Exploratory analysis of serum HER2 extracellular domain for HER2 positive gastric cancer treated with SOX plus trastuzumab

BACKGROUND

The aim of this study was to explore the clinical utility of serum HER2 extracellular domain (sHER2 ECD) using data from a clinical trial evaluating trastuzumab combined S-1 plus oxaliplatin (SOX) in HER2 positive gastric cancer.

METHODS

sHER2 ECD were prospectively measured at baseline and subsequent treatment courses. Based on each quantile point of baseline sHER2 ECD levels and its early changes, patients were divided into two groups and compared clinical outcomes.

RESULTS

43 patients were enrolled, and 17 patients (39.5%) were positive for baseline sHER2 ECD. Higher baseline sHER2 ECD levels tended to have lower hazard ratios (HRs). When divided into two groups by baseline sHER2 ECD of 19.1 ng/ml, median progression-free survival (PFS) and overall survival (OS) was longer in the higher group (mPFS: 16.8 vs 8.7 months, p = 0.359. mOS: 35.5 vs 20.6 months, p = 0.270), respectively. After initiation of treatment, sHER2 ECD significantly decreased up until the third cycle. Higher reduction rates of sHER2 ECD within 3 cycles also tended to have lower HRs. When divided into two groups by reduction rate of 42.5%, mPFS and mOS was longer in the higher reduced group (mPFS: 17.2 vs 8.7 months, p = 0.095. mOS: 65.0 vs 17.8 months, p = 0.047), respectively. Furthermore, higher reduction rates could surrogate higher objective response rates (ORR) (ORR: 90% vs 63.2% for 29.5%, p = 0.065. 100% vs 70% for 42.5%, p = 0.085), respectively.

CONCLUSIONS

Baseline sHER2 ECD levels and its early decline may be useful biomarkers for SOX plus trastuzumab efficacy in HER2 positive gastric cancer.

Development and performance evaluations of an HER-2 kit

Objective To develop a kit for detecting human epidermal growth factor receptor 2 (HER-2) in the human body. Methods The HER-2 kit was evaluated based on an automated magnetic particle chemiluminescence platform. The kit was developed using the double antibody sandwich-complexation method. Results The kit showed a linear range of 0.01-800 ng/mL, with a linear R2 of >0.999. The limit of the blank was 0.0039 ng/mL, and the precision at 1.00 ng/mL was 9.4%. The recovery rate at 10.00 ng/mL was 97.81-101.81%. The negative serum reference range was 0-8.23 ng/mL. Conclusions The kit had a wide linear range, high accuracy, good precision, and high sensitivity, indicating that it has good application prospects.

Prognostic Value of the Serum HER2 Extracellular Domain Level in Breast Cancer: A Systematic Review and Meta-Analysis

An elevated serum HER2 extracellular domain is associated with poor prognosis in breast cancer, but the relationship between sHER2 and the efficacy of different modalities remains controversial. Herein, we aimed to evaluate the prognostic value of serum HER2 extracellular domain (sHER2 ECD) in breast cancer and to identify its correlation with the efficacy of different treatment regimens. A systematic search of the PubMed, Embase, Cochrane Library, Web of Science, and Scopus databases was conducted to identify studies exploring the association between HER2 ECD level and clinical outcomes among patients with breast cancer. Using the random effects models, pooled hazard ratios (HRs), and odds ratios (ORs) with 95% confidence intervals (CI), were calculated for progression-free survival (PFS), overall survival (OS), disease-free survival (DFS), and the objective response rate (ORR). Heterogeneity was further evaluated by subgroup and sensitivity analysis. Overall, 40 studies comprising 12,229 patients were included in this systematic review and meta-analysis. Elevated HER2 ECD levels were associated with worse PFS (HR 1.74, 95% CI 1.40−2.17; p < 0.001), and this effect was observed in patients treated with chemotherapy (HR 1.81, 95% CI 1.37−2.39; p < 0.001), endocrine therapy (HR 1.91, 95% CI 1.57−2.32; p < 0.001), and trastuzumab (HR 1.74, 95% CI 1.31−2.30; p < 0.001). However, this association was not present in patients treated with tyrosine kinase inhibitors (TKIs) (HR 1.44, 95% CI 0.85−2.43, p = 0.17). The HRs/ORs for an elevated HER2 ECD level for DFS, OS, and ORR were 2.73 (95% CI 2.17−3.42; p < 0.001), 2.13 (95% CI 1.77−2.57; p < 0.001), and 0.80 (95% CI 0.49−1.31; p = 0.381), respectively. An elevated sHER2 ECD was an unfavorable prognostic factor in breast cancer but did not affect the efficacy of tyrosine kinase inhibitors such as lapatinib. Detection of sHER2 ECD may be helpful for clinicians selecting the appropriate anti-HER2 therapy for patients with HER2-positive breast cancer.

Circulating proteins as predictive and prognostic biomarkers in breast cancer

Breast cancer (BC) is the most common cancer and among the leading causes of cancer death in women. It is a heterogeneous group of tumours with numerous morphological and molecular subtypes, making predictions of disease evolution and patient outcomes difficult. Therefore, biomarkers are needed to help clinicians choose the best treatment for each patient. For the last years, studies have increasingly focused on biomarkers obtainable by liquid biopsy. Circulating proteins (from serum or plasma) can be used for inexpensive and minimally invasive determination of disease risk, early diagnosis, treatment adjusting, prognostication and disease progression monitoring. We provide here a review of the main published studies on serum proteins in breast cancer and elaborate on the potential of circulating proteins to be predictive and/or prognostic biomarkers in breast cancer.

Recent advances in biosensor devices for HER-2 cancer biomarker detection

The human epidermal growth factor receptor 2 (HER-2) protein is a member of the epidermal growth factor receptor (EGFR or ErbB) family and is a transmembrane tyrosine kinase receptor. HER-2 is highly regulated in ovarian, lung, gastric, oral, and breast cancers. The low specificity, complexity, expensiveness and the lack of sensitivity are essential restrictions in traditional diagnosis methods such as FISH, immunohistochemistry and PCR and these disadvantages led to the need for more studies on alternative methods. Biosensor technology has greatly affected the quality of human life owing to its features including, sensitivity, specificity, and rapid diagnosis and monitoring of different patient diseases. In this review article, we examine various biosensors, considering that they have been categorized based on the transducers used including piezoelectric biosensors, optical sensors such as fluorescence and surface plasmon resonance, and electrochemical types for the diagnosis of HER-2 and the effectiveness of some drugs against that. Attention to developing some types of biosensor devices such as colorimetric biosensors for HER-2 detection can be an important point in future studies.

