Estrogen Receptor-negative Breast Cancer Patients Research Articles

Stratification of Estrogen Receptor-Negative Breast Cancer Patients by Integrating the Somatic Mutations and Transcriptomic Data.

Patients with estrogen receptor-negative breast cancer generally have a worse prognosis than estrogen receptor-positive patients. Nevertheless, a significant proportion of the estrogen receptor-negative cases have favorable outcomes. Identifying patients with a good prognosis, however, remains difficult, as recent studies are quite limited. The identification of molecular biomarkers is needed to better stratify patients. The significantly mutated genes may be potentially used as biomarkers to identify the subtype and to predict outcomes. To identify the biomarkers of receptor-negative breast cancer among the significantly mutated genes, we developed a workflow to screen significantly mutated genes associated with the estrogen receptor in breast cancer by a gene coexpression module. The similarity matrix was calculated with distance correlation to obtain gene modules through a weighted gene coexpression network analysis. The modules highly associated with the estrogen receptor, called important modules, were enriched for breast cancer-related pathways or disease. To screen significantly mutated genes, a new gene list was obtained through the overlap of the important module genes and the significantly mutated genes. The genes on this list can be used as biomarkers to predict survival of estrogen receptor-negative breast cancer patients. Furthermore, we selected six hub significantly mutated genes in the gene list which were also able to separate these patients. Our method provides a new and alternative method for integrating somatic gene mutations and expression data for patient stratification of estrogen receptor-negative breast cancers.

NGS Panel Testing of Triple-Negative Breast Cancer Patients in Cyprus: A Study of BRCA-Negative Cases.

Simple SummaryIn Cyprus, approximately 9% of triple-negative (negative in common breast cancer receptors—estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2) receptors) breast cancer (TNBC) patients carry inherited mutations in the BRCA1/2 breast cancer (BC) susceptibility genes. These mutations increase the risk of BC. However, the contribution of other BC susceptibility genes has not yet been determined. To this end, we aimed to investigate the prevalence of mutations in BRCA1/2-negative TNBC patients in Cyprus. Ninety-five cancer susceptibility genes were sequenced for 163 TNBC patients. The frequency of non-BRCA mutations and especially PALB2 in TNBC patients in Cyprus appears to be higher compared to other populations, and half of the mutation-positive patients were diagnosed over the age of 60 years. Based on these results, we believe that PALB2 and TP53 along with BRCA1/2 genetic testing could be beneficial for a large proportion of TNBC patients in Cyprus, irrespective of their age of diagnosis.In Cyprus, approximately 9% of triple-negative (estrogen receptor-negative, progesterone receptor-negative, and human epidermal growth factor receptor 2-negative) breast cancer (TNBC) patients are positive for germline pathogenic variants (PVs) in BRCA1/2. However, the contribution of other genes has not yet been determined. To this end, we aimed to investigate the prevalence of germline PVs in BRCA1/2-negative TNBC patients in Cyprus, unselected for family history of cancer or age of diagnosis. A comprehensive 94-cancer-gene panel was implemented for 163 germline DNA samples, extracted from the peripheral blood of TNBC patients. Identified variants of uncertain clinical significance were evaluated, using extensive in silico investigation. Eight PVs (4.9%) were identified in two high-penetrance TNBC susceptibility genes. Of these, seven occurred in PALB2 (87.5%) and one occurred in TP53 (12.5%). Interestingly, 50% of the patients carrying PVs were diagnosed over the age of 60 years. The frequency of non-BRCA PVs (4.9%) and especially PALB2 PVs (4.3%) in TNBC patients in Cyprus appears to be higher compared to other populations. Based on these results, we believe that PALB2 and TP53 along with BRCA1/2 genetic testing could be beneficial for a large proportion of TNBC patients in Cyprus, irrespective of their age of diagnosis.

Circulating miRNAs in HER2-Positive and Triple Negative Breast Cancers: Potential Biomarkers and Therapeutic Targets.

