HER2 Status In Breast Carcinoma Research Articles

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

AimsWe aimed to compare digital image analysis (DIA) of human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) in breast cancer by two platforms: (i) to validate DIA against standard diagnostics; and (ii) to evaluate the added value of DIA in clinical practice.Methods and results HER2 IHC and in‐situ hybridisation (ISH) were performed on 152 consecutive invasive breast carcinomas. IHC scores were determined with DIA using two independent platforms. Manual scoring was performed by two independent observers. HER2 status was considered positive in 3+ and ISH‐positive 2+ cases. HER2 status using DIA was compared to HER2 status with standard diagnostics (manual scoring with ISH in 2+ cases). Interplatform agreement of IHC scores was ‘moderate’ (linear weighted κ = 0.58), agreement between manual scoring and platform A was ‘moderate’ (κ = 0.60) and between manual scoring and platform B ‘almost perfect’ (κ = 0.85). Compared to manual scoring, DIA resulted in a reduction of 2+ cases from 17.1 to 1.3% with platform A and from 17.1 to 15.8% with platform B. However, compared to standard diagnostics, there were three false‐negative cases with DIA using platform A [81.3% sensitivity, 100% specificity, 100% positive predictive value (PPV), 97.8% negative predictive value (NPV)]. Sensitivity, specificity, PPV and NPV were 100% with DIA using platform B.Conclusions DIA of HER2 IHC is a valid tool in determining HER2 status in breast carcinoma. Algorithms in different platforms can behave differently, and optimal calibration is essential. In clinical practice, DIA offers an objective alternative to manual scoring, but a reduction in 2+ cases could result in loss of sensitivity.

Analysis of HER2 status in breast carcinoma using fully automated HER2 staining and fluorescence in-situ hybridization technology

To determine human epidermal growth factor receptor 2 (HER2) status in breast carcinoma by the techniques of a fully automated immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), to compare the concordance of protein expression with gene amplification and to explore the optimization in process quality control. A prospective study of invasive breast cancer specimens excised between May 2009 and April 2011 at the Cancer Hospital, Chinese Academy of Medical Sciences was conducted by automated IHC staining with the new 4B5 rabbit monoclonal antibody and FISH. An evaluation was performed according to the ASCO/CAP guidelines (2007) and Chinese guidelines (2009). The gene amplification status of 740 cases were detected by FISH. A total of 2420 cases of breast invasive ductal carcinoma without pre-operation therapy were tested by automated IHC. 551 cases (22.8%) were scored as positive (3+), 664 cases (27.4%) as equivocal (2+), and 1205 cases (49.8%) as negative (1+/0). Gene amplification was detected in 98.0% (242/247) HER2 protein expression positive (3+) cases and in 13.6% (53/389) equivocal (2+) cases. One of 247 (0.4%) HER2 expression 3+ cases and 5 of 389 (1.3%) HER2 expression 2+ cases were equivocal for gene amplification. No gene amplification was detected in expression negative (1+/0) cases by FISH (0/104). The overall concordance between IHC and FISH was 98.6% [(242 + 104)/(247 + 104)]. There is a high concordance rate between automated IHC with 4B5 rabbit monoclonal antibody and FISH results for assessing the HER2 gene amplification status in surgically-excised breast cancer specimens, suggesting that automated IHC with 4B5 antibody can provide a reliable method to detect HER2 overexpression for eligibility of HER2 targeted therapy.

Intratumoral heterogeneity of HER2 status in breast carcinoma

Intratumoral heterogeneity of HER2 protein expression and HER2 gene amplification can negatively affect determination of HER2 status in a subset of invasive breast carcinomas. The frequency and clinical significance of HER2 genetic heterogeneity are unknown due to the lack of uniform criteria for diagnosis. Recent ASCO/CAP guidelines (2009) define HER2 genetic heterogeneity as the presence of between 5% and 50% of tumor cells with a HER2/CEP17 ratio >2.2. We describe a tool (a customized Excel spreadsheet) for easy and reproducible diagnosis of HER2 genetic heterogeneity according to ASCO/CAP criteria. Our tool may be useful for routine HER2 diagnostics and for studies to analyse the hitherto unknown predictive significance of HER2 genetic heterogeneity.

