations in architecture and cell morphology as well as loss of myoepithelial cells and stromal elements have been described in LBC specimens, requiring training before applying this technique for diagnosis. Studies have shown a similar accuracy between LBC and CS for the diagnosis of breast lesions. LBC also permits the use of residual material for ancillary tests, which is an important advantage compared to CS.

CONCLUSIONS

LBC can be safely applied to breast FNA, showing a similar diagnostic accuracy to CS.

Evaluation of chromogenic in situ hybridization for the determination of monosomy 3 in uveal melanoma

CONTEXT

Loss of 1 copy of chromosome 3 is considered a significant indicator of metastatic dissemination in uveal melanoma. Fresh or paraffin-embedded tumor tissue is most commonly used for current cytogenetic techniques for determining chromosome 3 status in uveal melanoma and often requires referral to an external specialist laboratory for analysis.

OBJECTIVES

To assess the chromogenic in situ hybridization assay for detecting chromosome 3 alterations using frozen tumor imprints and to compare the results obtained with those obtained by standard fluorescence in situ hybridization or single-nucleotide polymorphism array techniques.

DESIGN

Chromogenic in situ hybridization was performed on 52 frozen uveal melanoma tumor imprints. The genetic status of 26 of the 52 cases had been determined previously by fluorescence in situ hybridization (group 1); the status of 26 cases had been determined using single-nucleotide polymorphism array (group 2).

RESULTS

Chromogenic in situ hybridization was successfully performed on 48 of 52 tumor imprints. Chromogenic in situ hybridization showed excellent agreement in all 24 cases determined by fluorescence in situ hybridization (100% concordance; κ = 1; P < .001; 95% confidence interval, 100%-100%), and disagreed in 4 of the 24 cases previously studied by single-nucleotide polymorphism array (83% concordance; κ = 0.67; P < .001; 95% confidence interval, 95%-39%). All 4 discordant cases were classified as disomic for chromosome 3 by chromogenic in situ hybridization and monosomic by SNP array. On histologic examination, the 4 discordant cases corresponded to 2 mixed cell tumors and 2 spindle cell tumors.

CONCLUSIONS

Chromogenic in situ hybridization using tumor imprints is a reliable technique for determining chromosome 3 status in uveal melanoma. Furthermore, it can also be easily integrated into a routine histopathology laboratory.

Recommendations for human epidermal growth factor receptor 2 testing in breast cancer: American Society of Clinical Oncology/College of American Pathologists clinical practice guideline update

PURPOSE

To update the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline recommendations for human epidermal growth factor receptor 2 (HER2) testing in breast cancer to improve the accuracy of HER2 testing and its utility as a predictive marker in invasive breast cancer.

METHODS

ASCO/CAP convened an Update Committee that included coauthors of the 2007 guideline to conduct a systematic literature review and update recommendations for optimal HER2 testing.

RESULTS

The Update Committee identified criteria and areas requiring clarification to improve the accuracy of HER2 testing by immunohistochemistry (IHC) or in situ hybridization (ISH). The guideline was reviewed and approved by both organizations.

RECOMMENDATIONS

The Update Committee recommends that HER2 status (HER2 negative or positive) be determined in all patients with invasive (early stage or recurrence) breast cancer on the basis of one or more HER2 test results (negative, equivocal, or positive). Testing criteria define HER2-positive status when (on observing within an area of tumor that amounts to >10% of contiguous and homogeneous tumor cells) there is evidence of protein overexpression (IHC) or gene amplification (HER2 copy number or HER2/CEP17 ratio by ISH based on counting at least 20 cells within the area). If results are equivocal (revised criteria), reflex testing should be performed using an alternative assay (IHC or ISH). Repeat testing should be considered if results seem discordant with other histopathologic findings. Laboratories should demonstrate high concordance with a validated HER2 test on a sufficiently large and representative set of specimens. Testing must be performed in a laboratory accredited by CAP or another accrediting entity. The Update Committee urges providers and health systems to cooperate to ensure the highest quality testing.

