HER2 and TOP2A in high-risk early breast cancer patients treated with adjuvant epirubicin-based dose-dense sequential chemotherapy

Mechanisms of action and resistance to anti-HER2 antibody-drug conjugates in breast cancer

Human epidermal growth factor 2 (HER2)-positive breast cancer (BC) represents nearly 20% of all breast tumors. Historically, these patients had a high rate of relapse and dismal prognosis. The advent of HER2-targeting monoclonal antibodies such as trastuzumab followed by pertuzumab had improved the prognosis of HER2-positive metastatic BC. More recently, antibody-drug conjugates (ADCs) are now reshaping the treatment paradigm of solid tumors, especially breast cancer. Tratsuzumab emtansine (T-DM1) was one of the first ADC developed in oncology and was approved for the management of HER2-positive metastatic BC. In a head-to-head comparison, trastuzumab deruxtecan (T-DXd) defeated T-DM1 as a second-line treatment. The efficacy of ADCs is counterbalanced by the appearance of acquired resistance to these agents. In this paper, we summarize the mechanisms of action and resistance of T-DM1 and T-DXd, as well as their clinical efficacy. Additionally, we also discuss potential strategies for addressing resistance to ADC.

The correlation study between TOP2A gene expression in circulating tumor cells and chemotherapeutic drug resistance of patients with breast cancer

BACKGROUND

Patients with breast cancer (BC) at advanced stages have poor outcomes because of high rate of recurrence and metastasis. Biomarkers for predicting prognosis remain to be explored. This study aimed to evaluate the relationships between circulating tumor cells (CTCs) and outcomes of BC patients.

PATIENTS AND METHODS

A total of 50 female were enrolled in this study. Their diagnoses were determined by clinical characteristics, image data, and clinical pathology. CTC subtypes and TOP2A gene expression on CTCs were detected by CanPatrol™ technology and triple color in situ RNA hybridization (RNA-ISH), which divided into epithelial CTCs (eCTCs), mesenchymal CTCs (MCTCs), and hybrid CTCs (HCTCs) based on their surface markers. Hormone receptor, including estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) expression, was measured by immunohistochemistry (IHC) method before treatment. The risk factors for predicting recurrence and metastasis were calculated by COX risk regression model. The progression-free survival (PFS) of patients was determined using Kaplan-Meier survival curve.

RESULTS

The patients with a large tumor size (≥ 3 cm) and advanced tumor node metastasis (TNM) stages had high total CTCs (TCTCs) (P < 0.05). These patients also had high TOP2A expression level. COX risk regression analysis indicated that TOP2A expression levels in TCTCs, ER + , HER-2 + , and TNM stages were critical risk factors for recurrence and metastasis of patients (P < 0.05). The PFS of patients with ≥ 5 TCTCs, ≥ 3 HCTCs, and positive TOP2A expression in ≥ 3 TCTCs was significantly longer than that in patient with < 5 TCTCs, < 3 HCTCs, and TOP2A expression in < 3 TCTCs (P < 0.05). In contrast, the PFS of patients with positive hormone receptors (ER + , PR + , HER-2 +) also was dramatically lived longer than that in patients with negative hormone receptor expression.

CONCLUSIONS

High TCTC, HCTCs, and positive TOP2A gene expression on CTCs were critical biomarkers for predicting outcomes of BC patients. Positive hormone receptor expression in BC patients has significant favor PFS.

Automated Prognosis Marker Assessment in Breast Cancers Using BLEACH&STAIN Multiplexed Immunohistochemistry

Prognostic markers in routine clinical management of breast cancer are often assessed using RNA-based multi-gene panels that depend on fluctuating tumor purity. Multiplex fluorescence immunohistochemistry (mfIHC) holds the potential for an improved risk assessment. To enable automated prognosis marker detection (i.e., progesterone receptor [PR], estrogen receptor [ER], androgen receptor [AR], GATA3, TROP2, HER2, PD-L1, Ki67, TOP2A), a framework for automated breast cancer identification was developed and validated involving thirteen different artificial intelligence analysis steps and an algorithm for cell distance analysis using 11+1-marker-BLEACH&STAIN-mfIHC staining in 1404 invasive breast cancers of no special type (NST). The framework for automated breast cancer detection discriminated normal glands from malignant glands with an accuracy of 98.4%. This approach identified that five (PR, ER, AR, GATA3, PD-L1) of nine biomarkers were associated with prolonged overall survival (p ≤ 0.0095 each) and two of these (PR, AR) were found to be independent risk factors in multivariate analysis (p ≤ 0.0151 each). The combined assessment of PR-ER-AR-GATA3-PD-L1 as a five-marker prognosis score showed strong prognostic relevance (p < 0.0001) and was an independent risk factor in multivariate analysis (p = 0.0034). Automated breast cancer detection in combination with an artificial intelligence-based analysis of mfIHC enables a rapid and reliable analysis of multiple prognostic parameters. The strict limitation of the analysis to malignant cells excludes the impact of fluctuating tumor purity on assay precision.

Understanding and Tackling Immune Responses to Adeno-Associated Viral Vectors

As the clinical experience in adeno-associated viral (AAV) vector-based gene therapies is expanding, the necessity to better understand and control the host immune responses is also increasing. Immunogenicity of AAV vectors in humans has been linked to several limitations of the platform, including lack of efficacy due to antibody-mediated neutralization, tissue inflammation, loss of transgene expression, and in some cases, complement activation and acute toxicities. Nevertheless, significant knowledge gaps remain in our understanding of the mechanisms of immune responses to AAV gene therapies, further hampered by the failure of preclinical animal models to recapitulate clinical findings. In this review, we focus on the current knowledge regarding immune responses, spanning from innate immunity to humoral and adaptive responses, triggered by AAV vectors and how they can be mitigated for safer, durable, and more effective gene therapies.

Prediction of recurrence from metabolites and expression of TOP2A and EZH2 in prostate cancer patients treated with radiotherapy

BACKGROUND

The dual upregulation of TOP2A and EZH2 gene expression has been proposed as a biomarker for recurrence in prostate cancer patients to be treated with radical prostatectomy. A low tissue level of the metabolite citrate has additionally been connected to aggressive disease and recurrence in this patient group. However, for radiotherapy prostate cancer patients, few prognostic biomarkers have been suggested. The main aim of this study was to use an integrated tissue analysis to evaluate metabolites and expression of TOP2A and EZH2 as predictors for recurrence among radiotherapy patients.

METHODS

From 90 prostate cancer patients (56 received neoadjuvant hormonal treatment), 172 transrectal ultrasound-guided (TRUS) biopsies were collected prior to radiotherapy. Metabolic profiles were acquired from fresh frozen TRUS biopsies using high resolution-magic angle spinning MRS. Histopathology and immunohistochemistry staining for TOP2A and EZH2 were performed on TRUS biopsies containing cancer cells (n = 65) from 46 patients, where 24 of these patients (n = 31 samples) received hormonal treatment. Eleven radical prostatectomy cohorts of a total of 2059 patients were used for validation in a meta-analysis.

