Current use of HER2 tests

An insight into the invasion of breast ductal carcinoma in situ based on clinical, pathological and hematological data

Background

Ductal carcinoma in situ (DCIS) has become a non-negligible part of breast cancers owing to the greatly increased incidence. While its natural history was not fully elucidated, which is the reason for current controversies in clinical treatment. Exploration of this issue from a clinical perspective is meaningful.

Methods

Medical records of 389 patients diagnosed with DCIS or DCIS with invasive ductal carcinoma (IDC) were reviewed. All of them received appropriate medical care in our center. All 324 patients in training cohort were divided into invasion and non-invasion groups based on pathology. Differences in DCIS immunohistochemical markers and hematological indicators between them were analyzed. In the invasion group, differences between DCIS and matched IDC were compared to explore changes in the tumor heterogeneity during invasion. Conclusions are validated in the validation cohort of 65 patients.

Results

Patients in invasion and non-invasion groups were balanced in baseline characteristics and no statistically significant differences were noticed for DCIS immunohistochemical markers. For hematological indicators, high expression of platelet >291.50) (odds ratio, 2.46; CI [1.35-4.46]; p = 0.003) and SII (>347.20) (odds ratio, 2.54; CI [1.56-4.12]; p < 0.001) were established as independent predictors for invasion by logistic analysis and were validated in the validation cohort. Ki-67 of IDC was significantly higher than that of matched DCIS (p < 0.001). HER2 expression and histological grade of DCIS were separately linearly related to those of IDC.

Conclusion

The change in hematological indicators is an independent predictor for invasion and can be incorporated into the treatment decision-making process for DCIS. Invasion tumor cells exhibit a stronger proliferative capacity compared with the in-situ ones. There are linear relationships in HER2 expression and histological grades between DCIS and matched IDC. DCIS subclones with different histological grades will develop into invasive carcinomas separately.

Novel Emerging Molecular Targets in Non-Small Cell Lung Cancer

In the scenario of systemic treatment for advanced non-small cell lung cancer (NSCLC) patients, one of the most relevant breakthroughs is represented by targeted therapies. Throughout the last years, inhibitors of the epidermal growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK), c-Ros oncogene 1 (ROS1), and V-raf murine sarcoma viral oncogene homolog B (BRAF) have been approved and are currently used in clinical practice. However, other promising molecular drivers are rapidly emerging as therapeutic targets. This review aims to cover the molecular alterations with a potential clinical impact in NSCLC, including amplifications or mutations of the mesenchymal–epithelial transition factor (MET), fusions of rearranged during transfection (RET), rearrangements of the neurotrophic tyrosine kinase (NTRK) genes, mutations of the Kirsten rat sarcoma viral oncogene (KRAS) and phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA), as well as amplifications or mutations of human epidermal growth factor receptor 2 (HER2). Additionally, we summarized the current status of targeted agents under investigation for such alterations. This revision of the current literature on emerging molecular targets is needed as the evolving knowledge on novel actionable oncogenic drivers and targeted agents is expected to increase the proportion of patients who will benefit from tailored therapeutic approaches.

ELISA assay employing epitope-specific monoclonal antibodies to quantify circulating HER2 with potential application in monitoring cancer patients undergoing therapy with trastuzumab

Circulating HER2 extracellular domain (HER2 ECD) levels were proposed as a surrogate for HER2 tissue expression to monitor breast cancer patients for early relapse or responses to standard or HER2-targeted therapies, such as the monoclonal antibody (mAb) trastuzumab. Currently, available commercial ELISA assays for HER2 ECD rely on antibodies recognizing undisclosed or unknown epitopes. In this work, two ELISA assays employing MGR2 and MGR3 epitope-specific mAbs for HER2 ECD were developed and validated, showing good assay precision and linearity of the dose-response signal within the dynamic range of 0.19-12.50 ng mL^-1 and detection limits of 0.76 and 0.75 ng mL^-1 for the MGR2 and MGR3 assays, respectively. The developed assay showed a good agreement with two widely used commercial kits for HER2 ECD quantification in serum samples from breast cancer patients. A complete characterization of mAb-HER2 ECD interaction was performed by means of surface plasmon resonance using trastuzumab as control for both epitope mapping and kinetics analysis. The epitopes recognized by the two mAbs showed no overlap with trastuzumab, which was confirmed by trastuzumab interference analysis in serum samples. The method showed to be a practical approach to determine HER2 ECD with a high degree of sensitivity, reliability and recovery in samples containing mAbs-based therapies.

