Serum HER-2 concentration in patients with primary breast cancer

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.

The extracellular domain of Her2 in serum as a biomarker of breast cancer

Breast cancer is a major health problem worldwide. In ~15% of breast cancers, the epidermal growth factor receptor HER2, a transmembrane protein, is overexpressed. This HER2 overexpression is associated with an aggressive form of the disease and a poor clinical prognosis. The extracellular domain (ECD) of HER2 is released into the blood by a proteolytic mechanism known as "ECD shedding". This proteolytic shedding leaves a constitutively active truncated receptor in the membrane that is 10-100-fold more oncogenic than the full-length receptor and promotes the growth and survival of cancer cells. Shedding of the HER2 ECD is increased during metastasis: whereas 15% of primary breast cancer patients have elevated levels of serum HER2 ECD (sHER2 ECD), the levels reach 45% in patients with metastatic disease. Thus, sHER2 ECD has been proposed as a promising biomarker for cancer recurrence and for monitoring the disease status of patients overexpressing HER2. Nevertheless, in 2016, the American Society of Clinical Oncology advises clinicians not to use soluble HER2 levels to guide their choice of adjuvant therapy for patients with HER2-positive breast cancer, because the evidence was considered not strong enough. Currently, biomarkers such as carcinoembryonic antigen and cancer antigen 15-3 are widely used to monitor metastatic breast cancer disease even if the level of evidence of clinical impact of this monitoring is poor. In this article, we review the evidence that sHER2 ECD might be used in some situations as a biomarker for breast cancer. Although this serum biomarker will not replace the direct measurement of tumor HER2 status for diagnosis of early-stage tumors; it might be especially useful in metastatic disease for prognosis, as an indicator of cancer progression and of therapy response, particularly to anti-HER2 therapies. Owing to these data, sHER2 ECD should be considered as a promising biomarker to detect cancer recurrence and metastasis.

Evaluation of HER2/neu oncoprotein in serum & tissue samples of women with breast cancer

Background & objectives:

The proto-oncogene HER2/neu has been extensively studied in breast cancer patients. Serum levels of HER2/neu by ELISA in breast cancer patients were compared with tissue HER2/neu expression and with other clinicopathological parameters with the aim to investigate whether the serum assay could replace the established tests (IHC/FISH) for HER-2 status.

Methods:

Blood and Tru-cut biopsy samples were collected for determining HER2/neu status in 64 breast cancer patients. The tissue specimens were processed routinely and immunohistochemistry (IHC) for HER2/ER/PR (oestrogen/progesterone receptors) performed. Fluorescence in-situ hybridization (FISH) was performed on all HER2/neu 2 positive cases. Sixty age matched healthy females and females with benign breast disease were taken as controls for ELISA.

Results:

Of the 64 breast cancer cases, 25 (39.1%) had elevated serum HER2/neu levels accompanied with increased tissue expression of HER2/neu receptors. On IHC, HER2/neu score was 3+ in 24 (37.5%) cases, 2+ in three (4.6%), 1+ in 18 (28.1%); while 19 cases (29.7%) showed no HER2/neu expression. Of the three 2+ cases on IHC, two showed amplification on FISH. Twenty one (32.8%) patients were ER positive and 17 (26.6%) were PR positive. There was a significant correlation (P<0.001) of serum HER2 concentration with tumour size, lymph node involvement, stage of disease and histological grade. Serum HER2/neu levels showed a negative correlation with ER status (P=0.047) but no correlation with PR status.

Interpretation & conclusions:

The results suggest that elevated serum HER2 level was associated with a clinicopathological aggressive phenotype of breast carcinoma and was related to tissue HER2 overexpression. Therefore, serum HER2 may be useful for monitoring the course of the disease and response to treatment.

