Accuracy of HER2 status determination on breast core-needle biopsies (immunohistochemistry, FISH, CISH and SISH vs FISH)

The Clinical Utility of lncRNAs and Their Application as Molecular Biomarkers in Breast Cancer

Given their tumor-specific and stage-specific gene expression, long non-coding RNAs (lncRNAs) have demonstrated to be potential molecular biomarkers for diagnosis, prognosis, and treatment response. Particularly, the lncRNAs DSCAM-AS1 and GATA3-AS1 serve as examples of this because of their high subtype-specific expression profile in luminal B-like breast cancer. This makes them candidates to use as molecular biomarkers in clinical practice. However, lncRNA studies in breast cancer are limited in sample size and are restricted to the determination of their biological function, which represents an obstacle for its inclusion as molecular biomarkers of clinical utility. Nevertheless, due to their expression specificity among diseases, such as cancer, and their stability in body fluids, lncRNAs are promising molecular biomarkers that could improve the reliability, sensitivity, and specificity of molecular techniques used in clinical diagnosis. The development of lncRNA-based diagnostics and lncRNA-based therapeutics will be useful in routine medical practice to improve patient clinical management and quality of life.

Her2 Status Discrepancy Between Core Needle Biopsy and Surgically Resected Mastectomy Specimen: A Clinical Case

The biomarker concordance between core needle biopsy (CNB) and surgical specimen (SS), in breast cancer, has long been a matter of discussion because of its influence on oncologic treatment choice. Particularly, human epidermal growth factor receptor 2 (Her2) status is quite important, because of the impact on breast cancer classification and target therapy. Many factors could influence the difference in biomarker status between samples, such as the technic itself, sample procedures and intratumoral heterogeneity. Neoadjuvant chemotherapy (NAC) can also contribute to this variation and should be taken into consideration. We report a clinical case of a 33-year-old man who was diagnosed with right breast cancer, initially Her2 negative in the CNB. Therefore, the NAC was completed without anti-Her2 treatment. Later, after the mastectomy, revision of the SS was found to be positive for Her2, after the silver in situ hybridization (SISH) technique. Consequently, the patient lost the chance of doing anti-Her2 therapy in the neoadjuvant setting, reducing his possibility to achieve a complete pathologic response and later jeopardizing his clinical outcome.

Concordance between core needle biopsy and surgical excision for breast cancer tumor grade and biomarkers

PURPOSE

Histopathological biomarkers guide breast cancer management. Testing histopathological biomarkers on both core needle biopsy (CNB) and surgical excision (SE) in patients who are treated with upfront surgery is unnecessary and costly if there is high concordance between the two. This study investigated the concordance between CNB and SE for estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor-2 (HER2), tumor grade and Ki-67.

METHODS

Histopathological biomarker information were retrospectively collected from preoperative CNB and SE on patients diagnosed with breast cancer through the BreastScreen Sydney West program over a four-year period between January 2017 and December 2020. Data were then analyzed to calculate percentage of agreement and concordance using kappa values for ER, PR, HER2, tumor grade and Ki-67.

RESULTS

A total of 504 cases of invasive breast cancers were analyzed. There was substantial level of concordance for ER 96.7% (κ = 0.687) and PR 93.2% (κ = 0.69). Concordance for HER2 negative (IHC 0, IHC 1 +) or positive (IHC 3 +) tumor on CNB was 100% (κ = 1.00). Grade and Ki-67 showed moderate level of concordance, 72.6% (κ = 0.545) and 70.5% (κ = 0.453), respectively.

CONCLUSION

ER, PR and HER2 show high level of concordance. CNB is reliable in determining histopathological biomarkers for ER, PR positive and HER2 positive or negative tumors indicating that retesting these on SE may not be necessary.

[2021 update of the GEFPICS' recommendations for HER2 status assessment in invasive breast cancer in France]

The last international guidelines on HER2 determination in breast cancer have been updated in 2018 by the American Society of Clinical Oncology and College of American Pathologists, on the basis of a twenty-year practice and results of numerous clinical trials. Moreover, the emerging HER2-low concept for 1+ and 2+ non amplified breast cancers lead to refine French practices for HER2 status assessment. The GEFPICS group, composed of expert pathologists, herein presents the latest French recommendations for HER2 status evaluation in breast cancer, taking into account the ASCO/CAP guidelines and introducing the HER2-low concept. In the era of personalized medicine, HER2 status assessment remains one of the most important biomarkers in breast cancer and its quality guaranties the optimal patients' care. French pathologists' commitment in theranostic biomarker quality is more than ever required to provide the most efficient cares in oncology.