Breast cancer is one of the most prevalent diseases among women worldwide and is highly associated with cancer-related mortality. Of the four major molecular subtypes, HER2-positive and triple-negative breast cancer (TNBC) comprise more than 30% of all breast cancers. While the HER2-positive subtype lacks estrogen and progesterone receptors and overexpresses HER2, the TNBC subtype lacks estrogen, progesterone and HER2 receptors. Although advances in molecular biology and genetics have substantially ameliorated breast cancer disease management, targeted therapies for the treatment of estrogen-receptor negative breast cancer patients are still restricted, particularly for TNBC. On the other hand, it has been demonstrated that microRNAs, miRNAs or small non-coding RNAs that regulate gene expression are involved in diverse biological processes, including carcinogenesis. Moreover, circulating miRNAs in serum/plasma are among the most promising diagnostic/therapeutic tools as they are stable and relatively easy to quantify. Various circulating miRNAs have been identified in several human cancers including specific breast cancer subtypes. This review aims to discuss the role of circulating miRNAs as potential diagnostic and prognostic biomarkers as well as therapeutic targets for estrogen-receptor negative breast cancers, HER2+ and triple negative.

Uncovering Tumor-Stroma Inter-relationships Using MALDI Mass Spectrometry Imaging.

Tumorigenesis involves a complex interplay between genetically modified cancer cells and their adjacent normal tissue, the stroma. We used an established breast cancer mouse model to investigate this inter-relationship. Conditional activation of Rho-associated protein kinase (ROCK) in a model of mammary tumorigenesis enhances tumor growth and progression by educating the stroma and enhancing the production and remodeling of the extracellular matrix. We used peptide matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to quantify the proteomic changes occurring within tumors and their stroma in their regular spatial context. Peptides were ranked according to their ability to discriminate between the two groups, using a receiver operating characteristic tool. Peptides were identified by liquid chromatography tandem mass spectrometry, and protein expression was validated by quantitative immunofluorescence using an independent set of tumor samples. We have identified and validated four key proteins upregulated in ROCK-activated mammary tumors relative to those expressing kinase-dead ROCK, namely, collagen I, α-SMA, Rab14, and tubulin-β4. Rab14 and tubulin-β4 are expressed within tumor cells, whereas collagen I is localized within the stroma. α-SMA is predominantly localized within the stroma but is also expressed at higher levels in the epithelia of ROCK-activated tumors. High expression of COL1A, the gene encoding the pro-α 1 chain of collagen, correlates with cancer progression in two human breast cancer genomic data sets, and high expression of COL1A and ACTA2 (the gene encoding α-SMA) are associated with a low survival probability (COLIA, p = 0.00013; ACTA2, p = 0.0076) in estrogen receptor-negative breast cancer patients. To investigate whether ROCK-activated tumor cells cause stromal cancer-associated fibroblasts (CAFs) to upregulate expression of collagen I and α-SMA, we treated CAFs with medium conditioned by primary mammary tumor cells in which ROCK had been activated. This led to abundant production of both proteins in CAFs, clearly highlighting the inter-relationship between tumor cells and CAFs and identifying CAFs as the potential source of high levels of collagen 1 and α-SMA and associated enhancement of tissue stiffness. Our research emphasizes the capacity of MALDI-MSI to quantitatively assess tumor-stroma inter-relationships and to identify potential prognostic factors for cancer progression in human patients, using sophisticated mouse cancer models.

Prediction of Successful Ovarian Protection Using Gonadotropin-Releasing Hormone Agonists During Chemotherapy in Young Estrogen Receptor-Negative Breast Cancer Patients.

Background: It is important to identify factors predicting successful ovarian protection using gonadotropin-releasing hormone (GnRH) agonists during chemotherapy. However, only a few studies have prospectively assessed this issue in young breast cancer patients.Objective: This study evaluated the predictive factors for successful ovarian protection with GnRH agonists during chemotherapy in young estrogen receptor-negative breast cancer patients.Materials and Methods: This prospective study analyzed 67 estrogen receptor-negative breast cancer patients ≤40 years of age who were longitudinally assessed after receiving GnRH agonists during cyclophosphamide-based chemotherapy for ovarian protection. Associations between clinical characteristics or pretreatment hormones and successful ovarian protection [resumption of menstruation and anti-Müllerian hormone (AMH) ≥1 ng/ml].Results: The mean age and pretreatment serum level of AMH were 33.2 years and 4.57 ng/ml, respectively. At 12 months after the completion of chemotherapy, most women (97%) experienced the resumption of menstruation. However, the proportion of patients with AMH ≥1 ng/ml at 12 months was 70.1%. In multivariate analyses, only the pretreatment serum AMH level (P < 0.001) was predictive for AMH ≥1 ng/ml at 12 months. Receiver operating characteristic curve analyses of pretreatment AMH exhibited an area under the curve of 0.866 (95% CI = 0.777–0.955) for AMH ≥1 ng/ml at 12 months. The cutoff value for the prediction of AMH concentration ≥1 ng/ml at 12 months was 2.87 ng/ml of pretreatment AMH with a sensitivity of 0.87 and a specificity of 0.75.Conclusions: Pretreatment AMH (2.87 ng/ml) is a useful predictor for AMH ≥1 ng/ml at 12 months after receiving GnRH agonists in young estrogen receptor-negative breast cancer patients. This finding can help improve decision-making regarding fertility preservation.