RESULTS

Among radiotherapy patients with up to 11 years of follow-up, a low level of citrate was found to predict recurrence, p = 0.001 (C-index = 0.74). Citrate had a higher predictive ability compared with individual clinical variables, highlighting its strength as a potential biomarker for recurrence. The dual upregulation of TOP2A and EZH2 was suggested as a biomarker for recurrence, particularly for patients not receiving neoadjuvant hormonal treatment, p = 0.001 (C-index = 0.84). While citrate was a statistically significant biomarker independent of hormonal treatment status, the current study indicated a potential of glutamine, glutamate and choline as biomarkers for recurrence among patients receiving neoadjuvant hormonal treatment, and glucose among patients not receiving neoadjuvant hormonal treatment.

CONCLUSION

Using an integrated approach, our study shows the potential of citrate and the dual upregulation of TOP2A and EZH2 as biomarkers for recurrence among radiotherapy patients.

Predictive value of topoisomerase II alpha protein for clinicopathological characteristics and prognosis in early breast cancer

PURPOSE

Topoisomerase II alpha (TOP2A) has been identified as a proliferation marker, of which the most common method for detection is immunohistochemistry (IHC). However, the optimal cut-off of TOP2A expression regarding prognostic value remains controversial. This study was to identify the optimal cut-off value of TOP2A expression and its correlation with clinicopathological variables and prognosis in early stage breast cancer in China.

METHODS

Between January 2013 and January 2015, a total of 1084 early breast cancer patients were enrolled. The optimal cut-off of TOP2A expression was assessed using the minimum P value approach. Correlations between TOP2A expression and clinicopathological characteristics were explored by the Spearman's correlation analysis, while the impact of TOP2A expression on disease-free survival (DFS) and overall survival (OS) was evaluated by the Kaplan-Meier methods. Univariate and multivariate Cox regression analyses were executed to identify statistically significant prognostic factors.

RESULTS

The optimal cut-off value of TOP2A was recommended as 15%. Overall, 603 (55.6%) patients were TOP2A over-expression and 481 (44.4%) patients were TOP2A low expression. TOP2A over-expression was in positive associations with a higher Ki67 index (r = 0.83, P < 0.001), HER2 positive (r = 0.26, P < 0.001), a larger tumor size (r = 0.14, P < 0.001), and a higher histologic grade (r = 0.59, P < 0.001), and in a significantly negative correlation with hormone receptor (HR) positive expression (r =  - 0.40, P < 0.001) in early breast cancer. TOP2A over-expression significantly associated with worse DFS (P = 0.001) and OS (P < 0.001) and was an independent prognostic factor for both DFS (hazard ratio [HR] = 2.04; 95% confidence interval [95% CI] 1.30-3.18, P = 0.0018) and OS (HR = 3.54; 95%CI 1.53-8.23, P = 0.003) in stage I-II breast cancer patients.

CONCLUSION

To our knowledge, this is the first study to recommend the optimal cut-off value of TOP2A expression in breast cancer. The TOP2A expression is significantly correlated with HER2 status, Ki67 index, tumor size, histologic grade and HR status, and could be a surrogate indicator for poor prognosis of early breast cancer.

Prognostic and predictive value of the combination of TOP2A and HER2 in node-negative tumors 2 cm or smaller (T1N0) breast cancer

BACKGROUND

We aim to evaluate the prognostic and predictive value of TOP2A and HER2 expression in T1N0 breast cancer patients.

METHODS

299 cases with T1N0 breast cancer were obtained from the Oncomine database (Cohort 1) and 963 of T1N0 breast cancer patients from Sun Yat-sen Memorial Hospital (Cohort 2) were retrospectively enrolled. Kaplan-Meier product was applied to estimate survival curve. Cox proportional hazard models was used to identify prognostic factors. We used PSM (propensity score matching) to balance clinicopathologic characteristics among four groups of different HER2/TOP2A status. Survival between groups and chemotherapy regimens were analyzed, before and after PSM.

RESULTS

In Cohort 1, we found that the group with HER2+ and higher expression of TOP2A mRNA was associated with poor breast cancer-specific survival (BCSS) compared to the group of HER2- with lower expression of TOP2A mRNA. In Cohort 2, HER2+ patients with higher TOP2A protein expression had greater risk of recurrence and distant recurrence compared to HER2- patients with lower expression of TOP2A protein. Among the patients who developed both HER2+ and higher expression of TOP2A protein and received chemotherapy, patients who received an anthracycline-based regimen had a significantly better recurrence-free survival (RFS) than those with a non-anthracycline-based regime.

CONCLUSION

Patients with both HER2+ and high expression level of TOP2A protein predicts poor prognosis in T1N0 breast cancer patients. Patients with double positive for TOP2A protein and HER2 may benefit from anthracycline-based regimens.

Assessment of ERBB2 and TOP2α gene status and expression profile in feline mammary tumors: findings and guidelines

In humans, the ERBB2 gene amplification and overexpression are biomarkers for invasive breast cancer and a therapeutic target. Also, TOP2α gene aberrations predict the response to anthracycline-based adjuvant chemotherapy. Although feline mammary tumors (FMTs) are good models in comparative oncology, scarce data is available regarding the ERBB2 and TOP2α status. In this study, and for the first time, the ERBB2 DNA status and RNA levels of intracellular (ICD) and extracellular (ECD) coding regions were compared with TOP2α gene status and expression profile, in samples of FMTs and disease-free tissues from the same animal. Results showed that ERBB2 and TOP2α gene status are highly correlated (r=0.87, p<0.0001, n=25), with few tumor samples presenting amplification. Also, the majority of the FMTs showed ERBB2 overexpression coupled with TOP2α overexpression (r=0.87, p<0.0001, n=27), being the ERBB2-ICD and ECD transcripts highly correlated (r=0.97, p<0.0001, n=27). Significant associations were found between TOP2α gene status or ERBB2 and TOP2α RNA levels with several clinicopathological parameters. This work highlights the need of experimental designs for a precise evaluation of ERBB2 and TOP2α gene status and its expression in FMTs, to improve their clinical management and to further validate them as a suitable model for comparative oncology studies.

