Comparison of fluorescence in situ hybridization and immunohistochemistry for the evaluation of HER-2/neu in breast cancer

Enzyme-free and highly sensitive detection of human epidermal growth factor receptor-2 based on MNAzyme signal amplification in breast cancer

As a common cancer biomarker, human epidermal growth factor receptor-2 (HER2) is highly expressed in breast cancer. Consequently, developing a simple and accurate HER2 sensing platform is of great significance for early diagnosis and treatment of breast cancer. Herein, we developed a rapid enzyme-free fluorescent assay biosensor based on MNAzyme signal amplification for breast cancer biomarker, HER2. The MNAzyme consists of multiple parts, including complementary DNA (cDNA) and two parts of DNAzyme (partzyme A/B). Initially, cDNA is blocked by combining with the HER2 aptamer to form a double-stranded DNA. When HER2 is present, cDNA is released as a result of the binding between HER2 and its aptamer. Due to the complementary sequences among cDNA and partzyme A/B, the MNAzyme is successfully assembled to cleave the substrate, recovering the fluorescence output. The MNAzyme biosensor exhibited a low detection limit of 0.02 ng mL-1 and excellent selectivity. Furthermore, the proposed biosensor can also change the recognition element by changing the aptamer sequence to detect various biomarkers, holding great potential for cancer diagnosis and other related biomedical applications.

MYB immunohistochemistry as a predictor of MYB::NFIB fusion in the diagnosis of adenoid cystic carcinoma of the head and neck

OBJECTIVES

Diagnosing adenoid cystic carcinoma (AdCC) is challenging due to histopathological variability and similarities with other tumors. In AdCC pathogenesis, the cellular myeloblastosis gene (c-MYB) often exhibits a MYB::NFIB fusion from a reciprocal translocation. This study aimed to assess the predictive accuracy of MYB immunohistochemistry for detecting this translocation compared to fluorescence in situ hybridization (FISH).

STUDY DESIGN

This study included 110 AdCC patients (1999-2017) from two Dutch head and neck centers using tissue microarrays and full slides. Median MYB expression levels by immunohistochemistry were compared based on translocation status by FISH, and differences within clinicopathological parameters were examined. An immunohistochemical cut-off was established to estimate the translocation.

RESULTS

MYB immunohistochemistry was available in 90/110 patients, with a median expression of 27%. FISH was interpretable in 79/108 tumors, identifying MYB::NFIB fusion in 44 (56%). Among 62 patients with both MYB expression and translocation data, the fusion was present in 38 (61%). These tumors had higher MYB expression (30%) than nontranslocated tumors (6%); P = .02. A 60% MYB expression cut-off yielded 100% specificity for detecting the translocation but had no prognostic value.

CONCLUSIONS

Although MYB protein expression alone lacks diagnostic precision, protein expression >60% predicted the MYB::NFIB fusion in all tumors.

Breast carcinoma arising in a fibroadenoma: A case series of 16 patients and review of the literature

Breast carcinoma arising from a fibroadenoma is an uncommon entity and is frequently detected incidentally during pathological examination or excisional biopsy of a benign breast tumor. Due to only sporadic cases being reported, evidence-based guidelines are not well-established to date. The present report describes 16 patients diagnosed with breast carcinoma arising within a fibroadenoma in the Third Hospital of Nanchang (Nanchang, China) between January 2019 and December 2021 and discusses the clinicopathological characteristics, imaging findings and treatment. The age of patients at diagnosis ranged between 19 and 58 years and a well-defined asymptomatic mass was the most common clinical presentation. Carcinoma occurring in fibroadenoma generally mimics a benign tumor and potential carcinomatous changes may not be detected. Pathologically, carcinoma in situ was the predominant subtype in the present study. Additionally, ductal carcinoma in situ was more common compared with lobular carcinoma in situ in the present case series. Regarding the molecular phenotypes, the majority of cases were categorized as luminal subtype, although other subtypes such as triple-negative and HER2 positive breast cancer were also identified. In the present study, seven patients were treated with breast-conserving surgery and nine patients were treated with mastectomy. Sentinel lymph node biopsy was performed in all patients and none exhibited axillary node metastasis. Additionally, six patients underwent radiotherapy and two received chemotherapy. During the follow-up, all patients were alive and no evidence of disease relapse was observed. In summary, clinicians should be aware of the possibility of carcinoma within a fibroadenoma, which could alter the therapeutical course. Adequate biopsy or excision should be performed in patients with indicators of malignant transformation in a presumed benign breast tumor.

Encapsulated papillary carcinoma of the breast: A single institution experience

Encapsulated papillary carcinoma (EPC) is a relatively rare form of breast cancer. To date, no evidence-based guidelines for the treatment of EPC have been established. Between January 2015 and December 2021, patients with histologically confirmed EPC of the breast were recorded in a database by The Third Hospital of Nanchang City (Nanchang, China). A total of 46 patients with EPC were retrieved from the database. Age at diagnosis ranged from 41-88 years (median age, 62 years). A total of 21 of these patients had pure EPC, 6 patients had EPC associated with ductal carcinoma in situ and 19 patients had EPC associated with invasive carcinoma. The majority of EPC cases were low nuclear grade, hormone receptor-positive and human epidermal growth factor receptor-2-negative. Additionally, myoepithelial cells were always absent in the papillae of the EPC. All patients underwent lumpectomy or mastectomy with sentinel lymph node biopsy, and almost all of the patients received adjuvant hormonal therapy. Adjuvant chemotherapy was only suggested to 4 patients who were diagnosed with axillary lymph node involvement. Subsequently, the clinicopathological features of non-invasive EPC were compared with invasive EPC. The results indicated that larger tumor sizes and axillary lymph node metastases were more common in invasive tumors. During the follow-up, only 2 patients with invasive EPC experienced recurrence or metastasis. In conclusion, a substantial proportion of invasive EPC cases display aggressive characteristics and metastatic potential, despite it being considered a subtype of carcinoma in situ with excellent prognosis, and local surgical resection is the initial method of treatment. Therefore, adjuvant endocrine therapy, radiotherapy and chemotherapy should be considered in select patients, especially in those diagnosed with invasive EPC tumors.

Applications of Artificial Intelligence in Breast Pathology

CONTEXT.—

Increasing implementation of whole slide imaging together with digital workflow and advances in computing capacity enable the use of artificial intelligence (AI) in pathology, including breast pathology. Breast pathologists often face a significant workload, with diagnosis complexity, tedious repetitive tasks, and semiquantitative evaluation of biomarkers. Recent advances in developing AI algorithms have provided promising approaches to meet the demand in breast pathology.

OBJECTIVE.—

To provide an updated review of AI in breast pathology. We examined the success and challenges of current and potential AI applications in diagnosing and grading breast carcinomas and other pathologic changes, detecting lymph node metastasis, quantifying breast cancer biomarkers, predicting prognosis and therapy response, and predicting potential molecular changes.

DATA SOURCES.—

We obtained data and information by searching and reviewing literature on AI in breast pathology from PubMed and based our own experience.

CONCLUSIONS.—

With the increasing application in breast pathology, AI not only assists in pathology diagnosis to improve accuracy and reduce pathologists' workload, but also provides new information in predicting prognosis and therapy response.

Development and characterization of an ETV1 rabbit monoclonal antibody for the immunohistochemical detection of ETV1 expression in cancer tissue specimens

BACKGROUND

Aberrant ETV1 overexpression arising from gene rearrangements or mutations occur frequently in prostate cancer, round cell sarcomas, gastrointestinal stromal tumors, gliomas, and other malignancies. The absence of specific monoclonal antibodies (mAb) has limited its detection and our understanding of its oncogenic function.

METHODS

An ETV1 specific rabbit mAb (29E4) was raised using an immunogenic peptide. Key residues essential for its binding were probed by ELISA and its binding kinetics were measured by surface plasmon resonance imaging (SPRi). Its selective binding to ETV1 was assessed by immunoblots and immunofluorescence assays (IFA), and by both single and double-immuno-histochemistry (IHC) assays on prostate cancer tissue specimens.

RESULTS

Immunoblot results showed that the mAb is highly specific and lacked cross-reactivity with other ETS factors. A minimal epitope with two phenylalanine residues at its core was found to be required for effective mAb binding. SPRi measurements revealed an equilibrium dissociation constant in the picomolar range, confirming its high affinity. ETV1 (+) tumors were detected in prostate cancer tissue microarray cases evaluated. IHC staining of whole-mounted sections revealed glands with a mosaic staining pattern of cells that are partly ETV1 (+) and interspersed with ETV1 (-) cells. Duplex IHC, using ETV1 and ERG mAbs, detected collision tumors containing glands with distinct ETV1 (+) and ERG (+) cells.