Cytogenetic and Biochemical Genetic Techniques for Personalized Drug Therapy in Europe

For many authorized drugs, accumulating scientific evidence supports testing for predictive biomarkers to apply personalized therapy and support preventive measures regarding adverse drug reactions and treatment failure. Here, we review cytogenetic and biochemical genetic testing methods that are available to guide therapy with drugs centrally approved in the European Union (EU). We identified several methods and combinations of techniques registered in the Genetic Testing Registry (GTR), which can be used to guide therapy with drugs for which pharmacogenomic-related information is provided in the European public assessment reports. Although this registry provides information on genetic tests offered worldwide, we identified limitations regarding standard techniques applied in clinical practice and the information on test validity rarely provided in the according sections.

Novel Tyrosine Kinase Targets in Urothelial Carcinoma

Urothelial carcinoma represents one of the most prevalent types of cancer worldwide, and its incidence is expected to grow. Although the treatment of the advanced disease was based on chemotherapy for decades, the developments of different therapies, such as immune checkpoint inhibitors, antibody drug conjugates and tyrosine kinase inhibitors, are revolutionizing the therapeutic landscape of this tumor. This development coincides with the increasing knowledge of the pathogenesis and genetic alterations in urothelial carcinoma, from the non-muscle invasive setting to the metastatic one. The purpose of this article is to provide a comprehensive review of the different tyrosine kinase targets and their roles in the therapeutic scene of urothelial carcinoma.

Impact of the 2018 ASCO/CAP guidelines on HER2 fluorescence in situ hybridization interpretation in invasive breast cancers with immunohistochemically equivocal results

The American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) recently issued updated guidelines on human epidermal growth factor receptor 2 (HER2) testing by fluorescence in situ hybridization (FISH) in invasive breast cancers. In this study, we aimed to investigate the impact of the new recommendations on HER2 FISH interpretation in invasive breast cancers with immunohistochemically (IHC) equivocal results. 1810 breast cancer cases with IHC equivocal results were enrolled in this study between January 2012 and May 2019. Concomitant IHC was performed on the same tissue blocks detected by FISH testing. According to the 2018 guidelines, all the cases in ISH group 2 were categorized as HER2 negative; three of four cases in ISH group 3 were considered as HER2 positive, while the one scored IHC 1+ was reclassified as HER2 negative; Fifty-three previously ISH equivocal cases were redistributed into ten HER2-positive cases and forty-three HER2-negative cases. In conclusion, the utility of 2018 ASCO/CAP guidelines resulted in a slight decrease in HER2 positive rate, due to the reclassification of cases in ISH group 2 and group 4. The implementation of the new guidelines can reduce reflex FISH test and make the diagnosis of HER2 gene status more definitive.

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.

Breast cancer global tumor biomarkers: a quality assurance study of intratumoral heterogeneity

Biomarker analysis of invasive breast carcinoma is useful for prognosis, as surrogate for molecular subtypes of breast cancer, and prediction of response to adjuvant and neoadjuvant systemic therapies. Breast cancer intratumoral heterogeneity is incompletely studied. Comprehensive biomarker analysis of estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki67 labeling index was performed on each tissue block of 100 entirely submitted breast tumors in 99 patients. Invasive carcinoma and in situ carcinoma was scored using semiquantitative histologic score (H-score) for ER and PR, HER2 expression from 0 to 3+, and percentage positive cells for Ki67. Core biopsy results were compared with surgical excision results, invasive carcinoma was compared with in situ carcinoma, and interblock tumoral heterogeneity was assessed using measures of dispersion (coefficient of variation and quartile coefficient of dispersion). Overall concordance between core biopsy and surgical excision was 99% for ER and 95% for PR. Mean histologic score of ER was significantly lower in invasive carcinoma between core biopsy and surgical excision (p = 0.000796). Intratumoral heterogeneity was higher for PR than for ER (mean coefficient of variation for ER 0.08 stdv 0.13 vs. PR 0.26 stdv 0.41). Ki67 labeling index was significantly higher in invasive carcinoma as compared with associated ductal carcinoma in situ on surgical resection specimen (p ≤ 0.0001). Ki67 hotspots were identified in 47% of cases. Of 52 HER2 negative cases on core biopsy, 10 were scored as equivocal on surgical resection. None (0/10) were amplified by Her-2/neu fluorescence in situ hybridization. Overall, biomarkers on core biopsy showed concordance with the surgical excision specimen in the vast majority of cases. Biomarker expression of in situ closely approximates associated invasive carcinoma. Intratumoral heterogeneity of PR is greater than ER. Biomarker expression on diagnostic core biopsy or single tumor block is representative of breast carcinoma as a whole in most cases and is appropriate for clinical decision-making.