An updated evaluation of serum sHER2, CA15.3, and CEA levels as biomarkers for the response of patients with metastatic breast cancer to trastuzumab-based therapies

Background

The transmembrane receptor tyrosine kinase HER2 is overexpressed in approximately 15% of breast tumors and correlates with poor clinical prognosis. Several treatments that target HER2 are approved for treatment of HER2-positive metastatic breast cancer. The serum biomarkers most widely used to monitor anti-HER2 therapies in patients with HER2-positive metastatic breast cancer currently are CA15.3 and CEA. Nevertheless, their clinical utility in patients with breast cancer remains a subject of discussion and controversy; thus, additional markers may prove useful in monitoring the therapeutic responses of these patients. The extracellular domain of HER2 can be shed by proteolytic cleavage into the circulation and this shed form, sHER2, is reported to be augmented during metastasis of HER2-positive breast tumors. Here, we studied the clinical usefulness of sHER2, CA15.3, and CEA for monitoring treatment for breast cancer.

Methods

We measured prospectively pretreatment and post-treatment serum levels (day 1, 30, 60 and 90) of these three biomarkers in 47 HER2-positive, metastatic breast cancer patients treated with trastuzumab in combination with paclitaxel. Evaluation of the disease was performed according to the Response Evaluation Criteria in Solid Tumor (RECIST) at day 90.

Results

Patients with progressive disease at day 90 had smaller relative changes between day 1 and day 30 than those with complete, partial or stable responses at day 90: -9% versus -38% for sHER2 (P = 0.02), +23% versus -17% for CA15.3 (P = 0.005) and +29% versus -26% for CEA (P = 0.02). Patients with progressive disease at day 90 were less likely than the other patients to have a relative decrease of > 20% in their biomarker levels at day 30: 6% vs 33% for sHER2 (P = 0.03), 0% vs 27% for CA15.3 (P = 0.03), 4% vs 29% for CEA (P = 0.04). No patient with progressive disease at day 90 had > 20% reduction of the average combined biomarker levels at day 30 whereas 63% of the other patients had (P = 0.003). Moreover, when we analyzed a > 10% reduction of the average biomarker levels no patient with progressive disease at day 90 had a decrease > 10% at day 30 whereas 78% of other patients had (P<0.001, Se = 100%, Sp = 78%).

Conclusion

We show that regular measurement of sHER2, CA15.3, and CEA levels is useful for predicting the therapeutic response and for monitoring HER2-targeted therapy in patients with HER2-positive metastatic breast cancer. The average decrease of the three biomarkers with a threshold of > 10% appears to be the best parameter to distinguish patients who go on to have progressive disease from those who will have a complete, partial or stable response.

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.

Specific antibodies and sensitive immunoassays for the human epidermal growth factor receptors (HER2, HER3, and HER4)

The use of trastuzumab in patients with breast cancer that overexpresses human epidermal growth factor receptor 2 has significantly improved treatment outcomes. However, a substantial proportion of this patient group still experiences progression of the disease after receiving the drug. Evaluation of the changes in expression of the human epidermal growth factor receptors could be of interest. Monoclonal antibodies against the extracellular domain of the human growth factor receptors, 2, 3, and 4, have been raised, and specific and sensitive immunoassays have been established. Sera from healthy individuals (Nordic Reference Interval Project and Database) were analyzed in the human epidermal growth factor receptor 2 assay (N = 805) and the human epidermal growth factor receptor 3 and 4 assays (N = 114), and reference limits were calculated. In addition, sera from 208 individual patients with breast cancer were tested in all three assays. Finally, the human epidermal growth factor receptor 2 assay was compared with a chemiluminescent immunoassay for serum human epidermal growth factor receptor 2/neu. Reference values were as follows: human epidermal growth factor receptor 2, <2.5 µg/L; human epidermal growth factor receptor 3, <2.8 µg/L; and human epidermal growth factor receptor 4, <1.8 µg/L. There were significant differences in human epidermal growth factor receptor 2 and human epidermal growth factor receptor 3 serum levels between the patients with tissue human epidermal growth factor receptor 2-positive and tissue human epidermal growth factor receptor 2-negative ( p = 0.0026, p = 0.000011) tumors, but not in the serum levels of human epidermal growth factor receptor 4 ( p = 0.054). There was good agreement between the in-house human epidermal growth factor receptor 2 assay and the chemiluminescent immunoassay. Our new specific antibodies for all the three human epidermal growth factor receptors may prove valuable in the development of novel anti-human epidermal growth factor receptor targeted therapies with sensitive immunoassays for measuring serum levels of the respective targets and in monitoring established treatment.

A prospective study to assess the clinical utility of serum HER2 extracellular domain in breast cancer with HER2 overexpression

Purpose

We explored the clinical utility of human epidermal growth factor receptor-2 extracellular domain (HER2/ECD) in patients treated for an invasive breast cancer with HER2 overexpression.

Methods

We prospectively studied HER2/ECD levels in the sera of 334 women included between 2007 and 2014, all treated with trastuzumab. HER2/ECD levels were measured at diagnosis, during treatments, and along the follow-up. We investigated the relationship of HER2/ECD with other clinicopathological parameters at diagnosis, its prognosis value, and its utility during the monitoring of a neoadjuvant treatment and the follow-up.

Results

Elevated HER2/ECD at diagnosis correlated positively with parameters associated with tumor aggressiveness. Disease-free survival of non-metastatic patients was significantly shorter in patients with high HER2/ECD at diagnosis (HR = 13.6, 95 % CI 1.6–113.6, P < 0.0001). Progression-free survival of metastatic patients was better for patients with low HER2/ECD (HR = 2.6, 95 % CI 1.2–5.3, P = 0.033). A multivariate analysis revealed that HER2/ECD level at diagnosis was an independent prognosis factor. During neoadjuvant therapy, a significant decrease in HER2/ECD was reported only for the complete histological response group (P = 0.031). During the follow-up, HER2/ECD helped predict relapse, disease progression, and metastases before imaging in 18.6 % cases of the studied cohort.

Conclusions

HER2/ECD is a prognosis factor that is valuable in evaluating the neoadjuvant treatment efficiency. HER2/ECD also appears to be a helpful surveillance biomarker for the early diagnosis of relapses and to predict the fate of metastases. This study brings evidences to support the use of HER2/ECD in the management of HER2-positive breast cancer.