CONCLUSIONS

The selective detection of ETV1 by the 29E4 mAb in immunoblots, IFA, and IHC assays using human prostate tissue specimens reveals a potential utility for the diagnosis, the prognosis of prostate adenocarcinoma and other cancers, and the stratification of patients for treatment by ETV1 inhibitors.

LncRNA UCA1 promotes SOX12 expression in breast cancer by regulating m6A modification of miR-375 by METTL14 through DNA methylation

Breast cancer, a multifactorial disease, represents one of the leading causes of cancer-related morbidity and mortality in women. This study set out to elucidate the underlying mechanism by which lncRNA UCA1 affects the m⁶A modification of miR-375 by mediating the DNA methylation of METTL14 and then altering SOX12 expression in breast cancer. First, the expression patterns of lncRNA UCA1, miR-375, and apoptosis-related factors were quantitated by means of RT-qPCR and western blot analysis. In addition, the proliferation, invasion, and apoptosis of cells were detected using CCK-8, Transwell, and flow cytometry, respectively. RIP was performed to further uncover the interaction of lncRNA UCA1 and DNA methyltransferases, and MSP was employed for METTL14 promoter region methylation. The DNA methyltransferase enrichment in the METTL14 promoter region was measured by ChIP. The targeting relationship between miR-375 and SOX12 was confirmed by bioinformatics analysis and dual-luciferase report assay. Lastly, the aforementioned mechanism was also verified using tumor xenograft in vivo. It was found the elevated lncRNA UCA1 expression levels serve as a risk factor of poor prognosis in breast cancer. Meanwhile, silencing lncRNA UCA1 could inhibit the proliferation and invasion, but promote apoptosis of breast cancer cells by reducing the DNA methylation of METTL14 and augmenting its expression. Furthermore, METTL14 was observed to mediate the low miR-375 expression through m⁶A modification, leading to increased SOX12 expression levels in breast cancer. Altogether, findings obtained in our study indicated that silencing lncRNA UCA1 curbed the progression of breast cancer through the METTL14-miR-375-SOX12 axis.

Update on prognostic and predictive biomarkers of breast cancer

Breast cancer represents a heterogeneous group of human cancer at both histological and molecular levels. Estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) are the most commonly used biomarkers in clinical practice for making treatment plans for breast cancer patients by oncologists. Recently, PD-L1 testing plays an important role for immunotherapy for triple-negative breast cancer. With the increased understanding of the molecular characterization of breast cancer and the emergence of novel targeted therapies, more potential biomarkers are needed for the development of more personalized treatments. In this review, we summarized several main prognostic and predictive biomarkers in breast cancer at genomic, transcriptomic and proteomic levels, including hormone receptors, HER2, Ki67, multiple gene expression assays, PD-L1 testing, mismatch repair deficiency/microsatellite instability, tumor mutational burden, PIK3CA, ESR1 andNTRK and briefly introduced the roles of digital imaging analysis in breast biomarker evaluation.

Molecular Assessment of HER2 to Identify Signatures Associated with Therapy Response in HER2-Positive Breast Cancer

Trastuzumab, the prototype HER2-directed therapy, has markedly improved survival for women with HER2-positive breast cancers. However, only 40-60% of women with HER2-positive breast cancers achieve a complete pathological response to chemotherapy combined with HER2-directed therapy. The current diagnostic assays have poor positive-predictive accuracy in identifying therapy-responsive breast cancers. Here, we deployed quantitative single molecule localization microscopy to assess the molecular features of HER2 in a therapy-responsive setting. Using fluorescently labeled trastuzumab as a probe, we first compared the molecular features of HER2 in trastuzumab-sensitive (BT-474 and SK-BR-3) and trastuzumab-resistant (BT-474R and JIMT-1) cultured cell lines. Trastuzumab-sensitive cells had significantly higher detected HER2 densities and clustering. We then evaluated HER2 in pre-treatment core biopsies from women with breast cancer undergoing neoadjuvant therapy. A complete pathological response was associated with a high detected HER2 density and significant HER2 clustering. These results established the nano-organization of HER2 as a potential signature of therapy-responsive disease.

Molecular Imaging of HER2 in Patient Tissues with Touch Prep-Quantitative Single Molecule Localization Microscopy

Biomolecules can be investigated at the nanoscale with quantitative single molecule localization microscopy (qSMLM). This technique, which achieves single molecule sensitivity, can probe how membrane receptors are organized under both normal and pathological conditions. While a number of receptors have been extensively studied in cultured cells, technical challenges have largely impeded their robust quantification in tissue samples. To rigorously interrogate tissue samples, methodological advancements are needed in three areas: analytical preparation of the sample, proper characterization of fluorescent reporters, and rapid/unbiased data analysis. Towards these ends, we have combined qSMLM with a touch preparation technique (touch prep-qSMLM). In this new method, touch prep is first used to obtain monolayers of patient cells. Then, highly selective, fluorescently labeled probes are used to detect the receptors of interest on the plasma membranes of cells. Finally, quantitative algorithms are used to analyze the imaging data. Using this touch prep-qSMLM methodology, we interrogated the density and nano-organization of human epidermal growth factor receptor 2 (HER2) in fresh breast cancer tissues. Touch prep-qSMLM agreed well with current clinical methods. Importantly, touch prep-qSMLM can be easily extended to other pathological conditions and ultimately used in precision medicine.

Validation of HER2 Status in Whole Genome Sequencing Data of Breast Cancers with the Ploidy-Corrected Copy Number Approach

BACKGROUND AND OBJECTIVE

Human epidermal growth factor receptor 2 (HER2) protein overexpression is one of the most significant biomarkers for breast cancer diagnostics, treatment prediction, and prognostics. The high accessibility of HER2 inhibitors in routine clinical practice directly translates into the diagnostic need for precise and robust marker identification. Even though multigene next-generation sequencing methodologies have slowly taken over the field of single-biomarker molecular tests, the copy number alterations such as amplification of the HER2-coding ERBB2 gene are hard to validate on next-generation sequencing platforms as they are characterized by chromosomal structural heterogeneity, polysomy, and genomic context of ploidy. In our study, we tested the approach of using whole genome sequencing instead of next-generation sequencing panels to determine HER2 status in the clinical set-up.

METHODS

We used a large dataset of 876 patients with breast cancer whole genomes with curated clinical data and an additional set of 551 patients' external genomic data. We used the decision-tree-based algorithm for optimization of the diagnostic tool for HER2 status assessment by whole genome sequencing.

RESULTS

The most efficient approach to assess HER2 status in whole genome sequencing data was the ploidy-corrected copy number, utilizing ERBB2 copy number and mean tumor ploidy. The classifier achieved sensitivity of 91.18% and specificity of 98.69% on the internal validation dataset and 89.86% and 96.06% on the external data, which is similar to other next-generation sequencing methods, currently tested in the clinic.

CONCLUSIONS

We provide evidence that the HER2 status may be reliably determined by whole genome sequencing and is applicable across different laboratory protocols and pipelines. We suggest using the ploidy-corrected copy number for diagnostic purposes.

Quantitative Image Analysis for Tissue Biomarker Use: A White Paper From the Digital Pathology Association

Tissue biomarkers have been of increasing utility for scientific research, diagnosing disease, and treatment response prediction. There has been a steady shift away from qualitative assessment toward providing more quantitative scores for these biomarkers. The application of quantitative image analysis has thus become an indispensable tool for in-depth tissue biomarker interrogation in these contexts. This white paper reviews current technologies being employed for quantitative image analysis, their application and pitfalls, regulatory framework demands, and guidelines established for promoting their safe adoption in clinical practice.

Diagnostic value of serum HER2 levels in breast cancer: a systematic review and meta-analysis

BACKGROUND

Measurement of serum human epidermal growth factor receptor-2 (HER-2/neu) levels might play an essential role as a diagnostic/screening marker for the early selection of therapeutic approaches and predict prognosis in breast cancer patients. We aimed to undertake a systematic review and meta-analysis focusing on the diagnostic/screening value of serum HER-2 levels in comparison to routine methods.

METHODS

We performed a systematic search via PubMed, Scopus, Cochrane-Library, and Web of Science databases for human diagnostic studies reporting the levels of serum HER-2 in breast cancer patients, which was confirmed using the histopathological examination. Meta-analyses were carried out for sensitivity, specificity, accuracy, area under the ROC curve (AUC), positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), and negative likelihood ratio (NLR).