733 HER2 status in breast carcinomas: comparison between silver in situ hybridization, chromogenic in situ hybridization and fluorescence in situ hybridization

733 HER2 status in breast carcinomas: comparison between silver in situ hybridization, chromogenic in situ hybridization and fluorescence in situ hybridization

HER2 status of breast carcinoma developed as a secondary malignancy after Hodgkin lymphoma treatment.

e21112 Background: HER2 overexpression is present in ∼20% of all breast carcinoma (BC) but it is not quite known whether this percentage is maintained in potentially radiotherapy induced BC. Radiotherapy is frequently part of curative treatment for Hodgkin lymphoma (HL) and BC is most frequent secondary malignancy in those patients.The aim of this analysis is to explore HER2 status in BC developed as a secondary malignancy after HL treatment. Methods: From January 2000 to December 2008, 10 female patients with unilateral BC stage I-III, and previous history of HL were identified. HL was diagnosed from 1981-2004. All patients have been treated with chemotherapy, and 7/10 also with radiotherapy to the chest wall. All patients underwent radical mastectomy, postoperative chemotherapy, and hormonal therapy in 7/10. Median follow up after BC is 3 years (range 1-8). Pathological specimens for IHC (HerceptTest Dako) were identified for 9/10. All HER2 2+ results were tested with CISH. Results: Results are presented in the Table. Conclusions: Seven patients developed BC after previous radiotherapy to the chest wall and three without previous radiotherapy. In this small subgroup of BC patients previously treated for HL, HER2 3 + have not been registered. No (%) Median age at HL diagnosis (years) Median interval to BC diagnosis (months) Previous radiotherapy to the chest Median age et BC diagnosis (years) HER-2 negative(0, 1+, 2+) HER-2 positive (3+, CISH+) NA 10 (67%) 26.8 (13-53) 185.2 (72-348) 7/10 43.5 (26-69) 9/9 0/9 1/10 No significant financial relationships to disclose.

HER2 assessment on core biopsy specimens using monoclonal antibody CB11 accurately determines HER2 status in breast carcinoma

HER2 status is a prognostic factor in breast carcinoma and predicts response to trastuzumab therapy. Trastuzumab is effective in the neoadjuvant, adjuvant and advanced disease settings. Knowledge of HER2 status early in the diagnostic and therapeutic process is vital for treatment planning. HER2 analysis is usually carried out by immunohistochemistry or fluorescence in situ hybridization (FISH). The aim of this study was to establish whether HER2 immunohistochemistry using monoclonal antibody CB11 and carried out on the initial diagnostic core biopsy specimen accurately predicts HER2 amplification status. This is the largest study to date in which HER2 protein expression has been assessed by CB11 immunohistochemistry on the diagnostic core biopsy specimen and correlated with the result of FISH. Using FISH as the definitive HER2 status, we studied 568 invasive breast cancers using CB11 immunohistochemistry on core biopsy. This analysis had a sensitivity of 99.4%, specificity of 93.9%, false-positive frequency of 3.9% and false-negative frequency of 1.1%. These data are as good as those obtained from analysing resection specimens alone in UK national reference centres. CB11 immunohistochemistry accurately predicts HER2 amplification status and can be reliably carried out on core biopsy specimens of breast carcinoma.

PP45 Analytical performance of a novel dual color dual hapten brightfield genotypic assay for determination of HER2 status in breast carcinoma (DDISH)

Mitochondrial NADPH-dependent isocitrate dehydrogenase, IDH2, and cytosolic IDH1, catalyze reductive carboxylation of 2-oxoglutarate. Both idh2 and idh1 monoallelic mutations are harbored in grade 2/3 gliomas, secondary glioblastomas and acute myeloid leukemia. Mutant IDH1/IDH2 enzymes were reported to form an oncometabolite r-2-hydroxyglutarate (2HG), further strengthening malignancy. We quantified CO2-dependent reductive carboxylation glutaminolysis (RCG) and CO2-independent 2HG production in HTB-126 and MDA-MB-231 breast carcinoma cells by measuring 13C incorporation from 1-13C-glutamine into citrate, malate, and 2HG. For HTB-126 cells, 13C-citrate, 13C-malate, and 13C-2-hydroxyglutarate were enriched by 2-, 5-, and 15-fold at 5 mM glucose (2-, 2.5-, and 13-fold at 25 mM glucose), respectively, after 6 h. Such enrichment decreased by 6% with IDH1 silencing, but by 30–50% upon IDH2 silencing while cell respiration and ATP levels rose up to 150%. Unlike 2HG production RCG declined at decreasing CO2. At hypoxia (5% O2), IDH2-related and unrelated 13C-accumulation into citrate and malate increased 1.5–2.5-fold with unchanged IDH2 expression; whereas hypoxic 2HG formation did not. 13C–2HG originated by ∼50% from other than IDH2 or IDH1 reactions, substantiating remaining activity in IDH1&2-silenced cells. Relatively high basal 12C–2HG levels existed (5-fold higher vs. non-tumor HTB-125 cells) and 13C–2HG was formed despite the absence of any idh2 and idh1 mutations in HTB-126 cells. Since RCG is enhanced at hypoxia (frequent in solid tumors) and 2HG can be formed without idh1/2 mutations, we suggest 2HG as an analytic marker (in serum, urine, or biopsies) predicting malignancy of breast cancer in all patients.