HER2-positive gastric cancer identified by serum HER2: A case report

Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are the current standards methods for the determination of tissue human epidermal growth factor receptor 2 (HER2) status in gastric cancer, as for breast cancer. However, HER2-positive gastric cancer occasionally exhibits heterogeneous tissue HER2 overexpression, raising concern regarding false-negative results in unresectable cases diagnosed by biopsy samples. Serum HER2, the concentration of the extracellular domain of HER2 protein shed into the bloodstream, has the potential to supplement the use of IHC or FISH to determine HER2 status. However, the clinical significance of serum HER2 has not been well studied in gastric cancer. The present study describes an illustrative case of metastatic gastric cancer initially diagnosed as HER2-negative (IHC score 1+). The patient exhibited an elevated serum HER2 level, which prompted a reevaluation of the tissue by IHC, using an alternative antibody, and FISH; re-biopsy analyses confirmed the case as HER2-positive, and trastuzumab was subsequently added to the combination chemotherapy with capecitabine and cisplatin. Serum HER2 may aid in avoiding false-negative diagnoses of HER2 gastric cancer.

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 Human Epidermal Growth Factor 2 Extracellular Domain as a Predictive Biomarker for Lapatinib Treatment Efficacy in Patients With Advanced Breast Cancer

Purpose

We examined the prognostic and predictive value of serum human epidermal growth factor 2 (HER2) extracellular domain (sHER2) in patients with advanced breast cancer treated with lapatinib using data from three randomized trials.

Patients and Methods

We analyzed sHER2 and tissue HER2 (tHER2) data from 1,902 patients (84%) who were randomly assigned to receive lapatinib or control in the trials EGF30001, EGF30008, and EGF100151. Cox regression analyses were performed to correlate both biomarkers with progression-free survival (PFS) and overall survival (OS).

Results

Median sHER2 levels were 25.1 and 10.1 ng/mL in tHER2-amplified (tHER-positive) and nonamplified (tHER-negative) populations, respectively (r = 0.42 for sHER2-tHER2 correlation). Lapatinib had significant PFS benefit over control (hazard ratio [HR], 0.855; P = .004), but not OS (HR, 0.941; P = .33). Lapatinib PFS benefit is independently predicted by higher sHER2 values (HR per 10-ng/mL increase in sHER2: lapatinib-containing therapies, 1.009 v nonlapatinib-containing therapies, 1.044; Pinteraction < .001) and by positive tHER2 (HR [lapatinib v nonlapatinib]: tHER2 positive, 0.638 v tHER2 negative, 0.940; Pinteraction = .001). Within the tHER2-positive subpopulation (n = 515), higher sHER2 values still independently predicted lapatinib PFS benefit (HR per 10-ng/mL increase in sHER2: lapatinib-containing therapies, 1.017 v nonlapatinib-containing therapies, 1.041; Pinteraction = .008). In control arms (n = 936), higher sHER2 was associated with worse prognosis in multivariable analyses (PFS HR per 10 ng/mL: PFS, 1.024; P < .001; and OS, 1.018; P < .001).

Conclusion

Higher sHER2 predicts greater PFS benefit with lapatinib independent of tHER2 status. High sHER2 is also independently prognostic for worse survival in patients who received nonlapatinib-containing therapies. The predictive role of sHER2 for other anti-HER2 agents requires further research.

Serum HER2 as an adjunct to assess HER2 status for advanced gastric cancer: A prospective multicenter trial (SHERLOCK)

BACKGROUND

Intratumoral human epidermal growth factor receptor 2 (HER2) heterogeneity of gastric cancer can be an obstacle to accurate HER2 assessment. Serum HER2, concentrations of the HER2 extracellular domain shed into the bloodstream, has a potential to compensate HER2 immunohistochemistry (IHC) but has not been scrutinized in gastric cancer. This study sought to explore the clinical utility of serum HER2 in gastric cancer.

METHODS

We performed a prospective multicenter trial (SHERLOCK trial) involving patients with all-stage gastric or gastro-esophageal junction cancer. Serum HER2 was measured using direct chemiluminescence while tissue HER2 status was determined using IHC and fluorescent in situ hybridization. For stage IV cases, concordance between local and central laboratories in tissue HER2 assessment was also evaluated.

RESULTS

Of 224 patients enrolled, both tissue HER2 status and serum HER2 levels were successfully determined in 212 patients and 21% (45/212) were tissue HER2-positive. Serum HER2 levels, ranged from 4.5 to 148.0 ng/ml (median 10.3), correlated with tissue HER2 status (p = 0.003). At a cut-off level of 28.0 ng/ml determined by receiver operating characteristics analysis, sensitivity, specificity, positive and negative predictive values of serum HER2 were 22.6%, 100%, 100% and 82.3%, respectively. All nine cases with elevated serum HER2 were tissue HER2-positive stage IV cases. Among 61 stage IV cases, the agreement rate for IHC scoring between the local and the central laboratories was 82% and tissue HER2 judgment was conflicting in five (8.2%) cases. Of these five cases, four were confirmed as false-negative and two of these four patients demonstrated elevated serum HER2.

CONCLUSIONS

Serum HER2 levels correlated with tissue HER2 status in gastric cancer. Although the low sensitivity is a drawback, serum HER2 might be a useful adjunct tool to detect tissue HER2 false-negative gastric cancer.

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 in combination with CA 15-3 as a parameter for prognosis in patients with early breast cancer

AIM

HER2 in breast cancer tissue is a marker of high prognostic and predictive relevance. Soluble HER2, the extracellular domain of the HER2/neu receptor (HER2 ECD), which is shed into the blood, has been suggested to be a helpful tumor marker. We investigated the relationship between the concentrations of HER2 ECD, CEA and CA 15-3, the association of these markers with clinicopathological features and the impact of HER2 ECD alone and in combination with known prognostic factors on disease free survival (DFS) and cancer specific survival (CSS) in untreated early breast cancer patients.

PATIENTS AND METHODS

HER2 ECD (ADVIA, Bayer), CEA (AxSYM, Abbott) and CA 15-3 (Elecsys, Roche) were measured at time of primary diagnosis in the pre-therapeutic (pre-operative) sera of 241 breast cancer patients and were correlated with clinicopathological parameters and outcome.