Shed HER2 surrogacy evaluation in primary breast cancer patients: a study assessing tumor tissue HER2 expression at both extracellular and intracellular levels

The aim of the present study was to investigate serum HER2 extracellular domain (ECD) as a putative surrogate marker of the shedding phenomenon of HER2 receptor from the tumor tissue of primary breast cancer (BC) patients. A pilot retrospective study was conducted on 100 matched serum and tissue samples from patients with node-positive primary BC, stage II/III. Analysis of association and concordance between serum HER2 ECD levels (measured by chemiluminescence immunoassay) and the expression in matched tumor tissue of HER2 ECD and intracellular receptor domain (ICD) (determined by immunohistochemistry) were performed. The median serum HER2 ECD level was 9.4 ng/ml and cutoff values were set at 15.2 ng/ml or 13.0 ng/ml. HER2 ICD and ECD were overexpressed in tumor tissue of 19.8% and 6.9% of patients, respectively. Statistically significant associations were found between serum HER2 ECD levels and tissue expression of both HER2 ICD and ECD (p < .001; Fisher analysis). Moreover, strong concordances were found between serum HER2 ECD levels and tissue expression of HER2 ICD or ECD (cutoff 15.2 ng/ml: 80 and 92.5%, respectively). Our findings support a role for serum HER2 ECD as a surrogate marker of tissue HER2 status in primary BC, both for HER2 ICD or ECD expression.

68Ga-DTPA Anti-HER2 positron emission tomography/CT successfully predicts the overexpression of human epidermal growth factor receptor in lung metastases from breast cancer

Molecular identification of a metastatic tumour without the inconvenience of a biopsy and the time required for pathological characterization is possible using molecular imaging. Here, we present the case of a patient with breast cancer in whom ⁶⁸Ga-diethylenetriamine pentaacetic acid anti-human epidermal growth factor receptor 2 positron emission tomography-CT was successfully employed to characterize the expression of human epidermal growth factor receptor 2 in metastatic sites.

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.

Trastuzumab for patients with axillary-node-positive breast cancer: results of the FNCLCC-PACS 04 trial

PURPOSE

To evaluate the efficacy of trastuzumab in patients with node-positive breast cancer treated with surgery, adjuvant chemotherapy, radiotherapy, and hormone therapy if applicable.

PATIENTS AND METHODS

Three thousand ten patients with operable node-positive breast cancer were randomly assigned to receive adjuvant anthracycline-based chemotherapy with or without docetaxel. Patients who presented human epidermal growth factor receptor 2 (HER2) -overexpressing tumors were secondary randomly assigned to either a sequential regimen of trastuzumab (6 mg/kg every 3 weeks) for 1 year or observation. The primary end point was disease-free survival (DFS).

RESULTS

Overall 528 patients were randomly assigned between trastuzumab (n = 260) and observation (n = 268) arm. Of the 234 patients (90%) who received at least one administration of trastuzumab, 196 (84%) received at least 6 months of treatment, and 41 (18%) discontinued treatment due to cardiac events (any grade). At the date of analysis (October 2007), 129 DFS events were recorded. Random assignment to the trastuzumab arm was associated with a nonsignificant 14% reduction in the risk of relapse (hazard ratio, 0.86; 95% CI, 0.61 to 1.22; P = .41, log-rank stratified on pathologic node involvement). Three-year DFS rates were 78% (95% CI, 72.3 to 82.5) and 81% (95% CI, 75.3 to 85.4) in the observation and trastuzumab arms, respectively.

CONCLUSION

After a 47-month median follow-up, 1 year of trastuzumab given sequentially after adjuvant chemotherapy was not associated with a statistically significant decrease in the risk of relapse.