Advanced glycation end products are elevated in estrogen receptor-positive breast cancer patients, alter response to therapy, and can be targeted by lifestyle intervention

PurposeLifestyle factors associated with personal behavior can alter tumor-associated biological pathways and thereby increase cancer risk, growth, and disease recurrence. Advanced glycation end products (AGEs) are reactive metabolites produced endogenously as a by-product of normal metabolism. A Western lifestyle also promotes AGE accumulation in the body which is associated with disease phenotypes through modification of the genome, protein crosslinking/dysfunction, and aberrant cell signaling. Given the links between lifestyle, AGEs, and disease, we examined the association between dietary-AGEs and breast cancer.MethodsWe evaluated AGE levels in bio-specimens from estrogen receptor-positive (ER+) and estrogen receptor-negative (ER−) breast cancer patients, examined their role in therapy resistance, and assessed the ability of lifestyle intervention to reduce circulating AGE levels in ER+ breast cancer survivors.ResultsAn association between ER status and AGE levels was observed in tumor and serum samples. AGE treatment of ER+ breast cancer cells altered ERα phosphorylation and promoted resistance to tamoxifen therapy. In a proof of concept study, physical activity and dietary intervention was shown to be viable options for reducing circulating AGE levels in breast cancer survivors.ConclusionsThere is a potential prognostic and therapeutic role for lifestyle derived AGEs in breast cancer. Given the potential benefits of lifestyle intervention on incidence and mortality, opportunities exist for the development of community health and nutritional programs aimed at reducing AGE exposure in order to improve breast cancer prevention and treatment outcomes.

Role of DNA methylation as a diagnostic biomarker of sporadic breast cancer

The initiation and progression of breast cancer have been recognized for many years to be secondary to the accumulation of genetic mutations which lead to aberrant cellular function. Genetic mutations, either inherited or sporadic, may result in the activation of oncogenes and the inactivation of tumor suppressor genes. The more recent discovery that reversible alterations in histone proteins and deoxyribonucleic acid (DNA) can also lead to tumorigenesis has introduced a novel term to the field of cancer research: epigenetics . Epigenetics refers to the study of heritable changes in gene regulation that do not involve a change in the DNA sequence. The most often studied in epigenetics of breast cancer is DNA methylation. That a promoter methylation result in transcription blockade supports the notion that cellular inhibition takes place. Compared to normal tissues, hypermethylation occurs from double to triple in cancerous ones. DNA methylation plays a crucial role in oncogenesis and is one of the hallmarks of cancer. Detection of aberrantly methylated CpG islands in promoter region of several genes in DNA sample derived from nipple aspirates, serum, or cancer tissue associated with down regulation of expression or loss of function of these genes has been associated with early stages of breast cancer, where hypermethylation of CpG island points to poorer prognosis in breast cancer. DNA methylation has been identified as signature for TNBC. Methylation of BRCA1 gene is frequently demonstrated in young, estrogen receptor-negative breast cancer patients. Methylation of specific genes is known to differ across race and socioeconomic status. BRCA1 methylation in premenopausal women with sporadic breast cancer in West Sumatra region has been higher than in Western women. DNA methylation may be used to enhance current breast cancer classification. There is such a distinction between methylation and gene expression profiles of breast cancer that not all methylation profiles fit within the same molecular subtype. Specific gene methylation profiles are identified for basal-like, luminal A and HER2-overexpressing breast cancers. A number of studies have analyzed the methylation status of BRCA1 , a key player in TNBC. One study demonstrated that BRCA1 promoter was methylated in TNBC. It was discovered that the sensitivity of TNBC cell lines to PARP inhibitors was increased when BRCA1 was methylated. Concurrently, BRCA1 methylation quantity was higher in patients with complete response than in those who are non-responders of neoadjuvant chemotherapy. Epigenetics is now the cutting edge of cancer research. Advances in this field will have major implications in diagnosis, prevention, treatment of cancer, and formulation of new epigenetically targeted cancer drugs.

