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

Serum HER2 Level Predicts Therapeutic Efficacy and Prognosis in Advanced Breast Cancer Patients

Background

The purpose of this study was to investigate the therapeutic efficacy and prognosis of serum HER2 (sHER2) in patients with advanced breast cancer.

Methods

We analyzed the sHER2 levels of 200 patients with advanced breast cancer receiving first or second line treatment, the tissue HER2 (tHER2) level was also analyzed. Indicators of therapeutic efficacy and prognosis were objective response rate (ORR), disease control rate (DCR), and time to progression (TTP).

Results

The baseline sHER2 level was high in 132 patients and low in 68 patients. The high level of sHER2 is correlated with molecular subtype (p=0.016), visceral metastasis (p<0.001), liver metastasis (p<0.001), tissue HER-2 (tHER2) (p=0.001), and, among tHER2-low tumors (59 patients), the baseline sHER2 high level was associated with a higher proportion of brain metastasis. The ORR of patients with baseline sHER2 high level is higher than those with baseline sHER2 low level (p=0.026). The TTP of patients with baseline sHER2 low level is longer than the patients with baseline sHER2 high level (p=0.024). For patients with baseline sHER2 high level, a significant decrease in sHER2 after two cycles of treatment indicates higher ORR, DCR, and an extension of TTP. After multiple cycles of treatment, for patients with tHER-2 positive and baseline sHER2 high level, the DCR in the sHER2 decrease in the negative group was higher than that in the continuous positive group (p=0.037). Patients with a rapid decline type of sHER2 dynamic change curve had higher ORR and prolonged TTP compared with patients with other types of sHER2 dynamic change curve. There is no correlation between OS and sHER2 levels.

Conclusion

Our study showed that patients with advanced breast cancer had a high level of sHER2 at recurrence, regardless of whether they are tHER2 positive or negative. Dynamic detection of sHER2 can help predict therapeutic efficacy and prognosis, regardless of whether tHER-2 is positive or negative.

Comprehensive Analysis of Human Epidermal Growth Factor Receptor 2 Through DNA, mRNA, and Protein in Diverse Malignancies

PURPOSE

Human epidermal growth factor receptor 2 (HER2) expression (protein immunohistochemistry [IHC] or gene amplification [copy-number variation, CNV]) predicts anti-HER2 therapy responsiveness, although recently it was shown that even low HER2-expressing breast cancers benefit from trastuzumab-deruxtecan. Little is known about HER2 transcriptomic (mRNA) expression, and comparisons between genomic, mRNA, and protein HER2 assays.

METHODS

HER2 status was evaluated using clinical-grade IHC (protein), quantitative reverse transcription polymerase chain reaction (mRNA), and next-generation sequencing (NGS; amplifications).

RESULTS

Multi-institutional HER2 testing was performed on 5,305 diverse cancers including non-small-cell lung (n = 1,175), breast (n = 1,040), and colon cancers (n = 566; N = 3,926 tested for CNV; N = 1,848, mRNA; N = 2,533, IHC). Overall, 4.1% (161/3,926) had NGS HER2 amplification; 33.3% (615/1,848) had mRNA overexpression; and 9.3% (236/2,533) were IHC-positive. In 723 patients with all three tests (CNV/mRNA/IHC), various amplification/expression patterns occurred: 7.5% (54/723) had all three HER2 tests positive; 62.8% (454/723) had all three tests negative. Discrepant patterns between amplification and overexpression emerged. For instance, 20% (144/723) of patients had mRNA overexpression alone with negative CNV and IHC. A range in values for only mRNA+ cases occurred in different tumor types (eg, 16.9%, breast; 5%, hepatobiliary). There were 53 patients with various tumors from our institution who had all three assays attempted; 22 tested positive for HER2, and seven received anti-HER2 therapy: two patients achieved response: one (esophageal cancer), complete response (≥42 months); one (cholangiocarcinoma), who only had HER2 mRNA positivity (tissue was inadequate for IHC and CNV assessment), partial response (≥24 months) on HER2-based regimens.