Real time RT-PCR approach for the evaluation of ERBB2 overexpression in breast cancer archival samples: a comparative study with FISH, SISH, and immunohistochemistry

We tested the reliability of real time reverse transcription polymerase chain reactions as an alternative method for the assessment of ERBB2 status in paraffin-embedded tissues of 83 patients with breast cancer and 20 non-neoplastic controls. PCR was also compared with the immunohistochemical (IHC) HercepTest score and with fluorescence (FISH) and silver (SISH) in-situ hybridization, in 42 selected cases. ERBB2 mRNA was overexpressed in 26/83 (31%) breast cancer samples, using a cutoff calculated as the mean value of the controls plus 3 SD or with the receiver operating curve. The PCR test showed a 96% sensitivity and a 100% specificity when compared with FISH, with an area under the receiver operating curve of 98.4%. Overexpression of ERBB2 at PCR was also significantly correlated with amplification in FISH (P<0.001, Mann-Whitney test) and in SISH (P<0.001, Mann-Whitney test), and with the IHC HercepTest scores 2 or 3 (P<0.001, Spearman rank correlation). FISH, SISH, and IHC were also compared with each other. ERBB2 amplification in FISH significantly correlated with that in SISH (P=0.002, chi test with a concordance of the 87%), but not with IHC HercepTest scores (P=0.214, chi test). Real time PCR is a reliable and cost-effective method for the assessment of ERBB2 status in archival breast cancer samples, compared with FISH. Its introduction in routine diagnostic pathology practice is feasible even if it requires amendments to the current clinical oncology protocols.

99mTc-chelator engineering to improve tumour targeting properties of a HER2-specific Affibody molecule

PURPOSE

Monitoring HER2 expression is crucial for selection of breast cancer patients amenable to HER2-targeting therapy. The Affibody molecule Z(HER2:342) binds to HER2 with picomolar affinity and enables specific imaging of HER2 expression. Previously, Z(HER2:342) with the additional N-terminal mercaptoacetyl-glycyl-glycyl-glycyl (maGGG) sequence was labelled with (99m)Tc and demonstrated specific targeting of HER2-expressing xenografts. However, hepatobiliary excretion caused high radioactivity accumulation in the abdomen. We investigated whether the biodistribution of Z(HER2:342) can be improved by substituting glycyl residues in the chelating sequence with more hydrophilic seryl residues.

METHODS

The Affibody molecule Z(HER2:342), carrying the chelators mercaptoacetyl-glycyl-seryl-glycyl (maGSG), mercaptoacetyl-glycyl-D: -seryl-glycyl [maG(D-S)G] and mercaptoacetyl-seryl-seryl-seryl (maSSS), were prepared by peptide synthesis and labelled with (99m)Tc. The differences in the excretion pathways were evaluated in normal mice. The tumour targeting capacity of (99m)Tc-maSSS-Z(HER2:342) was studied in nude mice bearing SKOV-3 xenografts and compared with the capacity of radioiodinated Z(HER2:342).

RESULTS

A shift towards renal excretion was obtained when glycine was substituted with serine in the chelating sequence. The radioactivity in the gastrointestinal tract was reduced threefold for the maSSS conjugate in comparison with the maGGG conjugate 4 h post injection (p.i.). The tumour uptake of (99m)Tc-maSSS-Z(HER2:342) was 11.5 +/- 0.5% IA/g 4 h p.i., and the tumour-to-blood ratio was 76. The pharmacokinetics and uptake characteristics of technetium-labelled Z(HER2:342) were better than those of radioiodinated Z(HER2:342).

CONCLUSION

The introduction of serine residues in the chelator results in better tumour imaging properties of the Affibody molecule Z(HER2:342) compared with glycyl-containing chelators and is favourable for imaging of tumours and metastases in the abdominal area.

Accurate Identification of HER2-Positive Patients Is Essential for Superior Outcomes With Trastuzumab Therapy

PURPOSE/OBJECTIVES

To review the clinical significance, methods of testing, and outcomes of trastuzumab (Herceptin) treatment for HER2 gene amplification and HER2 protein overexpression in breast cancer.

DATA SOURCES

Published articles and abstracts, online resources, a clinical handbook, and product information.