The Circadian Rhythm Gene Arntl2 Is a Metastasis Susceptibility Gene for Estrogen Receptor-Negative Breast Cancer.

Breast cancer mortality is primarily due to metastasis rather than primary tumors, yet relatively little is understood regarding the etiology of metastatic breast cancer. Previously, using a mouse genetics approach, we demonstrated that inherited germline polymorphisms contribute to metastatic disease, and that these single nucleotide polymorphisms (SNPs) could be used to predict outcome in breast cancer patients. In this study, a backcross between a highly metastatic (FVB/NJ) and low metastatic (MOLF/EiJ) mouse strain identified Arntl2, a gene encoding a circadian rhythm transcription factor, as a metastasis susceptibility gene associated with progression, specifically in estrogen receptor-negative breast cancer patients. Integrated whole genome sequence analysis with DNase hypersensitivity sites reveals SNPs in the predicted promoter of Arntl2. Using CRISPR/Cas9-mediated substitution of the MOLF promoter, we demonstrate that the SNPs regulate Arntl2 transcription and affect metastatic burden. Finally, analysis of SNPs associated with ARNTL2 expression in human breast cancer patients revealed reproducible associations of ARNTL2 expression quantitative trait loci (eQTL) SNPs with disease-free survival, consistent with the mouse studies.

Activated human mesenchymal stem/stromal cells suppress metastatic features of MDA-MB-231 cells by secreting IFN-β.

Our recent study showed that human mesenchymal stem/stromal cells (hMSCs) are activated to express tumor necrosis factor (TNF)-α-related apoptosis-inducing ligand (TRAIL) by exposure to TNF-α and these activated hMSCs effectively induce apoptosis in triple-negative breast cancer MDA-MB-231 (MDA) cells in vitro and in vivo. Here, we further demonstrated that activated hMSCs not only induced apoptosis of MDA cells but also reduced metastatic features in MDA cells. These activated hMSC-exposed MDA cells showed reduced tumorigenicity and suppressed formation of lung metastasis when implanted in the mammary fat pad. Surprisingly, the activated hMSC-exposed MDA cells increased TRAIL expression, resulting in apoptosis in MDA cells. Interestingly, upregulation of TRAIL in MDA cells was mediated by interferon-beta (IFN-β) secreted from activated hMSCs. Furthermore, IFN-β in activated hMSCs was induced by RNA and DNA released from apoptotic MDA cells in absent in melanoma 2 (AIM2) and IFN induced with helicase C domain 1 (IFIH1)-dependent manners. These observations were only seen in the TRAIL-sensitive breast cancer cell lines but not in the TRAIL-resistant breast cancer cell lines. Consistent with these results, Kaplan–Meier survival analysis also showed that lack of innate sensors detecting DNA or RNA is strongly associated with poor survival in estrogen receptor-negative breast cancer patients. In addition, cancer-associated fibroblasts (CAF) isolated from a breast cancer patient were also able to express TRAIL and IFN-β upon DNA and RNA stimulation. Therefore, our results suggest that the crosstalk between TRAIL-sensitive cancer cells and stromal cells creates a tumor-suppressive microenvironment and further provide a novel therapeutic approach to target stromal cells within cancer microenvironment for TRAIL sensitive cancer treatment.

Abstract B2-55: Critical role of immune spatial heterogeneity and the molecular scaffold in estrogen receptor-negative breast cancer