Significant prognostic values of differentially expressed-aberrantly methylated hub genes in breast cancer

Introduction: Abnormal status of gene expression plays an important role in tumorigenesis, progression and metastasis of breast cancer. Mechanisms of gene silence or activation were varied. Methylation of genes may contribute to alteration of gene expression. This study aimed to identify differentially expressed hub genes which may be regulated by DNA methylation and evaluate their prognostic value in breast cancer by bioinformatic analysis. Methods: GEO2R was used to obtain expression microarray data from GSE54002, GSE65194 and methylation microarray data from GSE20713, GSE32393. Differentially expressed-aberrantly methylated genes were identified by FunRich. Biological function and pathway enrichment analysis were conducted by DAVID. PPI network was constructed by STRING and hub genes was sorted by Cytoscape. Expression and DNA methylation of hub genes was validated by UALCAN and MethHC. Clinical outcome analysis of hub genes was performed by Kaplan Meier-plotter database for breast cancer. IHC was performed to analyze protein levels of EXO1 and Kaplan-Meier was used for survival analysis. Results: 677 upregulated-hypomethylated and 361 downregulated-hypermethylated genes were obtained from GSE54002, GSE65194, GSE20713 and GSE32393 by GEO2R and FunRich. The most significant biological process, cellular component, molecular function enriched and pathway for upregulated-hypomethylated genes were viral process, cytoplasm, protein binding and cell cycle respectively. For downregulated-hypermethylated genes, the result was peptidyl-tyrosine phosphorylation, plasma membrane, transmembrane receptor protein tyrosine kinase activity and Rap1 signaling pathway (All p< 0.05). 12 hub genes (TOP2A, MAD2L1, FEN1, EPRS, EXO1, MCM4, PTTG1, RRM2, PSMD14, CDKN3, H2AFZ, CCNE2) were sorted from 677 upregulated-hypomethylated genes. 4 hub genes (EGFR, FGF2, BCL2, PIK3R1) were sorted from 361 downregulated-hypermethylated genes. Differential expression of 16 hub genes was validated in UALCAN database (p<0.05). 7 in 12 upregulated-hypomethylated and 2 in 4 downregulated-hypermethylated hub genes were confirmed to be significantly hypomethylated or hypermethylated in breast cancer using MethHC database (p<0.05). Finally, 12 upregulated hub genes (TOP2A, MAD2L1, FEN1, EPRS, EXO1, MCM4, PTTG1, RRM2, PSMD14, CDKN3, H2AFZ, CCNE2) and 3 downregulated genes (FGF2, BCL2, PIK3R1) contributed to significant unfavorable clinical outcome in breast cancer (p<0.05). High expression level of EXO1 protein was significantly associated with poor OS in breast cancer patients (p=0.03). Conclusion: Overexpression of TOP2A, MAD2L1, FEN1, EPRS, EXO1, MCM4, PTTG1, RRM2, PSMD14, CDKN3, H2AFZ, CCNE2 and downregulation of FGF2, BCL2, PIK3R1 might serve as diagnosis and poor prognosis biomarkers in breast cancer by more research validation. EXO1 was identified as an individual unfavorable prognostic factor. Methylation might be one of the major causes leading to abnormal expression of those genes. Functional analysis and pathway enrichment analysis of those genes would provide novel ideas for breast cancer research.

A TOP2A-derived cancer panel drives cancer progression in papillary renal cell carcinoma

The aim of the present study was to investigate the function of the DNA topoisomerase IIα (TOP2A) gene and its associated genes in the progression of papillary renal cell carcinoma (PRCC). Online cancer databases, including cBioportal, Oncomine, OncoLnc and Search Tool for the Retrieval of Interacting Genes/Proteins were used to analyze the TOP2A gene expression profile, function and regulation network in PRCC. The genes that were significantly co-expressed or mutually exclusively expressed with TOP2A were identified. The genes co-expressed with TOP2A were defined as a 'TOP2A-cancer panel', which cooperatively promotes PRCC progression. This gene panel performed well in predicting the prognosis of PRCC. In addition, the TOP2A-cancer panel significantly affected the outcome of PRCC compared with clear cell renal cell carcinoma (CCRCC). The protein-protein interaction network of all genes associated with TOP2A was also generated. This interaction network may provide foundation for the additional investigation of TOP2A. Integrative understating of the TOP2A-cancer panel may result in a novel avenue for treatment intervention in PRCC.

Copy number variation and high expression of DNA topoisomerase II alpha predict worse prognosis of cancer: a meta-analysis

Background: Increasing numbers of literatures have investigated the association between TOP2A and cancer prognosis. But the results of the relationship between the two were inconclusive. The aim of this meta-analysis was to elucidate whether TOP2A could predict prognosis of cancer. Materials and Methods: A systematically searching for potentially valuable literature was conducted through electronic databases containing PubMed and Web of Science. Hazard Ratio (HR) and their 95% confidence interval (CI) were used to assess the strength of association between TOP2A and cancer prognosis. Results: Finally twenty-five studies were included in this meta-analysis. High expression of TOP2A was associated with shorter disease free survival (DFS) of cancer prognosis compared with low expression of TOP2A (HR= 1.36, 95% CI= 1.18-1.57, P<0.001). Amplification of TOP2A gene showed no significant association with overall survival (OS), disease free survival (DFS) or relapse free survival (RFS) compared with non-amplification of TOP2A (OS: HR= 0.96, 95%CI= 0.75-1.22, P= 0.735; DFS: HR= 0.93, 95%CI= 0.70-1.23, P= 0.621; RFS: HR= 0.97, 95%CI= 0.71-1.34, P= 0.867). In the subgroup of regions, TOP2A amplification was associated with longer overall survival (HR= 0.66, 95%CI= 0.46-0.96, P= 0.029) in Australia. Alteration (amplification or deletion) of TOP2A gene demonstrated shorter survival according to OS and RFS compared with those with normal TOP2A status (OS: HR= 1.37, 95%CI= 1.22-1.55, P<0.001; RFS: HR= 1.26, 95%CI= 1.12-1.41, P<0.001). Conclusion: High TOP2A expression suggested significant relationship with worse cancer prognosis. Alteration (amplification or deletion) of TOP2A gene was also significantly related to shorter survival of cancer patients. Therefore, TOP2A might be used as an indicator for poor prognosis of cancer in the future.

The prognostic significance of topoisomerase II alpha protein in early stage luminal breast cancer

BACKGROUND

Topoisomerase II alpha (TOP2A) protein has been shown to be a proliferation marker associated with tumor grade and Ki67 index. The prognostic effect of TOP2A seems different among different subtypes of breast cancer. The current study evaluated the prognostic impact of TOP2A protein on luminal breast cancer.

METHOD

Altogether 434 stage I-II luminal breast cancer patients who underwent curative surgery in Sun Yat-Sen University Cancer Center between 2007 and 2009 were enrolled. TOP2A protein expression was assessed by immunohistochemistry. Clinical and pathological data were retrospectively collected.