Breast Cancer Tissue Markers, Genomic Profiling, and Other Prognostic Factors: A Primer for Radiologists

An understanding of prognostic factors in breast cancer is imperative for guiding patient care. Increased tumor size and more advanced nodal status are established independent prognostic factors of poor outcomes and are incorporated into the American Joint Committee on Cancer (AJCC) TNM (primary tumor, regional lymph node, distant metastasis) staging system. However, other factors including imaging findings, histologic evaluation results, and molecular findings can have a direct effect on a patient's prognosis, including risk of recurrence and relative survival. Several microarray panels for gene profiling of tumors are approved by the U.S. Food and Drug Administration and endorsed by the American Society of Clinical Oncology. This article highlights prognostic factors currently in use for individualizing and guiding breast cancer therapy and is divided into four sections. The first section addresses patient considerations, in which modifiable and nonmodifiable prognostic factors including age, race and ethnicity, and lifestyle factors are discussed. The second part is focused on imaging considerations such as multicentric and/or multifocal disease, an extensive intraductal component, and skin or chest wall involvement and their effect on treatment and prognosis. The third section is about histopathologic findings such as the grade and presence of lymphovascular invasion. Last, tumor biomarkers and tumor biology are discussed, namely hormone receptors, proliferative markers, and categorization of tumors into four recognized molecular subtypes including luminal A, luminal B, human epidermal growth factor receptor 2-enriched, and triple-negative tumors. By understanding the clinical effect of these prognostic factors, radiologists, along with a multidisciplinary team, can use these tools to achieve individualized patient care and to improve patient outcomes. ^©RSNA, 2018.

Single-day HER2neu amplification assessment using chip-based digital PCR in formalin-fixed paraffin-embedded breast carcinoma tissue

Introduction

Human epidermal growth factor receptor 2 (HER2) amplification is present in almost 15%–20% of breast cancer tumors, making it an important parameter for testing. The present study was designed to evaluate a chip-based digital PCR (dPCR) system for assessing HER2 amplification from formalin-fixed paraffin-embedded breast carcinoma tissue and to compare this system with immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH).

Materials and methods

A total of 84 breast carcinoma tissue samples were analyzed by IHC, FISH, and chip-based dPCR in a blinded manner.

Results

All nine IHC-positive and 35 IHC-negative samples had equivalent results with dPCR, taking an amplification ratio threshold of 1.8 as a positive result. Of the 40 IHC equivocal samples, 10 were assessed as positive, 27 as negative, and three as equivocal by dPCR.

Conclusion

These results demonstrate that chip-based dPCR is suitable for HER2 amplification detection in formalin-fixed paraffin-embedded samples in a clinical setting, providing the advantages of superior turnaround time, cost-effectiveness, and increased precision with absolute quantification compared with conventional tests such as FISH and IHC. This methodology was especially beneficial in tissue samples with low DNA concentration.

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.