CONCLUSION

We demonstrate variability of HER2 (protein and mRNA) expression and amplification using comprehensive assays (CNV, mRNA, and IHC) among diverse cancers. As HER2-targeted therapy indications expand, the relative importance of these modalities merits further evaluation.

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.

Serum HER2 levels predict treatment efficacy and prognosis in patients with HER2-positive breast cancer undergoing neoadjuvant treatment

Background

Controversy remains regarding the predictive and prognostic value of serum human epidermal growth factor receptor 2 (HER2) in breast cancer. The purpose of this retrospective study was to determine the clinical utility and efficacy of serum HER2 (sHER2) in predicting treatment response and prognosis in patients with HER2-positive breast cancer undergoing neoadjuvant chemotherapy and trastuzumab treatment.

Methods

A total of 309 HER2-positive breast cancer patients diagnosed at Fudan University Shanghai Cancer Center from July 2015 to January 2019 were analyzed. Baseline sHER2 levels were obtained for all patients and sHER2 levels were collected after 2 cycles of treatment in 208 patients. A sHER2 level ≥15 ng/mL was regarded as "high expression" and sHER2 <15 ng/mL was regarded as "low expression". Outcome measures of treatment efficacy and prognosis were pathological complete response (pCR) and invasive disease-free survival (iDFS), respectively.

Results

In patients with high baseline sHER2, more were ER-negative (P=0.029), had larger tumor size (P=0.006), more advanced clinical stage (P=0.002), higher Miller-Payne grade (P=0.024) and higher likelihood of iDFS events (P=0.015). Patients with high sHER2 levels after 2 cycles of treatment had lower pCR rates (P=0.038), higher Miller-Payne grade (P=0.013) and higher likelihood of iDFS events (P=0.003). Kaplan-Meier analysis showed significant differences in iDFS between patients with high and low sHER2 levels at baseline (P=0.019) and after 2 cycles of treatment (P=0.000). Further analyses according to cancer subtypes found baseline sHER2 to be significantly correlated with the iDFS of Luminal B patients (p=0.002), while sHER2 levels after 2 cycles of treatment was significantly correlated with the iDFS of HER2-enriched patients (P=0.000). Univariate analysis showed significant association between iDFS and tumor size (P=0.026), lymph node status (P=0.008), clinical stage (P=0.031), baseline sHER2 (P=0.024), overall tumor response (P=0.011), pCR (P=0.043) and Miller-Payne grade (P=0.001). Multivariate analysis found Miller-Payne grade (P=0.037) to be significantly associated with iDFS.

Conclusions

Our results demonstrate the clinical value of sHER2 in a population of Chinese breast cancer patients, suggesting that sHER2 levels after 2 cycles of neoadjuvant therapy may be more predictive of treatment outcomes and that the prognostic value of sHER2 may be time point and subtype dependent.

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.

The coexpression of EphB4 and EphrinB2 is associated with poor prognosis in HER2-positive breast cancer

Objective

HER2 overexpression is associated with aggressive phenotypes in breast cancer, including increased tumor proliferation, greater invasiveness, and reduced overall survival. The overall response rate to HER2-targeted therapies remains <30%. There is an urgent need for the identification of efficient markers to predict patients with a poor prognosis. This study was designed to investigate the correlation between EphB4 and EphrinB2 expression and the clinicopathological characteristics of HER2-positive breast cancer.

Materials and methods

A total of 111 primary HER2-positive breast cancer patients were enrolled in this study (diagnosed since December 2005 to November 2010 from the Second Hospital of Dalian Medical University). The protein expression of EphB4 and EphrinB2 was examined by immunohistochemistry using paraffin-embedded tumor tissues.

Results

There was a significant correlation between EphB4 and EphrinB2 expression (P=0.013, r=0.255). Kaplan–Meier analysis showed that the prognosis of patients with a high expression of both EphB4 and EphrinB2 was significantly worse than the prognosis of patients with either EphB4 or EphrinB2 expression and patients with negative expression (hazard ratio [HR] =1.935, P=0.0224). However, high expression of EphB4 or EphrinB2 alone was not an independent prognostic factor to predict worse overall survival. To summarize, HER2-positive breast cancer patients with overexpression of both EphB4 and EphrinB2 were associated with the worst prognosis.