Abstract Purpose: The abundance of tumor-infiltrating lymphocytes has been associated with a favorable prognosis in estrogen receptor-negative breast cancer. However, a high degree of spatial heterogeneity in lymphocytic infiltration is often observed in histology samples and its clinical implications and underpinning molecular scaffold remain unclear. Materials and methods: To quantify spatial heterogeneity in the distribution of tumor infiltrating lymphocytes, we combined automated histological image processing with methods of spatial statistics used in ecological data analysis. Hematoxylin and eosin-stained sections from two cohorts of estrogen receptor-negative breast cancer patients (discovery: n=120; validation: n=125) were processed with our automated cell classification algorithm to identify the location of lymphocytes and cancer cells. Subsequently, hotspot analysis (Getis-Ord Gi*) was applied to identify statistically significant hotspots of cancer and immune cells, defined as tumor regions with a significantly high number of cancer or immune cells respectively. To identify molecular aberrations that explain tumor spatial heterogeneity, we integrated our image-based hotspots results with microarray gene expression and copy number data profiled for the same set of tumors. Molecular data were generated with tumor materials sandwiched between these sections, thereby maximizing the biological relevance of multiple data types being generated. Results: We found that the amount of colocalized cancer and immune hotspots weighted by tumor area, rather than number of cancer or immune hotspots, significantly correlates with a better prognosis in estrogen receptor-negative breast cancer in uni- and multivariate Cox analysis. Moreover, colocalization of cancer and immune hotspots further stratified patients with immune cell-rich tumors. Subsequently, we developed a bioinformatics tool, iMmune hOTspoT Omics (iMOTTO), to explain the hotspots as a clinically relevant phenotype using molecular profiling data. Our preliminary analysis revealed significant correlations between this phenotype and expression of immune-specific genes such as CD79, CCL19 and SLAMF1, as well as an immunotherapy target, CTLA4. By incorporating the expression of hotspots-associated genes and copy number alteration data into a multivariate regression model, we aim to define a minimal set of genes to explain the observed degree of cancer-immune hotspot colocalization. Conclusion: Taken together, our study demonstrates the importance of quantifying not only the abundance of lymphocytes but also their spatial variation in the tumor specimen for which methods from other disciplines such as spatial statistics can be successfully applied. Systematic integration of histology and omics data revealed key immune regulators as well as novel genes which warrant further investigation to help elucidate the biological processes underlying immune spatial heterogeneity with potentially important clinical implications. Furthermore, our computational approach can be adapted for studying other cancer types for which immunotherapy has been applied, such as melanoma and non-small cell lung cancer, where our hotspot measures can potentially serve as prognostic and predictive biomarkers. Citation Format: Sidra Nawaz, Andreas Heindl, Andrea Agostinelli, Yinyin Yuan. Critical role of immune spatial heterogeneity and the molecular scaffold in estrogen receptor-negative breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Computational and Systems Biology of Cancer; Feb 8-11 2015; San Francisco, CA. Philadelphia (PA): AACR; Cancer Res 2015;75(22 Suppl 2):Abstract nr B2-55.

Beyond immune density: critical role of spatial heterogeneity in estrogen receptor-negative breast cancer

The abundance of tumor-infiltrating lymphocytes has been associated with a favorable prognosis in estrogen receptor-negative breast cancer. However, a high degree of spatial heterogeneity in lymphocytic infiltration is often observed and its clinical implication remains unclear. Here we combine automated histological image processing with methods of spatial statistics used in ecological data analysis to quantify spatial heterogeneity in the distribution patterns of tumor-infiltrating lymphocytes. Hematoxylin and eosin-stained sections from two cohorts of estrogen receptor-negative breast cancer patients (discovery: n=120; validation: n=125) were processed with our automated cell classification algorithm to identify the location of lymphocytes and cancer cells. Subsequently, hotspot analysis (Getis–Ord Gi*) was applied to identify statistically significant hotspots of cancer and immune cells, defined as tumor regions with a significantly high number of cancer cells or immune cells, respectively. We found that the amount of co-localized cancer and immune hotspots weighted by tumor area, rather than number of cancer or immune hotspots, correlates with a better prognosis in estrogen receptor-negative breast cancer in univariate and multivariate analysis. Moreover, co-localization of cancer and immune hotspots further stratified patients with immune cell-rich tumors. Our study demonstrates the importance of quantifying not only the abundance of lymphocytes but also their spatial variation in the tumor specimen for which methods from other disciplines such as spatial statistics can be successfully applied.

RARRES3 suppresses breast cancer lung metastasis by regulating adhesion and differentiation.

In estrogen receptor-negative breast cancer patients, metastatic relapse usually occurs in the lung and is responsible for the fatal outcome of the disease. Thus, a better understanding of the biology of metastasis is needed. In particular, biomarkers to identify patients that are at risk of lung metastasis could open the avenue for new therapeutic opportunities. Here we characterize the biological activity of RARRES3, a new metastasis suppressor gene whose reduced expression in the primary breast tumors identifies a subgroup of patients more likely to develop lung metastasis. We show that RARRES3 downregulation engages metastasis-initiating capabilities by facilitating adhesion of the tumor cells to the lung parenchyma. In addition, impaired tumor cell differentiation due to the loss of RARRES3 phospholipase A1/A2 activity also contributes to lung metastasis. Our results establish RARRES3 downregulation as a potential biomarker to identify patients at high risk of lung metastasis who might benefit from a differentiation treatment in the adjuvant programme.