RESULTS

Higher HER2 ECD levels were significantly correlated with postmenopausal status (p=0.016) and tissue HER2-overexpression (p<0.0001). Higher serum levels of CA 15-3 were associated with larger tumor size (p=0.019), positive lymph nodes (p=0.019), UICC stage III (p<0.01), positive tissue HER2-overexpression (p<0.05) and negative hormone receptor status (p=0.016). In multivariate analysis, serum HER2 ECD levels, CA 15-3 levels, large tumor size and negative hormonal status were independent prognostic factors in DFS. Patients with both high levels of HER2 ECD (>15 ng/mL) and high serum levels of CA 15-3 (>24 U/mL) had the poorest prognosis with a DFS after 3 years of 50.0%. Patients without elevated serum levels had a better outcome with a DFS of 91.2%.

CONCLUSIONS

In our retrospective analysis, HER2 ECD and CA 15-3 were independent and better prognostic tools than HER2 in tissue. Prospective validation is necessary to confirm their usefulness in clinical practice.

Serum HER2 levels and HER2 status in tumor cells in advanced gastric cancer patients

OBJECTIVE

Increased serum human epidermal growth factor receptor 2 levels have been found in metastatic breast cancer patients and are correlated with human epidermal growth factor receptor 2 overexpression in tumor cells. However, the prevalence of serum human epidermal growth factor receptor 2 in gastric cancer patients has not been elucidated.

METHODS

We retrospectively analyzed formalin-fixed paraffin-embedded tumor tissues and serum samples from 96 advanced gastric cancer patients. Human epidermal growth factor receptor 2 expression and gene amplification in tumor cells were determined by immunohistochemistry and fluorescence in situ hybridization. Serum human epidermal growth factor receptor 2 levels were measured using a chemiluminescent immunoassay. Human epidermal growth factor receptor 2 positivity in tumor cells was defined as immunohistochemistry 2+ with fluorescence in situ hybridization positive or immunohistochemistry 3+ with any fluorescence in situ hybridization results.

RESULTS

All tissue samples and serum samples were successfully measured. Nineteen patients (20%) were human epidermal growth factor receptor 2-positive in tumor cells. The median serum human epidermal growth factor receptor 2 level was 9.3 ng/ml (range, 5.0-332.4 ng/ml), and serum human epidermal growth factor receptor 2 levels were significantly separated according to human epidermal growth factor receptor 2 status in tumor cells (P < 0.0001, Wilcoxon's rank sum test); median serum human epidermal growth factor receptor 2 levels in human epidermal growth factor receptor 2-negative patients and -positive patients were 8.9 (range, 5.0-20.5) and 24.0 (range, 9.7-332.4), respectively. There were 15 serum human epidermal growth factor receptor 2-positive patients (16%) using a cutoff value of 15 ng/ml. The sensitivity and the specificity of serum human epidermal growth factor receptor 2 with respect to human epidermal growth factor receptor 2 positivity in tumor cells were 53 and 94%, respectively.

CONCLUSIONS

Serum human epidermal growth factor receptor 2 measurements cannot be substituted for tissue human epidermal growth factor receptor 2 diagnosis in advanced gastric cancer patients. However, serum human epidermal growth factor receptor 2 levels are associated with human epidermal growth factor receptor 2 overexpression in tumor cells. Further investigations of clinical significance of serum human epidermal growth factor receptor 2 as a predictive marker and a therapy-monitoring marker are warranted.

Circulating Her-2/neu extracellular domain in breast cancer patients-correlation with prognosis and clinicopathological parameters including steroid receptor, Her-2/neu receptor coexpression

HER-2/neu extracellular domain (ECD) can be detected in blood as a soluble circulating protein. The aim of this study was to analyze the relationship between HER-2/neu extracellular domain in the serum and the prognosis in breast cancer patients. We also correlated HER-2/neu ECD with various clinicopathological factors including steroid receptor, HER-2/neu receptor coexpression. The serum from seventy nine patients with invasive breast cancer and twenty individuals without malignancy was analyzed using the enzyme-linked immune adsorbent assay method. The cut-off value was estimated by the ROC curve analysis (15.86 μg/L). HER-2/neu ECD values in the serum of patients with breast cancer were significantly higher than in control subjects. Circulating HER-2/neu ECD was significantly associated with the histological grade of tumors and the status of axillary lymph nodes. Negative correlation was observed between HER-2/neu ECD in the serum and estrogen receptor positivity. When we analyzed HER-2/neu ECD in relation with coexpression of steroid receptor and HER-2/neu receptor in tissue, statistically higher values were found in the subgroup of patients with steroid receptor negative, HER-2/neu negative tumors than in the other subgroups. HER-2/neu ECD was not an independent factor in the univariate and multivariate analysis. However, elevated HER-2/neu ECD levels were found in patients with breast cancer possessing more aggressive phenotype.

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.

Critical research gaps and translational priorities for the successful prevention and treatment of breast cancer

INTRODUCTION

Breast cancer remains a significant scientific, clinical and societal challenge. This gap analysis has reviewed and critically assessed enduring issues and new challenges emerging from recent research, and proposes strategies for translating solutions into practice.

METHODS

More than 100 internationally recognised specialist breast cancer scientists, clinicians and healthcare professionals collaborated to address nine thematic areas: genetics, epigenetics and epidemiology; molecular pathology and cell biology; hormonal influences and endocrine therapy; imaging, detection and screening; current/novel therapies and biomarkers; drug resistance; metastasis, angiogenesis, circulating tumour cells, cancer 'stem' cells; risk and prevention; living with and managing breast cancer and its treatment. The groups developed summary papers through an iterative process which, following further appraisal from experts and patients, were melded into this summary account.

RESULTS

The 10 major gaps identified were: (1) understanding the functions and contextual interactions of genetic and epigenetic changes in normal breast development and during malignant transformation; (2) how to implement sustainable lifestyle changes (diet, exercise and weight) and chemopreventive strategies; (3) the need for tailored screening approaches including clinically actionable tests; (4) enhancing knowledge of molecular drivers behind breast cancer subtypes, progression and metastasis; (5) understanding the molecular mechanisms of tumour heterogeneity, dormancy, de novo or acquired resistance and how to target key nodes in these dynamic processes; (6) developing validated markers for chemosensitivity and radiosensitivity; (7) understanding the optimal duration, sequencing and rational combinations of treatment for improved personalised therapy; (8) validating multimodality imaging biomarkers for minimally invasive diagnosis and monitoring of responses in primary and metastatic disease; (9) developing interventions and support to improve the survivorship experience; (10) a continuing need for clinical material for translational research derived from normal breast, blood, primary, relapsed, metastatic and drug-resistant cancers with expert bioinformatics support to maximise its utility. The proposed infrastructural enablers include enhanced resources to support clinically relevant in vitro and in vivo tumour models; improved access to appropriate, fully annotated clinical samples; extended biomarker discovery, validation and standardisation; and facilitated cross-discipline working.

