Comparison of the 2007 and 2013 ASCO/CAP evaluation systems for HER2 amplification in breast cancer

Outcome of HER2 Testing by FISH applying ASCO/CAP 2007 and 2013 guideline in IHC equivocal group of breast cancer: Experience at tertiary cancer care centre

BACKGROUND AND OBJECTIVES

HER2 testing guideline of ASCO/CAP for interpretation and reporting has recently been revised. The study is aimed to measure the impact of 2013 CAP guideline on equivocal HER2 test outcome (immunohistochemistry [IHC] 2+) when tested by fluorescent in situ hybridization (FISH). The study also aims at finding the frequency of polysomy and monosomy of chromosome 17.

MATERIALS AND METHODS

Specimens were collected in Rajiv Gandhi Cancer Institute and Research Centre, New Delhi, India. IHC was performed in every case, and FISH was performed in IHC2+ cases.

RESULTS

In final analysis includes 557 subjects on the basis of CAP guideline 2007 and CAP guideline 2013. One hundred ninety-two subjects (34.4%) were HER2 amplified according to CAP scoring 2007, and 246 subjects (44%) according to 2013 CAP scoring.

CONCLUSIONS

FISH results were evaluated (IHC2 + interpreted according to CAP 2007 guideline) with both 2007 and 2013 ASCO/CAP scoring criteria, we identified significantly more HER2 positive cases as compared to cases evaluated using the 2007 criteria (P < 0.05). We also found that in breast carcinoma, HER2 status in the presence of polysomy 17 may vary with the scoring criteria used. Evaluation of FISH result using 2013 ASCO/CAP criteria means that more patients with breast cancer may be appropriate for targeted treatment with trastuzumab, potentially improving their outcome.

Clinicopathologic features of breast cancer reclassified as HER2-amplified by fluorescence in situ hybridization with alternative chromosome 17 probes

OBJECTIVE

Dual probe fluorescence in situ hybridization (FISH) assays for determination of human epidermal growth factor receptor 2 (HER2) gene amplification in breast cancer provide a ratio of HER2 to chromosome 17. The ratio may be skewed by copy number alterations (CNA) in the control locus for chromosome 17 (CEP17). We analyzed the impact of alternative chromosome 17 control probes on HER2 status in a series of breast cancers with an emphasis on patients reclassified as amplified.

METHODS

Breast cancer patients with equivocal HER2 immunohistochemistry (2+) and equivocal FISH with CEP17 were included. Reclassification of HER2 status was assessed with alternative chromosome 17 control probes (LIS1 and RARA).

RESULTS

A total of 40 unique patients with 46 specimens reflexed to alternative chromosome 17 probe testing were identified. The majority (>80%) of patients had pT1-2, hormone receptor-positive tumors with an intermediate or high combined histologic grade. There were 34/46 (73.9%) specimens reclassified as amplified with alternative probes, corresponding to 29/40 (72.5%) patients. Of the patients reclassified as amplified with alternative probes, 34.5% (10/29) received HER2-targeted therapy.

CONCLUSION

In this series, the majority of breast cancers tested with alternative chromosome 17 control probes under the 2013 ASCO/CAP Guidelines were converted to HER2-amplified. The treatment data and the clinicopathologic profile of the tumors suggest that most of these patients will neither receive nor benefit from HER2-targeted therapy. The findings support the recommendation in the 2018 ASCO/CAP HER2 Guidelines to discontinue the use of alternative chromosome 17 probes.

The updated 2018 American Society of Clinical Oncology/College of American Pathologists guideline on human epidermal growth factor receptor 2 interpretation in breast cancer: comparison with previous guidelines and clinical significance of the proposed in situ hybridization groups