Assessment of Her-2/neu status using immunocytochemistry and fluorescence in situ hybridization on fine-needle aspiration cytology smears: experience from a tertiary care centre in India

Breast carcinoma shows amplification/overexpression of Her-2/neu in ∼20-30% of cases. The determination of Her-2/neu expression accurately is vital in clinical practice as it has significant predictive value and eligibility for anti Her-2/neu therapy. Amplification and overexpression of Her-2/neu gene is traditionally identified by fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) on tissue sections; only a few studies have evaluated feasibility of these techniques on cytological smears. One hundred cases of breast cancer with fine-needle aspiration cytology (FNAC) samples and corresponding surgically resected specimen were selected. Immunocytochemistry (ICC) and FISH for Her-2/neu was done on FNA smears, whereas IHC was performed on corresponding tissue sections. Diagnostic accuracy of ICC was 99% when compared with IHC. Comparison of FISH results with IHC showed 100% concordance. Unlike many centers in West, FNAC is still routinely performed in developing countries like India where vast majority of breast cancer cases present as palpable lumps. The high rates of accuracy of ICC and FISH for Her-2/neu detection can make FNAC a relevant first line of investigation as a cost effective model with a rapid turn-around time, providing complete information necessary for initial management of breast cancer patients.

Recommendations for human epidermal growth factor receptor 2 testing in breast cancer: American Society of Clinical Oncology/College of American Pathologists clinical practice guideline update

PURPOSE

To update the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline recommendations for human epidermal growth factor receptor 2 (HER2) testing in breast cancer to improve the accuracy of HER2 testing and its utility as a predictive marker in invasive breast cancer.

METHODS

ASCO/CAP convened an Update Committee that included coauthors of the 2007 guideline to conduct a systematic literature review and update recommendations for optimal HER2 testing.

RESULTS

The Update Committee identified criteria and areas requiring clarification to improve the accuracy of HER2 testing by immunohistochemistry (IHC) or in situ hybridization (ISH). The guideline was reviewed and approved by both organizations.

RECOMMENDATIONS

The Update Committee recommends that HER2 status (HER2 negative or positive) be determined in all patients with invasive (early stage or recurrence) breast cancer on the basis of one or more HER2 test results (negative, equivocal, or positive). Testing criteria define HER2-positive status when (on observing within an area of tumor that amounts to > 10% of contiguous and homogeneous tumor cells) there is evidence of protein overexpression (IHC) or gene amplification (HER2 copy number or HER2/CEP17 ratio by ISH based on counting at least 20 cells within the area). If results are equivocal (revised criteria), reflex testing should be performed using an alternative assay (IHC or ISH). Repeat testing should be considered if results seem discordant with other histopathologic findings. Laboratories should demonstrate high concordance with a validated HER2 test on a sufficiently large and representative set of specimens. Testing must be performed in a laboratory accredited by CAP or another accrediting entity. The Update Committee urges providers and health systems to cooperate to ensure the highest quality testing. This guideline was developed through a collaboration between the American Society of Clinical Oncology and the College of American Pathologists and has been published jointly by invitation and consent in both Journal of Clinical Oncology and the Archives of Pathology & Laboratory Medicine.

Chromogenic in situ hybridization compared with other approaches to evaluate HER2/neu status in breast carcinomas

Human epidermal growth factor receptor 2 (HER2) has been evaluated in breast cancer patients to identify those most likely to benefit from herceptin-targeted therapy. HER2 amplification, detected in 20-30% of invasive breast tumors, is associated with reduced survival and metastasis. The most frequently used technique for evaluating HER2 protein status as a routine procedure is immunohistochemistry (IHC). HER2 copy number alterations have also been evaluated by fluorescence in situ hybridization (FISH) in moderate immunoexpression (IHC 2+) cases. An alternative procedure to evaluate gene amplification is chromogenic in situ hybridization (CISH), which has some advantages over FISH, including the correlation between HER2 status and morphological features. Other methodologies have also been used, such as silver-enhanced in situ hybridization (SISH) and quantitative real-time RT-PCR, to determine the number of HER2 gene copies and expression, respectively. Here we will present a short and comprehensive review of the current advances concerning HER2 evaluation in human breast cancer.