Serum HER2 levels are increased in cats with mammary carcinomas and predict tissue HER2 status

HER2 is overexpressed in about 30% of feline mammary carcinomas (FMC) and in 15-30% of breast cancers. Women with HER2-positive breast tumors are associated with shorter survival. This study aimed to optimize the detection and quantification of serum HER2 (sHER2) in cats and to evaluate its potential in diagnosing cats with mammary carcinomas (MC) overexpressing HER2. A prospective study was conducted in 60 queens showing MC and 20 healthy animals. Pre-operative serum samples were collected for sHER2 quantification using two immunoassays: ELISA and Dot blot assay. sHER2 levels were compared with tissue HER2 status assessed by immunohistochemistry. Queens with FMC showed significantly higher mean levels of sHER2 by both ELISA and Dot blot assay. A significant difference in the sHER2 levels was also found between cats with HER2-positive MC and those with low-expressing HER2 MC. A significant correlation between sHER2 levels and tumor HER2 status was also found, particularly when ELISA was used (r = 0.58, p < 0.0001). The value of 10 ng/ml was proposed as the optimal cutoff for both immunoassays by ROC analysis. Like in humans, sHER2 levels are increased in cats with MC HER2-positive, strongly suggesting that evaluation of sHER2 levels can be very useful in feline oncology. The results show that ELISA and Dot blot assay can replace the immunohistochemistry technique, due to their efficacy and lower costs for diagnostic purposes and for monitoring the response to anti-HER2 therapies in cats.

Serum HER2 extracellular domain levels and HER2 circulating tumor cell status in patients with metastatic breast cancer

Aim: To shed light on the clinical role of HER2 status in serum as extracellular domain (ECD) and corresponding circulating tumor cells (CTCs) in metastatic breast cancer patients. Methods: 68 patients were analyzed. Serum HER2 was determined by ADVIA Centaur® Serum HER2 test. CellSearch System was performed for CTC quantification. Results: HER2 was overexpressed in 21 primary tumors. In total, 19 patients had ECD >15 ng/ml (the cut-off used), 48 patients had at least one CTC. ECD positivity was associated with CTC number (p = 0.01), HER2-positive CTC (p = 0.01) and the ratio HER2-positive CTC/total CTC (p = 0.02). ECD was not associated with survival. Conclusion: ECD in combination with HER2 CTC status would deserve further investigation in larger series for addressing its putative prognostic relevance.

Meaningful interpretation of serum HER2 ECD levels requires clear patient clinical background, and serves several functions in the efficient management of breast cancer patients

BACKGROUND

This study was initiated to evaluate the clinical significant of HER2 extracellular domain (ECD) in the real-time management of breast cancer patients.

METHODS

Five-hundred forty-six eligible breast cancer patients were divided according to their clinical background. The correlation between ECD, tissue HER2, and clinical outcome of the patients were analyzed.

RESULTS

Receiver operating characteristic analysis revealed that ECD measured before receiving neoadjuvant therapy yielded the highest area under the curve (0.9185; P<0.0001), indicating that ECD and tissue HER2 levels are consistent in untreated tumor-bearing patients. At cut-off of 15.0ng/ml, the prognostic value of ECD was demonstrated using univariate (HR=1.664, P<0.0001) and multivariate (HR=1.547, P=0.011) Cox regression analysis. Kaplan-Meier survival curves revealed that patients with elevated ECD had shorter progression-free survival (PFS) (4.0 vs. 6.1months, P<0.0001). Elevated ECD was also an adverse predictor for PFS in response to anti-HER2 therapy (4.3 vs. 10.2months, P=0.0155). In contrast, ≥20%, decreased ECD was associated with longer PFS in patients who received anti-HER2 therapy (10.9 vs. 2.4months, P=0.0164) and overall (10.7 vs. 2.8months, P=0.0034).

CONCLUSIONS

A patient's clinical history can help determine whether ECD could provide added value for breast cancer management.