Conclusion

High expression of EphB4 and EphrinB2 correlated with poor overall survival, which can serve as an independent prognostic indicator in primary HER2-positive breast cancer patients.

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.

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.

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.

Advantages and disadvantages of technologies for HER2 testing in breast cancer specimens

OBJECTIVES

Human epidermal growth factor receptor 2 (HER2) plays a central role as a prognostic and predictive marker in breast cancer specimens. Reliable HER2 evaluation is central to determine the eligibility of patients with breast cancer to targeted anti-HER2 therapies such as trastuzumab and lapatinib. Presently, several methods exist for the determination of HER2 status at different levels (protein, RNA, and DNA level).

METHODS

In this review, we discuss the main advantages and disadvantages of the techniques developed so far for the evaluation of HER2 status in breast cancer specimens.

RESULTS

Each technique has its own advantages and disadvantages. It is therefore not surprising that no consensus has been reached so far on which technique is the best for the determination of HER2 status.

CONCLUSIONS

Currently, emphasis must be put on standardization of procedures, internal and external quality control assessment, and competency evaluation of already existing methods to ensure accurate, reliable, and clinically meaningful test results. Development of new robust and accurate diagnostic assays should also be encouraged. In addition, large clinical trials are warranted to identify the technique that most reliably predicts a positive response to anti-HER2 drugs.

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.

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.

Overall survival and clinicopathological characteristics of patients with breast cancer in relation to the expression pattern of HER-2, IL-6, TNF-α and TGF-β1

The present study was conducted to investigate the prognostic significance of co-expression patterna of HER-2, IL-6, TNF-a and TGF-β1 in breast cancer, by correlating the number of markers with positive expression with clinicopathological characteristics indicative of tumor progression and overall survival. One hundred thirty consecutive patients with primary breast cancer were prospectively included and evaluated. Serum concentrations of the above markers were measured by ELISA. Median split was used to subdivide patients with marker positive or negative expression. The presence of ≥ 3 positive markers was independently associated with extended lymph node (>3) involvement (aOR, 11.94, p=0.001) and lymphovascular invasion (aOR, 12.04, p=0.018), increasing the prognostic significance of each marker considered separately. Additional prognostic information regarding survival was also provided; as the number of positive markers increased, a gradually reduction of survival time was observed. In addition, patients with 4 positive markers had significantly shorter survival (25 vs 39 months, p=0.006) and a more than 4 fold increased risk of death (aHR, 4.35, p=0.003) compared to patients with 3 positive markers. Our findings suggest that the coexpression pattern of these four markers could be used clinically as a useful marker for tumor extension and outcome of breast cancer.

Salivary expression of soluble HER2 in breast cancer patients with positive and negative HER2 status

Background

The aim of this study was to investigate the relationship between salivary concentration of the soluble fragment of the HER2 (human epidermal growth factor receptor) protein and its status in mammary tissues.

Methods

This case-control study was done in 27 breast cancer patients with no visible metastatic disease treated at the gynecology service, Maternity Souissi Hospital, Rabat, Morocco. Two groups were selected, ie, patients with positive and negative HER2 status in mammary tissue. The salivary HER2 protein concentration was assessed by enzyme-linked immunosorbent assay. The salivary HER2 concentration was compared between the HER2-positive and HER2-negative groups using the Mann-Whitney U test. A P-value <0.05 was considered to be statistically significant.

Results

No statistically significant difference in salivary HER2 protein expression was found between the case and control groups. There was also no significant difference in clinical characteristics according to positive and negative HER2 status (P>0.05), except for the progesterone hormone receptor which was statistically significant in both the case and control groups (P=0.047).

Conclusion

According to our data, salivary expression of the HER2 receptor may not be a reliable alternative to tissue assessment.

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.

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.

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.