Performance of Chromogenic In Situ Hybridization on Testing HER2 Status in Breast Carcinomas With Chromosome 17 Polysomy and Equivocal (2+) HercepTest Results

This study specifically addressed the performance of chromogenic in situ hybridization (CISH) on HER2 testing in 66 breast carcinomas with chromosome 17 polysomy and 49 carcinomas with an equivocal HercepTest (DakoCytomation, Carpinteria, CA) score by comparing CISH with corresponding FISH results at 2 test sites and evaluating intersite agreement of CISH results. For tumors with chromosome 17 polysomy, when using the manufacturers' criteria, the concordance values between CISH and FISH at site A, site B, and intersite CISH agreement were 95.8%, 95.5%, and 93.5%, respectively; when using the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) criteria, the values were 100.0%, 100.0%, and 100.0%, respectively. For tumors with an equivocal HercepTest score, when using the manufacturers' criteria, the concordance values between the 2 methods at site A, site B, and intersite CISH agreement were 88.2%, 95.1%, and 91.1%, respectively; when using the ASCO/CAP criteria, the values were 96.7%, 97.3%, and 97.4%, respectively. These results indicate that CISH is reliable for testing these 2 types of tumors, especially when the ASCO/CAP criteria are used.

Quantitative real-time RT-PCR and chromogenic in situ hybridization: precise methods to detect HER-2 status in breast carcinoma

BackgroundHER-2 gene testing has become an integral part of breast cancer patient diagnosis. The most commonly used assay in the clinical setting for evaluating HER-2 status is immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). These procedures permit correlation between HER-2 expression and morphological features. However, FISH signals are labile and fade over time, making post-revision of the tumor difficult. CISH (chromogenic in situ hybridization) is an alternative procedure, with certain advantages, although still limited as a diagnostic tool in breast carcinomas.MethodsTo elucidate the molecular profile of HER-2 status, mRNA and protein expression in 75 invasive breast carcinomas were analyzed by real time quantitative RT-PCR (qRT-PCR) and IHC, respectively. Amplifications were evaluated in 43 of these cases by CISH and in 11 by FISH.ResultsThe concordance rate between IHC and qRT-PCR results was 78.9%, and 94.6% for qRT-PCR and CISH. Intratumoral heterogeneity of HER-2 status was identified in three cases by CISH. The results of the three procedures were compared and showed a concordance rate of 83.8%; higher discordances were observed in 0 or 1+ immunostaining cases, which showed high-level amplification (15.4%) and HER-2 transcript overexpression (20%). Moreover, 2+ immunostaining cases presented nonamplified status (50%) by CISH and HER-2 downexpression (38.5%) by qRT-PCR. In general, concordance occurred between qRT-PCR and CISH results. A high concordance was observed between CISH/qRT-PCR and FISH. Comparisons with clinicopathological data revealed a significant association between HER-2 downexpression and the involvement of less than four lymph nodes (P = 0.0350).ConclusionBased on these findings, qRT-PCR was more precise and reproducible than IHC. Furthermore, CISH was revealed as an alternative and useful procedure for investigating amplifications involving the HER-2 gene.

Evaluation of automated silver‐enhanced in situ hybridization (SISH) for detection of HER2 gene amplification in breast carcinoma excision and core biopsy specimens