Serum HER2 Is a Potential Surrogate for Tissue HER2 Status in Gastric Cancer: A Systematic Review and Meta-Analysis

Determining the expression level of human epidermal growth factor receptor 2 (HER2) in tumor tissue is of great importance for personalized therapy in gastric cancer. Although several studies have investigated whether serum HER2 can serve as a surrogate for tissue HER2 status, results have been inconsistent. We therefore performed a meta-analysis of published clinical studies in an attempt to address this problem. PubMed, Embase, Web of Science, the Cochrane Library and Science Direct were queried for eligible studies that could provide sufficient data to construct 2 × 2 contingency tables. The quality of the studies included in the meta-analysis was assessed in accordance with the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) criteria. The pooled sensitivity, specificity and diagnostic odds ratio (DOR) were calculated for the eligible studies. The summary receiver operating characteristic (SROC) curve was constructed and the area under the SROC (AUSROC) was used to evaluate overall diagnostic performance. Eight studies comprising a total of 1170 participants were included in our meta-analysis. The pooled sensitivity, specificity and DOR were 0.39 (95% CI: 0.21–0.61), 0.98 (95% CI: 0.87–1.00), and 27 (95% CI: 9–81), respectively. The AUSROC was 0.77 (95% CI: 0.73–0.80) and Deeks funnel plot suggested the absence of publication bias (p = 0.91). Meta-regression analysis indicated that threshold effect was the main source of heterogeneity. Assays for evaluating serum HER2 levels are highly specific and demonstrate moderate diagnostic performance for HER2 tissue status in gastric cancer.

A versatile snap chip for high-density sub-nanoliter chip-to-chip reagent transfer

The coordinated delivery of minute amounts of different reagents is important for microfluidics and microarrays, but is dependent on advanced equipment such as microarrayers. Previously, we developed the snap chip for the direct transfer of reagents, thus realizing fluidic operations by only manipulating microscope slides. However, owing to the misalignment between arrays spotted on different slides, millimeter spacing was needed between spots and the array density was limited. In this work, we have developed a novel double transfer method and have transferred 625 spots cm(-2), corresponding to >10000 spots for a standard microscope slide. A user-friendly snapping system was manufactured to make liquid handling straightforward. Misalignment, which for direct transfer ranged from 150-250 μm, was reduced to <40 μm for double transfer. The snap chip was used to quantify 50 proteins in 16 samples simultaneously, yielding limits of detection in the pg/mL range for 35 proteins. The versatility of the snap chip is illustrated with a 4-plex homogenous enzyme inhibition assay analyzing 128 conditions with precise timing. The versatility and high density of the snap chip with double transfer allows for the development of high throughput reagent transfer protocols compatible with a variety of applications.

Preoperative serum HER2 extracellular domain levels in primary invasive breast cancer

Background

Despite the preclinical outcomes and biologic significance of the presence of the human epidermal growth factor receptor-2 (HER2) extracellular domain (ECD), there is little evidence supporting the measurement of ECD levels in any clinical setting. The aim of this study was to determine the prevalence of elevated serum HER2 ECD levels, the association between these levels and tissue HER2 overexpression, and the potential clinical prognostic value of HER2 ECD in primary invasive breast cancer.

Methods

Serum HER2 ECD levels were examined preoperatively in 2,862 consecutive stage I–III primary breast cancer patients between 2007 and 2009. Serum HER2 ECD levels were measured by chemiluminescence immunoassay (ADVIA Centaur), and the tissue HER2 status was assessed by immunohistochemistry and fluorescence in situ hybridization. The cutoff value for the serum level of HER2 ECD was set at 15.2 ng/ml.

Results

Among the 2,862 patients, 126 (4.4%) had elevated serum HER2 ECD levels, and HER2 was overexpressed in the tumor tissue of 692 patients (24.2%), with a concordance of 78.7%. Multivariate analysis revealed that elevated serum HER2 ECD was a significant independent prognostic factor for worse distant-metastasis-free survival [DMFS; hazard ratio (HR) = 2.50, 95% confidence interval (CI) = 1.5–4.3, P = 0.001] and breast-cancer-specific survival (BCSS; HR = 2.0, 95% CI = 1.1–3.8, P = 0.036), which were much stronger in patients with tissue HER2-positive tumors (DMFS: HR = 3.8, 95% CI = 2.0–7.0, P < 0.001; BCSS: HR = 2.6, 95% CI = 1.2-5.3, P = 0.012).

Conclusions

Given the prevalence of HER2 expression, its measurement as an independent prognostic factor can be clinically useful, particularly in patients with tissue HER2-positive tumors.