RESULTS

Fourteen studies entered into this investigation. The meta-analysis indicated the low sensitivity for serum HER2 levels (Sensitivity: 53.05, 95%CI 40.82-65.28), but reasonable specificity of 79.27 (95%CI 73.02-85.51), accuracy of 72.06 (95%CI 67.04-77.08) and AUC of 0.79 (95%CI 0.66-0.92). We also found a significant differences for PPV (PPV: 56.18, 95%CI 44.16-68.20), NPV (NPV: 76.93, 95%CI 69.56-84.31), PLR (PLR: 2.10, 95%CI 1.69-2.50) and NLR (NLR: 0.58, 95%CI 0.44-0.71).

CONCLUSION

Our findings revealed that although serum HER-2 levels showed low se nsitivity for breast cancer diagnosis, its specificity, accuracy and AUC were reasonable. Hence, it seems that the measurement of serum HER-2 levels can play a significant role as a verification test for initial negative screening test results, especially in low-income regions due to its cost-effectiveness and ease of implementation.

A Validation Study of Human Epidermal Growth Factor Receptor 2 Immunohistochemistry Digital Imaging Analysis and its Correlation with Human Epidermal Growth Factor Receptor 2 Fluorescence In situ Hybridization Results in Breast Carcinoma

Background:

The Visiopharm human epidermal growth factor receptor 2 (HER2) digital imaging analysis (DIA) algorithm assesses digitized HER2 immunohistochemistry (IHC) by measuring cell membrane connectivity. We aimed to validate this algorithm for clinical use by comparing with pathologists’ scoring and correlating with HER2 fluorescence in situ hybridization (FISH) results.

Materials and Methods:

The study cohort consisted of 612 consecutive invasive breast carcinoma specimens including 395 biopsies and 217 resections. HER2 IHC slides were scanned using Philips IntelliSite Scanners, and the digital images were analyzed using Visiopharm HER2-CONNECT App to obtain the connectivity values (0–1) and scores (0, 1+, 2+, and 3+). HER2 DIA scores were compared with Pathologists’ manual scores, and HER2 connectivity values were correlated with HER2 FISH results.

Results:

The concordance between HER2 DIA scores and pathologists’ scores was 87.3% (534/612). All discordant cases (n = 78) were only one-step discordant (negative to equivocal, equivocal to positive, or vice versa). Five cases (0.8%) showed discordant HER2 IHC DIA and HER2 FISH results, but all these cases had relatively low HER2 copy numbers (between 4 and 6). HER2 IHC connectivity showed significantly better correlation with HER2 copy number than HER2/CEP17 ratio.

Conclusions:

HER2 IHC DIA demonstrates excellent concordance with pathologists’ scores and accurately discriminates between HER2 FISH positive and negative cases. HER2 IHC connectivity has better correlation with HER2 copy number than HER2/CEP17 ratio, suggesting HER2 copy number may be more important in predicting HER2 protein expression, and response to anti-HER2-targeted therapy.

Quantitative digital imaging analysis of HER2 immunohistochemistry predicts the response to anti-HER2 neoadjuvant chemotherapy in HER2-positive breast carcinoma

PURPOSE

Patients with HER2-positive breast cancer commonly receive anti-HER2 neoadjuvant chemotherapy and pathologic complete response (pCR) can be achieved in up to half of the patients. HER2 protein expression detected by immunohistochemistry (IHC) can be quantified using digital imaging analysis (DIA) as a value of membranous connectivity. We aimed to investigate the association HER2 IHC DIA quantitative results with response to anti-HER2 neoadjuvant chemotherapy.

METHODS

Digitized HER2 IHC whole slide images were analyzed using Visiopharm HER2-CONNECT to obtain quantitative HER2 membranous connectivity from a cohort of 153 HER2+ invasive breast carcinoma cases treated with anti-HER2 neoadjuvant chemotherapy (NAC). HER2 connectivity and other factors including age, histologic grade, ER, PR, and HER2 fluorescence in situ hybridization (FISH) were analyzed for association with the response to anti-HER2 NAC.

RESULTS

Eighty-three cases (54.2%) had pCR, while 70 (45.8%) showed residual tumor. Younger age, negative ER/PR, higher HER2 DIA connectivity, higher HER2 FISH ratio and copy number were significantly associated with pCR in univariate analysis. Multivariate analysis demonstrated only age, HER2 DIA connectivity, PR negativity, and HER2 copy number was significantly associated with pCR, whereas HER2 DIA connectivity had the strongest association.

CONCLUSIONS

HER2 IHC DIA connectivity is the most important factor predicting pCR to anti-HER2 neoadjuvant chemotherapy in patients with HER2-positive breast cancer.

Integrative Analysis of Methylation and Transcriptional Profiles to Reveal the Genetic Stability of Cashmere Traits in the Tβ4 Overexpression of Cashmere Goats

Simple Summary

Cashmere goats have double coats consisting of non-medullated fine inner hairs or cashmere fibers produced by secondary hair follicles (SHFs) and guard hairs produced by primary hair follicles (PHFs). Cashmere is an important economic product worldwide and the world market for cashmere is increasing while the current production of cashmere is limited. Thymosin β4 (Tβ4), a 4.9-kDa protein, contains 43 amino acids. Here, we produced Tβ4 overexpression (Tβ4-OE) offspring using two methods. The somatic cell nuclear transfer (SCNT) goats had increased hair follicle development and higher cashmere yields than wild type (WT) and natural mating (NM) goats. Taken together, our results showed that DNA methylation affected the expression of differentially expressed genes (DEGs) between generations and the genetic stability of cashmere traits.

Abstract

DNA methylation alteration is frequently observed in exogenous gene silencing and may play important roles in the genetic stability of traits. Cashmere is derived from the secondary hair follicles (SHFs) of cashmere goats, which are morphogenetically distinct from primary hair follicles (PHFs). Here, in light of having initially produced 15 Tβ4 overexpression (Tβ4-OE) cashmere goats which had more SHFs than the wild type (WT) goats, and produced more cashmere, we produced Tβ4-OE offsprings both via somatic cell nuclear transfer (SCNT) and via natural mating (NM). However, the desired trait exhibited lower fixation in the line-bred offspring compared to the SCNT offspring. Integrative analysis of methylation and transcriptional profiles showed that this might be due to the influence of methylation on the expression of differentially expressed genes (DEGs) between generations, which was mutually consistent with the results of the functional and pathway enrichment analysis of differentially methylated regions (DMRs) and DEGs. Overall, our study systematically describes the DNA methylation characteristics between generations of cashmere goats and provides a basis for improving genetic stability.

FISH and HER2/neu equivocal immunohistochemistry in breast carcinoma

AIM

The aim of this study was to validate the role of fluorescence in situ hybridization (FISH) in investigating HER2/neu gene amplification (human epidermal growth factor receptor 2) in patients with HER2/neu equivocal breast cancer diagnosed on immunohistochemistry (IHC).

MATERIALS AND METHODS

This was a retrospective study conducted from January 2013 to October 2017. A total of 134 patients diagnosed with invasive breast carcinoma and HER2/neu equivocal status on IHC were analyzed. Also, the cases for the years 2016 and 2017 formed a subgroup that was analyzed further to study the impact of pre-analytical factors on IHC and FISH results.

RESULTS

A total of 134 women with HER2/neu IHC equivocal breast cancer were included in the study with a median age of 50 years (range 25-81). HER2/neu amplification by FISH was noted in 72 (54%) cases, whereas it was non-amplified in 52 (39%) cases. Ten cases were reported as equivocal even on FISH (ASCO/CAP 2013 guidelines). Polysomy 17 was noted in 55 cases (41%), of which 26 patients were≤50 years and 29 patients were >50 years of age. Twenty (36%) of these 55 cases showed HER2/neu amplification, whereas 26 (48%) cases were non-amplified and 9 (16%) cases were reported as equivocal on FISH. Also, more than half of the polysomy cases were hormone receptor negative.

CONCLUSION

IHC is a good screening tool for negative and positive results. Any patient targeted for trastuzumab therapy should undergo confirmation of HER2/neu equivocal status by FISH analysis. We also suggest that if a non-classical FISH pattern is seen, the test should be repeated with a non-centromeric chromosome 17 reference locus probe for better treatment planning.

Pathologic complete response rate according to HER2 detection methods in HER2-positive breast cancer treated with neoadjuvant systemic therapy

PURPOSE

Human epidermal growth factor receptor 2 (HER2)-positive breast cancers are known to have significant clinical and pathological response to neoadjuvant systemic therapy (NST). The aim of this study was to identify factors associated with pathological complete response (pCR), defined as no residual invasive carcinoma in the breast and axillary lymph nodes (ypT0/is ypN0), among patients with HER2-positive breast cancer and to compare pCR rates between breast cancers with HER2 protein overexpression by immunohistochemistry (IHC) versus HER2 gene amplification by fluorescence in situ hybridization (FISH) in the absence of protein overexpression by IHC.

