Epigenetic modulators combination with chemotherapy in breast cancer cells

Despite the concerning adverse effects on tumour development, epigenetic drugs are very promising in cancer treatment. The aim of this study was to compare the differential effects of standard chemotherapy regimens (FEC: 5-fluorouracil plus epirubicine plus cyclophosphamide) in combination with epigenetic modulators (decitabine, valproic acid): (a) on gene methylation levels of selected tumour biomarkers (LINE-1, uPA, PAI-1, DAPK); (b) their expression status (uPA and PAI-1); (c) differentiation status (5meC and H3K27me3). Furthermore, cell survival as well as changes concerning the invasion capacity were monitored in cell culture models of breast cancer (MCF-7, MDA-MB-231). A significant overall decrease of cell survival was observed in the FEC-containing combination therapies for both cell lines. Methylation results showed a general tendency towards increased demethylation of the uPA and PAI-1 gene promoters for the MCF-7 cells, as well as the proapoptotic DAPK gene in the treatment regimens for both cell lines. The uPA and PAI-1 antigen levels were mainly increased in the supernatant of FEC-only treated MDA-MB-231 cells. DAC-only treatment induced an increase of secreted uPA protein in MCF-7 cell culture, while most of the VPA-containing regimens also induced uPA and PAI-1 expression in MCF-7 cell fractions. Epigenetically active substances can also induce a re-differentiation in tumour cells, as shown by 5meC, H3K27me3 applying ICC. SIGNIFICANCE OF THE STUDY: Epigenetic modulators especially in the highly undifferentiated and highly malignant MDA-MB-231 tumour cells significantly reduced tumour malignancy thus; further clinical studies applying specific combination therapies with epigenetic modulators may be warranted.

A Network-Based Model of Oncogenic Collaboration for Prediction of Drug Sensitivity

Tumorigenesis is a multi-step process, involving the acquisition of multiple oncogenic mutations that transform cells, resulting in systemic dysregulation that enables proliferation, invasion, and other cancer hallmarks. The goal of precision medicine is to identify therapeutically-actionable mutations from large-scale omic datasets. However, the multiplicity of oncogenes required for transformation, known as oncogenic collaboration, makes assigning effective treatments difficult. Motivated by this observation, we propose a new type of oncogenic collaboration where mutations in genes that interact with an oncogene may contribute to the oncogene's deleterious potential, a new genomic feature that we term "surrogate oncogenes." Surrogate oncogenes are representatives of these mutated subnetworks that interact with oncogenes. By mapping mutations to a protein-protein interaction network, we determine the significance of the observed distribution using permutation-based methods. For a panel of 38 breast cancer cell lines, we identified a significant number of surrogate oncogenes in known oncogenes such as BRCA1 and ESR1, lending credence to this approach. In addition, using Random Forest Classifiers, we show that these significant surrogate oncogenes predict drug sensitivity for 74 drugs in the breast cancer cell lines with a mean error rate of 30.9%. Additionally, we show that surrogate oncogenes are predictive of survival in patients. The surrogate oncogene framework incorporates unique or rare mutations from a single sample, and therefore has the potential to integrate patient-unique mutations into drug sensitivity predictions, suggesting a new direction in precision medicine and drug development. Additionally, we show the prevalence of significant surrogate oncogenes in multiple cancers from The Cancer Genome Atlas, suggesting that surrogate oncogenes may be a useful genomic feature for guiding pancancer analyses and assigning therapies across many tissue types.

Endocrine mucin-producing sweat gland carcinoma: a study of three cases and CK8, CK18 and CD5/6 immunoexpression

Endocrine mucin-producing sweat gland carcinoma is a cutaneous adnexal tumor that is rarely reported in the literature. We identified only 29 previously reported cases. All these cases share some clinical morphologic and immunohistochemical features. Among the immunohistochemical markers, cytokeratins 5/6, 8 and 18 (CK5/6, CK8 and CK18) had not been previously studied in this tumor. Although studies with cytokeratin Cam5.2 exist, we know at present that this marker does not correspond to antibodies CK8/18, but rather to CK7 and CK8. We studied three examples of endocrine mucin-producing sweat gland carcinoma with 18 immunostains. Our cases showed an immunoprofile CK8+, CK18+, CK5/6- (or only focally positive), CK7+, GCDFP-15+ (2 cases), estrogen receptor+, progesterone receptor+, HER2-, neuron-specific enolase + (2 cases), anti-synaptophysin+, chromogranin A +, CD56 variable (1 case +, 1 case-), CD57-, anti-human D2-40- (two cases), p63- or focally positive, smooth muscle actin + with variable pattern of expression and smooth muscle myosin heavy chain expressed in a peripheral discontinuous layer in some nodules, but absent in most.