Testing for her2 in breast cancer: current pathology challenges faced in Canada

This review is designed to highlight several key challenges in the diagnosis of human epidermal growth factor receptor 2 (her2)-positive breast cancer currently faced by pathologists in Canada: Pre-analysis issues affecting the accuracy of her2 testing in non-excision sample types: core-needle biopsies, effusion samples, fine-needle aspirates, and bone metastasesher2 testing of core-needle biopsies compared with surgical specimensCriteria for retesting her2 status upon disease recurrenceLiterature searches for each topic were carried out using the medline, Embase, International Pharmaceutical Abstracts, and biosis databases. In addition, the congress databases of the American Society of Clinical Oncology (2005-2011) and the San Antonio Breast Cancer Symposium (2007-2011) were searched for relevant abstracts.All authors are expert breast pathologists with extensive experience of her2 testing, and several participated in the development of Canadian her2 testing guidelines. For each topic, the authors present an evaluation of the current data available for the guidance of pathology practice, with recommendations for the optimization or improvement of her2 testing practice.

Trastuzumab

Trastuzumab is standard of care in the treatment of human epidermal growth factor receptor (HER)-2⁺ early and advanced breast cancer. Recently, it has been approved for the treatment of HER-2⁺ advanced gastric cancer. Trastuzumab is an IgG1 humanized monoclonal antibody administered by intravenous infusion on a weekly or three weekly schedule. In all registered indications, trastuzumab is almost always given in combination with chemotherapy. In hormonal receptor-positive breast cancer in postmenopausal women, trastuzumab can be combined with an aromatase inhibitor. Main toxicity is reduction in the left ventricular ejection fraction, which in a minority of patients can become symptomatic, but in many patients is at least partly reversible. Long-term safety needs to be further determined.

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) Histopathology56, 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

The cooperation between hMena overexpression and HER2 signalling in breast cancer

hMena and the epithelial specific isoform hMena^11a are actin cytoskeleton regulatory proteins belonging to the Ena/VASP family. EGF treatment of breast cancer cell lines upregulates hMena/hMena^11a expression and phosphorylates hMena^11a, suggesting cross-talk between the ErbB receptor family and hMena/hMena^11a in breast cancer. The aim of this study was to determine whether the hMena/hMena^11a overexpression cooperates with HER-2 signalling, thereby affecting the HER2 mitogenic activity in breast cancer. In a cohort of breast cancer tissue samples a significant correlation among hMena, HER2 overexpression, the proliferation index (high Ki67), and phosphorylated MAPK and AKT was found and among the molecular subtypes the highest frequency of hMena overexpressing tumors was found in the HER2 subtype. From a clinical viewpoint, concomitant overexpression of HER2 and hMena identifies a subgroup of breast cancer patients showing the worst prognosis, indicating that hMena overexpression adds prognostic information to HER2 overexpressing tumors. To identify a functional link between HER2 and hMena, we show here that HER2 transfection in MCF7 cells increased hMena/hMena^11a expression and hMena^11a phosphorylation. On the other hand, hMena/hMena^11a knock-down reduced HER3, AKT and p44/42 MAPK phosphorylation and inhibited the EGF and NRG1-dependent HER2 phosphorylation and cell proliferation. Of functional significance, hMena/hMena^11a knock-down reduced the mitogenic activity of EGF and NRG1. Collectively these data provide new insights into the relevance of hMena and hMena^11a as downstream effectors of the ErbB receptor family which may represent a novel prognostic indicator in breast cancer progression, helping to stratify patients.