RESULT

With a cut-off value of 30%, 127 (29.3%) patients were classified as TOP2A overexpression. TOP2A overexpression was associated with a higher tumor grade and Ki67 index. Patients with TOP2A high expression showed a significantly higher rate of distant metastasis and shorter distant metastasis free survival (DMFS) compared with patients with low TOP2A expression. The prognostic influence of TOP2A expression was more significant in years 5-8 after diagnosis, and more pronounced in stage II patients, luminal B disease, and patients treated with adjuvant endocrine therapy alone. Multivariate survival analysis revealed TOP2A overexpression was an independent fact for worse DMFS.

CONCLUSION

TOP2A protein showed a time dependent influence on prognosis in stage I-II luminal breast cancer, suggesting it might be a potential predictor of late recurrence for this group of patients.

Suppression of PTEN/AKT signaling decreases the expression of TUBB3 and TOP2A with subsequent inhibition of cell growth and induction of apoptosis in human breast cancer MCF-7 cells via ATP and caspase-3 signaling pathways

The aim of the present study was to evaluate the effects of PTEN/AKT signaling on TUBB3 and TOP2A expression and on the subsequent cell growth of human breast cancer MCF-7 cells. We found that the disease-free survival (DFS) and overall survival (OS) of breast cancer patients with TUBB3‑positive tumors were lower than these rates in the patients with TUBB3-negative tumors. Meanwhile, DFS and OS of breast cancer patients with TOP2A-positive tumors were also lower than these rates in patients with TOP2A-negative tumors. Suppression of PTEN reduced the protein expression of TUBB3 and TOP2A in MCF-7 cells. Suppression of PTEN also reduced cell proliferation and induced apoptosis and caspase-3 activity in MCF-7 cells. Moreover, an increase in ATP also reduced TUBB3 and TOP2A protein expression, reduced cell proliferation and induced apoptosis and caspase-3 activity in the MCF-7 cells following suppression of PTEN. Suppression of phosphorylation-AKT (p-AKT) reduced the protein expression of TUBB3 and TOP2A in the MCF-7 cells. Suppression of p-AKT also reduced cell proliferation and induced apoptosis and caspase-3 activity in the MCF-7 cells. Then, ATP also reduced TUBB3 and TOP2A protein expression, reduced cell proliferation and induced apoptosis and caspase-3 activity in MCF-7 cells following suppression of p-AKT. These results suggest that PTEN/AKT signaling affects the expression of TUBB3 and TOP2A reducing cell growth and inducing apoptosis of human breast cancer MCF-7 cells through ATP and caspase-3 signaling pathways. TUBB3 and TOP2A may be promising prognostic markers for the efficacy of adjuvant cisplatin-based chemotherapy.

A double-blind, randomized trial on the effect of a broad-spectrum dietary supplement on key biomarkers of cellular aging including inflammation, oxidative stress, and DNA damage in healthy adults

Background and Aim: Nutritional approaches that ameliorate cellular senescence may have the potential to counteract the effects of chronic disease. This study will investigate the effect of the Healthycell dietary supplement on markers of inflammation, oxidative stress, and DNA damage. Methods: Thirty adults between the ages of 18 and 55 were enrolled and randomly assigned to one of the two study conditions (n = 15 Healthycell and n = 15 placebo). Subjects participated in a four-week intervention and were assessed at baseline, four weeks, and six weeks (after a two-week washout period). Results: Pro-inflammatory cytokine interleukin (IL)-1α (t = 2.033; mean difference = -3.97 pg/ml; SE = 2.0; 95% CI: -8.0, -0.3; Cohen's d = 0.77; p = 0.05) decreased, while soluble cytokine receptors sTNFR-I (t = 2.057; mean difference = 52.39 pg/mL; SE = 18.5; 95% CI: 5.2, 99.6; Cohen's d = 0.53; p = 0.03) and sTNFR-II (t = 1.739; mean difference = 208.71 pg/ml; SE = 72.0; 95% CI: 24.4, 393.0; Cohen's d = 0.61; p = 0.02) increased in the treatment group versus control. C-reactive protein also rose in the Healthycell group during the trial (t = 2.568; mean difference = 1.41 mg/dL; SE = 0.4; 95% CI: 0.3, 2.5; Cohen's d = 0.66; p < 0.01), without accompanying increases in IL-6 and TNF-α. Additionally, cortisol levels decreased in the Healthycell group (t = 0.575; mean difference = -0.31 ug/dL; SE=0.1; 95% CI: -0.6, -0.03; Cohen's d = 0.88; p = 0.03). When groups were split by age (< 35 years vs. ≥ 35 years), 8-hydroxydeoxyguanosine, a marker of DNA damage, decreased in the older Healthycell group compared to placebo (t = 1.782; mean difference = -7.09 ng/mL; SE = 3.0; 95% CI: -13.3, -0.9; Cohen's d = 0.63; p = 0.03). Significant changes were also found for sTNFR-I, sTNFR-II, and IL-5 in the older group. All results were obtained from t tests by post-hoc analysis. Conclusions: Our findings show an improved inflammatory profile and decreased DNA damage. Additionally, the efficacy of Healthycell was primarily in older adults, where the processes that cause or are associated with cell senescence are more predominant. Relevance for patients: Healthycell may help to counteract the inflammatory effects of aging that lead to both cell senescence and the multitude of age-related chronic diseases.

Basis for molecular diagnostics and immunotherapy for esophageal cancer

INTRODUCTION

Esophageal cancer (EC) is an extremely aggressive neoplasm, diagnosed in about 17,000 Americans every year with a mortality rate of more than 80% within five years and a median overall survival of just 13 months. For decades, the go-to regimen for esophageal cancer patients has been the use of taxane and platinum-based chemotherapy regimens, which has yielded the field's most dire survival statistics. Areas covered: Combination immunotherapy and a more robust molecular diagnostic platform for esophageal tumors could improve patient management strategies and potentially extend lives beyond the current survival figures. Analyzing a panel of biomarkers including those affiliated with taxane and platinum resistance (ERCC1 and TUBB3) as well as immunotherapy effectiveness (PD-L1) would provide oncologists more information on how to optimize first-line therapy for EC. Expert commentary: Of the 12 FDA-approved therapies in EC, zero target the genome. A majority of the approved drugs either target or are effected by proteomic expression. Therefore, a broader understanding of diagnostic biomarkers could give more clarity and direction in treating esophageal cancer in concert with a greater use of immunotherapy.

Quantum dot-based immunofluorescent imaging and quantitative detection of TOP2A and prognostic value in triple-negative breast cancer

Background

Topoisomerase 2 alpha (TOP2A) is a key enzyme in DNA replication and a target of various cytotoxic agents including anthracyclines. Previous studies evaluating the predictive and prognostic values of TOP2A in breast cancer are contradictory, likely secondary to the use of both different detection methods and different cutoff thresholds for positive status. Our own studies have previously confirmed the advantages of quantum dot-based nanotechnology for quantitative analysis of biomarkers relative to conventional immunohistochemistry (IHC). This study was designed to 1) assess the expression of TOP2A, 2) investigate the relationship between TOP2A expression and major clinical pathological parameters, and 3) evaluate the prognostic value of TOP2A by quantum dot-based immunofluorescent imaging and quantitative analytical system (QD-IIQAS) in triple-negative breast cancer (TNBC).