CONCLUSIONS

With resources to conduct further high-quality targeted research focusing on the gaps identified, increased knowledge translating into improved clinical care should be achievable within five years.

Evaluation of Serum Levels of HER2, MMP-9, Nitric Oxide, and Total Antioxidant Capacity in Egyptian Breast Cancer Patients: Correlation with Clinico-Pathological Parameters

Breast cancer is by far the most common cancer in women worldwide and the main cause of cancer-related mortality. Breast cancer accounts for 38% of all malignancies among Egyptian women. The aim of our study was to evaluate the serum levels of human epidermal growth factor receptor-2 (HER2), matrix metalloproteinase-9 (MMP-9), nitric oxide (NO), and total antioxidant capacity (TAC) in breast cancer patients and to correlate these markers with clinico-pathological parameters. Serum HER2, MMP-9, and carcinoma antigen 15-3 (CA 15-3) were assessed in 80 breast cancer patients and ten healthy subjects as a control group by the enzyme-linked immunosorbent assay (ELISA) technique while NO and TAC were assessed by a colorimetric method. Serum HER2 was ≥15 ng/mL in nine patients (11.3%). High HER2 ECD levels were significantly associated with tissue HER2 (P<0.0001), metastasis (P= 0.0024), and negativity of both estrogen (P=0.0075) and progesterone (P=0.0239) receptors. Serum MMP-9 (P=0.0013), NO (P<0.0001), and CA 15-3 (P<0.0001) were significantly increased while serum TAC was significantly (P=0.01) decreased in breast cancer patients as compared to the control group. Serum MMP-9 was increased significantly (P=0.028) in metastatic patients as compared to non-metastatic patients. We found a positive correlation between serum HER2 and CA 15-3 (r=36, p=0.005). In conclusion, serum HER2 reflects the tissue HER2 status of breast cancer, so the determination of serum HER2 is helpful in assessing HER2 status, but in addition, a high level may reflect metastatic disease. Also, serum MMP-9 can be useful for denoting the development of metastasis in breast cancer patients. Follow-up is needed to evaluate the value of serum HER2 and MMP-9 as prognostic markers.

Circulating HER2 Extracellular Domain: A Specific and Quantitative Biomarker of Prognostic Value in all Breast Cancer Patients?

The HER2 oncoprotein has emerged as an essential biomarker in the treatment of breast cancer patients. Once the primary breast cancer is removed, there is an increasing need to detect breast cancer recurrence as early as possible with the hope that earlier intervention with new anti-HER2 therapies will improve quality of life and increase overall survival. Numerous publications have shown that increasing blood levels of circulating HER2 is an early indicator of progression, particularly in HER2-positive patients and that the rise and fall parallels the clinical course of disease and independent of therapy. Many studies show that the HER2 status of the primary tumor may not fully and accurately reflect the HER2 status of recurrent cancer. Thus, elevated serum HER2 levels may be an early signal of the emergence of a HER2-positive metastatic tumor and therefore alert the physician to re-assess HER2 status using a tissue test.

Clinical Significance of HER-2 Splice Variants in Breast Cancer Progression and Drug Resistance

Overexpression of human epidermal growth factor receptor (HER-2) occurs in 20-30% of breast cancers and confers survival and proliferative advantages on the tumour cells making HER-2 an ideal therapeutic target for drugs like Herceptin. Continued delineation of tumour biology has identified splice variants of HER-2, with contrasting roles in tumour cell biology. For example, the splice variant Δ16HER-2 (results from exon 16 skipping) increases transformation of cancer cells and is associated with treatment resistance; conversely, Herstatin (results from intron 8 retention) and p100 (results from intron 15 retention) inhibit tumour cell proliferation. This review focuses on the potential clinical implications of the expression and coexistence of HER-2 splice variants in cancer cells in relation to breast cancer progression and drug resistance. "Individualised" strategies currently guide breast cancer management; in accordance, HER-2 splice variants may prove valuable as future prognostic and predictive factors, as well as potential therapeutic targets.

Biomarkers for the clinical management of breast cancer: international perspective

The higher incidence of breast cancer in developed countries has been tempered by reductions in mortality, largely attributable to mammographic screening programmes and advances in adjuvant therapy. Optimal systemic management requires consideration of clinical, pathological and biological parameters. Oestrogen receptor alpha (ERα), progesterone receptor (PgR) and human epidermal growth factor receptor 2 (HER2) are established biomarkers evaluated at diagnosis, which identify cardinal subtypes of breast cancer. Their prognostic and predictive utility effectively guides systemic treatment with endocrine, anti-HER2 and chemotherapy. Hence, accurate and reliable determination remains of paramount importance. However, the goals of personalized medicine and targeted therapies demand further information regarding residual risk and potential benefit of additional treatments in specific circumstances. The need for biomarkers which are fit for purpose, and the demands placed upon them, is therefore expected to increase. Technological advances, in particular high-throughput global gene expression profiling, have generated multi-gene signatures providing further prognostic and predictive information. The rational integration of routinely evaluated clinico-pathological parameters with key indicators of biological activity, such as proliferation markers, also provides a ready opportunity to improve the information available to guide systemic therapy decisions. The additional value of such information and its proper place in patient management is currently under evaluation in prospective clinical trials. Expanding the utility of biomarkers to lower resource settings requires an emphasis on cost effectiveness, quality assurance and possible international variations in tumor biology; the potential for improved clinical outcomes should be justified against logistical and economic considerations.

Bringing cancer serological diagnosis to a new level: focusing on HER2, protein ectodomain shedding and neoepitope technology

Cancer is a heterogeneous disease and consequently an exact diagnosis is as important as the actual therapy. Therefore, identification of novel diagnostic biomarker targets is urgently needed. Physiological and pathological changes are reflected by post-translational modifications of proteins. Each post-translational modification (e.g., proteolytic cleavage) is the result of a specific local process and may produce disease-specific neoepitopes. Neoepitopes have been successfully used as biomarkers in many diseases, and may also serve as promising tools in the development of future diagnostic assays within oncology. By specifically targeting neoepitopes, more information regarding disease-type and -state may be obtained and future research into neoepitopes will provide important and novel means for the diagnosis, prognosis and treatment efficacy in cancer. In this paper, we focus on protein ectodomain shedding and the generation of neoepitopes as future noninvasive (serological) cancer biomarkers. We use the protein ectodomain shedding of the human epidermal growth factor receptor 2, which is associated with breast cancer, as an example. We assess the current status of measuring human epidermal growth factor receptor 2 and discuss how this potentially could be improved. Furthermore, we expand the discussion to include examples of other cancer associated proteins.