Predicting discordant HER2 results in ipsilateral synchronous invasive breast carcinomas: experience from a single institution

With the emergence of multiple lines of highly effective Human Epidermal Growth Factor Receptor 2 (HER2) directed therapy, accurate identification of HER2 positive tumour has become a critical aspect in the histopathological analysis of breast cancers. Multifocal invasive breast carcinomas are relatively common, and given the aggressive inherent biology of HER2 positive disease, identification of even small tumours with HER2 positive status may be of importance for treatment planning. There are currently no clear guidelines as to whether all of these foci should be tested for HER2 status. We reviewed the results of 172 patients in whom HER2 in situ hybridisation (ISH) testing was performed on at least two ipsilateral synchronous invasive carcinomas. Discordant results in different invasive foci were relatively uncommon and occurred in only eight (5%) of the 172 patients. This showed a statistically significant correlation with similarly discordant oestrogen receptor (ER) results. In addition HER2 discordance was more likely amongst different tumour foci if these arose in distinct and separate areas of DCIS. An algorithm based on a combination of College of American Pathologists (CAP) recommendation for HER2 testing, differing ER status and background DCIS profile may be useful in detecting these discordant cases.

Pattern of HER-2 Gene Amplification and Protein Expression in Benign, Borderline, and Malignant Ovarian Serous and Mucinous Neoplasms

Amplification of HER-2 gene and overexpression of HER-2 receptor play a significant role in the progression of a number of malignancies such as breast cancer. Trastuzumab (anti-HER-2 therapeutic agent) has been used successfully in treatment of breast cancer. The aim of this study was to assess the pattern of HER-2 gene amplification and of HER-2 receptor expression in a spectrum of serous and mucinous ovarian tumors to determine whether HER-2 is altered in these neoplasms similar to that occurring in breast cancer. Formalin-fixed paraffin-embedded microarray tissue sections from 212 specimens were stained with HER-2 antibody using immunohistochemistry and with anti-HER-2 DNA probe using chromogenic in situ hybridization. Specimens consisted of 65 benign tumors (50 serous and 15 mucinous), 26 borderline (13 serous and 13 mucinous), 73 malignant tumors (53 serous carcinoma and 20 mucinous carcinoma), 18 metastatic deposits (13 serous and 5 mucinous), in addition to 30 normal tissues (16 ovarian surface and 14 normal fallopian tube). HER-2 protein-positive expression was not detected in the normal or the benign tissues. Borderline neoplasms showed positive staining, but no overexpression. HER-2 overexpression was seen only in 4 carcinoma specimens: 1/53 (1.8%) primary serous carcinomas and 3/20 (15%) primary mucinous carcinomas. HER-2 gene amplification was seen in 4 specimens: 2 primary mucinous carcinomas and 2 malignant deposits of these 2 mucinous carcinomas. In conclusion, alteration of HER-2 was not detected in ovarian serous neoplasms; however, in mucinous carcinoma, HER-2 amplification and overexpression occur.

Significant intratumoral heterogeneity of human epidermal growth factor receptor 2 status in gastric cancer: A comparative study of immunohistochemistry, FISH, and dual-color in situ hybridization

The assessment of human epidermal growth factor receptor 2 (HER2) status is crucial for selecting patients with gastric cancer who may benefit from HER2‐targeted therapy. Accurate assessment using biopsy specimens is important for patients with advanced‐stage cancer. Intratumoral heterogeneity of HER2, however, is a major challenge in HER2 testing. Here, we aimed to examine whether assessment of HER2 status could be accurately carried out with currently used methods, namely, immunohistochemistry (IHC), FISH, and dual‐color in situ hybridization (DISH). Human epidermal growth factor receptor 2 status was evaluated in 108 biopsy tissues from patients with gastric adenocarcinoma and 70 matched surgical specimens by IHC, FISH, and DISH; HER2 amplification was detected in 11 (10.2%) out of 108 biopsy specimens. The IHC and FISH results were well correlated, and FISH and DISH results were consistent for all cases. The overall concordance rate of HER2 status between biopsy tissues and surgical specimens was 91.4%. All six discordant cases were false negative on biopsy; of these cases, five showed HER2 heterogeneity on surgical resection. Assessment of the HER2 status of biopsy tissues could predict the status of the whole tumor; however, a proportion of these cases may be discordant because of intratumoral heterogeneity.

This study demonstrated that HER2 assessment in biopsy tissues may predict the HER2 status of the whole tumor by IHC, FISH, and DISH. However, some cases of discordance may occur because of intratumoral HER2 heterogeneity in gastric cancers. In cases of intratumoral heterogeneity, more accurate HER2 assessment can be achieved by analysis of whole sections and by using a combination of IHC and DISH, if possible.