DATA SYNTHESIS

HER2 gene amplification or HER2 protein overexpression can be found in 20%-25% of breast cancers and is important pathogenic and prognostic information. HER2 also predicts patient response to trastuzumab. Patients with HER2-positive metastatic breast cancer benefit from trastuzumab whether selected by immunohistochemistry, which measures the HER2 protein, or fluorescence in situ hybridization (FISH), which measures the HER2 oncogene. However, patients who are identified accurately as HER2 gene-amplified by FISH derive the greatest benefit.

CONCLUSIONS

Accurate testing is crucial for appropriate identification of patients for trastuzumab therapy. FISH is the most reproducible and accurate method.

IMPLICATIONS FOR NURSING

Education regarding HER2 testing and trastuzumab helps patients to make informed decisions and facilitates active participation in their care as well as enhances dialogue with physicians.

The effects of antibody clone and pretreatment method on the results of HER2 immunostaining in cytologic samples of metastatic breast cancer: A query and a review of the literature

The standardization and use of heat-induced epitope retrieval (HIER) is particularly important with immunohistochemical markers that direct the course of cancer treatment, such as Herceptin therapy. Increasingly, many laboratories are performing immunohistochemical analysis using various antibodies and methodologies for HER2/neu. We attempted to determine the effects of antibody clone and pretreatment methods on the interpretation of HER-2/neu staining in cytologic samples. Cell block sections from 54 cases of metastatic breast cancer (24 FNAs, 30 effusions) were analyzed for HER2 expression using antibodies to CB-11, TAB250, and A0485. Antibodies were analyzed with and without HIER. One pathologist using the FDA-approved scoring system for the HercepTest reviewed all slides in a blinded fashion. Five of fifty-four cases (9%) using CB-11 showed a significant increase in HER2 immunoreactivity using HIER (i.e. from 0/1+ to 2-3+). However, in twenty-nine of fifty-four cases (54%), the cytoplasmic background was significantly higher after HIER. With the A0485 antibody, two of fifty four cases (4%) showed a significant increase in immunoreactivity using HIER, while seventeen of fifty-four cases (31%) exhibited only more pronounced cytoplasmic staining. HIER pretreatment did not increase HER2 staining in any TAB250 stained sample, rather four of fifty-four cases (7%) showed a significant decrease in staining with HIER. We conclude that HIER may enhance membrane staining with the CB-11 and A0485 antibodies, but also increases cytoplasmic background. Loss of antigenicity is seen when HIER is used with TAB250.

Prognostic significance of transforming growth factor beta receptor II in estrogen receptor-negative breast cancer patients

PURPOSE

The role of transforming growth factor beta (TGF-beta) in breast cancer is ambiguous; it can display both tumor suppressing and enhancing effects. Activation of the TGF-beta signal transduction system is subject to hormonal regulation. This study was conducted to further analyze the role of TGF-beta receptors in breast cancer and to evaluate their significance as prognostic markers.

EXPERIMENTAL DESIGN

Expression of TGF-beta receptor I (TbetaRI) and TGFbeta receptor II (TbetaRII) was retrospectively analyzed by immunohistochemistry in 246 breast cancer patients.

RESULTS

Expression of TbetaRI was strongly correlated with tumor size (P < 0.001) and nodal status (P = 0.012) but only weakly with overall survival (P = 0.056). In contrast, TbetaRII was prognostic for overall survival in univariate analysis (P = 0.0370). In estrogen receptor (ER) -negative patients TbetaRII expression was correlated with highly reduced overall survival (P = 0.0083). In multivariate analysis TbetaRII proved to be an independent and highly significant prognostic marker with a hazard ratio of 6.8. Simultaneous loss of both ER and TbetaRII was associated with longer overall survival times comparable with those of ER-positive patients.

CONCLUSIONS

The results of this exploratory study show that TbetaRII is an independent, highly significant prognostic indicator for overall survival in ER-negative patients. In addition our results are supportive of a mechanism of breast cancer progression in which a selective loss of the tumor inhibitory action of TGFbeta takes place, whereas tumor- promoting aspects remain intact.