METHODS

We conducted a retrospective review of HER2-positive breast cancer patients treated with NST and surgery at Memorial Sloan Kettering Cancer Center between January 2013 and May 2018. Estrogen receptor (ER), progesterone receptor (PR), and HER2 status were assessed according to the 2018 ASCO/CAP guidelines.

RESULTS

During the study period, 560 patients were identified. Of 531 patients with IHC results available, 455 patients had HER2 IHC 3+, and 76 had IHC < 3+ but HER2 amplification detected by FISH. The overall pCR rate was 59% (330/560). The pCR rate among patients with HER2 protein overexpression (IHC 3+) was 67%, compared to 17% among patients with HER2 amplification by FISH (IHC < 3+). On univariate and multivariate analyses, HER2 protein overexpression by IHC (IHC 3+) was a significant predictor of pCR, along with grade 3 histology, PR-negative status, and dual anti-HER2 therapy.

CONCLUSION

Although both HER2 IHC and FISH are standard HER2 testing methods in breast cancer, achievement of pCR is associated with HER2 IHC expression level, among other factors.

Significance of HER2 protein expression and HER2 gene amplification in colorectal adenocarcinomas

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) is an oncogenic driver, and a well-established therapeutic target in breast and gastric cancers. While the role of HER2 as a prognostic biomarker in colorectal adenocarcinomas (CRCs) remains uncertain, its relevance as a therapeutic target has been established. We undertook the present study to evaluate the frequency of HER2 expression in CRC and to correlate it with various clinicopathological variables.

AIM

To correlate HER2 protein expression and HER2 gene amplification with clinicopathological features and survival in surgically resected CRC.

METHODS

About 1195 consecutive surgically resected CRCs were analyzed by immunohistochemical staining (IHC) to assess HER2 protein expression, and 141 selected tumors were further evaluated by fluorescence in situ hybridization (FISH) to assess HER2 gene amplification. Follow-up information was available for 1058 patients, and using this information we investigated the prevalence of HER2 protein overexpression and gene amplification in a large series of surgically resected CRCs, and evaluated the relationship between overexpression and clinicopathological parameters and prognosis.

RESULTS

HER2 IHC scores of 3+, 2+, 1+, and 0 were seen in 31 (2.6%), 105 (8.8%), 475 (39.7%), and 584 (48.9%) tumors, respectively. HER2 gene amplification was seen in 24/29 tumors with an IHC score of 3+ (82.8%; unreadable in 2/31), 12/102 tumors with an IHC score of 2+ (11.8%; unreadable in 2/104), and 0 tumors with IHC score of 1+ (0/10). HER2 gene amplification was seen in 36/1191 tumors (3.0%; unreadable in 4/1195). Among the tumors with HER2 IHC scores of 3+ and 2+, the mean percentage of tumor cells with positive IHC staining was 90% (median 100%, range 40%-100%) and 67% (median 75%, range 5%-95%), respectively (P < 0.05). Among tumors with IHC scores of 2+, those with HER2 gene amplification had a higher number of tumors cells with positive IHC staining (n = 12, mean 93%, median 95%, range 90%-95%) than those without (n = 90, mean 70%, median 50%, range 5%-95%) (P < 0.05). HER2 gene status was significantly associated with distant tumor metastasis and stage (P = 0.028 and 0.025). HER2 protein overexpression as measured by IHC or HER2 gene amplification as measured by FISH was not associated with overall survival (OS) or disease-specific survival for the overall group of 1058 patients. However, further stratification revealed that among patients with tubular adenocarcinomas who were 65 years old or younger (n = 601), those exhibiting HER2 gene amplification had a shorter OS than those without (mean: 47.9 mo vs 65.1 mo, P = 0.04). Among those patients with moderately to poorly differentiated tubular adenocarcinomas, those with positive HER2 tumor IHC scores (2+, 3+) had a shorter mean OS than those with negative HER2 IHC scores (0, 1+) (47.2 mo vs 64.8 mo, P = 0.033). Moreover, among patients with T2 to T4 stage tumors, those with positive HER2 IHC scores also had a shorter mean OS than those with negative HER2 IHC scores (47.1 mo vs 64.8 mo, P = 0.031).

CONCLUSION

HER2 protein levels are correlated with clinical outcomes, and positive HER2 expression as measured by IHC confers a worse prognosis in those patients 65 years old or younger with tubular adenocarcinomas.

What is the added value of digital image analysis of HER2 immunohistochemistry in breast cancer in clinical practice? A study with multiple platforms

AIMS

We aimed to compare digital image analysis (DIA) of human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) in breast cancer by two platforms: (i) to validate DIA against standard diagnostics; and (ii) to evaluate the added value of DIA in clinical practice.

METHODS AND RESULTS

HER2 IHC and in-situ hybridisation (ISH) were performed on 152 consecutive invasive breast carcinomas. IHC scores were determined with DIA using two independent platforms. Manual scoring was performed by two independent observers. HER2 status was considered positive in 3+ and ISH-positive 2+ cases. HER2 status using DIA was compared to HER2 status with standard diagnostics (manual scoring with ISH in 2+ cases). Interplatform agreement of IHC scores was 'moderate' (linear weighted κ = 0.58), agreement between manual scoring and platform A was 'moderate' (κ = 0.60) and between manual scoring and platform B 'almost perfect' (κ = 0.85). Compared to manual scoring, DIA resulted in a reduction of 2+ cases from 17.1 to 1.3% with platform A and from 17.1 to 15.8% with platform B. However, compared to standard diagnostics, there were three false-negative cases with DIA using platform A [81.3% sensitivity, 100% specificity, 100% positive predictive value (PPV), 97.8% negative predictive value (NPV)]. Sensitivity, specificity, PPV and NPV were 100% with DIA using platform B.

CONCLUSIONS

DIA of HER2 IHC is a valid tool in determining HER2 status in breast carcinoma. Algorithms in different platforms can behave differently, and optimal calibration is essential. In clinical practice, DIA offers an objective alternative to manual scoring, but a reduction in 2+ cases could result in loss of sensitivity.

Rapid pathology of lumpectomy margins with open-top light-sheet (OTLS) microscopy

Open-top light-sheet microscopy is a technique that can potentially enable rapid ex vivo inspection of large tissue surfaces and volumes. Here, we have optimized an open-top light-sheet (OTLS) microscope and image-processing workflow for the comprehensive examination of surgical margin surfaces, and have also developed a novel fluorescent analog of H&E staining that is robust for staining fresh unfixed tissues. Our tissue-staining method can be achieved within 2.5 minutes followed by OTLS microscopy of lumpectomy surfaces at a rate of up to 1.5 cm2/minute. An image atlas is presented to show that OTLS image quality surpasses that of intraoperative frozen sectioning and can approximate that of gold-standard H&E histology of formalin-fixed paraffin-embedded (FFPE) tissues. Qualitative evidence indicates that these intraoperative methods do not interfere with downstream post-operative H&E histology and immunohistochemistry. These results should facilitate the translation of OTLS microscopy for intraoperative guidance of lumpectomy and other surgical oncology procedures.

Gastrointestinal nervous system α-synuclein as a potential biomarker of Parkinson disease

Lewy bodies (LB) play an essential role in the development, survival, and function maintenance of midbrain dopaminergic (DA) neurons in Parkinson disease (PD). Alpha-synuclein (α-synuclein) is the major component of Lewy bodies and is a potential target for Parkinson's disease (PD) therapies. α-synuclein can be detected in the gastrointestinal (GI) nervous system, but whether there is any association between altered α-synuclein expression in the GI nervous system and the onset of PD is not known. The answer to this question presents the opportunity for a promising biomarker in the pre-clinical diagnosis of PD. As such, this study aimed to measure the α-synuclein level in the GI nervous system of Parkinson's disease patients.The protein levels of α-synuclein in the GI nervous system of 31 PD patients (PD group) and 32 patients without PD or Parkinsonism-plus syndrome (control group) were evaluated via immunohistochemical staining. The χ test was performed to evaluate the differences between the PD group and control group. In addition to the distribution of α-synuclein positive protein, regional distribution of the protein in the stomach was also evaluated across groups.Alpha synuclein overexpression was found in the GI nervous tissue of PD patients. The PD group included 17 positive results and 14 negative results. The control group exhibited 7 positive results and 24 negative results. The χ test showed that χ = 7.255, P = .01. The distribution of these positive cases in the gastrointestinal system, the χ test showed that P = .949. The 21 stomach tissues had 7 α-synuclein positive protein tissues, while the body of stomach (4 α-synuclein positive protein) was higher than in other regions.Aberrant expression of α-synuclein was detected in the GI tissues of PD patients, though the distribution of α-synuclein in the gastrointestinal tract had no specificity. Gastrointestinal mucous biopsy could be regarded as a potential opportunity for the early-stage diagnostic exploration of PD, through the detection of α-synuclein inclusions.