The aim of the study was to evaluate the impact of the updated 2018 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guideline on human epidermal growth factor receptor 2 (HER2) interpretation in breast cancer compared with that of the previous guidelines and also the significance of in situ hybridization (ISH) groups proposed by the updated guideline. HER2 ISH reports and immunohistochemistry (IHC) data from 1,348 invasive breast cancers diagnosed at a single institution were included in this study. HER2 IHC was reassessed using the 2018 guideline, and HER2 ISH status was determined by the 2007, 2013, and 2018 guidelines. When applying the updated guideline, most of the HER2 ISH-equivocal cases as per the previous guidelines were reclassified as ISH negative, and 0.8% of HER2 ISH-positive tumors as per the 2007 guideline and 2.5% of those as per the 2013 guideline were changed to ISH negative. Accordingly, the negative HER2 ISH results significantly increased in the 2018 guideline compared with the 2013 guideline. HER2 ISH-positive tumors in ISH group 3 (HER2/chromosome enumeration probe 17 [CEP17] ratio <2.0 and average HER2 copy number ≥6.0 per cell) were characterized by equivocal HER2 protein expression, CEP17 copy number gain, and low HER2 copy numbers compared with classic HER2 ISH-positive tumors in ISH group 1 (HER2/CEP17 ratio ≥2.0 and average HER2 copy number ≥4.0 per cell). HER2 ISH-negative tumors in ISH group 4 (HER2/CEP17 ratio <2.0 with average HER2 copy number ≥4.0 and < 6.0 per cell) revealed more aggressive clinicopathologic features and poorer clinical outcomes than those in ISH group 5 (HER2/CEP17 ratio <2.0 and average HER2 copy number <4.0 per cell), especially in the hormone receptor-positive subgroup. In conclusion, implementation of the updated 2018 ASCO/CAP guideline leads to a significant increase in HER2 ISH-negative results compared with the 2013 guideline, mainly via reclassification of the ISH-equivocal cases to ISH-negative ones. ISH groups proposed by the updated guideline provide additional information on the clinicopathologic characteristics of the tumors.

Practical application of non-contact alternating current electric field mixing for reagent-saving in situ hybridisation of HER2

AIMS

Human epidermal growth factor receptor 2 (HER2)-targeted agents are effective against HER2-positive breast cancers. However, their lack of survival benefit in HER2-negative patients as well as their toxic effects and high cost highlight the need for accurate assessment of HER2 status. Our aim was to evaluate the clinical utility of a reagent-saving in situ hybridisation (Saving ISH) that facilitates hybridisation and saves HER2/chromosome enumeration probe by taking advantage of the non-contact mixing effect of an alternating current (AC) electric field.

METHODS

With a new device, we apply a high-voltage, low-frequency AC electric field to the tissue sections, which mixes the probe within microdroplets as the voltage is switched on and off. Specimens (n=113) from patients with breast cancers identified immunohistochemically as HER2 0/1(+), (2+) or (3+) were used. The specimens were all tested using conventional dual ISH (DISH), DISH with an automated slide stainer (ASS) and Saving ISH (1:1-1:3 dilution).

RESULTS

The Saving ISH with 1:2 probe dilution produced stable results with less non-specific staining while using smaller amounts of probe. The accuracy of HER2 status with Saving ISH was equal to standard. We found 96.4% agreement between DISH using ASS and Saving ISH (kappa coefficient=0.912).

CONCLUSIONS

These results suggest reagent-saving HER2 ISH could be used as a clinical tool for accurate and stable HER2 assessment, even when reagent concentrations vary.

Reagent-saving immunohistochemistry for HER2 using non-contact alternating current electric field mixing

Aims

Human epidermal growth factor receptor 2 (HER2)-targeted agents are an effective approach to treating patients with HER2-positive breast cancer. However, the lack of survival benefit in HER2-negative patients, as well as the toxic effects and high cost of the drugs, highlight the need for accurate and prompt assessment of HER2 status. Our aim was to evaluate the clinical utility of a novel reagent-saving immunohistochemistry method (AC-IHC) that saves HER2 antibody by taking advantage of the non-contact mixing effect in microdroplets subjected to an alternating current electric field.

Methods

Ninety-five specimens were used from patients diagnosed with primary breast cancers identified immunohistochemically as HER2 0/1+, 2+ or 3+ using ASCO/CAP guideline-certified standard IHC. The specimens were all tested using the conventional IHC method (1:50 antibody dilution) as well as AC-IHC (1:50 dilution) and reagent-saving AC-IHC (1:100 dilution).

Results

The reagent-saving AC-IHC produced stable results with less non-specific staining using smaller amounts of labelled antibody. Moreover, the staining and accuracy of HER2 status evaluated with the reagent-saving AC-IHC method was equal to that achieved with standard IHC.

Conclusions

These results suggest reagent-saving AC-IHC could be used as a clinical tool for accurate and stable HER2 IHC, even when reagent concentrations vary.