The prognostic role of HER2 expression in ductal breast carcinoma in situ (DCIS); a population-based cohort study

Background

HER2 is a well-established prognostic and predictive factor in invasive breast cancer. The role of HER2 in ductal breast carcinoma in situ (DCIS) is debated and recent data have suggested that HER2 is mainly related to in situ recurrences. Our aim was to study HER2 as a prognostic factor in a large population based cohort of DCIS with long-term follow-up.

Methods

All 458 patients diagnosed with a primary DCIS 1986–2004 in two Swedish counties were included. Silver-enhanced in situ hybridisation (SISH) was used for detection of HER2 gene amplification and protein expression was assessed by immunohistochemistry (IHC) in tissue microarrays. HER2 positivity was defined as amplified HER2 gene and/or HER2 3+ by IHC. HER2 status in relation to new ipsilateral events (IBE) and Invasive Breast Cancer Recurrences, local or distant (IBCR) was assessed by Kaplan-Meier survival analyses and Cox proportional hazards regression models.

Results

Primary DCIS was screening-detected in 75.5 % of cases. Breast conserving surgery (BCS) was performed in 78.6 % of whom 44.0 % received postoperative radiotherapy. No patients received adjuvant endocrine- or chemotherapy. The majority of DCIS could be HER2 classified (N = 420 (91.7 %)); 132 HER2 positive (31 %) and 288 HER2 negative (69 %)). HER2 positivity was related to large tumor size (P = 0.002), high grade (P < 0.001) and ER- and PR negativity (P < 0.001 for both). During follow-up (mean 184 months), 106 IBCRs and 105 IBEs were identified among all 458 cases corresponding to 54 in situ and 51 invasive recurrences. Eighteen women died from breast cancer and another 114 had died from other causes. The risk of IBCR was statistically significantly lower subsequent to a HER2 positive DCIS compared to a HER2 negative DCIS, (Log-Rank P = 0.03, (HR) 0.60 (95 % CI 0.38–0.94)). Remarkably, the curves did not separate until after 10 years. In ER-stratified analyses, HER2 positive DCIS was associated with lower risk of IBCR among women with ER negative DCIS (Log-Rank P = 0.003), but not for women with ER positive DCIS.

Conclusions

Improved prognostic tools for DCIS patients are warranted to tailor adjuvant therapy. Here, we demonstrate that HER2 positive disease in the primary DCIS is associated with lower risk of recurrent invasive breast cancer.

Evaluation of HER2 Gene Status in Breast Cancer Samples with Indeterminate Fluorescence in Situ Hybridization by Quantitative Real-Time PCR

Administration of drugs targeting HER2 (official symbol ERBB2) is an important component of therapy for breast cancer patients with HER2 amplification/overexpression as determined by in situ hybridization (ISH) and immunohistochemistry (IHC). In approximately 5% of breast cancers, ISH assays fail. In these cases, HER2 protein expression is evaluated by IHC alone that may yield false negatives/positives for poor-quality samples. Therefore, we developed a method that was based on quantitative real-time PCR applicable for DNA from formalin-fixed, paraffin-embedded tissue samples. Its limit of detection was determined with breast cancer cell lines and validated with 223 breast cancer patient samples. On the basis of comparisons with fluorescent ISH (FISH) and IHC data, the sensitivity of the new method was 94.2% and 95.1%, its specificity was 100% and 99.1%, and overall concordance between results obtained with the quantitative real-time PCR method and FISH/IHC was 97.6% for both methods. The quantitative real-time PCR method was then used to evaluate the HER2 status of 198 of 3696 breast cancer tissues that yielded indeterminate FISH results. The HER2 copy number was successfully determined in 69.2% of these indeterminate samples. Thus, the DNA-based technique appears to be a specific, sensitive method for determining HER2 copy numbers when the FISH assay fails, which may complement IHC tests.

HER2 assessment by silver in situ hybridization: where are we now?