Cytokeratin19-2g2, a novel fragment of cytokeratin19 in serum, indicating a more invasive behavior and worse prognosis in breast cancer patients

Background

Various studies have been searching for new tumor biomarkers for breast cancer for years. However, so far, few markers have been proved clinically useful except CA153. Based on knowledge that most adenocarcinomas including breast carcinoma expressed Cytokeratin19, the authors studied CK19-2G2,a novel fragment of cytokeratin19 shedding into serum in breast cancer patients.

Patients and Methods

The serum samples of four hundred and seventeen patients including three hundred and three (fifty-four DCIS and two hundred and forty-nine stage I-III) PBC patients and one hundred and fourteen MBC patients, eighty-one healthy controls and twenty-one breast benign disease patients were provided for measurement of CK19-2G2, CEA and CA153.The correlation between clinicopathological characters, prognosis and CK19-2G2 levels was further studied.

Results

The serum CK19-2G2 levels in breast cancer patients were significantly higher than that in healthy and benign controls. For breast cancer patients, CK19-2G2 levels in MBC were significantly higher than that in PBC patients. The sensitivities of CK19-2G2 for breast carcinoma are as high as CEA and CA153, and up to 71% in MBC patients. Serum CK19-2G2 levels (≥2 mU/mL) were associated with pathological stages, tumor size (≥2 cm), lymph node involvement, and HER2 status. Multivariate analysis revealed that high serum CK19-2G2 level was an independent factor for relapse (P = 0.029) and death (P = 0.040) in breast cancer patients.

Conclusion

Serum CK19-2G2 may be an independent indicator for prognosis and a candidate marker for monitoring metastasis in breast cancer.

Clinical usefulness of human epidermal growth factor receptor-2 extracellular domain as a biomarker for monitoring cancer status and predicting the therapeutic efficacy in breast cancer

We assessed the clinical usefulness of human epidermal growth factor receptor-2 extracellular domain (HER2ECD) as a biomarker for detecting cancer and monitoring disease status and for predicting the efficacy of anticancer treatment in breast cancer. Five-hundred and eighty serum samples from 252 patients with breast cancer were examined for the concentration of HER2ECD to compare with conventional tumor markers (CEA, CA15-3, NCC-ST439 and BCA225). Also, in 19 patients with HER2-overexpressed advanced or recurrent breast cancer who were treated with trastuzumab, clinical outcomes were evaluated retrospectively to determine whether their serum HER2ECD levels predict clinical responses. The proportion of patients with elevated HER2ECD levels was 15.1%, which was compatible with those with elevated conventional marker levels. In patients with HER2-overexpressed breast cancer, the positive rate of HER2ECD was significantly higher (24.1%) than those of conventional markers (7.4-12.9%), suggesting the usefulness of HER2ECD for detecting cancer in this population. HER2-overexpressed patients responding to trastuzumab (12 of 19 patients) showed significantly higher serum HER2ECD level (p = 0.033) and longer time to progression (TTP) (p = 0.039) and overall survival (OS) (p = 0.031) than did patients not responding (seven patients). Furthermore, higher response rates were observed in patients with elevated HER2ECD levels than in patients without elevated HER2ECD levels (91.3% vs. 14.3%, p = 0.032), whereas there was no difference in survival between the two groups. The results suggest that HER2ECD is a useful biomarker not only for detecting breast cancer recurrence but also for predicting tumor responses to trastuzumab.

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.

Discrepancies between primary tumor and metastasis: a literature review on clinically established biomarkers

The identification of predictive factors of response is critical for the development and appropriate use of anti-cancer agents. The evaluation of biomarkers is usually performed by analyzing the primary tumor tissues but this approach does not take into account potential discrepancies between primary tumor and secondary lesions. This review proposes to describe currently available data regarding differential expression of established biomarkers between primary tumor and matched metastasis. In light of recent data, the need of iterative biopsies in metastatic setting has been suggested but technical and methodological limits in such analyses should not be ignored and this strategy cannot be definitively validated. Complementary studies are still needed since the question of spatial and temporal variability of biomarkers in solid tumors is clearly a key issue in an era where personalized therapy is strongly advocated by clinicians, researchers and patients.

Relationships between serum HER2 ECD, TIMP-1 and clinical outcomes in Taiwanese breast cancer

BACKGROUND

Serum levels of the extracellular domain of HER2/neu (HER2 ECD) have been demonstrated to be associated with clinical outcomes. A disintegrin and metalloproteinase-10, a sheddase of HER2/neu, can drive cancer progression and its activity is inhibited by tissue inhibitor of metalloproteinase-1 (TIMP-1). However, elevated TIMP-1 expression has been associated with a poor prognosis of breast cancer. Therefore, this study was performed to explore the relationships between serum HER2 ECD, TIMP-1 and clinical outcomes.

METHODS

One hundred and eighty-five female breast cancer patients, who received curative mastectomy without neo-adjuvant chemotherapy at Chang-Gung Memorial Hospital, were recruited with informed consent for this study. Pre-operative serum levels of HER2 ECD and TIMP-1 were measured using an enzyme-linked immunosorbent assay.

RESULTS

Twenty-three cases (12.4%) were classified HER2 ECD positive. HER2 ECD positivity was significantly associated with age, lymph node involvement, histological grade, estrogen receptor status, progesterone receptor status, tissue HER2/neu overexpression, and disease-free survival (DFS). In an age, stage, ER and HER2/neu status matched subgroup (N = 41), the serum level of TIMP-1 was significantly associated with HER2 ECD positivity and DFS.

CONCLUSIONS

A high serum TIMP-1 was significantly associated with HER2 ECD positivity and a poorer DFS among Taiwanese primary breast cancer patients with HER2 overexpression.

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.