Discordant Results Obtained for Different Methods of HER-2/Neu Testing in Breast Cancer – A Question of Standardization, Automation and Timing

Background

HER-2/neu positivity is required for the selection of stage IV breast cancer patients for trastuzumab therapy. We compared the results of the recommended immunohistochemistry (IHC) evaluation with the automated ACIS™ IHC system and with fluorescence in situ hybridization (FISH). These HER-2/neu tissue results were correlated with the serum HER-2/neu (sHER-2/neu) levels at the time of metastatic spread.

Patients and Methods

A total of 61 IHC slides from 30 patients were stained using the HercepTest™. HER-2/neu gene amplification was determined using the Ventana™ FISH assay. sHER-2/neu levels were measured with the Oncogene Science” ELISA kit. The concordance of HER-2/neu results was determined using the concordance index Kappa (κ).

Results

The best concordance between any IHC and FISH was found for the automated ACIS system (88.5%, κ=0.68, category “good”). The comparison between the manual interpretations and the automated IHC was categorized as “very good” (95.1%, κ=0.85). The median sHER-2/neu level of FISH positive patients was significantly higher (67 ng/mL) than that of FISH negative patients (17 ng/mL, p=0.018). The increase in HER-2/neu positivity comparing tissue to stage IV serum was statistically significant (p=0.001).

Conclusions

The concordance between conventional IHC and computerized analysis was very good. The number of patients with stage IV breast cancer with an elevated sHER-2/neu level was much higher than HER-2/neu positivity in tissue. This discrepancy is only partially explained by the influence of tumor load. Patients with an elevated sHER-2/neu level and no tissue overexpression should be considered for retesting of tissue or a new biopsy.

Transplantation of copper-doped calcium polyphosphate scaffolds combined with copper (II) preconditioned bone marrow mesenchymal stem cells for bone defect repair

Calcium polyphosphate is a bioactive ceramic that possesses similar mineral components to bone and possess good physicochemical properties. However, pure calcium polyphosphate scaffold is brittle, and it is insufficient in promoting vascularization and osteoinductivity. This study was conducted to assess whether copper (Cu) incorporated into calcium polyphosphate could improve the scaffolds' inherent shortcomings. In the experiments, Cu-calcium polyphosphate scaffolds' mechanical strength, biocompatibility, and biodegradability were researched primarily. And then, hypoxia-inducible factor 1-alpha expression along with angiogenesis and osteogenesis potential when the scaffolds treated with the bone marrow mesenchymal stem cells (BMMSCs) were analyzed in vitro. In in vivo studies, the Cu-calcium polyphosphate scaffolds combined with the liquid extract preconditioned BMMSCs were implanted into animal model to repair the bone defects. Meanwhile, we also evaluate the expression of angiogenic and osteogenic factors. For comparison, Cu-calcium polyphosphate, calcium polyphosphate, and blank control groups were designed. According to the results, proper content of Cu incorporated with calcium polyphosphate (0.1% Cu-calcium polyphosphate) did not significantly change the scaffold's degradation velocity, but it obtained higher compress mechanical strength and Cu-doped scaffolds were less brittle. Besides, these scaffolds incorporated with Cu showed better cytocompatibility and cell proliferation activity. Moreover, after Cu was doped, the hypoxia-inducible factor 1-alpha expression was up-regulated with the angiogenic and osteogenic factors levels increased both in in vitro and in vivo study. The bone defect healing capacity was accessed, using Cu-calcium polyphosphate combined with preconditioned BMMSCs further enhanced new bone formation and improved hypoxia-inducible factor 1-alpha, alkaline phosphatase, osteocalcin, and vascular endothelial growth factor expression. In conclusion, doped Cu into calcium polyphosphate was an alternative strategy for improving calcium polyphosphate's mechanical property and promoting the osteogenesis and angiogenesis potential. Using Cu-calcium polyphosphate scaffolds combined with Cu preconditioned BMMSCs to treat bone defect could enhance bone defect healing.

Evolution of anti-HER2 therapies for cancer treatment

The development of HER2-directed monoclonal antibodies and tyrosine kinase inhibitors have provided benefits to cancer patients, as well as produced many insights into the biology of the ErbB receptor family. Current therapies based on ErbB family members have resulted in improved overall survival with associated improvements in quality of life for the cancer patients that respond to treatment. Compared to monotherapy using either two antibodies to block the HER2 receptor blockade or combinatorial approaches with HER2 antibodies and standard therapies has provided additional benefits. Despite the therapeutic success of existing HER2 therapies, personalising treatment and overcoming resistance to these therapies remains a significant challenge. The heterogeneous intra-tumoural HER2 expression and lack of fully predictive and prognostic biomarkers remain significant barriers to improving the use of HER2 antibodies. Imaging modalities using radiolabelled pertuzumab and trastuzumab allow quantitative assessment of intra-tumoural HER2 expression, HER2 antibody saturation and the success of different drug delivery systems to be assessed. Molecular imaging with HER2 antibodies has the potential to be a non-invasive, predictive and prognostic technique capable of influencing therapeutic decisions, predicting response and failure of treatments as well as providing insights into receptor recycling and signalling. Similarly, conjugating HER2 antibodies with novel toxic payloads or combining HER2 antibodies with cellular immunotherapy provide exciting new opportunities for the management of tumours overexpressing HER2. Future research will lead to higher therapeutic responses, lower toxicities and providing insight into the mechanisms of resistance to HER2-targeted treatments.

Role of thymic stromal lymphopoietin in the pathogenesis of lumbar disc degeneration

BACKGROUND

This study aims to investigate the role of thymic stromal lymphopoietin (TSLP) in the pathogenesis of lumbar disc degeneration (LDD).

METHODS

Nucleus pulposus tissues were collected from 77 LDD patients (the case group), in addition, normal tissues were extracted from 21 patients suffering from lumbar fractures (the control group). Immunohistochemistry was applied in order to detect TSLP positive expression. In accordance with varying transfection, the cells were divided into TSLP-siRNA, TSLP-siRNA + TSLPR-siRNA, control, blank, anti-TSLPR, and IgG groups. Western blotting was used in order to detect TSLP expression in tissues, and TSLP and type II collagen (COL2AL) in cell culture media were detected using enzyme linked immunosorbent assay (ELISA). Cell viability was measured using a MTT assay. Aggrecan levels were detected using antonopulos, and cell apoptosis was determined using flow cytometry.

RESULTS

TSLP-positive expression was found to be significantly higher in the case group compared with the control group. LDD patients' Pfirrmann grades and preoperative visual analogue scale (VAS) scores were associated with TSLP-positive rate. Cells transfected with TSLP-siRNA and TSLPR-siRNA plasmids exhibited lower TSLP and thymic stromal lymphopoietin receptor (TSLPR) protein expression compared with the control and blank groups. Compared with the control and blank groups, there was significantly higher cell viability, lower cell apoptosis, and higher COL2AL and Aggrecan levels in the TSLP-siRNA, anti-TSLPR, and TSLP-siRNA+TSLPR-siRNA groups; there were significant differences between the TSLP-siRNA, anti-TSLPR, and TSLP-siRNA+TSLPR-siRNA groups and IgG group (all P < .05) CONCLUSION:: Our study provides evidence for the hypothesis that TSLP could reflect the histological severity of LDD, and TSLP-siRNA and, TSLPR-siRNA could inhibit apoptosis of nucleus pulposus cells. The evident information obtained from the investigation could lead the way for new therapeutic approaches regarding LDD treatment.

HER2/neu Testing In 432 Consecutive Breast Cancer Cases using FISH and IHC - A Comparative Study

INTRODUCTION

The development of trastuzumab, a HER-2/neu targeted monoclonal antibody resulted in significant improvements in clinical response and survival in HER-2/neu gene amplified group of patients. Thus, accurate assessment of HER-2/neu status becomes critical. Fluorescence In Situ Hybridization (FISH) and Immunohistochemistry (IHC) are the most commonly used methods for this purpose and specific recommendations exist with regard to the concordance to be observed between the two tests.

AIM

Here, we report and evaluate the concordance rate between FISH and IHC for HER-2/neu status in breast cancer specimens.

MATERIALS AND METHODS

Archival paraffin blocks of tumour tissue from 450 patients of breast cancer were analyzed for Her-2/neu status using FISH and IHC.

RESULTS

There was a highly significant concordance between the results of FISH and IHC assays in HER-2/neu status assessment in invasive breast cancer cases. There were inverse associations between the expression of Oestrogen Receptors/Progesterone Receptors (ER/PR) and HER-2/neu amplification.

CONCLUSION

Although, IHC gave significant concordant results with FISH in determining HER-2/neu status, its subjective grading system precludes its use as a gold standard. FISH should always be used to determine true gene amplification when the IHC results are equivocal.