HER2 testing in breast and gastric cancer is critical not only as a prognostic tool but also as a predictive marker for response to the humanized monoclonal antibody trastuzumab. Currently, HER2 status is assessed on histological and cytological specimens by conventional validated methods such as immunohistochemistry and FISH, while bright-field in situ hybridization techniques, such as silver in situ hybridization and chromogenic in situ hybridization, may offer performance benefits over FISH. The major points are first, technical issues, advantages and disadvantages relevant to each methods, and their clinical implications and second, the well-known genetic heterogeneity of HER2, and the occurrence of polysomy of chromosome 17. This review aims to summarize the growing body of literature on the accuracy of bright-field in situ techniques, notably silver in situ hybridization, in assessing HER2 status, and to discuss the role of such methods in pathology practice.

Updated UK Recommendations for HER2 assessment in breast cancer

Human epidermal growth factor receptor 2 (HER2) overexpression is present in approximately 15% of early invasive breast cancers, and is an important predictive and prognostic marker. The substantial benefits achieved with anti-HER2 targeted therapies in patients with HER2-positive breast cancer have emphasised the need for accurate assessment of HER2 status. Current data indicate that HER2 test accuracy improved following previous publication of guidelines and the implementation of an external quality assessment scheme with a decline in false-positive and false-negative rates. This paper provides an update of the guidelines for HER2 testing in the UK. The aim is to further improve the analytical validity and clinical utility of HER2 testing by providing guidelines of test performance parameters, and recommendations on the postanalytical interpretation of test results. HER2 status should be determined in all newly diagnosed and recurrent breast cancers. Testing involves immunohistochemistry with >10% complete strong membrane staining defining a positive status. In situ hybridisation, either fluorescent or bright field chromogenic, is used either upfront or in immunohistochemistry borderline cases to detect the presence of HER2 gene amplification. Situations where repeat HER2 testing is advised are outlined and the impact of genetic heterogeneity is discussed. Strict quality control and external quality assurance of validated assays are essential. Testing laboratories should perform ongoing competency assessment and proficiency tests and ensure the reliability and accuracy of the assay. Pathologists, oncologists and surgeons involved in test interpretation and clinical use should adhere to published guidelines and maintain accurate performance and consistent interpretation of test results.

Concomitant detection of HER2 protein and gene alterations by immunohistochemistry (IHC) and silver enhanced in situ hybridization (SISH) identifies HER2 positive breast cancer with and without gene amplification

Introduction

HER2 status assessment became a mandatory test assay in breast cancer, giving prognostic and predictive information including eligibility for adjuvant anti-HER2 therapy. Precise and reliable assessment of HER2 status is therefore of utmost importance. In this study we analyzed breast cancer samples by a novel technology for concomitant detection of the HER2 protein and gene copy number.

Methods

Tissue microarrays containing 589 invasive breast cancer samples were analyzed with a double immunohistochemistry (IHC) and silver labeled in situ hybridization (SISH) assay simultaneously detecting HER2 protein and gene copy number in the same tumor cells. This bright-field assay was analyzed using scores according to the modified ASCO guidelines and the results were correlated with patient prognosis.

Results

Overall concordance rate between protein expression and the presence of gene amplification was 98%. Fifty-seven of 60 tumors (95%) with IHC score 3+, 6 of 10 tumors with IHC score 2+ (60%) and only 3 of 519 tumors (0.6%) with IHC score 0/1+ were amplified by SISH. Patients with gene amplification despite IHC score 0/1+ had a tendency for worse overall survival (p = 0.088, reaching nearly statistical significance) compared to IHC score 0/1+ without amplification. In contrast, there was no difference in overall survival in IHC score 3+/2+ tumors with and without gene amplification.

Conclusions

The novel double IHC and SISH assay for HER2 is efficient in the identification of breast cancer with discordant HER2 protein and HER2 gene status, especially for the prognostically relevant groups of HER2 protein negative tumors with HER2 amplification and HER2 protein positive tumors without HER2 amplification. Breast cancer without HER2 amplification among IHC score 2+/3+ tumors (10% in our cohort) suggests that other mechanisms than gene amplification contribute to protein overexpression in these cells.

Determination of HER2 gene amplification in breast cancer using dual-color silver enhanced in situ hybridization (dc- SISH) and comparison with fluorescence ISH (FISH)

BACKGROUND

The two basic methods that are currently accepted to identify the HER2 status are immunohistochemistry and flyorescence in situ hybridization (FISH) . The aim of this study was to perform the dual-color silver in situ hybridization (dc-SISH) technique as an alternative to FISH.