Serum HER2 supports HER2-testing in tissue at the time of primary diagnosis of breast cancer

AIM

HER2 in tissue is of high prognostic value. Soluble HER2, the extracellular domain (ECD), has been suggested to be a helpful biomarker. We investigated whether there is a relationship between HER2 ECD and HER2 in tissue and whether this relationship could be used for diagnostic purposes.

METHODS

HER2 ECD was measured in healthy individuals (N=283, 184 females, 99 males), in patients with history of breast cancer (BC) with no evidence of disease (N=249) as well as in BC patients before any treatment (N=565). HER2 in tissue was determined by immunohistochemistry and HER2 ECD was analyzed by immunoassay.

RESULTS

HER2 ECD levels were higher in healthy men than in healthy women (medians 12.9 ng/mL vs. 9.9 ng/mL, p<0.001). We observed an age dependency in women that means the older the women the higher the HER2 ECD level. In treated BC patients there was only a weak difference between younger and older women. For patients without distant metastases as well as patients with metastatic disease we observed a correlation of HER2 in serum and tissue. The median concentrations of HER2 ECD were 11.7 ng/mL (13.2 ng/mL) for the HER2-negative (HER2-positive) patients in the non-metastatic-group (p<0.001) and 11.9 ng/mL (16.0 ng/mL) in the metastatic-group (p=0.01). Using a cut-off of 30 ng/mL the HER2 in tissue was always positive, corresponding to a specificity of 99.8% and a sensitivity of 10.3%.

CONCLUSIONS

There is a strong correlation between HER2 ECD and HER2 in tissue. HER2 ECD supports the HER2 testing in tissue and may reveal false-negative tissue findings.

Over-expression of Her-2 in colorectal cancer tissue, but not in serum, constitutes an independent worse prognostic factor

BACKGROUND

Currently, conflicting information exists regarding Her-2 over-expression and its clinicopathological implications in colorectal cancer (CRC). This study was undertaken to determine Her-2 over-expression in both serum and tumor tissue of CRC patients, and to assess its clinicopathological and targeted therapeutic implications.

METHODS

Ninety five CRC patients and sixty healthy controls were prospectively enrolled. Her-2 expression status in serum and CRC tissue were examined by chemiluminescent immunoassay and immunohistochemical staining, respectively. The results were confirmed using fluorescent in situ hybridization. Clinicopathological parameters were analyzed according to Her-2 expression status.

RESULTS

Serum Her-2 levels were found to be increased in CRC patients as compared to those of healthy controls. However, serum Her-2 levels were not found to be significantly associated with prognostic parameters. Her-2 expression analysis of CRC tissues revealed Her-2 over-expression in 23 patients (25%), i.e., 13 patients (14%) showed moderate over-expression and 10 patients (11%) showed strong over-expression. The overall survival of patients negative for Her-2 expression was significantly better than that of patients positive for Her-2 expression (P=0.018). The disease-free survival of patients with Her-2 over-expression was significantly shorter than that of patients with no Her-2 expression (P=0.021).

CONCLUSIONS

Her-2 over-expression in CRC tissue, but not in serum, acts as a significant independent worse prognostic factor. Assessment of Her-2 expression status may be valuable for the targeted therapeutic management of CRC.

The Predictive Value of Serum HER2/neu for Response to Anthracycline-Based and Trastuzumab-Based Neoadjuvant Chemotherapy

PURPOSE

Little information exists about the possible influence of serum HER2/neu on response to chemotherapy. We propose that the assessment of serum HER2/neu in a pretreatment serum sample may be useful in predicting response to neoadjuvant chemotherapy.

METHODS

All breast cancer patients were tested by immunohistochemical stain and fluorescent in situ hybridization for HER2/neu before treatment. Serum HER2/neu was twice measured by chemiluminescence immunoassay (ADVIA Centaur System) before neoadjuvant chemotherapy and before operation. The cut-off value was 10.2 mg/mL, according to the previous study. Pathologic complete response (pCR) was considered as no residual tumor or remnant ductal carcinoma in situ; partial response (PR) was a less than 50% decrease in maximal diameter in pathologic tumor size. The measurements for the changes of serum HER2/neu were defined as pretreatment HER2/neu-preoperation HER2/neu. We compared the change of serum HER2/neu between that from before chemotherapy and that after chemotherapy, the pathologic complete response and partial response, and the trastuzumab group and anthracycline group.