ADAM9 is over-expressed in human ovarian clear cell carcinomas and suppresses cisplatin-induced cell death

ADAMs (a disintegrin and metalloproteinases) are involved in various biological events such as cell adhesion, migration and invasion, membrane protein shedding and proteolysis. However, there have been no systematic studies on the expression of ADAMs in human ovarian carcinomas. We therefore examined mRNA expression of all the proteolytic ADAM species including ADAM8, 9, 10, 12, 15, 17, 19, 20, 21, 28, 30, 33 and ADAMDEC1 in human ovarian carcinomas, and found that prototype membrane-anchored ADAM9m, but not secreted isoform ADAM9s, is significantly over-expressed in carcinomas than in control non-neoplastic ovarian tissue. Among the histological subtypes of serous, endometrioid, mucinous and clear cell carcinomas, ADAM9m expression was highest in clear cell carcinomas. Immunohistochemistry showed that all the clear cell carcinoma samples displayed ADAM9m primarily on the carcinoma cell membrane. By immunoblotting, ADAM9m was detected mainly in an active form in the clear cell carcinoma tissues. When two clear cell carcinoma cell lines (RMG-I and TOV21G cells) with ADAM9m expression were treated with cisplatin, viability was significantly reduced and apoptosis increased in ADAM9m knockdown cells compared with mock transfectants. In addition, treatment of the cells with neutralizing anti-ADAM9m antibody significantly decreased viability compared with non-immune IgG, whereas ADAM9m over-expression significantly increased viability compared with mock transfectants. Our data show, to the best of our knowledge, for the first time, that ADAM9m is over-expressed in an activated form in human ovarian clear cell carcinomas, and suggest that ADAM9m plays a key role in cisplatin resistance.

The clinicopathological significance of UBE2C in breast cancer: a study based on immunohistochemistry, microarray and RNA-sequencing data

BACKGROUND

Ubiquitin-conjugating enzyme E2C (UBE2C) has been previously reported to correlate with the malignant progression of various human cancers, however, the exact molecular function of UBE2C in breast carcinoma (BRCA) remained elusive. We aimed to investigate UBE2C expression in BRCA and its clinical significance.

METHODS

The expression of UBE2C in 209 BRCA tissue samples and 53 adjacent normal tissue samples was detected using immunohistochemistry. The clinical role of UBE2C was analyzed. Public databases including the human protein atlas and Oncomine were used to assess UBE2C expression in BRCA. Moreover, the cancer genome atlas (TCGA) database was employed to investigate the prognostic value of UBE2C in BRCA.

RESULTS

The positive expression rate of UBE2C in BRCA was 70.8% (148/209), and UBE2C expression in the adjacent breast tissue was negative. The expression of UBE2C was positively correlated with tumor size (r = 0.32, P < 0.001), histological grade (r = 0.237, P = 0.001), clinical stage (r = 0.198, P = 0.004), lymph node metastasis (r = 0.155, P = 0.026), HER2 expression level (r = 0.356, P < 0.001), Ki-67 expression level (r = 0.504, P < 0.001), and P53 expression level (r = 0.32, P = 0.001). Negative correlations were found between UBE2C expression and the ER (r = - 0.403, P < 0.001) and PR (r = - 0.468, P < 0.001) status. UBE2C gene expression data from the public databases all proved that UBE2C was overexpressed in BRCA. According to the TCGA data analysis, a higher positive expression of UBE2C was associated with worse survival of BRCA patients (P = 0.0428), and data from cBioPortal indicated that 11% of all sequenced BRCA patients possessed a gene alteration of UBE2C, predominately gene amplification and mRNA regulation.

CONCLUSION

Ubiquitin-conjugating enzyme E2C might pose an oncogenic effect on the progression of BRCA.

Counting invasive breast cancer cells in the HER2 silver in-situ hybridization test: how many cells are enough?

AIM

To evaluate the intraobserver and interobserver reproducibility of the HER2 in-situ hybridization (ISH) test in breast cancer by measuring the impact of counting different numbers of invasive cancer cells.

METHODS AND RESULTS

A cohort of 101 primary invasive breast cancer cases were evaluated for HER2 gene amplification by silver ISH, and the concordance among four observers with different levels of experience, counting different numbers of invasive cancer cells, was determined. The evaluation of the samples included scoring 20 nuclei, in three different areas. The cases were scored twice, with a washout interval of at least 2 weeks. We observed an increase in the intraobserver concordance rate between the first and second evaluations with an increase in cell count. A count of 60 invasive cells was needed to obtain a concordance rate near 95% and an agreement rate greater than 0.80 by all observers. The interobserver concordance rate of the HER2 test also increased with the increase in cell count, reaching at least a 90% concordance rate with a count of 60 invasive cells. The median variability of both the HER2/CEP17 ratio and the average HER2 copy number between different evaluations decreased with the increase in cell count, being statistically higher in HER2-positive cases.