MATERIALS AND METHODS

A total of 40 invasive breast carcinoma cases were assessed for HER2 gene amplification by FISH and dual- color SISH.

RESULTS

Significant correlation was found in the HER2 expression results obtained with the two approaches (p=0.001, p<0.05). The concordance rate was 92.3%.

CONCLUSIONS

Foutine practical use of the dc-SISH method, which is much easier to apply, score, and evaluate, has many advantages. HER2 and CEN17 status can be evaluated simultaneously with the newly developed "Dual-Color Probe". All these specifications and the reliable results obtained support the widespread use of SISH technique in clinical practice.

Assessment of HER2 status in breast cancer: overall positivity rate and accuracy by fluorescence in situ hybridization and immunohistochemistry in a single institution over 12 years: a quality control study

Background

The gold standard of HER2 status assessment in breast cancer is still debated. Immunohistochemistry (IHC) and in-situ technology as fluorescent-labeled methodology (FISH) can be influenced by pre-analytical factors, assay-conditions and interpretation of test results. We retrospectively conducted this quality control study and analyzed HER2 test results in breast cancer within the routine diagnostic service in a single institution over a period of 12 years. We addressed the question how stable and concordant IHC and FISH methods are and whether HER2 positivity rate has changed over this period.

Methods

Data of 7714 consecutive HER2-FISH-assays in a period of 12 years (2001–2012) on breast cancer biopsies and excision specimens were retrospectively analyzed. From 2001 to 2004, FISH tests were performed from all cases with IHC score 3+ and 2+ (and in some tumors with IHC score 1+ and 0). From 2005–2010, HER2 status was only determined by FISH. From 2011–2012, all breast carcinomas were analyzed by both IHC and FISH. Scoring and cut-off-definition were done according to time-current ASCO-CAP and FDA-guidelines.

Results

Between 2001–2004, IHC score 3+ was diagnosed in 22% of cases, 69% of these 3+ cases were amplified by FISH. 6% of IHC score 0/1+ cases were amplified by FISH. There was a mean amplification rate of 15.8% (range 13 -19%) using FISH only HER2-assays (2005–2010). Starting 2008, a slight drop in the amplification rate from 17% to 14% was noticed due to the modified ASCO-criteria in 2007. From 2011–2012, 12% of cases were 3+ by IHC, 84% of them were amplified by FISH. Less than 1% of IHC score 0/1+ cases were amplified by FISH. Concordance between FISH and IHC increased from 83% to 97%.

Conclusions

Our quality control study demonstrates that HER2 positivity rate remained stable by FISH-technology but showed a significant variation by IHC over the analyzed 12 years. Improvement in concordance rate was due to standardization of pre-analytical factors, scoring and interpretation.

Instant-quality fluorescence in-situ hybridization as a new tool for HER2 testing in breast cancer: a comparative study

AIMS

HER2 instant-quality fluorescence in-situ hybridization (IQFISH) is a new fluorescence in-situ hybridization (FISH) assay developed with a non-toxic buffer that reduces the hybridization time to 1-2 h, enabling a turnaround time of 3 h 30 min from dewax to counting. The aim of this study was to compare assessment of HER2 status using IQFISH and assessment using standard FISH.

METHODS AND RESULTS

We selected 160 breast cancer samples according to their HER2 status as determined by immunohistochemistry (IHC) in a retrospective multicentre cohort (40 cases in each scoring category, i.e. 0/1+/2+/3+). Each participating site (n = 5) constructed its tissue microarray (TMA) of 32 archival cases and sent it to the central site (site 1). HER2 IHC, HER2 FISH and HER2 IQFISH were performed blindly at site 1. IQFISH provided excellent quality signals without any background staining, thus allowing excellent reading conditions even on TMA. Statistical analysis showed almost perfect agreement between IQFISH and FISH (99.3%, κ = 0.98). The only discordant case was an equivocal one with an HER2/CEP17 ratio near the ASCO/CAP cut-off.

CONCLUSIONS

The highly concordant data support IQFISH as a useful alternative to FISH, allowing reliable assessment of HER2 status. Use of this method could lead to reporting of HER status to the oncologist within a day.