RESULTS

Serum HER2/neu was decreased after neoadjuvant chemotherapy. The mean of serum HER2/neu in prechemotherapy was 15.4±9.0 ng/mL, and that of postchemotherapy was 10.5±2.0 ng/mL (p=0.04). Pathologic response was correlated with the change of serum HER2/neu (PR, 11.7±2.2 ng/mL vs. pCR, 23.7±13.1 ng/mL; p=0.01). In the trastuzumab group, pCR was marginally correlated with the change of serum HER2/neu (PR, 0.8±0.84 ng/mL vs. pCR, 21.1±13.2 ng/mL; p=0.08).

CONCLUSION

Serum HER2/neu levels during treatment were associated with pathologic response in patients receiving neoadjuvant chemotherapy, particularly, in a trastuzumab-based regimen. The change of serum HER2/neu levels may serve in monitoring neoadjuvant therapy in HER2/neu-overexpressed breast cancer.

Microarray-to-microarray transfer of reagents by snapping of two chips for cross-reactivity-free multiplex immunoassays

Whereas microarray and microfluidic technologies have progressed on many fronts, servicing microchips with minute amounts of reagents still constitutes an important challenge for many applications. Recently, chip-to-chip reagent transfer methods were introduced that simplify the delivery of reagents but required manual, visual alignment, custom-built microwells, and only showed the reaction of a single sample with multiple chemicals. Here, we present the snap chip, which uses common glass slides for transfer, back-side alignment for achieving precise alignment in spite of mirroring, and a snap-apparatus for facile transfer of arrays of chemicals at once by snapping the two slides together. We recently established that cross-reactivity was a significant problem in multiplex assays both theoretically and experimentally and found that it can be eliminated by avoiding mixing, but which necessitates delivering each detection antibody to a single spot with the cognate capture antibody. Using the snap chip, multiplexed sandwich immunoassays without mixing were performed: a slide with multiple arrays of 10 different capture antibodies was incubated with a sample, and then all detection antibodies transferred at once by snapping, each to the single cognate spot. All binding curves were established and limits of detection in the pg/mL range were obtained. Snap chips were stored up to 3 months prior to usage. The snap chip, by dissociating microarray production, which requires expensive equipment, from assay execution, which can be achieved using a hand-held alignment apparatus, will allow for multiplex reactions to be performed using a user-friendly kit. This new liquid handling format can be easily adapted to other applications that require transfer of minute amounts of different reagents in parallel.

Challenges in the clinical utility of the serum test for HER2 ECD

Approximately 15-30% of breast cancers over-express the HER2/neu receptor. Historically, over-expression of HER2/neu has been identified using IHC or FISH, both of which are invasive approaches requiring tissue samples. Recent evidence has shown that some tumors identified as "negative" using these methods can respond to HER2/neu targeted therapy. Shedding of the extracellular domain (ECD) of the receptor into the circulation has led to the development of a serum test of HER2 ECD as an additional approach to probe HER2/neu overexpression. The serum test will be able to monitor the dynamic changes of HER2 status over the course of disease progression. Some studies further suggest that the serum HER2 ECD level and its change may serve as a biomarker to reflect patients' response to therapy. Yet more than 10years after the first serum HER2 ECD test was approved by the FDA, serum HER2 testing has yet to be widely used in clinical practice. In this article we will review the progress of the serum HER2 ECD test and discuss some obstacles impeding its incorporation into broad clinical practice. We will also discuss recent improvements in the sensitivity and specificity of the assay that offer some hope for the future of serum HER2 test.