Single-chain antibody-based immunotoxins targeting Her2/neu: design optimization and impact of affinity on antitumor efficacy and off-target toxicity

Recombinant immunotoxins, consisting of single-chain variable fragments (scFv) genetically fused to polypeptide toxins, represent potentially effective candidates for cancer therapeutics. We evaluated the affinity of various anti-Her2/neu scFv fused to recombinant gelonin (rGel) and its effect on antitumor efficacy and off-target toxicity. A series of rGel-based immunotoxins were created from the human anti-Her2/neu scFv C6.5 and various affinity mutants (designated ML3-9, MH3-B1, and B1D3) with affinities ranging from 10(-8) to 10(-11) mol/L. Against Her2/neu-overexpressing tumor cells, immunotoxins with increasing affinity displayed improved internalization and enhanced autophagic cytotoxicity. Targeting indices were highest for the highest affinity B1D3/rGel construct. However, the addition of free Her2/neu extracellular domain (ECD) significantly reduced the cytotoxicity of B1D3/rGel because of immune complex formation. In contrast, ECD addition had little impact on the lower affinity constructs in vitro. In vivo studies against established BT474 M1 xenografts showed growth suppression by all immunotoxins. Surprisingly, therapy with the B1D3-rGel induced significant liver toxicity because of immune complex formation with shed Her2/neu antigen in circulation. The MH3-B1/rGel construct with intermediate affinity showed effective tumor growth inhibition without inducing hepatotoxicity or complex formation. These findings show that while high-affinity constructs can be potent antitumor agents, they may also be associated with mistargeting through the facile formation of complexes with soluble antigen leading to significant off-target toxicity. Constructs composed of intermediate-affinity antibodies are also potent agents that are more resistant to immune complex formation. Therefore, affinity is an exceptionally important consideration when evaluating the design and efficacy of targeted therapeutics.

Her2/neu extracellular domain shedding in uterine serous carcinoma: implications for immunotherapy with trastuzumab

Background:

We evaluated shedding of epidermal growth factor type II receptor (Her2/neu) extracellular domain (ECD) in primary uterine serous carcinoma (USC) cell lines and in the serum of USC patients and its biological effects in experiments of trastuzumab-induced cytotoxicity in vitro.

Methods:

Her2/neu expression was evaluated by immunohistochemistry (IHC), real-time PCR and flow cytometry, while c-erbB2 gene amplification was assessed using fluorescent in situ hybridisation (FISH). Her2/neu ECD levels in the supernatants of USC cell lines and in the serum of 38 USC patients and 19 controls were tested using ELISA. The biologic effect of Her2/neu ECD on trastuzumab-induced antibody-dependent cell-mediated cytotoxicity (ADCC) was evaluated in 5-h chromium-release assays.

Results:

Five out of ten USC cell lines overexpressed Her2/neu by IHC and showed amplification of the c-erbB2 gene. High levels of Her2/neu ECD were found in supernatants of all FISH-positive tumours. In contrast, FISH-negative USC was negative for Her2/neu ECD shedding. Serum Her2/neu ECD levels in patients harbouring 3+Her2/neu tumours were higher than those found in healthy women (P=0.02) or USC patients with 2+ or 1+/negative Her2/neu expression (P=0.02). In cytotoxicity experiments, trastuzumab-mediated ADCC was significantly decreased by the addition of Her2/neu ECD-containing supernatants (P=0.01).

Conclusion:

FISH-positive c-erbB2 USC cell lines shed high levels of Her2/neu ECD. High levels of Her2/neu ECD in USC patients may reduce trastuzumab-mediated ADCC in vitro and potentially neutralise its therapeutic effect in vivo.

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.

Optimizing the management of advanced non-small-cell lung cancer: a personal view

The management of advanced non-small-cell lung cancer (a-nsclc) is currently undergoing one of its rare paradigm shifts. Just as the nihilism of the 1970s gave way to the empiricism of the 1980s and 1990s, so the current decade has seen the first truly rational therapies based on informed design. In addition, molecular markers and traditional parameters can now be combined to provide a framework of knowledge that will guide the application of not just the new therapies, but also the older ones that remain effective. This framework—as important a component of the rational paradigm as the new drugs themselves are—is necessary to decide who should and, crucially, who should not receive the various components of this rapidly expanding armamentarium. Here, I have provided a historical overview of the drug treatment of a-nsclc, a mini-review of important new data, and an integrative approach that tries to ensure that patients receive the optimal treatment choice at the appropriate time.

The speed at which new knowledge now arrives, coupled with the persistent high level of unmet medical need, suggests that the traditional pace of evidence-based review needs to be accelerated. Indeed, the increased scope for personalized management constitutes something of a challenge to “business as usual” evidence-based medicine. As a result, substantial investment on the part of payers, which may or may not be possible, will be required. In the meantime, some patients may wish and may be financially able to take advantage of modern developments before they have been fully digested by the public-payer system. Responsive clinicians face difficult tradeoffs as they try to balance the pros and cons of early adoption versus excessive conservatism.

The present article is my personal view of how to navigate these waters, and although it is written especially for patients who like to be the captain of their own ship, there is good reason to believe that all patients will eventually be managed by similar, if not identical, means. Nonetheless, the recommendations herein should not be construed as appropriately reviewed provincial or national guidelines. Finally, if appropriate, a clinical trial should always be offered.

Identifying responders to trastuzumab therapy in breast cancer

In breast cancer, HER2-targeted therapy with trastuzumab has gained significant attention, owing to the dramatic response observed in a subset of HER2-positive patients. The mechanisms of action are complex and not fully understood, and much effort has been spent in order to identify responders. Good patient management, side effects of the humanized monoclonal antibody and socioeconomics all demand that the drug should be administered only to the patients who will benefit from it. This has been a difficult task and contributions to solve it have been proposed from a variety of research. In this article we describe some of these contributions based on the literature and provide our viewpoint as to which identifiers will emerge in the following decade.

Serum HER2 levels determined by two methods in patients with metastatic breast cancer

BACKGROUND

The role and the optimal measurement method of serum HER2 levels are not defined in patients with metastatic breast cancer (MBC). We prospectively assessed the prognostic value of serum HER2 levels in MBC using two methods, enzyme immunoassay (EIA) and chemiluminescence immunoassay (CLIA).

METHODS

We collected blood samples from patients with MBC at baseline and at subsequent 3- to 4-week intervals up to 12 weeks. Samples were divided, and serum HER2 levels were determined using EIA and CLIA. We also determined whether serum HER2 levels had decreased by ≥20% at first follow-up. These results were evaluated against overall survival, progression-free survival, and tumor response.

RESULTS

We obtained 196 samples from 52 patients. In 59 samples from patients who received trastuzumab, serum HER2 positivity rates were significantly lower for EIA (n = 22) than for CLIA (n = 33, P = 0.042); in 137 samples from patients who did not receive trastuzumab, there was no significant difference in rates of serum HER2 positivity for CLIA (n = 83) and EIA (n = 80). Serum HER2 level at baseline, the level at first follow-up, and a decrease of ≥20% between baseline and first follow-up were not associated with overall survival, progression-free survival, and tumor response.