Chromogenic in situ hybridization to detect EGFR gene copy number in cell blocks from fine-needle aspirates of non small cell lung carcinomas and lung metastases from colo-rectal cancer

Background

Several studies demonstrated that epidermal growth factor receptor (EGFR) gene copy number (GCN) correlates to the response to tyrosine kinase inhibitors in non small cell lung cancer (NSCLC) and to anti-EGFR monoclonal antibodies (MoAbs) in metastatic colorectal cancer (CRC). In the presence of lung nodules, cytology is often the only possible diagnostic approach. Chromogenic in situ hybridization (CISH) is an alternative technique to fluorescence in situ hybridization (FISH), but its feasibility in detecting EGFR GCN in cell blocks from fine-needle aspiration cytology (FNAC) of lung nodules has not yet been established.

Methods

We evaluated the feasibility of CISH on 33 FNAC from 20 primary NSCLC (5 squamous carcinomas, 8 large cell carcinomas and 7 adenocarcinomas) and 13 lung metastases from CRC.

Results

Of the 33 FNAC analyzed by CISH, 27 (82%) presented a balanced increase in EGFR gene and chromosome 7 number: 10 cases (30%) showed a low polysomy, 15 (45%) a high polysomy and 2 (6%) NSCLC were amplified. No significant differences between NSCLC and CRC lung metastases were found in relation to disomic or polysomic status. In addition, no correlation between EGFR GCN and EGFR immunohistochemical overexpression was found. Furthermore, we compared CISH results with those obtained by FISH on the same samples and we found 97% overall agreement between the two assays (k = 0.78, p < 0.0001). Two cases were amplified with both assays, whereas 1 case of NSCLC was amplified by FISH only. CISH sensitivity was 67%, the specificity and positive predictive value (PPV) was 100%, and the negative predictive value (NPV) was 97%.

Conclusions

Our study shows that CISH is a valid method to detect EGFR GCN in cell blocks from FNAC of primary NSCLC or metastatic CRC to the lung.

Reproducibility of human epidermal growth factor receptor 2 analysis in primary breast cancer: a national survey performed at pathology departments in Sweden

BACKGROUND

HER2 is a treatment predictive factor for the effect of trastuzumab and associated with poor prognosis in breast cancer. The analysis of HER2 must be performed with good quality, with regard to both the immunohistochemical (IHC) and in situ hybridization (ISH) analysis.

MATERIAL AND METHODS

A tissue microarray (TMA) including 11 breast cancer samples was sent twice (once in 2005 and again in 2006) to 24 pathology departments in Sweden. A questionnaire was also sent to the departments in 2006.

RESULTS

With IHC, all departments reported the same results (0/1+ vs. 2+ vs. 3 + ) for three (2005) and six samples (2006). The mean kappa-value increased from 0.67 to 0.77, indicating a good reproducibility at both occasions. With fluorescence-ISH (FISH), the 11 departments using this technique reported the same results (amplified vs. normal) for nine (2005) and ten samples (2006). The mean kappa-value showed very good reproducibility both 2005 and 2006 (0.92 and 0.96, respectively). Based on the answers from the participating departments, the questionnaire revealed that 31% of primary breast cancer diagnosed in 2006 (n = 5 043) were 2 + /3+. FISH analysis of 2+ confirmed 12% of the samples to be amplified. The corresponding figure for 3 + was 90%. In total, 14.3% of the samples were HER2 positive (2+ and amplified, or 3 + ).

DISCUSSION

The results obtained in this study indicate that the reproducibility for HER2 analysis is good (IHC) and very good (FISH) between the pathology departments in Sweden using TMA-based tumor samples. In 2006, 14.3% of invasive breast cancers were HER2 positive.

Visualization of FISH Probes by dual-color chromogenic in situ hybridization

The overall purpose of the study was to demonstrate applicability of the DAKO dual-color chromogenic in situ hybridization (CISH) assay (DAKO Denmark, Glostrup) with respect to 4 fluorescence in situ hybridization (FISH) probes: MYC (c-MYC), EGFR, ERBB2 (HER2), and TOP2A. The study showed that the dual-color CISH assay can convert Texas red and fluorescein isothiocyanate (FITC) signals into chromogenic signals with an almost complete 1:1 conversion ratio. Agreement studies between the FISH assays for HER2 and TOP2A and the corresponding CISH conversion assays showed 100% concordance (kappa values of 1.0) between the CISH and FISH methods for HER2 and TOP2A status. The correlations of the gene copy number to centromere-17 ratios were similarly high, with a correlation coefficient (r) for HER2 and TOP2A of more than 0.95. Owing to the relatively small number of specimens in this study, it is important that the data are confirmed in a larger study.