High serum HER2 extracellular domain levels: correlation with a worse disease-free survival and overall survival in primary operable breast cancer patients

PURPOSE

High serum human epidermal growth factors receptor-2 (HER2) extracellular domain (ECD) has been identified as an independent prognostic indicator of poor prognosis in metastatic breast cancer. However, its prognostic value in primary operable breast cancer was still controversial. We aim to investigate the correlation between serum HER2 ECD levels and tissue HER2 status, the association between serum HER2 ECD levels and clinicopathological characteristics, and their impacts on disease-free survival (DFS) and overall survival (OS) in primary operable breast cancer.

METHODS

Two hundred and fifty-two primary operable breast cancer patients pretreated from 2002 to 2009 in Sun Yat-Sen University Cancer Center were enrolled in this study. Serum HER2 ECD was measured by chemiluminescent assay, and tissue HER2 status was accessed by immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) assay.

RESULTS

There was a significant correlation between serum HER2 ECD levels and HER2 tissue status (P < 0.001, R = 0.36). High serum HER2 ECD levels (≥15 ng/mL) were significantly associated with age (≥35 years) (P = 0.028), postmenopausal status (P < 0.001), stage III (P < 0.001), tumor size (≥2 cm) (P < 0.001), lymph node involvement (P < 0.001), negative estrogen receptor (P = 0.005), and progesterone receptor status (P = 0.001). Multivariate analysis showed that high serum HER2 ECD level was an independent prognostic factor of worse DFS (P = 0.014) and OS (P = 0.014) in primary operable breast cancer patients.

CONCLUSION

Serum HER2 ECD level can reflect tissue HER2 status and can be an independent prognostic indicator for primary operable breast cancer patients.

Serum HER2 testing in patients with HER2-positive breast cancer: the death knell tolls

Determination of the human epidermal growth factor receptor 2 (HER2; also known as ERBB2) status of breast tumours is emphasised in various national guidelines as a necessary step for the diagnosis of breast cancer. As an alternative to tissue-based diagnostic methods, there has been substantial interest in the establishment of an easily accessible serum-based alternative that could be used for prognosis and diagnosis. Detection of serum-soluble-HER2 extracellular domain (ECD) and establishment of its potential clinical usefulness has created much debate. We assessed whether identification of circulating concentrations of HER2 ECD have clinical usefulness for management of patients with HER2-positive breast cancer. We examined data from 63 studies of patients with breast cancer. Prevalence of increased concentrations varied greatly between studies. Some studies showed significant associations between raised concentrations and poor prognosis, poor response to treatments including trastuzumab, or tumour characteristics associated with aggressive disease, whereas others did not. Examination of existing data showed that concentrations of HER2 ECD are not consistently related to patient outcomes; therefore, there is insufficient evidence to support the clinical use of serum HER2 ECD testing. Design and execution of future large-scale trials to investigate the clinical use of HER2 ECD testing, in view of the progressive non-supportive evidence, is not recommended. Oncologists should continue to adhere to national guidelines for determining HER2 status. Furthermore, oncologists should continue to use clinical parameters when making decisions about initiation, continuation, and discontinuation of HER2-targeted treatments.

Measurement of human epidermal growth factor receptor type-2 extracellular domain and cancer antigen 15-3 levels in needle washout fluid: a potential adjunct to the cytological diagnosis of breast cancer

To determine whether the measurement of biomarkers in the needle washout fluid after fine needle aspiration cytology could strengthen cytological diagnosis, 29 benign lesions, 26 ductal carcinomas in situ (DCIS), and 95 invasive carcinomas of the breast were analyzed. Immediately after the aspiration samples were expelled onto glass slides, the needle was rinsed out with 2 ml of saline. Human epidermal growth factor receptor two extracellular domain (HER2-ECD) and cancer antigen 15-3 (CA 15-3) in the washout fluid were measured using chemiluminescence. The measuring limit for HER2-ECD (0.5 ng/ml) and that for CA 15-3 (4 U/ml) were used as the cutoff values, respectively. The proportion of patients with positive HER2-ECD values was 6.9% in cases of benign lesions, 26.9% in DCIS, and 10.5% in invasive carcinomas. The proportion of patients with positive CA 15-3 values was 6.9% in cases of benign lesions, 42.3% in DCIS, and 10.5% in invasive carcinomas. The proportion of patients with any biomarker elevation was 6.9% in cases of benign lesions, 46.2% in DCIS, and 15.8% in invasive carcinomas. Thus, biomarker elevation was most frequent in cases of DCIS, followed by invasive carcinomas (P < 0.01). HER2-ECD values over 6 ng/ml or CA 15-3 values over 25 U/ml were seen exclusively in cases of DCIS or invasive ductal carcinomas with an extensive intraductal component. If the biomarker status is included, 5 of 12 cases of DCIS with equivocal cytology categories would be upgraded. Further clinicopathological validation is necessary before applying this new approach to the clinical setting.