Patients and methods

TOP2A expression in 145 TNBC specimens was detected using IHC and QD-IIQAS, and a comparative analysis of the two methods was conducted, including an exploration of the relationship between TOP2A expression and major clinical pathological parameters in TNBC. The prognostic value of TOP2A in TNBC was assessed.

Results

A similar antigen localization, a high correlation of staining rates (r=0.79), and a high agreement of measurements (κ=0.763) of TOP2A expression in TNBC were found by QD-IIQAS and conventional IHC (cutoff: 45.0 and 0.45, respectively). TOP2A was significantly higher in larger tumors (P=0.002), higher grade tumors (P=0.005), and lymph node positive patients (P<0.001). The 5-year disease-free survival (5-DFS) of the high and low TOP2A subgroups was significantly different for both QD-IIQAS and IHC (P<0.001, log-rank test for both). TOP2A expression was an independent predictor of survival in TNBC (P=0.001).

Conclusion

QD-IIQAS was an easy and accurate method for detecting and assessing TOP2A. The TOP2A expression was an independent prognostic indicator of 5-DFS in TNBC. Our study provides a good foundation for future studies exploring the relationship between TOP2A expression and response to anthracyclines.

Recent progress in HER2 associated breast cancer

Breast cancer is the most common cancer worldwide among women and the second most common cancer. Approximately 15-23% of breast cancers over-express human epidermal growth factor receptor2 (HER2), a 185-kDa transmembrane tyrosine kinase, which is mainly found at the cell surface of tumor cells. HER2-positive breast cancer, featuring amplification of HER2/neu and negative expression of ER and PR, has the three following characteristics: rapid tumor growth, lower survival rate, and better response to adjuvant therapies. Clinically, it is notable for its role in a pathogenesis that is associated with increased disease recurrence and acts as a worse prognosis. At the same time, it represents a good target for anti-cancer immunotherapy despite the prevalence of drug resistance. New treatments are a major topic of research, and a brighter future can be expected. This review discusses the role of HER2 in breast cancer, therapeutic modalities available and prognostic factors.

Intact or broken-apart RNA: an alternative concept for ALK fusion screening in non-small cell lung cancer (NSCLC)

Anaplastic lymphoma kinase (ALK) break-apart fluorescent in situ hybridization (FISH) is currently used in diagnostics for the selection of non-small cell lung cancer (NSCLC) patients to receive crizotinib. We evaluated ALK status in NSCLC with a novel ALK mRNA test based on the break-apart FISH concept, which we called break-apart transcript (BAT) test. ALK5' and ALK3' transcript patterns were established with qPCR for ALK-expressing controls including fusion-negative neuroblastomas, as well as fusion-positive anaplastic large cell lymphomas and NSCLC. The BAT test was evaluated on 271 RNA samples from routinely processed paraffin NSCLC tissues. Test results were compared with ALK FISH (n=121), immunohistochemical (IHC) analysis (n=86), and automated quantitative analysis (AQUA, n=83). On the basis of the nonoverlapping ALK BAT patterns in ALK-expressing controls (P<0.0001), 8/174 adenocarcinomas (4.6%) among 259 informative NSCLC were predicted as fusion positive. Overall concordance for paired method results was high (94.1% to 98.8%) but mainly concerned negative prediction because of the limited availability of positive-matched cases. Tumors with 100% cytoplasmic IHC staining of any intensity (n=3) were positive for AQUA, FISH, and BAT test; tumors with lower IHC positivity and different staining patterns were AQUA-negative. Upon multiple reevaluations, ALK gene status was considered as originally misinterpreted by FISH in 3/121 cases (2.5%). Tumors with >4 ALK gene copies were associated with longer overall survival upon first-line chemotherapy. In conclusion, application of the ALK BAT test on routinely processed NSCLC tissues yields the same fusion partner independent information as ALK break-apart FISH but is more robust and cost-effective. The BAT concept may be considered for the development of further drug-predictive translocation tests.

Developing stem cell therapies for juvenile and adult-onset Huntington's disease

Stem cell therapies have been explored as a new avenue for the treatment of neurologic disease and damage within the CNS in part due to their native ability to mimic repair mechanisms in the brain. Mesenchymal stem cells have been of particular clinical interest due to their ability to release beneficial neurotrophic factors and their ability to foster a neuroprotective microenviroment. While early stem cell transplantation therapies have been fraught with technical and political concerns as well as limited clinical benefits, mesenchymal stem cell therapies have been shown to be clinically beneficial and derivable from nonembryonic, adult sources. The focus of this review will be on emerging and extant stem cell therapies for juvenile and adult-onset Huntington's disease.

Topoisomerase II alpha and TLE3 as predictive markers of response to anthracycline and taxane-containing regimens for neoadjuvant chemotherapy in breast cancer

Purpose

Anthracyclines and taxanes are considered the standard for neoadjuvant chemotherapy of breast cancer, although they are often associated with serious side effects and wide variability of individual response. In this study, we analyzed the value of topoisomerase II alpha (TOP2A) and transducin-like enhancer of split 3 (TLE3) as predictive markers of response to therapy with anthracyclines and taxanes.

Materials and methods

TOP2A and TLE3 protein expressions were evaluated using immunohistochemistry on 28 samples, obtained by core needle biopsy in patients with locally advanced breast carcinoma, subsequently subjected to epirubicin- and paclitaxel-based neoadjuvant chemotherapy. The immunohistochemical staining was correlated with the clinical response measured by the tumor size reduction evaluated by breast magnetic resonance imaging, prior and after chemotherapy, and by pathologic evaluation of the surgical specimen.

Results

Neoadjuvant chemotherapy achieved a size reduction in 26/28 tumors (92.9%), with an average percentage decrease of 45.6%. A downstaging was achieved in 71.4% of the cases of locally advanced carcinoma. TOP2A positivity was correlated with a greater reduction in tumor diameter (P=0.06); negative staining for TLE3 was predictive of a better response to neoadjuvant chemotherapy (P=0.07). A higher reduction in tumor diameter (P=0.03) was also found for tumors that were concurrently TLE3-negative and TOP2A-positive.

Conclusion

TOP2A and TLE3 showed a correlation with response to neoadjuvant chemotherapy. While TOP2A is a well-known marker of response to anthracyclines-based chemotherapy, TLE3 is a new putative predictor of response to taxanes. Data from the current study suggest that TOP2A and TLE3 warrant further investigation in a larger series as predictors of response to neoadjuvant chemotherapy for locally advanced breast carcinoma.