Emerging technologies for assessing HER2 amplification

Patients with human epidermal growth factor receptor-2 (HER2)+ breast cancer are eligible for trastuzumab treatment; therefore, accurate assessment of HER2 status is essential. Until recently, only 2 methods were validated for determining the HER2 status of breast tumors in the routine diagnostic setting: immunohistochemical analysis and fluorescence in situ hybridization (FISH). Recently, bright-field in situ hybridization techniques such as chromogenic in situ hybridization (CISH) and silver-enhanced in situ hybridization (SISH), which combine features of immunohistochemical analysis and FISH, have been introduced for the determination of HER2 status. These new techniques use a peroxidase enzyme-labeled probe with chromogenic detection, instead of a fluorescent-labeled probe, allowing results to be visualized by standard bright-field microscopy. Thus, the histologic features and HER2 status of a specimen can be evaluated in parallel. Moreover, signals do not decay over time. This review discusses recent publications regarding CISH and SISH testing, including results scoring and concordance between FISH and immunohistochemical analysis.

Immunohistochemical detection of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 expression in breast carcinomas: comparison on cell block, needle-core, and tissue block preparations

BACKGROUND

Fine-needle aspiration (FNA) is a rapid and accurate procedure for the detection of breast carcinomas. The evaluation of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) expression by immunohistochemistry (IHC) is performed routinely on formalin-fixed, paraffin-embedded needle-core (NC) or excision tissue block (TB) preparations, according to the American Society of Clinical Oncology/College of American Pathologist guidelines. In this retrospective study, the authors compared expression levels of ER, PR, and HER2 in ethanol-fixed BC FNA cell block (CB) samples with expression levels in formalin-fixed NC and TB samples.

METHODS

Forty-one breast carcinoma CB samples with concurrent or subsequent NC and TB samples were identified. Patients who had received neoadjuvant or adjuvant chemotherapy were excluded. CB samples initially were fixed in 50% ethanol (4-12 hours), and this was followed by formalin fixation (minimum, 6 hours). NC samples were placed promptly in formalin for a minimum of 6 hours. Within 4 to 8 hours, TB samples were fixed in formalin for 6 to 48 hours. Fluorescence in situ hybridization (FISH) results were also compared.

RESULTS

IHC for ER on alcohol-fixed CB samples had good correlation with NC and TB samples. PR results on TB samples had excellent agreement with NC samples. A higher discordance rate wais observed when PR results were compared between CB samples and NC samples. HER2 detection on ethanol-fixed CB samples resulted in a higher rate of positive and equivocal staining than NC or TB samples. HER2 IHC on TB samples demonstrated better correlation with FISH results than CB or NC samples.

CONCLUSIONS

Alcohol fixation did not affect ER results in breast carcinoma, but it may alter tumor cell PR antigenicity. The authors concluded that CB samples could be used to triage patients for tamoxifen therapy, but they are not reliable for the assessment of HER2 status; therefore, CB results should be correlated with results from NC or TB samples.

Quantitative real-time RT-PCR and chromogenic in situ hybridization: precise methods to detect HER-2 status in breast carcinoma

Background

HER-2 gene testing has become an integral part of breast cancer patient diagnosis. The most commonly used assay in the clinical setting for evaluating HER-2 status is immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). These procedures permit correlation between HER-2 expression and morphological features. However, FISH signals are labile and fade over time, making post-revision of the tumor difficult. CISH (chromogenic in situ hybridization) is an alternative procedure, with certain advantages, although still limited as a diagnostic tool in breast carcinomas.