To validate the use of the silver-enhanced in situ hybridization (SISH) technique in assessing HER2 status of breast carcinoma in excision biopsy specimens, and to assess its reliability in determining HER2 status in core biopsy specimens. Routinely processed paraffin sections of 65 excised breast carcinomas and 56 available preoperative core biopsy specimens from the same patients were selected from the archives for testing with the SISH technique using the automated Ventana Benchmark XT machine. For each case, two sections were used, one for the assessment of HER2 gene amplification and the other for assessment of chromosome 17. Of the 65 excision specimens tested, sections of 53 cases were also available for fluorescence in situ hybridization (FISH) examination. HER2 gene amplification was detected by SISH in 14 (21%) out of 65 excision specimens and in eight (14%) out of 56 core biopsy specimens. The results of SISH and FISH were identical in 50 (94%) out of the 53 excision cases examined by the two techniques. Two cases were SISH-, FISH+, and one case was the other way round. SISH results of core biopsy specimens and corresponding excision biopsy specimens were identical in 50 (89%) out of 56 cases. Four cases (7%) were SISH- in cores but positive in excision specimens, whereas two cases were the other way round. The results validate the use of the SISH technique for assessing HER2 status of excised breast carcinoma tissue sections. The results are comparable to those obtained with FISH, but SISH has the advantage of having a permanent end result that can be visualized by an ordinary light microscope. There is a reasonable 89% concordance between SISH results obtained in core and excision biopsy specimens. However, it may be prudent to postpone doing SISH, if possible, until sections of the resected specimen are available, as these seem to be more reliable.

High Concordance of SP3 Rabbit Monoclonal Antibody With FISH to Evaluate HER2 in Breast Carcinoma

HER2 gene amplification or HER2 protein overexpression predicts a more aggressive clinical course in breast cancer, with a worse response to hormonal therapy, and determines eligibility for the use of the anti-HER2 antibody trastuzumab. For these reasons, the diagnostic assays that determine HER2 status in breast carcinoma have become increasingly important. Our goal was to evaluate the concordance, sensitivity, and specificity of a rabbit monoclonal antibody directed to the extracellular domain of the HER2 receptor (SP3) and compare it with fluorescence in situ hybridization and HercepTest in 179 invasive breast carcinomas. We found that SP3 was in agreement with fluorescence in situ hybridization results in 94.6% of cases. HercepTest and fluorescence in situ hybridization results were in agreement in 95.1% of the cases. Only 4.3% (4/93) of the cases that scored 0/1+ by SP3 were amplified by fluorescence in situ hybridization, and 8.3% (3/36) of cases that scored 3+ were not amplified by fluorescence in situ hybridization. Comparing SP3 with HercepTest, we observed that HercepTest demonstrated higher sensitivity (100.0% vs. 89.0%) but SP3 demonstrated higher specificity (97.0% vs. 89.0%). An important advantage of SP3 (in comparison with HercepTest) is its higher discrimination power (72.1% vs. 34.1%). For these reasons, this antibody could be helpful in the determination of HER2 status in a routine basis.

Tissue Microarrays for Routine Diagnostic Assessment of HER2 Status in Breast Carcinoma

The use of tissue microarray (TMA) technology may substantially reduce the costs of routine testing of breast carcinomas for human epidermal growth factor receptor 2 (HER2) status. After a preliminary pilot study comparing the TMA results with those obtained on whole section, which showed an excellent agreement (with kappa values >0.90) for both immunohistochemical and fluorescent in situ hybridization (FISH) method, we introduced the TMA technique in our routine work. A total of 1158 invasive breast carcinomas were submitted for the determination of HER2 status, which was assessed in 74 weekly runs. One hundred twenty-five of 1084 surgical specimens (11.5%) were judged as unsuitable for inclusion into TMAs. In 32 of 959 tumors included in TMAs (3.3%), the respective cores were uninformative, and HER2 status was determined on whole sections. Thus, HER2 status was finally determined on TMA in 927 cases (81.1%). A typical weekly run comprised 1 TMA (consisting, on average, of 13 tumors), 2 whole sections of surgical specimens and 1 whole section of core needle biopsy, and the number of processed slides for each method decreased from 16 to 4 per week. In all, 14.7% of tumors were HER2 positive by FISH. In both TMAs and whole sections, immunohistochemical results were in good agreement with FISH for cases scored as 0/1+ (98% and 97%) and for those scored as 3+ (96% and 87%), whereas concordance was poor in cases scored as 2+ (30% and 13%, respectively).