Overexpression of HER2/neu as a Prognostic Value in Iranian Women With Early Stage Breast Cancer; A Single Institute Study

Background:

Patients with early stage breast cancer with same treatment strategy can have markedly different outcomes. Human epidermal growth factor receptor 2 (HER2/nue) gene amplification or the subsequent overexpression of protein has been proved to be associated with patient's outcome and response to anthracyclins-based regimens.

Objectives:

This study assessed prognostic value of HER2/nue marker in patients with early stage breast cancer who received adjuvant chemotherapy with anthracyclins-based regimens.

Materials and Methods:

Fifty tissue samples from patients with primary breast cancer of moderate risk receiving sequential adjuvant chemotherapy with anthracyclins-based regimens were assessed to evaluate HER2/nue gene status (quantified by Immunohistochemistry and fluorescence in situ hybridization) retrospectively. Besides, correlation of HER2/neu with patients' characteristics and outcome was studied.

Results:

HER2/neu amplification was identified in 19 (38%) of 50 patients. No significant difference regarding HER2/neu status was seen in clinic pathological characteristics of patients. Although Progression Free Survival (PFS) was shorter in HER2 overexpressed group, but uni/multivariate analysis adjusted for HER2 overexpression, nodal involvement, hormone receptor status, age and tumor size revealed no significant predictive and/or prognostic value for HER2 regarding PFS.

Conclusions:

This study on a limited number of patients treated with adjutant anthracyclins-based regimens, revealed that HER2/neu is not a unique strong predictor for outcome, thus according to combination of HER2/neu status and other clinical factors, it is necessary to distinguish patients at high risk of recurrence.

Adjusting breast cancer patient prognosis with non-HER2-gene patterns on chromosome 17

Background

HER2 and TOP2A gene status are assessed for diagnostic and research purposes in breast cancer with fluorescence in situ hybridization (FISH). However, FISH probes do not target only the annotated gene, while chromosome 17 (chr17) is among the most unstable chromosomes in breast cancer. Here we asked whether the status of specifically targeted genes on chr17 might help in refining prognosis of early high-risk breast cancer patients.

Methods

Copy numbers (CN) for 14 genes on chr17, 4 of which were within and 10 outside the core HER2 amplicon (HER2- and non-HER2-genes, respectively) were assessed with qPCR in 485 paraffin-embedded tumor tissue samples from breast cancer patients treated with adjuvant chemotherapy in the frame of two randomized phase III trials.

Principal Findings

HER2-genes CN strongly correlated to each other (Spearman’s rho >0.6) and were concordant with FISH HER2 status (Kappa 0.6697 for ERBB2 CN). TOP2A CN were not concordant with TOP2A FISH status (Kappa 0.1154). CN hierarchical clustering revealed distinct patterns of gains, losses and complex alterations in HER2- and non-HER2-genes associated with IHC4 breast cancer subtypes. Upon multivariate analysis, non-HER2-gene gains independently predicted for shorter disease-free survival (DFS) and overall survival (OS) in patients with triple-negative cancer, as compared to luminal and HER2-positive tumors (interaction p = 0.007 for DFS and p = 0.011 for OS). Similarly, non-HER2-gene gains were associated with worse prognosis in patients who had undergone breast-conserving surgery as compared to modified radical mastectomy (p = 0.004 for both DFS and OS). Non-HER2-gene losses were unfavorable prognosticators in patients with 1–3 metastatic nodes, as compared to those with 4 or more nodes (p = 0.017 for DFS and p = 0.001 for OS).

Conclusions

TOP2A FISH and qPCR may not identify the same pathology on chr17q. Non-HER2 chr17 CN patterns may further predict outcome in breast cancer patients with known favorable and unfavorable prognosis.

Topoisomerase II-alfa gene as a predictive marker of response to anthracyclines in breast cancer

Amplification or deletion of the topoisomerase IIα (TOP2A) gene in breast cancer has been related with responsiveness to anthracyclines-based chemotherapy. The purpose of this study was to evaluate the predictive value of TOP2A gene for the efficacy of neo-adjuvant anthracycline in a population with locally advanced breast cancer. Sixty-two patients were included, and the status of TOP2A gene was determined by in situ hybridization method. Treatment efficacy was determined by clinical and pathological response and overall survival. TOP2A gene alterations were found in 22.6% (21.0% of cases with amplification and 1.6% with deletion), and these tumors were biologically more aggressive, with higher nuclear grade, more frequently with HER2 amplification and inflammatory type. Also in these tumors response to chemotherapy appeared to be increased. There was a higher clinical and pathological response rate (complete pathological response of 21.4% vs. 8.3%), a trend toward longer progression-free survival (82.51 vs. 63.12 months) and a trend to increased overall survival (92.08 months; 95% CI 82.81-101.35 vs. 73.40 months; 95% CI 63.44-83.36; p=0.113). These results corroborate that the TOP2A gene alterations may play an important role in determining anthracycline sensitivity in breast cancer.

Human epidermal growth factor receptor 2 and estrogen receptor status in respect to tumor characteristics in non-metastatic breast cancer

BACKGROUND

The expressions of estrogen receptor (ER) and cell surface receptor, Tyrosine Kinase Human Epidermal Growth Factor Receptor 2 (HER 2), have emerged as the most important molecular biomarkers determining the breast cancer prognosis. In this study, interactions between ER and HER2 were assessed to determine if they modulate tumor characteristics.

MATERIALS AND METHODS

Tissue samples from 120 patients with early stage breast cancer receiving adjuvant chemotherapy were reviewed to evaluate ER and HER2 status quantified by immunohistochemistry and fluorescence in situ hybridization, and the correlation of ER and HER2 with patient characteristics and tumor pathology was studied.

RESULTS

A total of 37(30.8%) and 80(66.6%) out of 120 samples were HER2 (3+ by immunohistochemistry or positive by fluorescent in situ hybridization) and ER positive (by immunohistochemistry), respectively. ER-negative tumors were significantly more likely to be HER-2 positive than were ER-positive tumors (21.25%; odds ratio, 0.270; 95% CI, 0.119 to 0.612; P = 0.002). ER positivity was associated with <2 cm tumor size and higher histological grade (P = 0.007 and 0.019, respectively). No significant correlation was seen between the co-expression of HER2 and ER and tumor characteristics.

CONCLUSION

HER2 positive tumors were less common compared to ER positive tumors in early stage breast cancer Iranian patients. Also, higher histological grade among ER negative tumors showed higher aggressiveness of the tumor. Future studies are needed to evaluate the effect of receptor status on prognosis.