CONCLUSIONS

The minimal cell number recommended in current guidelines should be raised to at least 40, and preferably 60, invasive cells. Moreover, cases with amplification levels close to the threshold should be subjected to a dual count from an experienced observer.

ErbB Family Signalling: A Paradigm for Oncogene Addiction and Personalized Oncology

ErbB family members represent important biomarkers and drug targets for modern precision therapy. They have gained considerable importance as paradigms for oncoprotein addiction and personalized medicine. This review summarizes the current understanding of ErbB proteins in cell signalling and cancer and describes the molecular rationale of prominent cases of ErbB oncoprotein addiction in different cancer types. In addition, we have highlighted experimental technologies for the development of innovative cancer cell models that accurately predicted clinical ErbB drug efficacies. In the future, such cancer models might facilitate the identification and validation of physiologically relevant novel forms of oncoprotein and non-oncoprotein addiction or synthetic lethality. The identification of genotype-drug response relationships will further advance personalized oncology and improve drug efficacy in the clinic. Finally, we review the most important drugs targeting ErbB family members that are under investigation in clinical trials or that made their way already into clinical routine. Taken together, the functional characterization of ErbB oncoproteins have significantly increased our knowledge on predictive biomarkers, oncoprotein addiction and patient stratification and treatment.

The European Organization for Research and Treatment of Cancer perspective on designing clinical trials with immune therapeutics

Cancer immunotherapy has had a major impact on the established paradigms of drug development and clinical trial research. The innovative mechanism of action of these compounds has resulted in new patterns of response and safety profiles, which pose challenges for the classical trial methodology. In this review we report on the search for the maximum tolerated dose, the recommended phase II dose and the appropriate target population in phase I trials. We provide some statistical considerations on the choice of endpoints for phase II and III trials and the limitations of frequently used trial designs in the presence of a delayed treatment effect, which may be induced by the immune modulating effect of the checkpoint inhibitors. We summarize the currently available data on the safety profile of these new compounds, which can guide protocol safety recommendations. Finally, we report on the current evidence of biomarker development.

Assessment of dual-probe Her-2 fluorescent in situ hybridization in breast cancer by the 2013 ASCO/CAP guidelines produces more equivocal results than that by the 2007 ASCO/CAP guidelines

Dual-probe fluorescence in situ hybridization (D-FISH) is a widely accepted method to determine the gene amplification status of human epidermal growth factor receptor 2 (Her-2). In 2013, the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) updated the guidelines on the Her-2 testing for invasive breast cancer (BCa). The interpretation criteria for D-FISH changed accordingly. In this study, we compared the Her-2 FISH statuses based on the 2013 and 2007 ASCO/CAP guidelines in 1931 cases of BCa with Her-2 D-FISH testing at our hospital. We analyzed the clinicopathologic features of cases with equivocal results by the 2013 ASCO/CAP guidelines. Although the guideline update significantly improved the detection rate of Her-2 amplification, it also significantly increased the rate of equivocal results, posing a dilemma for clinical management. The equivocal results had a good reproducibility. The distribution of D-FISH-equivocal cases did not correlate with Her-2 status by immunohistochemistry, suggesting that Her-2 D-FISH equivocality may not reflect Her-2 overexpression. Compared with Her-2-negative cases by D-FISH, Her-2 D-FISH-equivocal cases had higher Ki67 expression, higher histological grade, more frequent lymph node metastasis, and lower estrogen receptor α expression, indicating a group of BCa with worse prognosis. The clinical significance of Her-2-equivocal results by D-FISH warrants further investigation.

Novel method for rapid in-situ hybridization of HER2 using non-contact alternating-current electric-field mixing

Human epidermal growth factor receptor 2 (HER2)-targeted agents are an effective approach to treating HER2-positive breast cancer patients. However, the lack of survival benefit in HER2-negative patients as well as the toxic effects and high cost of the drugs highlight the need for accurate and prompt assessment of HER2 status. Our aim was to evaluate the clinical utility of a novel rapid dual in-situ hybridization (RISH) method developed to facilitate hybridization. The method takes advantage of the non-contact mixing effect of an alternating current (AC) electric field. One hundred sixty-three specimens were used from patients diagnosed with primary breast cancers identified immunohistochemically as HER2 0/1(+), (2+) or (3+). The specimens were all tested using conventional dual in-situ hybridization (DISH), DISH with an automated slide stainer, and RISH. With RISH the HER2 test was completed within 6 h, as compared to 20–22 h needed for the standard protocol. Although RISH produced results more promptly using smaller amounts of labeled antibody, the staining and accuracy of HER2 status evaluation with RISH was equal to or greater than with DISH. These results suggest RISH could be used as a clinical tool to promptly determine HER2 status.