Cancer Immunotherapy Using γδT Cells: Dealing with Diversity

The broad and potent tumor-reactivity of innate-like γδT cells makes them valuable additions to current cancer immunotherapeutic concepts based on adaptive immunity, such as monoclonal antibodies and αβT cells. However, clinical success using γδT cells to treat cancer has so far fallen short. Efforts of recent years have revealed a striking diversity in γδT cell functions and immunobiology, putting these cells forward as true “swiss army knives” of immunity. At the same time, however, this heterogeneity poses new challenges to the design of γδT cell-based therapeutic concepts and could explain their rather limited clinical efficacy in cancer patients. This review outlines the recent new insights into the different levels of γδT cell diversity, including the myriad of γδT cell-mediated immune functions, the diversity of specificities and affinities within the γδT cell repertoire, and the multitude of complex molecular requirements for γδT cell activation. A careful consideration of the diversity of antibodies and αβT cells has delivered great progress to their clinical success; addressing also the extraordinary diversity in γδT cells will therefore hold the key to more effective immunotherapeutic strategies with γδT cells as additional and valuable tools to battle cancer.

Helping Eve overcome ADAM: G-quadruplexes in the ADAM-15 promoter as new molecular targets for breast cancer therapeutics

ADAM-15, with known zymogen, secretase, and disintegrin activities, is a catalytically active member of the ADAM family normally expressed in early embryonic development and aberrantly expressed in various cancers, including breast, prostate and lung. ADAM-15 promotes extracellular shedding of E-cadherin, a soluble ligand for the HER2/neu receptor, leading to activation, increased motility, and proliferation. Targeted downregulation of both ADAM-15 and HER2/neu function synergistically kills breast cancer cells, but to date there are no therapeutic options for decreasing ADAM-15 function or expression. In this vein, we have examined a unique string of guanine-rich DNA within the critical core promoter of ADAM-15. This region of DNA consists of seven contiguous runs of three or more consecutive guanines, which, under superhelical stress, can relax from duplex DNA to form an intrastrand secondary G-quadruplex (G4) structure. Using biophysical and biological techniques, we have examined the G4 formation within the entire and various truncated regions of the ADAM-15 promoter, and demonstrate strong intrastrand G4 formation serving to function as a biological silencer element. Characterization of the predominant G4 species formed within the ADAM-15 promoter will allow for specific drug targeting and stabilization, and the further development of novel, targeted therapeutics.

2 years versus 1 year of adjuvant trastuzumab for HER2-positive breast cancer (HERA): an open-label, randomised controlled trial

BACKGROUND

Trastuzumab has established efficacy against breast cancer with overexpression or amplification of the HER2 oncogene. The standard of care is 1 year of adjuvant trastuzumab, but the optimum duration of treatment is unknown. We compared 2 years of treatment with trastuzumab with 1 year of treatment, and updated the comparison of 1 year of trastuzumab versus observation at a median follow-up of 8 years, for patients enrolled in the HERceptin Adjuvant (HERA) trial.

METHODS

The HERA trial is an international, multicentre, randomised, open-label, phase 3 trial comparing treatment with trastuzumab for 1 and 2 years with observation after standard neoadjuvant chemotherapy, adjuvant chemotherapy, or both in 5102 patients with HER2-positive early breast cancer. The primary endpoint was disease-free survival. The comparison of 2 years versus 1 year of trastuzumab treatment involved a landmark analysis of 3105 patients who were disease-free 12 months after randomisation to one of the trastuzumab groups, and was planned after observing at least 725 disease-free survival events. The updated intention-to-treat comparison of 1 year trastuzumab treatment versus observation alone in 3399 patients at a median follow-up of 8 years (range 0-10) is also reported. This study is registered with ClinicalTrials.gov, number NCT00045032.

FINDINGS

We recorded 367 events of disease-free survival in 1552 patients in the 1 year group and 367 events in 1553 patients in the 2 year group (hazard ratio [HR] 0·99, 95% CI 0·85-1·14, p=0·86). Grade 3-4 adverse events and decreases in left ventricular ejection fraction during treatment were reported more frequently in the 2 year treatment group than in the 1 year group (342 [20·4%] vs 275 [16·3%] grade 3-4 adverse events, and 120 [7·2%] vs 69 [4·1%] decreases in left ventricular ejection fraction, respectively). HRs for a comparison of 1 year of trastuzumab treatment versus observation were 0·76 (95% CI 0·67-0·86, p<0·0001) for disease-free survival and 0·76 (0·65-0·88, p=0·0005) for overall survival, despite crossover of 884 (52%) patients from the observation group to trastuzumab therapy.