Methods

To elucidate the molecular profile of HER-2 status, mRNA and protein expression in 75 invasive breast carcinomas were analyzed by real time quantitative RT-PCR (qRT-PCR) and IHC, respectively. Amplifications were evaluated in 43 of these cases by CISH and in 11 by FISH.

Results

The concordance rate between IHC and qRT-PCR results was 78.9%, and 94.6% for qRT-PCR and CISH. Intratumoral heterogeneity of HER-2 status was identified in three cases by CISH. The results of the three procedures were compared and showed a concordance rate of 83.8%; higher discordances were observed in 0 or 1+ immunostaining cases, which showed high-level amplification (15.4%) and HER-2 transcript overexpression (20%). Moreover, 2+ immunostaining cases presented nonamplified status (50%) by CISH and HER-2 downexpression (38.5%) by qRT-PCR. In general, concordance occurred between qRT-PCR and CISH results. A high concordance was observed between CISH/qRT-PCR and FISH. Comparisons with clinicopathological data revealed a significant association between HER-2 downexpression and the involvement of less than four lymph nodes (P = 0.0350).

Conclusion

Based on these findings, qRT-PCR was more precise and reproducible than IHC. Furthermore, CISH was revealed as an alternative and useful procedure for investigating amplifications involving the HER-2 gene.

Evaluation of immunohistochemistry and enzyme linked immunosorbent assay for HER-2/neu expression in breast carcinoma

HER-2 is overexpressed in approximately 20-30% of invasive Breast Cancer. ECD of the HER-2 protein is frequently cleaved and released into the circulation, where it can be detected by ELISA in up to 45% of patients with metastatic breast cancer. The objective of our study was to compare the current methods for the detection of HER-2 protein. Tissue HER-2 levels were studied in 100 breast cancer patients by IHC and compared with serum HER-2 levels by ELISA. IHC frequency was 29%. Serum HER-2 ECD was positive in 42% of patients. A statistically significant correlation was observed. HER-2 detected by IHC correlates significantly with serum HER-2 levels detected by ELISA. Thus, ELISA is a reliable and economical tool to assess the HER-2 status in tumors, when breast tissue sample is not available.

HER2 evaluation using the novel rabbit monoclonal antibody SP3 and CISH in tissue microarrays of invasive breast carcinomas

BACKGROUND

Laboratory methods for HER2 assessment currently include immunohistochemical (IHC) methods (measuring protein overexpression) and fluorescence in situ hybridisation (FISH) (measuring gene amplification). The measure of HER2 protein by IHC is usually assessed by the mouse monoclonal antibody CB11, and polyclonal antibodies (Herceptest) directed against the internal portion of the receptor. Recently, chromogenic in situ hybridisation (CISH), in which HER2 is detected by a peroxidase reaction and the gene amplification can be determined by regular bright-field microscopy, has emerged as an alternative to FISH.

AIMS

To evaluate the status of HER2 in tissue microarrays (TMAs) of invasive breast cancer using the novel rabbit monoclonal antibody SP3 directed against the external portion of HER2, and correlate the results with CB11 and CISH.

METHODS

IHC was performed with two antibodies (CB11 and SP3) and CISH for HER2 in 10 TMA blocks with 190 formalin-fixed paraffin-embedded cases of invasive breast carcinomas.

RESULTS

The correlation between SP3 and CB11 was significant (p<0.001) with an agreement rate of 86.9%. When the staining pattern of the two antibodies was compared, the majority of SP3 immunostainings were assessed more easily, with a strong complete membrane staining pattern without non-specific cytoplasmic staining. There was a good correlation between SP3 and CISH (p<0.001). 23/24 SP3 3+ cases showed gene amplification, 97.3% of the cases without gene amplification were SP3 negative, and 6/7 SP3 2+ were amplified.

CONCLUSION

The high level of agreement between SP3, a monoclonal antibody that recognises the extracellular domain of the HER2 receptor, and CB11 and CISH, shows that this novel antibody is a reliable candidate to evaluate the expression of HER2 in breast cancer.