Implications of the Updated 2013 American Society of Clinical Oncology/College of American Pathologists Guideline Recommendations on Human Epidermal Growth Factor Receptor 2 Gene Testing Using Immunohistochemistry and Fluorescence In Situ Hybridization for Breast Cancer

Context

Human epidermal growth factor receptor 2 (HER2/neu) amplification is used as a predictive marker for trastuzumab treatment in breast cancer. Both immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) testing algorithms have been based on the 2007 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines. In late 2013, the guidelines were updated with new scoring criteria.

Objective

—To assess the impact of the revised ASCO/CAP recommendations on both IHC and FISH results by using the dual-color HER2/neu and centromeric FISH probes.

Design

Retrospective analysis of 590 invasive carcinomas with concurrent IHC and dual-color HER2/neu and centromeric 17 (CEP17) FISH results, based on 2007 ASCO/CAP guidelines, was conducted from July 2011 to June 2013. With the revised guidelines, patients were recategorized and concordance rates between the 2 assays were recalculated.

Results

—Overall concordance rates for FISH and IHC decreased from 94.9% to 93.8% with reclassification. Negative FISH cases decreased from 79.1% to 69.3%. However, equivocal FISH cases were significantly increased from 0.7% to 9.5%, leading to more retesting. Both positive IHC and FISH cases were also noted to be increased, leading to more patients being eligible for trastuzumab treatment, especially those patients with concurrent HER2/neu and CEP17 polysomy. Approximately 1% of patients with initial FISH negative results were reclassified as having positive results when both the ratios and average copy number of HER2/neu were considered under the revised guidelines.

Conclusions

The revised 2013 ASCO/CAP guidelines can potentially lead to more patients being eligible for trastuzumab therapy but additional retesting is to be expected owing to an increased number of equivocal FISH cases.

Application of the 2013 ASCO/CAP guideline and the SISH technique for HER2 testing of breast cancer selects more patients for anti-HER2 treatment

The aim of this study is to assess the impact of changes of the 2013 ASCO/CAP guideline on the results of HER2 testing in breast cancer. A series of 916 primary invasive breast cancer cases, assessed as HER2 2+ by IHC in part using the 2007 and in part the 2013 ASCO/CAP criteria, was evaluated for HER2 amplification status by SISH and classified according to both 2007 and 2013 ASCO/CAP ISH guideline criteria. We observed a significant increase of HER2-positive cases (12.4 to 16.8%) and a decrease of HER2-equivocal cases (3.6 to 0.7%). Of the cases studied, 52.1% fulfilled both criteria of HER2/CEP17 ratio and average HER2 copy number per cell to be classified as HER2-positive. Reclassification of the cases from before the introduction of the new ASCO/CAP guideline with the 2013 ISH criteria resulted in an increase of cases with a HER2-positive status (12.4 to 14.2%) and in a decrease of HER2-equivocal cases (3.6 to 1.6%). The 2013 ASCO/CAP guideline selects more patients for anti-HER2 targeted therapy, mostly based on the modifications of criteria to evaluate ISH-HER2.

Impact of Modified 2013 ASCO/CAP Guidelines on HER2 Testing in Breast Cancer. One Year Experience

Introduction

The latest guidelines of the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) to test Human Epidermal Growth Factor Receptor 2 (HER2) in breast cancer after being revised in 2008 underwent a second modification in October 2013. The modification includes changes in cut-offs: 10% strong membranous staining for score 3+ on immunohistochemistry (IHC) (previously 30%) and using the ratio of >2 or absolute gene-copy-number (6 or more) alone or in combination with each other by in-situ-hybridisation technology (previously >2.2 and average copy-number of 6 or more). Hereby we addressed the question, which impact the modified cut-offs had on overall HER2-positivity in a single institution.