Multigene Assays for Classification, Prognosis, and Prediction in Breast Cancer: a Critical Review on the Background and Clinical Utility

Gene signatures which are based on multigene profiling assays have been developed for the purpose to better define the prognosis and prediction of therapy results in early-stage breast cancer. These assays were designed to be more specific than conventional clinico-pathologic parameters in the selection of patients for (neo-)adjuvant treatment and in effect help to avoid unnecessary cytotoxic treatment. In this review we describe molecular risk scores, for which tests are commercially available (PAM50®, MammaTyper®, MammaPrint®, Oncotype DX®, Endopredict®, Genomic Grade Index®) and IHC risk scores (Mammostrat® and IHC4), and discuss the current evidence of their clinical use.

Feline HER2 protein expression levels and gene status in feline mammary carcinoma: optimization of immunohistochemistry (IHC) and in situ hybridization (ISH) techniques

Human epidermal growth factor receptor (HER2) is a tumor biomarker that when overexpressed and/or amplified is associated with a poor prognosis for women with breast cancer. This specific tumor subtype is eligible for a specific immunotherapy that increases survival period. However, in feline oncology, only a few studies have been performed on molecular characterization of feline (fHER2) in feline mammary carcinoma (FMC), and the available data are inconsistent. In this study, fHER2 protein levels and gene status in FMC were evaluated by immunohistochemistry and in situ hybridization. After being optimized, these techniques revealed that fHER2 is overexpressed in 33% of FMC cases, although fHER2 and fTOP2A gene amplification could not be observed. Our results support the possibility of using FMC as a natural model for comparative oncology. Additional data obtained may also improve the diagnostics, and consequently the treatment, of this type of tumor in veterinary medicine.

TOP2A overexpression as a poor prognostic factor in patients with nasopharyngeal carcinoma

Despite the advances in diagnostic imaging and treatment modalities, the risk stratification and final outcomes in patients with nasopharyngeal carcinomas (NPC) still remain suboptimal. Through data mining from published transcriptomic database, topoisomerase IIα (TOP2A) was first identified as a differentially upregulated gene in NPC tissues, which implicates cell division via selective cleavage, rearrangement, and re-ligation of DNA strands. Given the roles of TOP2A in prognostication and in the frontline therapeutic regimen of common carcinomas, such as breast cancer, we explored TOP2A immunoexpression status and its associations with clinicopathological variables and survival in a well-defined cohort of NPC patients. TOP2A immunohistochemistry was retrospectively performed and analyzed using H-score method for biopsy specimens from 124 NPC patients who received standard treatment without distant metastasis at initial diagnosis. Those cases with H-score larger than the median value were construed as featuring TOP2A overexpression. The findings were correlated with the clinicopathological variables, disease-specific survival (DSS) and distant metastasis-free survival (DMFS). TOP2A overexpression was significantly associated with American Joint of Cancer Committee (AJCC) stages III-IV (p = 0.019) and univariately predictive of adverse outcomes for DSS (p = 0.0078) and DMFS (p = 0.0003). In the multivariate comparison, TOP2A overexpression remained prognostically independent to portend worse DSS (p = 0.047, hazard ratio = 1.732) and DMFS (p = 0.003, hazard ratio = 2.569), together with advanced AJCC stages III-IV. TOP2A expression is upregulated in a subset of NPCs and its increased immunoexpression significantly correlated with advanced stages and tumor aggressiveness, justifying the potentiality of TOP2A as a prognostic biomarker and a novel therapeutic target of NPC.

The HER2 amplicon in breast cancer: Topoisomerase IIA and beyond

HER2 gene amplification is observed in about 15% of breast cancers. The subgroup of HER2-positive breast cancers appears to be heterogeneous and presents complex patterns of gene amplification at the locus on chromosome 17q12-21. The molecular variations within the chromosome 17q amplicon and their clinical implications remain largely unknown. Besides the well-known TOP2A gene encoding Topoisomerase IIA, other genes might also be amplified and could play functional roles in breast cancer development and progression. This review will focus on the current knowledge concerning the HER2 amplicon heterogeneity, its clinical and biological impact and the pitfalls associated with the evaluation of gene amplifications at this locus, with particular attention to TOP2A and the link between TOP2A and anthracycline benefit. In addition it will discuss the clinical and biological implications of the amplification of ten other genes at this locus (MED1, STARD3, GRB7, THRA, RARA, IGFPB4, CCR7, KRT20, KRT19 and GAST) in breast cancer.

"Omics" of HER2-positive breast cancer

HER2/neu amplification/overexpression is the only somatic mutation widely considered to be a marker of disease outcome and response to treatment in breast cancer. Pathologists have made large efforts to achieve accuracy in characterizing HER2/neu status. The introduction of transtuzumab contributed to development of additional measures to identify sensitive and resistant subclasses of HER2/neu-positive tumors. In this article, we describe the latest advances in HER2/neu status diagnostic assessment and the most relevant research emerging from "Omics" (genomics, epigenetics, transcriptomics, and proteomics) studies on HER2/neu-positive breast cancer. A large quantity of biomarkers from different studies highlighted HER2/neu-positive specific proliferation, cell cycle arrest, and apoptosis mechanisms, as well as immunological and metabolic behavior. Major driver genes of tumor progression have had a candidate status (GRB7, MYC, CCND1, EGFR, etc.), even though the main role for HER2/neu is largely recognized. Nonetheless, existing omics data and HER2/neu-positive molecular profiles seem to suggest that few proteogenomic alterations in HER2, EGFR, and PI3K networks could significantly affect the effectiveness of transtuzumab. The systematic search of molecular alterations in and across these pathways can help to select the most appropriate drug for a given patient based on in-depth understanding of complexity in tumor biology.

In silico discovery of mitosis regulation networks associated with early distant metastases in estrogen receptor positive breast cancers

The aim of this study was to perform comparative analysis of multiple public datasets of gene expression in order to identify common genes as potential prognostic biomarkers. Additionally, the study sought to identify biological processes and pathways that are most significantly associated with early distant metastases (<5 years) in women with estrogen receptor-positive (ER+) breast tumors. Datasets from three published studies were selected for in silico analysis of gene expression profiles of ER+ breast cancer, using time to distant metastasis as the clinical endpoint. A subset of 44 differently expressed genes (DEGs) was found common to all three studies and characterized by mitotic checkpoint genes and pathways that regulate mitotic spindle and chromosome dynamics. DEG promoter regions were enriched with NFY binding sites. Analysis of miRNA target sites identified significant enrichment of miR-192, miR-193B, and miR-16-1 targets. Aberrant mitotic regulation could drive increased genomic instability leading to a progression towards an early onset metastatic phenotype. The relative importance of mitotic instability may reflect the clinical utility of mitotic poisons in metastatic breast cancer, including poisons such as the taxanes, epothilones, and vinca alkaloids.