Hydrogel droplet microarrays with trapped antibody-functionalized beads for multiplexed protein analysis

Antibody microarrays are a powerful tool for rapid, multiplexed profiling of proteins. 3D microarray substrates have been developed to improve binding capacity, assay sensitivity, and mass transport, however, they often rely on photopolymers which are difficult to manufacture and have a small pore size that limits mass transport and demands long incubation time. Here, we present a novel 3D antibody microarray format based on the entrapment of antibody-coated microbeads within alginate droplets that were spotted onto a glass slide using an inkjet. Owing to the low concentration of alginate used, the gels were highly porous to proteins, and together with the 3D architecture helped enhance mass transport during the assays. The spotting parameters were optimized for the attachment of the alginate to the substrate. Beads with 0.2 µm, 0.5 µm and 1 µm diameter were tested and 1 µm beads were selected based on their superior retention within the hydrogel. The beads were found to be distributed within the entire volume of the gel droplet using confocal microscopy. The assay time and the concentration of beads in the gels were investigated for maximal binding signal using one-step immunoassays. As a proof of concept, six proteins including cytokines (TNFα, IL-8 and MIP/CCL4), breast cancer biomarkers (CEA and HER2) and one cancer-related protein (ENG) were profiled in multiplex using sandwich assays down to pg mL(-1) concentrations with 1 h incubation without agitation in both buffer solutions and 10% serum. These results illustrate the potential of beads-in-gel microarrays for highly sensitive and multiplexed protein analysis.

Value and Limitations of Measuring HER-2 Extracellular Domain in the Serum of Breast Cancer Patients

The human epidermal receptor-2 (HER-2) is overexpressed or amplified in 15% to 25% of breast cancers. Determination of HER-2 tumor status offers clinically useful information, as it selects patients who may benefit from treatment with trastuzumab, the monoclonal antibody against HER-2. Currently approved methods for HER-2 testing include immunohistochemistry or fluorescent in situ hybridization using tumor tissue. A fragment of HER-2 composed of its extracellular domain (ECD) can also be detected in the serum of some patients with breast cancer. As an easily accessible tumor marker, it could offer additional useful prognostic or predictive information. This review will briefly address the biology of the circulating HER-2 ECD and discuss the evidence to support the role, if any, for measuring HER-2 ECD levels in women with breast cancer. In particular, we focus on the value and limitations of serum ECD in both early and advanced breast cancer in the following clinical contexts: as a marker of HER-2 tumor tissue status; clinical implications of raised levels in women who have a tumor not overexpressing HER-2; as a prognostic indicator and as a predictor of response to treatment; and as a monitoring tool for early recurrence. On the basis of our review of the literature, we conclude that there is currently insufficient evidence to support the use of serum HER-2 ECD in the routine management of individual patients with breast cancer. This conclusion is in agreement with the 2007 American Society of Clinical Oncology guidelines on the use of biomarkers in breast cancer.

Breast cancer screening and biomarkers

Annual screening mammograms have been shown to be cost-effective and are credited for the decline in mortality of breast cancer. New technologies including breast magnetic resonance imaging (MRI) may further improve early breast cancer detection in asymptomatic women. Serum tumor markers such as CA 15-3, carcinoembyonic antigen (CEA), and CA 27-29 are ordered in the clinic mainly for disease surveillance, and not useful for detection of localized cancer. This review will discuss blood-based markers and breast-based markers, such as nipple/ductal fluid, with an emphasis on biomarkers for early detection of breast cancer. In the future, it is likely that a combination approach to simultaneously measure multiple markers would be most successful in detecting early breast cancer. Ideally, such a biomarker panel should be able to detect breast cancer in asymptomatic patients, even in the setting of normal mammogram and physical examination results.