Methods

We prospectively analysed 617 consecutive diagnostic breast-cancer cases which underwent double HER2 testing by immunohistochemistry and fluorescent in-situ hybridisation (FISH), using the modified 2013 ASCO/CAP-guidelines for one year (October 2013–October 2014). Results were compared with HER2-test results on 1,528 consecutive diagnostic breast-cancer cases from two previous years (2011–2012), using the 2008 ASCO/CAP guidelines, also tested with IHC and FISH in each case.

Results

Between October 2013 and October 2014, overall HER2-positivity was 15.8% (98 of 617 cases were either IHC 3+ or FISH amplified). 79 of 617 cases (13%) were IHC 3+, 96 of 617 cases (15.5%) were FISH amplified. Equivocal cases were seen in 25 of 617 cases (4.1%). 22 of 25 equivocal cases (88%) in 2013–2014 were IHC 1+ or 2+. In 13 equivocal cases, there was a repeated IHC/FISH testing: 2 of 13 cases (15%) became FISH amplified, 1 of 13 cases (7.5%) became IHC 3+. In 2011–2012, overall HER2-positivity (IHC/FISH) was 13.8% (211 of 1,528 cases). 185 of 1,528 cases (12%) were 3+ on IHC, 181 of 1,522 cases (12%) were amplified by FISH. Six of 1,528 cases were equivocal by FISH, and interpreted as non-amplified (0.3%).

Conclusions

Applying the modified ASCO/CAP guidelines from 2013 resulted in an increase (2%) in overall HER2-positivity rate compared to overall-HER2-positivity rate using the 2008 ASCO/CAP guidelines. The increased positivity rate was mainly due to more FISH-positive cases (3.5% more than until 2013). The high rate of equivocal cases (4.1%) did not contribute to increase in overall HER2-positivity, but resulted in delay in definitive HER2-status.

Surgical pathology in cancer diagnosis: implications for quaternary prevention

Surgical pathology is the medical specialty in charge of cancer diagnosis. Although very important since oncology development, its link with overdiagnosis and overtreatment remains understudied. Despite big mediatisation, molecular biology has not brought much progress to tumour classifications. On the contrary, the silent apparition of immunohistochemistry at the end of the 1980's improved much of tumour classifications so significantly that it could cast doubts in some trials’ results of that period. This article discusses how the booming and abuse of immunohistochemistry might have led to overdiagnosis. It also highlights that the ISO 15189 standardization, as well as the tumour classification complexity, might function to induce overtreatment. In summary, critical reading and understanding of pathology reports by general practitioners are essential. Therefore, family doctors should not hesitate to discuss the cancer diagnosis with the pathologist, and in some cases also question the oncologist decision. This approach can be considered a quaternary prevention action which can prevent overtreatment.

Expression of SATB1 and HER2 in breast cancer and the correlations with clinicopathologic characteristics

Background

Special AT-rich sequence binding protein 1 (SATB1) is found acting as a “genome organizer” that functions as a landing platform to regulate tissue-specific gene ex-pression. In breast cancer cell lines it has been proven that SATB1 could upregulate the expression of the HER2. In this paper, the relevance of SATB1 and HER2 expression was assessed in human breast cancer tissues, and their influence on tumor histological grade and patients’ survival was explored.

Methods

Using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), 169 patients with breast cancer were assessed for SATB1 expression, HER2 amplification and hormone-receptor (HR) expression. The effects of SATB1 expression on HER2 and HR expression as well as their association with clinicopathologic characteristics were further analyzed by statistical evaluation.

Results

SATB1 expression was correlated with HER2 expression in breast cancer(r = 0.191; p = 0.013). SATB1, HER2 and SATB1/HER2 co-expression was negatively correlated with HR expression (r = −0.228, p = 0.003; r = −0.338, p = 0.000; r = −0.527, p = 0.000, respectively). SATB1 and HER2 single positive and their co-expression were all significantly correlated with higher histological grade (r = 0.239, p = 0.002; r = 0.160, p = 0.038; r = 0.306, p = 0.003, respectively). Multivariate cox regression analyses showed that SATB1 and HER2 were independent risk factors for breast cancer patients, while HR was a protective factor for patients’ survival. Comparing to SATB1 or HER2 single positive expression, SATB1/HER2 co-expression tended to have even worse prognosis.

Conclusions

SATB1 and HER2 performed a synergistic effect in breast cancer. Their expression correlated with poorly differentiated breast cancer and indicated an unfavorable prognosis.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1400555050159723.