Comparison of HER2 Dual-Color and Fluorescence In Situ Hybridization in Breast Cancer: A Cohort Study Emphasizing Equivocal Cases

OBJECTIVES

Human epidermal growth factor receptor 2 (HER2; ERBB2 gene) is of prognostic and predictive significance in breast carcinoma. Both fluorescence in situ hybridization (FISH) and dual-color in situ hybridization (DISH) methods are available. DISH and FISH are highly concordant in validation studies, but differences may be more prevalent in the equivocal range. Our goal was to compare FISH and DISH on a cohort enriched for equivocal cases, with respect to HER2 determination.

METHODS

The cohort was enriched for equivocal (2+) cases. DISH and FISH were evaluated using standard protocols and the results compared with respect to HER2 status, HER2 copy number, and HER2/chromosome 17 (Chr17) ratio.

RESULTS

In total, 109 cases were identified. The agreement rate of DISH with FISH was 74%. The mean ± SD HER2/Chr17 ratio by DISH was 1.63 ± 0.08 vs 1.59 ± 0.26 by FISH (P = .45). The mean ± SD HER2 copy number by DISH was 4.56 ± 0.45 vs 4.75 ± 1.08 by FISH (P = .004). Individual signals were more easily resolved using FISH in cases with higher copy numbers.

CONCLUSIONS

In our cohort enriched for equivocal cases, the numerical values of HER2 copy number were significantly lower using DISH, resulting in discordances. Although DISH is a valid method, variations with FISH may be expected in high-equivocal cases and in quality assurance activities.

Microfluidics: Rapid Diagnosis for Breast Cancer

Breast cancer affected 1.7 million people worldwide in 2012 and accounts for approximately 23.3 % of all cancers diagnosed in women. The disease is characterized by a genetic mutation, either inherited or resulting from environmental factors, that causes uncontrollable cellular growth of breast tissue or adjacent tissues. Current means of diagnosing this disease depend on the individual analyzing the results from bulky, highly technical, and expensive equipment that is not globally accessible. As a result, patients can go undiagnosed due to a lack of available equipment or be over-diagnosed due to human error. This review attempts to highlight current means of diagnosing breast cancer and critically analyze their effectiveness and usefulness in terms of patient survival. An alternative means based on microfluidics biomarker detection is then presented. This method can be considered as a primary screening tool for diagnosing breast cancer based on its robustness, high throughput, low energy requirements, and accessibility to the general public.

Evaluation of Human Epidermal Growth Factor Receptor 2 (HER2) Gene Status in Human Breast Cancer Formalin-Fixed Paraffin-Embedded (FFPE) Tissue Specimens by Fluorescence In Situ Hybridization (FISH)

Current standard of care requires that HER2 gene testing be performed on all newly diagnosed invasive breast cancers in order to determine eligibility for anti-HER2 antibody therapy and should be performed in accordance with current ASCO-CAP guidelines (Hammond et al., J Clin Oncol 29(15):e458, 2011; Wolff et al., J Clin Oncol 31(31):3997-4013, 2013). Here we describe a HER2 FISH methodology to evaluate HER2 gene status in FFPE breast tumor specimens.

Evolution and prognosis of breast osteosarcoma: A case report

Breast osteosarcoma is a rare malignancy of unknown etiology, with no standard adjuvant treatment at present. The prognosis of the disease is poor, and it has a high propensity for recurrence and metastasis. The current report presents the case of a 52-year-old woman, in whom adenomyoepithelioma gradually developed into breast osteosarcoma following three separate surgeries. The patient survived for 41 months from the initial lesion occurrence and resection in the left breast; during this time, she underwent surgery and chemotherapy (liposomal doxorubicin and cisplatin) for the treatment of disease recurrence and lung metastasis, along with molecular-targeted therapy (sunitinib). However, the patient eventually succumbed to respiratory failure due to progressive disease. The present case underwent a clear pathological transformation process, and may provide a basis for an improved understanding of the clinical characteristics and treatment of breast osteosarcoma.

A meta-analysis on concordance between immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) to detect HER2 gene overexpression in breast cancer

BACKGROUND

We performed this meta-analysis study to evaluate the concordance and discordance between immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in detecting HER2 alteration in human breast cancer.

METHODS

As a meta-analysis, the present study evaluated the available data from previous studies on the HER2 gene detected by IHC and FISH. To indicate the meta-analysis results, a forest plot was used.

RESULTS

We identified 172 citations, for which our inclusion criteria were met by 18 articles, representing 6629 cases. The overall concordance and discordance rate between IHC staining with score 0/1+ and FISH for detection failure of HER2 expression was 96 and 4 %, respectively. The present study showed that the overall proportion of FISH positive and negative rate for IHC score 2+ for detection of HER2 expression was 36 and 64 %, respectively; and 91 and 9 % for 3+ IHC scores.

CONCLUSION

The results of this study show that IHC score 0/1+ and 3+ cannot be completely considered as negative and positive breast cancer test, respectively. Therefore, we suggest a valid and complementary test, the same as FISH, to explore HER2 expression.

Heterogeneity of amplification of HER2, EGFR, CCND1 and MYC in gastric cancer

BACKGROUND

Intra-tumor heterogeneity is a potential cause for failure of targeted therapy in gastric cancer, but the extent of heterogeneity of established (HER2) or potential (EGFR, CCND1) target genes and prognostic gene alterations (MYC) had not been systematically studied.

METHODS

To study heterogeneity of these genes in a large patient cohort, a heterogeneity tissue microarray was constructed containing 0.6 mm tissue cores from 9 different areas of the primary gastric cancers of 113 patients and matched lymph node metastases from 61 of these patients. Dual color fluorescence in-situ hybridization was performed to assess amplification of HER2, EGFR, CCND1 and MYC using established thresholds (ratio ≥ 2.0). Her2 immunohistochemistry (IHC) was performed in addition.

RESULTS

Amplification was found in 17.4% of 109 interpretable cases for HER2, 6.4% for EGFR, 17.4% for CCND1, and 24.8% for MYC. HER2 amplification was strongly linked to protein overexpression by IHC in a spot-by-spot analysis (p < 0.0001). Intra-tumor heterogeneity was found in the primary tumors of 9 of 19 (47.3%) cancers with HER2, 8 of 17 (47.0%) cancers with CCND1, 5 of 7 (71.4%) cancers with EGFR, and 23 of 27 (85.2%) cancers with MYC amplification. Amplification heterogeneity was particularly frequent in case of low-level amplification (<10 gene copies). While the amplification status was often different between metastases, unequivocal intra-tumor heterogeneity was not found in individual metastases.

CONCLUSION

The data of our study demonstrate that heterogeneity is common for biomarkers in gastric cancer. Given that both TMA tissue cores and clinical tumor biopsies analyze only a small fraction of the tumor bulk, it can be concluded that such heterogeneity may potentially limit treatment decisions based on the analysis of a single clinical cancer biopsy.

Pathologic diagnostics of HER2 positivity in gastroesophageal adenocarcinoma

OBJECTIVES

The human epidermal growth factor receptor 2 (HER2) oncogene shows overexpression in 15% to 30% of gastroesophageal adenocarcinomas. Targeted anti-HER2 therapy with trastuzumab has been recently validated in advanced gastric and gastroesophageal junction cancer treatment. A standardized modified scoring system was recently introduced for gastroesophageal HER2 scoring. We aimed to validate this scoring system, including an analysis of interobserver variability of immunohistochemistry (IHC) scoring.

METHODS

In total, 323 patients with histologically confirmed invasive gastric or esophageal adenocarcinoma were examined for HER2 by IHC and chromogenic in situ hybridization (CISH). IHC 3 + or IHC 2 +/CISH positive tumors were considered HER2 positive. Interobserver variability on IHC scoring using the currently standard modified HER2 scoring system was determined among three clinical pathologists. Clinicopathologic characteristics were retrospectively retrieved from the patient records.

RESULTS

HER2 positivity was found in 50 (15.5%) of 323 patients. Interobserver agreement on IHC scoring was high (κ = 0.78). Most disagreement was found in diffuse or mixed tumor types and in weak to moderate stained samples (IHC 2 +). The HER2 IHC scoring system is sensitive in differentiating HER2 status before ISH.

CONCLUSIONS

The currently used standardized HER2 scoring system is an excellent, clinically applicable method to establish HER2 status in appropriately educated and trained pathologists.

Effects of tissue decalcification on the quantification of breast cancer biomarkers by digital image analysis

Background

Recent technical advances in digital image capture and analysis greatly improve the measurement of protein expression in tissues. Breast cancer biomarkers provide a unique opportunity to utilize digital image analysis to evaluate sources of variability that are caused by the tissue preparation, in particular the decalcification treatment associated with the analysis of bone metastatic breast cancer, and to develop methods for comparison of digital data and categorical scores rendered by pathologists.