Sample parameters affecting the clinical relevance of RNA biomarkers in translational breast cancer research

In the frame of translational breast cancer research, eligibility criteria for formalin-fixed paraffin-embedded tissue (FFPE) material processing for gene expression studies include tumor cell content (TCC) and sample site (primary vs metastatic tumors). Herein we asked whether the observed differences in gene expression between paired samples with respect to TCC and sample site also have different clinical significance. We assessed ESR1, ERBB2, MAPT, MMP7, and RACGAP1 mRNA expression with real time PCR in paired samples before (NMD) and after macrodissection (MD) from 98 primary tumors (P_MD, P_NMD) and 72 metastatic lymph nodes (LN_MD, LN_NMD), as well as from 93 matched P (mP) and LN (mLN). TCC range was 2.5–75 % in the NMD series and 28–98 % in the MD and in the mP/mLN series. The prognostic effect of these markers, individually or in clusters, remained stable between paired P_MD/NMD. In comparison, cluster classification failed in the LN_NMD group with lower TCC. In the mP/mLN cohort, RACGAP1 mRNA expression was of prognostic significance when tested in mLN samples (p < 0.001). Similarly, luminal B, HER2, and triple negative tumors were of dismal prognosis when classified in the LN component of the same series (mLN, overall survival: p = 0.013, p = 0.034, and p = 0.007, respectively). In conclusion, the clinical relevance of the RNA markers examined may be affected by TCC in metastatic LN samples but not in primary tumors, while it differs between primary tumors and matched metastases. These data will facilitate the design of translational studies involving FFPE sample series.

Validity of the proliferation markers Ki67, TOP2A, and RacGAP1 in molecular subgroups of breast cancer

High proliferation rates are characteristic of cancer, and proliferation markers make up the majority of genes included in RNA-based prognostic gene signatures applied for breast cancer patients. Based on prior data on differences in molecular subgroups of breast cancer, we hypothesized that the significance of single proliferation markers might differ in luminal, Her2-positive and triple-negative subtypes. Therefore, we compared mRNA expression data of Ki67, TOP2A, and RacGAP1 using a pool of 562 Affymetrix U133A microarrays from breast cancer samples. "Luminal," "triple-negative," and "Her2-positive" subcohorts were defined by ESR1 and ERBB2 mRNA expression using pre-defined cut-offs. The analysis of the three potential proliferation markers revealed subtype-specific differences: in luminal carcinomas, expression of all three markers was a significant indictor of early recurrence in univariate and multivariate analysis, but RacGAP1 was superior to Ki67 and TOP2A in significance. In triple-negative tumors, only Ki67 was a significant and independent marker, whereas none of the markers showed a significant prognostic impact in Her2-positive cases. Within the group of luminal carcinomas, the proliferation markers had different impact depending on the treatment of patients: in untreated patients, Ki67, TOP2A, and RacGAP1 were significant and independent prognostic markers. In chemotherapy-treated patients, overexpression of all three markers was predictive for early recurrence, but only RacGAP1 retained significance in multivariate analysis. In contrast, RacGAP1 was the only predictive proliferation marker in the endocrine treatment group. These data point to subtype-specific differences in the relevance of proliferation-associated genes, and RacGAP1 might be a strong prognostic and predictive marker in the luminal subgroup.

Prognostic significance of TOP2A gene dosage in HER-2-negative breast cancer

BACKGROUND

Previous studies showed the prognostic and predictive impact of human epidermal growth factor receptor 2 (HER-2) gene alterations analyzed separately and jointly with topoisomerase II α (TOP2A) gene alterations; however, the role of TOP2A gene abnormalities alone has not been thoroughly investigated. Additionally, TOP2A aberrations were typically studied in HER-2-positive (HER-2(+)) tumors because these genes are frequently coamplified. Therefore, the knowledge concerning the impact of TOP2A abnormalities in HER-2-negative (HER-2(-)) patients is scarce. This study aimed to investigate the clinical significance of TOP2A anomalies in breast cancer patients with HER-2(-) and HER-2(+) tumors.

MATERIALS AND METHODS

Snap-frozen tumor samples from 322 consecutive stage I-III breast cancer patients were analyzed for TOP2A gene dosage using quantitative real-time PCR (qPCR).

RESULTS

A high TOP2A gene dosage was found in 94 tumors (29%)-32% and 27% of HER-2(+) and HER-2(-) tumors, respectively. The mean TOP2A gene dosages in the HER-2(+) and HER-2(-) groups were 1.49 ± 1.03 and 1.09 ± 0.35, respectively. High TOP2A gene dosage had an inverse prognostic impact in terms of shorter disease-free survival (DFS) and overall survival (OS) times in the entire group and in both the HER-2(-) and HER-2(+) subgroups. The unfavorable prognostic impact of TOP2A gene dosage was maintained in the multivariate Cox regression analysis in the entire group and in HER-2(-) patients.

CONCLUSIONS

A high gene dosage of TOP2A determined using qPCR occurs frequently both in HER-2(+) and HER-2(-) tumors and has a strong adverse prognostic impact.

TOP2A amplification in breast cancer is a predictive marker of anthracycline-based neoadjuvant chemotherapy efficacy

Anthracycline is a DNA topoisomerase 2-α (TOP2A) inhibitor and its concomitant over expression with Human Epidermal Growth Factor Receptor 2 (HER2) was investigated of being predictive for the response to anthracycline-based chemotherapies in breast cancer. 309 early and local advanced breast cancer patients were treated with anthracycline-based neoadjuvant chemotherapies in intense dose dense (IDD) (CE, Cyclophosphamide + Epirubicin) or conventional (TE, Paclitaxel + Epirubicin) regimens. HER2 proteins were qualitatively analyzed by immunohistochemistry (IHC) of primary tumor core biopsies, and TOP2A gene amplification levels of HER2 over-expressing cases were quantified by quantitative real-time polymerase chain reaction (qRT-PCR). Overall pathological complete response rate (pCR) was achieved in 14.3 %. HER2 was over expressed in 80/309 (25.9 %) cases, of which 61/80 cases have been tested for their TOP2A status. Over expression of HER2 was significantly positively correlated with higher pCR rates compared to low HER2 expression (27.5 % vs. 9.6 %, P < 0.001). Concurrent high TOP2A amplification led to a significantly higher pCR rate compared to low or no TOP2A amplification (56.3 % vs. 13.8 %, P = 0.001). HER2 over expression was associated with a significantly higher pCR rate only when TOP2A was also amplified (56.3 % vs. 9.6 %, P < 0.001), but not when it was deleted or normal (13.8 % vs. 9.6 %, P = 0.183) compared to HER2 low-expressing tumors. The interaction between HER2 or TOP2A and anthracycline-based regimen was observed in IDD and conventional neoadjuvant chemotherapies. The TOP2A amplification is related to anthracycline-based neoadjuvant chemotherapy sensitivity, and TOP2A should be included in future studies in breast cancer as a predictive marker.