Fulvestrant, a selective estrogen receptor down-regulator, sensitizes estrogen receptor negative breast tumors to chemotherapy

Drug resistance frequently results in poor prognosis and high 5-year recurrence rate in estrogen receptor-negative (ER−) breast cancer patients. Herein, we examined the reversal effects of fulvestrant on multidrug resistance (MDR) in ER− breast cancer cells. Co-administration of fulvestrant significantly sensitized ER− MDR tumors to paclitaxel both in vitro and in vivo. Further analyses indicated that fulvestrant did not affect P-gp expression, but could inhibit P-gp function and subsequently reverse P-gp mediated drug resistance in ER− breast cancer cells. These results showed that combination of fulvestrant and chemotherapeutic agents might provide an effective treatment for ER− MDR breast cancers.

Quantitative immunohistochemical (IHC) assessment of ataxia-telangiectasia mutated (ATM) in estrogen receptor (ER) negative early breast cancer (BC).

e21083 Background: ATM plays a key role in the cellular response to DNA damage and germline mutations are associated with a predisposition to BC. We evaluated the impact of ATM expression on outcomes in Stage I-III ER negative BC patients (pts). Methods: A tissue microarray was constructed from formalin-fixed paraffin-embedded specimens of ER negative Stage I-III BC pts from the Tom Baker Cancer Centre. ATM expression was assessed by quantitative fluorescence IHC using a rabbit anti-ATM monoclonal antibody (Epitomics) and the HistoRx AQUA platform. ATM expression index (EI) was calculated by the tumor cell to stroma expression ratio. Prognostic ability of ATM EI was explored univariately, and multivariately after adjusting for clinicopathological factors selected using algorithmic methods, with Cox regression methods. Results: Of 126 eligible pts treated from 1999-2004, 44.4% were HER2-neu + and 52.4% were triple negative. ATM EI was normalized using a logarithmic transformation. Univariately, higher ATM EI was associated with worse outcomes (Table). Multivariately, higher ATM EI remained significantly prognostic for recurrence-free survival (RFS) (HR=5.46, p=0.046), local RFS (HR=5.56, p=0.052), distant RFS (HR=4.38, p=0.080), but not overall survival (p=0.48). Conclusions: High ATM EI is associated with worse RFS in ER negative BC in this hypothesis-generating study. Validation of this finding is currently ongoing. [Table: see text]

Survival Benefit of Tamoxifen in Estrogen Receptor-Negative and Progesterone Receptor-Positive Low Grade Breast Cancer Patients

PurposeThis study aimed to analyze the efficacy and prognostic significance of adjuvant tamoxifen in breast cancer patients with various hormone receptor statuses.MethodsTypically, 1,260 female breast cancer patients were recruited in this study. The correlation between estrogen receptor (ER)/progesterone receptor (PR) phenotypes and clinical characteristics was investigated, and the survival rate was assessed after 5-year follow-up.ResultsThe 5-year overall survival (85%) was better in women under the age of 50 years. Patients with ER+/PR+ tumors had a better 5-year survival rate (94%); those with ER-/PR- tumors experienced the worst outcome (74% survival rate); whereas single-positive cases were in between. In 97 out of 128 patients with ER-/PR+ tumors, tamoxifen was given as adjuvant hormonal therapy, and it increased the survival benefit in the lower grade group in terms of overall survival and disease-free survival (p=0.01 and p=0.03, respectively).ConclusionFor high-grade tumors with ER-/PR+, adjuvant tamoxifen therapy may have no survival benefit, whereas for the patients with low-grade ER-/PR+ tumors, adjuvant tamoxifen therapy is highly suggestive.