Methods

Tissues were prospectively decalcified for up to 24 hours and stained by immunohistochemistry (IHC) for ER, PR, Ki-67 and p53. HER2 positive breast cancer sections were retrieved from the pathology archives, and annotated with the categorical HER2 expression scores from the pathology reports. Digital images were captured with Leica and Aperio slide scanners. The conversion of the digital to categorical scores was accomplished with a Gaussian mixture model and tested for accuracy by comparison to clinical scores.

Results

We observe significant effects of the decalcification treatment on common breast cancer biomarkers that are used in the clinic. ER, PR and p53 staining intensities decreased 15 – 20%, whereas Ki-67 decreased > 90% during the first 6 hrs of treatment and stabilized thereafter. In comparison with the Aperio images, pixel intensities generated by the Leica system are lower. A novel statistical model for conversion of digital to categorical scores provides a systematic approach for conversion of nuclear and membrane stains and demonstrated a high concordance with clinical scores.

Conclusion

Digital image analysis greatly improves the quantification of protein expression in human tissues. Decalcification affects the accuracy of immunohistochemical staining results and cannot be reversed by image analysis. Measurement data obtained on a continuous scoring scale can be converted to categorical scores for comparison with categorical dataset that are generated by pathologists.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_213

Electronic supplementary material

The online version of this article (doi:10.1186/s13000-014-0213-9) contains supplementary material, which is available to authorized users.

Intracellular delivery of peptide cargos using iron oxide based nanoparticles: studies on antitumor efficacy of a BCL-2 converting peptide, NuBCP-9

Delivering peptides into cells targeting the undruggable oncoproteins is an emerging area in cancer therapeutics. Here we report a novel nanoparticle-based delivery system that can transport therapeutic cargos to the intracellular sites without the need for a cell transduction or penetration domain (CPP). In the present study, we have used iron oxide nanoparticles to deliver an oncopeptide, NuBCP-9, targeting the BCL-2 BH3 domain. Citric acid/2-bromo 2-methylpropanoic acid (CA/BMPA)-capped SPIONs were used to immobilize and deliver the NuBCP-9 peptide to the cancer cells without any noticeable off-target effects. Our results have demonstrated that NuBCP-9-SPIONs efficiently penetrate into cancer cells and bind to its intracellular target protein BCL-2. Moreover, significant inhibition of proliferation and substantial induction of cell death were observed when cancer cells were treated with NuBCP-9-SPIONs at different time intervals. Importantly, the IC50 values for killing of breast cancer cells with NuBCP-9-SPIONs were much lower compared to cells treated with the NuBCP-9 peptide linked with a CPP (Arg-8; NuBCP-9-R8). Molecular and biochemical analyses further supported that NuBCP-9-SPIONs killed breast cancer cells by apoptosis-mediated mechanisms. Furthermore, our data demonstrated that administration of NuBCP-9-SPIONs to mice bearing Ehrlich ascites tumors (EAT) was associated with loss of tumorigenicity and extensive apoptosis in tumor tissues. Taken together, these findings show that a non-CPP-tagged peptide can be successfully delivered to undruggable intracellular oncotargets using SPIONs.

HER2 and TOP2A amplification in a hospital-based cohort of breast cancer patients: associations with patient and tumor characteristics

Gene amplification is an important factor for altered gene expression in breast cancers. TOP2A-amplification often occurs concomitantly with HER2 amplification, and it has been suggested to be predictive for the response to anthracycline chemotherapy. This study assessed the correlation between HER2 status and TOP2A co-amplification, the possible association of TOP2A single-nucleotide polymorphisms with the frequency of this co-amplification as well as confirmation of association with outcome. HER2 and TOP2A amplification were analyzed in a tissue microarray from a clinical cohort study. Additionally, a common genetic variant (rs13695) in the TOP2A gene was genotyped in germline DNA. HER2 gene amplification was compared with HER2-IHC findings assessed during clinical routine work, and the association between all the biomarkers analyzed and the clinical outcome was determined. As an exploratory aim, rs13695 genotypes were compared with TOP2A amplification status. HER2 amplification was seen in 101 of 628 (16.1 %) and TOP2A amplification in 32 (5.1 %) cancers. No TOP2A amplification occurred without HER2 co-amplification. HER2 amplification was found in 8, 13.6, and 55.1 % of patients with HER2-IHC 0/1+, 2+, and 3+ tumors, respectively. HER2-IHC was not associated with an effect on the prognosis, but HER2-FISH was. There was an association between the rs13695 genotype and TOP2A amplification status (P = 0.03). Although there was a significant correlation between HER2 status determined by IHC and HER2 by FISH, only HER2 gene amplification status by FISH was correlated with outcome indicating greater utility for FISH in routine clinical settings.

Theranostic and molecular classification of breast cancer

CONTEXT

Despite advances in breast cancer management, women continue to relapse and die of breast cancer. Traditionally, evaluation for hormone receptors (estrogen and progesterone), as well as HER2 overexpression, have guided therapy-related decision-making because they are both prognostic and predictive indicators. However, there are limitations with those studies, which can lead to improper treatment. Gene signatures have recently been shown to be of value in identifying molecular portraits of breast carcinoma and are beginning to play role in management and treatment algorithms.

OBJECTIVE

To provide a summary of the prognostic and predictive indicators of breast cancer, such as hormone receptors, HER2, and molecular gene signatures that currently help guide clinical decision making.

DATA SOURCES

Published articles from peer-reviewed journals in PubMed (US National Library of Medicine).

CONCLUSIONS

Emerging evidence shows promise that, in addition to hormone receptors and HER2 studies, evaluating tumors with gene expression profiling can provide additional prognostic and predictive information, further aiding clinical management and leading to a more personalized approach to treating breast cancer.

Generation of HER2 monoclonal antibodies using epitopes of a rabbit polyclonal antibody

One of the issues in using polyclonal antibodies is the limited amount of reagent available from an immunisation, leading to batch-to-batch variation and difficulties in obtaining the same antibody performance when the same antigen is re-immunised into several separate animals. This led to the development of hybridoma technology allowing, at least theoretically, for an unlimited production of a specific binder. Nevertheless, polyclonal antibodies are widely used in research and diagnostics and there exists a need for robust methods to convert a polyclonal antibody with good binding performance into a renewable monoclonal with identical or similar binding specificity. Here we have used precise information regarding the functional recognition sequence (epitope) of a rabbit polyclonal antibody with attractive binding characteristics as the basis for generation of a renewable mouse monoclonal antibody. First, the original protein fragment antigen was used for immunisation and generation of mouse hybridoma, without obtaining binders to the same epitope region. Instead a peptide designed using the functional epitope and structural information was synthesised and used for hybridoma production. Several of the monoclonal antibodies generated were found to have similar binding characteristics to those of the original polyclonal antibody. These monoclonal antibodies detected native HER2 on cell lines and were also able to stain HER2 in immunohistochemistry using xenografted mice, as well as human normal and cancer tissues.

Single-cell quantitative HER2 measurement identifies heterogeneity and distinct subgroups within traditionally defined HER2-positive patients

Human epidermal growth factor receptor 2 (HER2) is an important biomarker for breast and gastric cancer prognosis and patient treatment decisions. HER2 positivity, as defined by IHC or fluorescent in situ hybridization testing, remains an imprecise predictor of patient response to HER2-targeted therapies. Challenges to correct HER2 assessment and patient stratification include intratumoral heterogeneity, lack of quantitative and/or objective assays, and differences between measuring HER2 amplification at the protein versus gene level. We developed a novel immunofluorescence method for quantitation of HER2 protein expression at the single-cell level on FFPE patient samples. Our assay uses automated image analysis to identify and classify tumor versus non-tumor cells, as well as quantitate the HER2 staining for each tumor cell. The HER2 staining level is converted to HER2 protein expression using a standard cell pellet array stained in parallel with the tissue sample. This approach allows assessment of HER2 expression and heterogeneity within a tissue section at the single-cell level. By using this assay, we identified distinct subgroups of HER2 heterogeneity within traditional definitions of HER2 positivity in both breast and gastric cancers. Quantitative assessment of intratumoral HER2 heterogeneity may offer an opportunity to improve the identification of patients likely to respond to HER2-targeted therapies. The broad applicability of the assay was demonstrated by measuring HER2 expression profiles on multiple tumor types, and on normal and diseased heart tissues.