Clinical evaluation of the simultaneous determination of CA 15-3, CA 125 and sHER2 in breast cancer

OBJECTIVE

We investigated serum levels of CA 15-3, sHER2 and CA 125, and their usefulness in the detection of metastatic disease in breast cancer patients.

METHODS

The levels of CA 15-3, sHER2 and CA 125 tumour markers were determined in 60 patients, 40 with localized and 20 with metastatic breast carcinoma. The control group consisted of 10 healthy women.

RESULTS

We found that, at the time of diagnosis, serum levels of all three tumour markers were elevated in patients with distant metastases, but of minute importance in the detection of any breast cancer. When the data for the individual markers were combined the overall sensitivity of metastases detection with all three markers improved. In this regard, 90% of patients with distant metastases had an increase in serum level of at least one of tested tumour markers. Similar results were obtained using receiver operating characteristic curve (ROC). Moreover, using ROC we defined cut-off values for metastasis detection for each of the tested markers.

CONCLUSION

Our findings indicate that measurement of CA 15-3 serum values in conjunction with sHER2 and CA 15-3 can increase sensitivity in metastasis detection.

Soluble fragment of HER2/neu receptor in the serum of patients with breast cancer with different levels of this protein expression in the tumor

Serum level of soluble HER2/neu in patients with tumors characterized by high expression of this protein (2+/3+ according to immunohistochemical analysis) was significantly higher than in patients with low expression of HER2/neu and in women with benign diseases of the mammary glands. The level of HER2/neu in the serum decreased after removal of the primary tumor in the majority of patients.

Serum her-2/neu and survivin levels and their relationship to histological parameters in early-stage breast cancer

This study was conducted to investigate the serum levels of her-2/neu and survivin in patients with early-stage breast cancer and their relationship with known histological parameters. Forty-one patients with early-stage breast cancer were investigated. Serum samples were collected from patients on their first admission before adjuvant chemotherapy, and from healthy controls. Serum her-2/neu and survivin levels were determined using an enzyme-linked immunosorbent assay. There was no difference in the levels of serum her-2/neu and survivin between the breast cancer patients and the control group. Serum her-2/neu concentration showed moderate correlations with disease stage and the Ki-67 level, and the serum survivin level showed a moderate correlation with progesterone receptor concentration. Serum levels of her-2/neu and survivin were not significantly related to age and histological parameters in patients with early-stage breast cancer. However, much research continues on the prognostic value of serum her-2/neu and survivin levels, and important new knowledge may ultimately emerge.

3-mercaptopropyltrimethoxysilane as insulating coating and surface for protein immobilization for piezoelectric microcantilever sensors

We have examined coating (PbMg(13)Nb(23)O(3))(0.63)-(PbTiO(3))(0.37) (PMN-PT)/tin and lead zirconate titanate (PZT)/glass piezoelectric microcantilever sensor (PEMS) with 3-mercaptopropyl-trimethoxysilane (MPS) by a simple solution method to electrically insulate the PEMS for in-water applications. In contrast to earlier methytrimethoxysilane insulation coating, the MPS coating also facilitated receptor immobilization on the sensor surface via bonding of its sulhydryl group to a bifunctional linker, sulfosuccinimidyl-4-(N-maleimidomethyl)cyclohexane-1-carboxylate. We showed that a MPS coating of 21 nm in thickness is sufficient to electrically insulate and provide immobilization surface to the PEMS for in-liquid electrical self-excitation and self-sensing. The in-phosphate buffered saline solution resonance spectra were stable with Q values ranging from 41 to 55. The mass detection sensitivities were determined to be 5x10(-11) and 8x10(-12) gHz for the MPS-insulated PZT-glass and PMN-PT/tin PEMSs, respectively.