Detection of HER2 Amplification in Breast Carcinomas: Comparison of Multiplex Ligation-Dependent Probe Amplification (MLPA) and Fluorescence In Situ Hybridization (FISH) combined with Automated Spot Counting

In this study the detection of HER2 gene amplification was evaluated using Fluorescence In Situ Hybridization (FISH; PathVysion) in comparison with Multiplex Ligation-dependent Probe Amplification (MLPA), a PCR based technique. These two methods were evaluated on a series of 46 formalin fixed paraffin embedded breast carcinomas, previously tested for protein overexpression by HercepTest (grouped into Hercep 1+, 2+ and 3+). HER2 gene amplification (ratio ≥ 2.0) by FISH was found in 9/10, 10/30 and 0/6 in IHC 3+, 2+ and 1+/0 cases, respectively. Digitalized automated spot counting performed with recently developed CW4000 CytoFISH software was 100% concordant with manual FISH scoring. Using MLPA 18/46 samples showed a clear HER2 amplification. Comparing MLPA and IHC showed the same results as for FISH and IHC. All but one FISH positive cases (18/19) were confirmed by MLPA for the presence of the gene amplification. The overall concordance of detection of Her2 gene amplification by FISH and MLPA was 98% (45/46). Furthermore, both the level of amplification and equivocal results correlated well between both methods. In conclusion, MLPA is a reliable and reproducible technique and can be used as an either alternative or additional test to determine HER2 status in breast carcinomas.

Role of Chromogenic in Situ Hybridization (CISH™) in the Evaluation of HER2 Status in Breast Carcinoma: Comparison with Immunohistochemistry and Fish

We report our experience with Chromogenic in Situ Hybridization (CISH) for the evaluation of HER2 amplification on 55 cases of formalin-fixed, paraffin-embedded invasive breast carcinomas of different histology. All the results were corrected for chromosome 17 aneusomy and compared with immunohistochemistry (IHC); a subset of cases was compared to FISH. Thirty-one of 32 cases in which FISH and CISH were performed yielded the same results. CISH and IHC showed a good concordance in the 0/1+ and 3+ category, while a poor agreement with weakly protein overexpression was confirmed. Chromosome 17 analysis was necessary in cases with a low number of HER2 gene copies. CISH is a useful tool to evaluate breast cancer HER2 status that can be easily implemented in a laboratory of surgical pathology.

Analysis of Intratumoral Heterogeneity and Amplification Status in Breast Carcinomas With Equivocal (2+) HER-2 Immunostaining

Fluorescence in situ hybridization (FISH) and immunohistochemical analysis for assessment of HER-2 status in breast carcinomas are discordant in a significant proportion of cases with equivocal (2+) immunostaining. To evaluate the role of intratumoral heterogeneity and degree of amplification, we performed additional HER-2 immunostains and FISH on tumor-bearing blocks from 20 invasive breast carcinomas with immunohistochemical scores of 2+ with gene amplification and in 18 cases without amplification. Of the amplified cases, 11 (55%) had a 3+ immunohistochemical score on at least 1 additional slide, 8 (40%) remained 2+, and 1 (5%) had a slide scored 1+. All cases rescored 3+ showed high-level amplification in original and repeated FISH; cases remaining 2+ had a heterogeneous FISH profile (low-level amplification or a mosaic mixture of high-level amplified and nonamplified cells) in original and repeated FISH. Of nonamplified cases, 13 (72%) had a 1+ score on at least 1 additional slide, 4 (22%) remained 2+, and 1 (6%) had 1 slide scored 3+. In the nonamplified cases, 17 (94%) showed no amplification in repeated FISH. Significant intratumoral heterogeneity and minimal (low-level) HER-2 amplification account for many breast cancers with 2+ HER-2 protein expression.

Analysis of Intratumoral Heterogeneity and Amplification Status in Breast Carcinomas With Equivocal (2+) HER-2 Immunostaining

Fluorescence in situ hybridization (FISH) and immunohistochemical analysis for assessment of HER-2 status in breast carcinomas are discordant in a significant proportion of cases with equivocal (2+) immunostaining. To evaluate the role of intratumoral heterogeneity and degree of amplification, we performed additional HER-2 immunostains and FISH on tumor-bearing blocks from 20 invasive breast carcinomas with immunohistochemical scores of 2+ with gene amplification and in 18 cases without amplification. Of the amplified cases, 11 (55%) had a 3+ immunohistochemical score on at least 1 additional slide, 8 (40%) remained 2+, and 1 (5%) had a slide scored 1+. All cases rescored 3+ showed high-level amplification in original and repeated FISH; cases remaining 2+ had a heterogeneous FISH profile (low-level amplification or a mosaic mixture of high-level amplified and nonamplified cells) in original and repeated FISH. Of nonamplified cases, 13 (72%) had a 1+ score on at least 1 additional slide, 4 (22%) remained 2+, and 1 (6%) had 1 slide scored 3+. In the nonamplified cases, 17 (94%) showed no amplification in repeated FISH. Significant intratumoral heterogeneity and minimal (low-level) HER-2 amplification account for many breast cancers with 2+ HER-2 protein expression.