HER-2 expression in canine morphologically normal, hyperplastic and neoplastic mammary tissues and its correlation with the clinical outcome

The proto-oncogene HER-2/neu (c-erbB-2) encodes a transmembrane receptor protein with tyrosine-kinase activity. Previous studies have shown that HER-2 protein over-expression is present in canine mammary tumours, however, possible prognostic and predictive analogies between protein over-expression patterns in canine and human species are still controversial. Thirty-five canine mammary carcinomas, 11 mammary adenomas, and normal, hyperplastic or dysplastic tissues taken at the marginal area of the tumours were evaluated by immunohistochemistry (IHC) for HER-2 expression, using the Hercept Test® system scoring guidelines. HER-2 over-expression was detected in 3/11 adenomas and 10/35 carcinomas. Normal, hyperplastic and dysplastic mammary tissues were also found to be positive. The correlations between HER-2 expression and tumour histological grading, mitotic index, the presence of lymphatic invasion, and overall survival (OS) were evaluated. In carcinomas, HER-2 positive status only correlated with the mitotic index. A positive correlation was also found between HER-2 positive status and the presence of HER-2 over-expression in normal, hyperplastic or/and dysplastic mammary tissues surrounding the tumours. The percentage of HER-2 over-expressing tumours was similar to the percentage previously observed in canine benign and malignant mammary tumours. However an investigation regarding morphologically normal and hyperplastic or dysplastic tissues surrounding neoplastic lesions also showed HER-2 over-expression. In contrast with human mammary tumours, this study confirmed that in canine species, HER-2 over-expression does not identify a subgroup of tumours with a poor prognosis. In fact, we found HER-2 over-expression in morphologically non-neoplastic mammary tissues, surrounding hyperplastic and neoplastic lesions.

HER2 expression in breast cancer with nonamplified HER2 and gains of chromosome 17 centromere

Gains of chromosome 17 centromere (CEP17) may be accompanied by gains of chromosome 17q. To evaluate the effect of CEP17 gains (CEP17>3 copies per tumor nucleus) on the expression of the HER2 gene, which is located on chromosome 17q12-21.32, we analyzed HER2 amplification and expression in breast carcinomas with and without CEP17 gains. We isolated tumor nuclei from frozen tissues of 37 breast carcinomas for analysis of the HER2 gene and CEP17 by fluorescence in situ hybridization. HER2 expression was detected by immunohistochemistry (IHC) performed on formalin-fixed, paraffin-embedded sections of the corresponding tumors. Tumors with amplified HER2 as determined by both HER2 copy number and HER2/CEP17 ratio were detected in 29.7% (11/37). CEP17 gains were significantly associated with HER2 amplification (P=0.005) but not associated with estrogen receptor status, tumor grade, and lymph node status (P>0.05). In contrast, HER2 amplification was significantly associated with estrogen receptor negativity (P=0.020) but not with tumor grade and lymph node status (P>0.05). IHC analysis was performed in 7 HER2-amplified tumors and all of these were IHC 3+, which were used as positive controls. Among HER2-non-amplified tumors with CEP17 gains, only 1 tumor (1/8, 12.5%) was IHC 3+. However, none of the HER2-non-amplified tumors without CEP17 gains was IHC 3+. In HER2-non-amplified tumors, there was no significant association between HER2 protein expression as detected by IHC and CEP17 or HER2 copy number (P=0.999, P=0.785, respectively). These findings indicate that in the absence of HER2 amplification, CEP17 gains do not have a significant effect on HER2 protein expression.

'Genetic heterogeneity' in HER2/neu testing by fluorescence in situ hybridization: a study of 2,522 cases

Amplification for the ERBB2 oncogene encoding the HER2/neu protein (HER2) is of predictive and prognostic importance in breast carcinoma. Fluorescence in situ hybridization (FISH) is a widely accepted method for determining HER2 amplification status. A HER2-amplified tumor is defined as having a ratio of HER2 signals to chromosome 17 centromeric probe signals (HER2/CEP17 ratio) exceeding 2.2. However, the presence of scattered cells demonstrating HER2 amplification is of unclear significance. A 2009 panel guideline defined a tumor with 'genetic heterogeneity' as having at least 5% but fewer than 50% of (non-clustered) tumor nuclei with a ratio >2.2. The study objective was to examine the statistical distribution of breast tumors tested by FISH for HER2 amplification, after implementation of this 2009 guideline. We identified 2522 consecutive breast carcinoma cases (2009-2011) tested for HER2 amplification. All cases were tested by FISH using a standard clinical protocol, adhering to established guidelines. For each case, data on cell counts were retrieved electronically. Each tumor was compared with a theoretical normal distribution by quantile-quantile analysis. Of 2522 FISH tests for HER2, 1900 (75%) were non-amplified, 394 (16%) were amplified, and 228 (9%) were HER2-equivocal. A total of 666 (26%) had 'genetic heterogeneity.' Among these 'genetically heterogeneous' cases, the ratio was non-amplified in 430 (64.5%), amplified in 24 (4%), and equivocal in 212 (31.5%). The amplified subpopulation in 'genetically heterogeneous' tumors was larger if the overall ratio was close to 2.2. However, the percentage of nuclei >2.2 in a 'genetically heterogeneous' tumor was not informative of the underlying tumor-cell distribution. We conclude that the proportion of HER2-amplified nuclei within a tumor does not contribute information independent of the actual HER2/CEP17 ratio. Reassessment of the definition of 'genetic heterogeneity' in HER2 testing is warranted.

Assessment of Her-2/neu gene amplification status in breast carcinoma with equivocal 2+ Her-2/neu immunostaining

BACKGROUND AND PURPOSE

Amplification of Her-2/neu gene occurs in 25-30% of breast carcinomas. FDA approved trastuzumab (Herceptin) is effective only in tumors having the gene amplification. Immunohistochemistry (IHC) for Her-2/neu protein is widely used but false positive and false negative results exist. Fluorescence in-situ hybridization (FISH) has both excellent sensitivity and specificity in detecting Her-2/neu amplification. Comparative studies have shown discordant results in proportion of cases with equivocal 2+ immunostain. This study is thus conducted to ascertain the frequency of Her-2/neu gene amplification by FISH in breast carcinoma specified as score 2+ by IHC and to correlate these findings with parameters of prognosis in breast cancer.

METHODS

From October 2008 till May 2010 all paraffin blocks from cases with invasive breast carcinoma which were scored as 2+ by IHC were eligible for the study, there were 50 cases. Immunohistochemical evaluation of Her-2/neu was performed using the HercepTest. All cases were immunohistochemically evaluated for ER and PR. FISH was performed using FDA approved Path-Vysion Her-2/neu/CEP 17 dual color probe.

RESULTS

Nine cases (18%) out of 50 cases scored as Her-2/neu 2+ by IHC showed true gene amplification with a median value of scoring ratio 4.28 ranging from 2.37 to 13.26. Another two cases showed low level of amplification but when corrected for Her-2/neu/CEP ratio they did not show true amplification as they were associated with polysomy 17. With the exception of tumor size, neither patient's age, histologic grade nor lymph node status were correlated with Her-2/neu gene amplification. Significant inverse correlation existed between Her-2/neu gene amplification and ER (P=0.01), PR status (P<0.001).

CONCLUSION

Even though FISH is a more complex and expensive procedure, it should be considered the method of choice for assessment of Her-2/neu gene status especially for equivocal cases by IHC that are not accompanied by true gene amplification in the majority of breast carcinoma cases.

Prospective multi-centre study to validate chromogenic in situ hybridisation for the assessment of HER2 gene amplification in specimens from adjuvant and metastatic breast cancer patients

PURPOSE

As HER2 status is a strong predictor of the response to trastuzumab, clinical guidelines recommend that all breast tumours are first evaluated for HER2 protein expression by immunohistochemistry (IHC) followed by confirmatory testing for HER2 gene amplification using fluorescence in situ hybridisation (FISH) for 2+ cases. Alternatively, chromogenic in situ hybridisation (CISH) offers a simpler, less expensive approach to detect HER2 amplification.

METHODS

In this prospective, multi-centre study, based on the largest dataset for HER2 testing in Germany to date, we evaluated the concordance between FISH and CISH in 399 samples from adjuvant and metastatic breast cancer patients. Tumour specimens from routine diagnostic practice were analysed by IHC, FISH and CISH in four reference centres.

RESULTS

FISH and CISH results were strongly concordant (κ = 0.83), with 95% of cases showing agreement. Despite variable IHC scoring across testing centres, complete consensus among the three methods was observed for 246 cases, representing 91% of all IHC positive (3+) or negative (0/1+) cases. Confirmatory testing of 132 IHC equivocal (2+) cases also yielded highly concordant results between FISH and CISH.

CONCLUSIONS

These data validate CISH for the assessment of HER2 gene amplification in breast tumours and, confirm CISH as a valid alternative to FISH in HER2 testing.