Control of EVI-1 oncogene expression in metastatic breast cancer cells through microRNA miR-22

Metastasis in breast cancer carries a disproportionately worse prognosis than localized primary disease. To identify microRNAs (miRNA) involved in metastasis, the expression of 254 miRNAs was measured across the following cell lines using microarray analysis: MDA-MB-231 breast cancer cells, cells that grew as a tumor in the mammary fat pad of nude mice (TMD-231), metastatic disease to the lungs (LMD-231), bone (BMD-231) and adrenal gland (ADMD-231). A brain-seeking variant of this cell line (231-BR) was used additionally in validation studies. Twenty miRNAs were upregulated and seven were downregulated in metastatic cancer cells compared with TMD-231 cells. The expression of the tumor suppressor miRNAs let-7 and miR-22 was consistently downregulated in metastatic cancer cells. These metastatic cells expressed higher levels of putative/proven miR-22 target oncogenes ERBB3, CDC25C and EVI-1. Introduction of miR-22 into cancer cells reduced the levels of ERBB3 and EVI-1 as well as phospho-AKT, an EVI-1 downstream target. The miR-22 primary transcript is located in the 5'-untranslated region of an open reading frame C17orf91, and the promoter/enhancer of C17orf91 drives miR-22 expression. We observed elevated C17orf91 expression in non-basal subtype compared with basal subtype breast cancers. In contrast, elevated expression of EVI-1 was observed in basal subtype and was associated with poor outcome in estrogen receptor-negative breast cancer patients. These results suggest that metastatic cancer cells increase specific oncogenic signaling proteins through downregulation of miRNAs. Identifying such metastasis-specific oncogenic pathways may help to manipulate tumor behavior and aid in the design of more effective targeted therapies.

Increased NOS2 predicts poor survival in estrogen receptor–negative breast cancer patients

Inducible nitric oxide synthase (NOS2) is involved in wound healing, angiogenesis, and carcinogenesis. NOS2 upregulation and increased nitric oxide (NO) production affect the redox state of cells and can induce protein, lipid, and DNA modifications. To investigate whether NOS2 levels influence survival of breast cancer patients, we examined NOS2 expression and its association with tumor markers and survival in 248 breast tumors. In multivariable survival analysis, increased NOS2 predicted inferior survival in women with estrogen receptor α-negative (ER-negative) tumors. Microdissected tumor epithelium from ER-negative tumors with high NOS2 had increased IL-8 and a gene expression signature characteristic of basal-like breast cancer with poor prognosis. In cell culture, NO only induced selected signature genes in ER-negative breast cancer cells. ER transgene expression in ER-negative cells inhibited NO-induced upregulation of the stem cell marker CD44 and other proteins encoded by signature genes, but not of IL-8. Exposure to NO also enhanced cell motility and invasion of ER-negative cells. Last, pathway analysis linked the tumor NOS2 gene signature to c-Myc activation. Thus, NOS2 is associated with a basal-like transcription pattern and poor survival of ER-negative patients.

Gene expression of topoisomerase II alpha (TOP2A) by microarray analysis is highly prognostic in estrogen receptor (ER) positive breast cancer

Overexpression of Topoisomerase II alpha (TOP2A) has been implicated with gene amplification of the 17q21 amplicon and consecutively with ErbB2 overexpression and amplification. However, gene amplification does not necessarily correlate with RNA and protein expression. There is growing evidence that TOP2A protein expression is a strong prognostic and TOP2A gene amplification might be a predictive marker (particularly for the use of anthracyclines). Large scale analysis was performed using Affymetrix microarray data from n = 1,681 breast cancer patients to evaluate TOP2A expression. TOP2A expression showed a strong correlation with tumor size (chi(2)-test, P < 0.001), grading (P < 0.001), ErbB2 (P < 0.001) and Ki67 expression (P < 0.001) as well as nodal status (P = 0.042). Survival analysis revealed a significant prognostic value in ER positive (n = 994; log rank P < 0.001), but not in ER negative breast cancer patients (n = 369, P = 0.35). The prognostic impact of TOP2A expression was independent of Ki67 expression in ER positive tumors (P = 0.002 and P = 0.007 for high and low Ki67, respectively). Moreover a worse prognosis of high TOP2A expressing tumors was found in the subgroup of ErbB2 negative tumors (P < 0.001) and a trend among ErbB2 positive tumors (P = 0.11). The prognostic value of TOP2A was independent of whether the patients were untreated or had received adjuvant therapy. In multivariate Cox regression analysis including standard parameters TOP2A emerged to be the top prognostic marker (HR 2.40, 95% CI 1.68-3.43, P < 0.001). TOP2A expression is an independent prognostic factor in ER positive breast cancer and could be helpful for risk assessment in ER positive breast cancer patients.