Comparison of HER‐2 status determined by fluorescence in situ hybridization in primary and metastatic breast carcinoma

Accurate assessment of HER-2 status is necessary prior to anti-HER-2 antibody (trastuzumab) therapy for metastatic breast carcinoma. However, controversy exists regarding whether to assess HER-2 status in the primary tumor or in metastatic lesions. It is also unclear whether HER-2 status can change during disease progression or after chemotherapy. Breast carcinoma samples from 60 women with known HER-2 status in both primary tumors and paired metastases (locoregional disease, n = 43 patients; distant disease, n = 17 patients) were reviewed retrospectively. Thirty-two patients underwent chemotherapy before their metastatic lesions were sampled, including 18 patients who received neoadjuvant chemotherapy and 14 patients who received adjuvant chemotherapy. The HER-2 gene was examined by fluorescence in situ hybridization either in paraffin-embedded tissue samples (48 primary tumors and 9 metastatic tumors) or in fine-needle aspirates (12 primary tumors and 51 metastatic tumors). HER-2 gene amplification was defined as a HER-2:chromosome 17 signal ratio >/= 2.0. The HER-2 status of primary and metastatic tumors agreed in 58 of 60 patients (97%), including 18 (30%) amplified tumors and 40 (67%) nonamplified tumors. A discrepancy in HER-2 status was observed in specimens from two patients in which HER-2 amplification was detected in the primary tumor but not the metastatic tumors. In one patient, three foci of tumor nodules were found in the same breast; the HER-2 status was assessed in only one of them, which showed amplification; however, HER-2 amplification was not detected in the axillary lymph node metastasis. In another patient, the HER-2 gene was amplified in the primary tumor but not in the liver metastasis. No metastases showed HER-2 amplification without amplification in the primary tumor. Locoregional and distant metastases demonstrated similar concordance rates with their corresponding primary tumors (98% and 94%, respectively). Complete concordance of HER-2 status was found between primary tumors prior to chemotherapy and metastases that were sampled after chemotherapy. The HER-2 status in breast carcinoma generally was stable during metastasis, whether to locoregional or distant sites. Chemotherapy did not modify the HER-2 status in metastatic lesions. Therefore, HER-2 amplification can be evaluated reliably in material from either primary or metastatic tumors in most patients. Further study with larger series is warranted to elucidate the significance of discordant results.

Comparison of Pre- and Postsurgical Concentrations of Blood HER-2 mRNA and HER-2 Extracellular Domain Reflects HER-2 Status in Early Breast Cancer

The HER-2 gene (HER-2/neu or c-erbB-2) encodes an 185-kDa transmembrane glycoprotein that is a member of the type I family of growth factor receptors. HER-2 is constitutively activated by overexpression and contributes to cell growth, angiogenesis, survival, and metastasis (1). The assessment of HER-2 status in breast carcinomas provides valuable prognostic and predictive information. Immunohistochemistry, fluorescence in situ hybridization, chromosomal in situ hybridization, and quantitative reverse transcription-PCR (RT-PCR) may be used for this purpose. Other approaches have been proposed for the assessment of HER-2 status in peripheral blood, including evaluating either circulating HER-2 extracellular domain (ECD) or nucleated cell-associated HER-2 mRNA. Some studies have indicated that circulating ECD/HER-2 is frequently increased in metastatic disease (2)(3)(4). In addition, high concentrations of ECD/HER-2 are associated with cancer aggressiveness (5) and predict response to trastuzumab (6)(7)(8) and antiestrogen (4) therapies in advanced breast cancer. Recently, Martin et al. (9), using an array to assess circulating mRNA, pointed out that HER-2 mRNA was generally low in the blood of healthy individuals but was increased in 31% of patients with untreated invasive breast cancer. Almost all of these studies evaluated blood markers in patients with advanced or metastatic breast cancer using a single presurgical sample. Our study included 40 consecutive patients (median age, 58 years; range, 29–80 years) undergoing surgery for early breast cancer. Patients did not receive any systemic therapy before surgery and provided informed consent for the study. According to tumor size, 28 patients were classified as T1, whereas the remaining 12 were T2 or T3. Twenty-two were node negative, and 35 were positive for estrogen receptors. From each patient, we collected 12 mL of venous blood in EDTA tubes and divided the blood into two 5-mL aliquots. The first was centrifuged, and the plasma …