Monitoring the Circulating Levels of the HER2/neu Oncoprotein in Breast Cancer

The HER2/neu oncoprotein is a major target for the development of new cancer therapies and is similar to the estrogen receptor, which guides hormone therapy. The HER2/neu status is used to guide therapy decisions in patients with HER2/neu-overexpressing breast cancer tumors. The HER2/neu oncogene, or c-erbB-2, encodes a transmembrane receptor protein that is expressed on normal epithelial cells and can be overexpressed in breast cancer cells. Studies have shown that the extracellular domain (ECD) of the HER2/neu oncoprotein is released from the cell and can be measured in the circulation of women with breast cancer. Enzyme-linked immunosorbent assay methods used to measure the circulating HER2/neu ECD have shown that the prevalence of elevated ECD levels is approximately 18.1% in women with primary breast cancer and approximately 45.6% in women with metastatic breast cancer (MBC). Many studies have monitored the circulating ECD levels after surgery and indicate that increasing ECD levels can indicate recurrence of breast cancer earlier than clinical diagnosis. Studies in women with MBC showed that serial changes in circulating HER2/neu ECD levels paralleled the clinical course of disease, regardless of the treatment regimen. Several studies identified a subgroup of patients with MBC who had HER2/neu-negative disease by tissue testing but developed elevated ECD levels with MBC. In contrast to tissue testing, which is a one-time event, monitoring the circulating levels of the HER2/neu ECD in patients with breast cancer provides a real-time assessment of the HER2/neu status and provides important information for managing the therapy of patients with MBC.

Potential clinical utility of serum HER-2/neu oncoprotein concentrations in patients with breast cancer

BACKGROUND

The HER-2/neu oncogene and its p185 receptor protein are indicators of a more aggressive form of breast cancer. HER-2/neu status guides Herceptin therapy, specifically directed to the extracellular domain (ECD) of the HER-2/neu oncoprotein. The HER-2/neu ECD is shed from cancer cells into the circulation and is measurable by immunoassay.

METHODS

We performed a systematic review of the peer-reviewed literature on circulating ECD with respect to prevalence, prognosis, prediction of response to therapy, and monitoring of breast cancer.

RESULTS

The prevalence of increased ECD in patients with primary breast cancer varied between 0% and 38% (mean, 18.5%), whereas in metastatic disease the range was from 23% to 80% (mean, 43%). Some women with HER-2/neu-negative tumors by tissue testing develop increased ECD concentrations in metastatic disease. Increased ECD has been correlated with indicators of poor prognosis, e.g., overall survival and disease-free survival. Increased ECD predicts a poor response to hormone therapy and some chemotherapy regimens but can predict improved response to combinations of Herceptin and chemotherapy. Many studies support the value of monitoring ECD during breast cancer progression because serial increases precede the appearance of metastases and longitudinal ECD changes parallel the clinical course of disease.

CONCLUSIONS

The monitoring of circulating HER-2/neu ECD provides a tool for assessing prognosis, for predicting response to therapy, and for earlier detection of disease progression and timely intervention with appropriate therapy.

HER2 overexpression in various tumor types, focussing on its relationship to the development of invasive breast cancer

To date, poor standardization in HER2 status evaluation has precluded reliable comparison of overexpression rates in different tumors. However, standardized methodologies have been introduced recently for these analyses, and have identified frequencies of 51%, 44%, 26% and 25% in Wilm's tumor, bladder, pancreatic and breast carcinoma, respectively. Other tumors tested had frequencies below 20%. The frequency was greater than that predicted by gene amplification data in some tumor types, which may indicate overexpression due to gene deregulation, rather than gene amplification. Analysis of a large retrospective series of breast carcinomas demonstrated an association between HER2 positivity and a number of other prognostic markers. Together, these variables identify a subset of tumors with poor prognosis and early relapse post-surgery. HER2 expression is relatively stable, with 95% concordance between the HER2 status of primary and metastatic lesions. However, contralateral tumors are unrestricted with regard to HER2 status. Preliminary data indicate that the HER2 status of a hormone receptor-positive tumor may fluctuate according to the menstrual cycle. It is anticipated that the emerging wealth of standardized data for HER2 status will help to elucidate the role of HER2 in tumor progression.