Economic evaluation of the prevention and treatment of breast cancer-present status and open issues

More effective methods of preventing and treating breast cancer are being sought by clinicians every day, and new drugs and interventions for overcoming this cancer are being energetically evaluated. At present, there are wide treatment options and many different objectives for breast cancer. These circumstances led us to seek information about the relative costs of the different medical options for the prevention and treatment of breast cancer and to try to ascertain whether one course of action is more efficient than other courses. Economic evaluation of healthcare is indispensable for selection of the best alternatives among medical interventions which are becoming more diverse day after day. The total medical expenditure continues to rise each year and some sort of evaluation from an objective and external viewpoint is required to provide the information with which to suppress this rise. This paper surveys the three major reports published on this topic to date, for the purpose of demonstrating the importance and necessity of performing an economic analysis of the treatment and prevention of breast cancer. The three reports to be surveyed pertain to: (1) cost-effectiveness analysis of adjuvant chemotherapy for patients with lymph node negative breast cancer, (2) cost utility analysis of first-line hormonal therapy in advanced breast cancer, namely comparison of two aromatase inhibitors to tamoxifen, and (3) cost-effectiveness analysis of tamoxifen in the prevention of breast cancer. In addition, this paper discusses the advantages, limitations and perspective for the future of the economic evaluation of healthcare for breast cancer. (1) The authors concluded that if the average risk of all women of undergoing recurrence after this therapy is assumed to be 4% per year, adjuvant chemotherapy is definitely of benefit for node-negative, estrogen receptor-negative breast cancer patients. They additionally stated that this benefit decreases markedly if the changes in long-term survival are less than those in disease-free survival. In this connection, they pointed out that the benefit is considerably smaller among postmenopausal 60-year-old women. (2) The incremental cost per quality-adjusted progression-free life year (QAPFY) for letrozole and anastrozole, relative to tamoxifen, was Can $12,500-19,600, which was lower than the criterion level (US $50,000). On the basis of this result, the authors concluded that these two drugs are economically acceptable. Furthermore, when efficacy and cost effectiveness were analyzed together, it was concluded that letrozole is in fact preferable to anastrozole. (3) The model analysis of tamoxifen's cost effectiveness among women at increased risk for breast cancer yielded the following results. In the base-case analysis, involving the calculation of the costs and benefits of 5-year tamoxifen administration, the incremental cost effectiveness of tamoxifen was $41,372 per life-year gained for women age 35 to 49 years, whereas for women age 50 to 59 years and 60 to 69 years, these values were $68,349 and $74,981, respectively. For women who had undergone hysterectomy and thus had no risk of the onset of endometrial cancer, the incremental cost effectiveness of tamoxifen was $46,060 per life-year gained. Medico-economic evaluation of breast cancer is very significant and valuable and is expected to stimulate efficient utilization of healthcare resources. It can provide important information to physicians, patients, insurers, pharmaceutical and other industries, healthcare policy planners, and others.

Overexpression of cyclinD1 predicts for poor prognosis in estrogen receptor-negative breast cancer patients.

CyclinD1 plays a critical role in regulating cell cycle progression. CyclinD1 mRNA and protein are overexpressed in approximately 50% of primary breast cancer cases. However, its clinical significance as a predictive factor remains unclear. One hundred and seventy-three female patients diagnosed with invasive ductal carcinoma who had undergone a mastectomy (161 patients) or breast-conserving surgery (12 patients) were followed up for 6-119 months (median 86 months) postoperatively. Immunoreactivity for monoclonal anti-cyclinD1 antibody (clone DCS-6) with paraffin-embedded carcinoma tissues was investigated using a labeled streptavidin-biotin method. Overexpression of cyclinD1 was found in 42% (73 of 173), and strongly correlated with estrogen receptor (ER) expression (p < 0.000001). Univariate analysis revealed no association between overexpression of cyclinD1 and overall survival or relapse-free survival in all patient groups. However, in the ER-negative subgroup (n = 75), overexpression of cyclinD1 was significantly correlated with shorter overall survival (p = 0.018) and relapse-free survival (p = 0.014) as well as the lymph node status and tumor size. In contrast, there were no significant associations between overexpression of cyclinD1 and clinical outcome in the ER-positive subgroup. According to Cox's multivariate analysis in the ER-negative subgroup, overexpression of cyclinD1 had the most significant effect on overall survival (p = 0.02) and relapse-free survival (p = 0.0058), followed by nodal status and histologic grade. These findings suggest that overexpression of cyclinD1 is an independent prognostic indicator in ER-negative breast cancer patients.