[Discrepancies between primary tumor and metastasis: impact on personalized medicine]

Molecular characterization of tumors is critical for the development and appropriate use of many anti-cancer agents. Potential discrepancies between primary tumor and secondary lesions lead to question on the optimal modalities for evaluation of biomarkers. In light of recent data, the need of iterative biopsies in metastatic setting has been suggested but technical and methodological limits in such analyses should not be ignored and this strategy can not be definitively validated. The evaluation of spatial and temporal variability of biomarkers in solid tumors should take into account tumoral context and therapeutic history of each patient for the development of personalized medicine in oncology.

SISH/CISH or qPCR as alternative techniques to FISH for determination of HER2 amplification status on breast tumors core needle biopsies: a multicenter experience based on 840 cases

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

SP3, a reliable alternative to HercepTest in determining HER-2/neu status in breast cancer patients

Accurate assessment of HER-2/neu gene status in breast cancer patients has important prognostic and therapeutic implications. Overexpression/gene amplification of HER-2 is associated with a more aggressive clinical course and eligibility for targeted therapy with trastuzumab. A variety of immunohistochemical (IHC) antibodies and in situ hybridisation (ISH) methods have been employed to assess HER-2 status. SP3 is a rabbit monoclonal antibody that has been shown to have a high level of agreement with other anti-HER-2 antibodies and ISH methods. We assessed HER-2 status by SP3 and HercepTest IHC stains and by fluorescence in situ hybridisation (FISH) on invasive breast carcinomas from paired needle core biopsy and excisional biopsy specimens from 100 patients. We compared the two antibodies with respect to concordance rates with FISH, concordance rates between samples of the same tumour, and sensitivity and specificity using FISH as the reference test. Concordance between SP3 and FISH in needle core biopsy and excisional biopsy specimens was 96% (95% CI 91.9% to 99.7%) (κ=0.89 (95% CI 0.73 to 1.00)) and 97% (95% CI 90.3% to 99.3%) (κ=0.84 (95% CI 0.66 to 1.00)), respectively. Sensitivity and specificity of SP3 for detecting HER-2 overexpression/gene amplification were 78.3% and 100%, respectively, in needle core biopsy and excisional biopsy specimens. Concordance between SP3 results assessed on the needle core biopsy and excisional biopsy was 89% (95% CI 81.2% to 94.4%) (κ=0.62 (95% CI 0.42 to 0.82)). Concordance between SP3 and HercepTest antibodies, after excluding 2+ cases, was 97.6% (95% CI 94.0% to 99.3%) (κ=0.88 (95% CI 0.77 to 1.00)). SP3 is a reliable alternative to HercepTest in evaluating HER-2 status in breast cancer patients. Like other anti-HER-2 antibodies, SP3 may serve as a diagnostic tool in breast pathology and has potential utility as an IHC biomarker in non-mammary malignancies.

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.

Relative Prognostic Value of Human Epidermal Growth Factor Receptor 2 (HER2) Expression in Operable Oesophagogastric Cancer

Aims. The aim of this study was to determine the prognostic significance of HER2 receptor expression in operable oesophagogastric adenocarcinoma. Methods. Eighty-five consecutive patients diagnosed with oesophagogastric adenocarcinoma [18 oesophageal (OC), 32 junctional (JC) and 35 gastric (GC)] undergoing potentially curative resection were studied retrospectively. Immunohistochemistry was used to determine HER2 status at endoscopic biopsy and resection specimen. The primary outcome measure was survival. Results. Twenty (24%) patients had HER2 positive tumours which was commoner in JC (14/32, 44% versus 2/18, 11% in OC and 4/35, 11% in GC, P = 0.003). The sensitivity, specificity, positive and negative predictive values of HER2 status at endoscopic biopsy were 56%, 93%, 63%, 91% respectively (weighted Kappa = 0.504, P < 0.0001). Five-year survival in OC HER2 positive negative was 100% and 36% (P = 0.167) compared with 14% and 44% (P = 0.0726) in JC and 50% and 46% (P = 0.942) in GC respectively. Conclusions. Endoscopic biopsy had a high specificity and negative predictive value in determining HER2 status. Patients with JC had a significantly higher rate of HER2 overexpression and this was associated with a nonsignificant poorer survival trend. A larger study is needed to confirm these findings because of the implications for neoadjuvant and adjuvant chemotherapy regimens.