CONCLUSIONS

Chemiluminescence immunoassay was a more sensitive method than EIA for measuring serum HER2 levels in patients who received trastuzumab. However, because serum HER2 levels did not correlate with patient outcome, we do not currently recommend measuring serum HER2 levels by either method for prognostic evaluation in patients with MBC.

Proceedings of the First Global Workshop on Breast Cancer: pathways to the evaluation and clinical development of novel agents for breast cancer

The number of treatment options available to patients with breast cancer is larger and more complex than ever before. This is due in part to increased understanding of breast cancer tumor biology and the signaling pathways involved in tumor development and progression, which drives new areas of breast cancer research and the development of novel agents. Therapies targeting HER2 signaling, angiogenesis, DNA repair, and many other essential cellular processes that are dysregulated in cancer have produced significant improvements in disease outcome, although careful patient selection and toxicity management are required to maximize their therapeutic potential. Multigene assays have added to the ability to predict disease outcome and degree of response to adjuvant chemotherapy, but the application of these assays in the right clinical context is necessary. Unfortunately, despite the use of appropriate and effective local and adjuvant therapies, some patients with early-stage breast cancer will eventually develop metastatic disease. Most of these patients will have received standard therapies in the adjuvant setting and/or will develop resistance to these therapies at some point during treatment. Thus, implementation of novel strategies is necessary to overcome resistance and improve disease outcome. This in turn will require creative clinical trial designs, more efficient accrual, and rapid translation of results into the clinical setting. This summary highlights selected challenges in the current management of breast cancer and discusses expert perspectives, key questions, areas of debate, and future directions.

Concentrations of EpCAM ectodomain as found in sera of cancer patients do not significantly impact redirected lysis and T-cell activation by EpCAM/CD3-bispecific BiTE antibody MT110

Ectodomains of target antigens for antibody-based therapies can be shed from the target cell surface and found in sera of patients. Shed ectodomains of therapeutic targets not only pose the risk of sequestering therapeutic antibodies but, in a multimeric form, of triggering T cell activation by bispecific antibodies binding to CD3 on T cells. Recently, epithelial cell adhesion molecule (EpCAM) has been shown to be activated by release of its ectodomain, called EpEX. Here, we show that only very low amounts of EpEX are detectable in sera of cancer patients. Among 100 cancer patient samples tested, only 17 (17%) showed serum levels of EpEX in excess of 0.05 ng/ml with highest EpEX concentrations of 5.29, 1.37 and 0.52 ng/ml. A recombinant form of human EpEX (recEpEX) was produced to assess its possible effect on redirected lysis and T cell activation by EpCAM/CD3-bispecific BiTE antibody MT110, currently being tested in patients with solid tumor malignancies. RecEpEX had a very minor effect on redirected lysis by MT110 with an approximate IC 50 value of 3,000 ng/ml, which is a concentration close to three orders of magnitude higher than the highest EpEX concentration found in cancer patients. Concentrations of 30 ng/ml EpEX in combination with 250 ng/ml MT110 were minimally required to induce a detectable activation of CD4 (+) and CD8 (+) T cells. We conclude that soluble EpEX in sera of cancer patients is unlikely to pose an issue for the efficacy or safety of MT110, and perhaps other antibodies binding to N-terminal epitopes of EpCAM.

[Update of the GEFPICS' recommendations for HER2 status determination in breast cancers in France]

In Europe, patients who may benefit from an HER2 targeted drug are currently selected by immunohistochemistry (IHC). In situ hybridization (ISH) techniques should be used for complementary assessment of ambiguous 2+ IHC cases and for the calibration of the IHC technique. Eligibility to an HER2 target treatment is defined by an HER2 positive status being IHC test 3+ or 2+ amplified. Reliable detection of HER2 status is essential to the appropriate usage of HER2 targeted drugs because its specificity is limited to tumors overexpressing HER2. It is essential that the IHC evaluation of the HER2 status of a mammary carcinoma is optimized and reliable. This GEFPICS' guidelines look over the different steps of the IHC technique, the controls and, the rules for interpretation. Once acquired, this knowledge must be perpetuated by the observation of rules of good technical practice (internal and external controls, quality assurance programs).

Molecular circuits of solid tumors: prognostic and predictive tools for bedside use

The explosion of knowledge in cancer biology in the past two decades has led to the identification of specific molecular circuits in solid tumors. These pathways reflect specific abnormalities thought to drive malignant progression. This knowledge has also generated a vast panel of cancer biomarkers although many of these biomarkers lack sufficient research and validation to be used in the clinic. This Review discusses relevant molecular prognostic and/or predictive biomarkers in the six leading tumors with the highest contribution to cancer mortality: breast, lung, colorectal, prostate, pancreatic and ovarian cancer. Each biomarker is described according to its associated clinicopathological presentation and specific associated molecular interactions. Despite only few biomarkers being currently implemented in clinical practice, a new generation of predictors is emerging that could modify the classic organ-based cancer classification (for example, defects in DNA repair, aberrant MAPK signaling and aberrant PI3K/Akt/mTOR signaling). The advent of high-throughput strategies will also probably substitute monobiomarker strategies.

Clinical significance of EGFR, Her-2 and EGF in oral squamous cell carcinoma: a case control study

Background

The erbB receptors and their ligands are involved in the pathogenesis and progression of oral squamous cell carcinoma (OSCC). Although EGFR and Her-2 are frequently overexpressed in OSCC, few studies evaluated these proteins in saliva and their association with the tumor, which may represent potential usefulness in a clinical setting.

Methods

The levels of EGFR, Her-2, and EGF were evaluated in saliva of 46 patients with OSCC before and after the surgical removal of the lesion, as well as in matched healthy controls. The relationship of salivary levels and EGFR and Her-2 immunoexpression in tumor samples with clinicopathological features was analyzed.

Results

EGFR and Her-2 salivary levels did not show difference between to pre-surgery and control groups, however, both demonstrated an increase after surgical removal of the tumor. No association was detectable among receptor salivary levels, tissue expression and clinicopathological features. EGF levels in pre-surgery group were significantly lower when compared to the control group.

Conclusions

EGFR and Her-2 were not considered to be valuable salivary tumor markers in OSCC, however, lower levels of EGF in saliva may suggest a higher susceptibility for OSCC development.