INTERPRETATION

2 years of adjuvant trastuzumab is not more effective than is 1 year of treatment for patients with HER2-positive early breast cancer. 1 year of treatment provides a significant disease-free and overall survival benefit compared with observation and remains the standard of care.

FUNDING

F Hoffmann-La Roche (Roche).

Therapeutic antibodies against cancer

Antibody-based therapeutics against cancer are highly successful and currently enjoy unprecedented recognition of their potential; 13 monoclonal antibodies (mAbs) have been approved for clinical use in the European Union and in the United States. Bevacizumab, rituximab, and trastuzumab had sales in 2010 of more than $5 billion each. Hundreds of mAbs, including bispecific mAbs and multispecific fusion proteins, mAbs conjugated with small-molecule drugs, and mAbs with optimized pharmacokinetics, are in clinical trials. However, deeper understanding of mechanisms is needed to overcome major problems including resistance to therapy, access to targets, complexity of biological systems, and individual variations.

The HER2 World: Better Treatment Selection for Better Outcome

Understanding the mechanisms of trastuzumab efficacy and resistance is a step toward optimizing treatment outcome in HER2-positive breast carcinoma patients. Preclinical studies have indicated different trastuzumab antitumor mechanisms, that is, cytostatic inhibition of tumor proliferation, antibody-dependent cell cytotoxicity, and inhibition of HER2-mediated DNA repair. Clinical studies point to the clinical setting dependence of these mechanisms, with antibody-dependent cell cytotoxicity predominating when trastuzumab is used as monotherapy in neoadjuvant and metastatic settings, whereas inhibition of DNA repair predominates in neoadjuvant and adjuvant settings involving concomitant trastuzumab and chemotherapy; in sequential protocols, the antibody appears to act primarily through cytostatic activity by inhibiting HER2-mediated cell proliferation. Because the mechanisms of resistance to trastuzumab likely depend directly on those of its antitumor activity, resistance mechanisms must also be considered with respect to the different clinical settings. Moreover, the response to this reagent should be assessed according to its ability to induce tumor cytotoxic or cytostatic activity.

Therapeutic proteins

Protein-based therapeutics are highly successful in clinic and currently enjoy unprecedented recognition of their potential. More than 100 genuine and similar number of modified therapeutic proteins are approved for clinical use in the European Union and the USA with 2010 sales of US$108 bln; monoclonal antibodies (mAbs) accounted for almost half (48%) of the sales. Based on their pharmacological activity, they can be divided into five groups: (a) replacing a protein that is deficient or abnormal; (b) augmenting an existing pathway; (c) providing a novel function or activity; (d) interfering with a molecule or organism; and (e) delivering other compounds or proteins, such as a radionuclide, cytotoxic drug, or effector proteins. Therapeutic proteins can also be grouped based on their molecular types that include antibody-based drugs, Fc fusion proteins, anticoagulants, blood factors, bone morphogenetic proteins, engineered protein scaffolds, enzymes, growth factors, hormones, interferons, interleukins, and thrombolytics. They can also be classified based on their molecular mechanism of activity as (a) binding non-covalently to target, e.g., mAbs; (b) affecting covalent bonds, e.g., enzymes; and (c) exerting activity without specific interactions, e.g., serum albumin. Most protein therapeutics currently on the market are recombinant and hundreds of them are in clinical trials for therapy of cancers, immune disorders, infections, and other diseases. New engineered proteins, including bispecific mAbs and multispecific fusion proteins, mAbs conjugated with small molecule drugs, and proteins with optimized pharmacokinetics, are currently under development. However, in the last several decades, there are no conceptually new methodological developments comparable, e.g., to genetic engineering leading to the development of recombinant therapeutic proteins. It appears that a paradigm change in methodologies and understanding of mechanisms is needed to overcome major challenges, including resistance to therapy, access to targets, complexity of biological systems, and individual variations.

Novel Toll-like receptor-4 deficiency attenuates trastuzumab (Herceptin) induced cardiac injury in mice

Background

Cardiac inflammation and generation of oxidative stress are known to contribute to trastuzumab (herceptin) induced cardiac toxicity. Toll-like receptors (TLRs) are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signaling, we investigated whether or not TLR4 is involved in trastuzumab induced cardiotoxicity.

Methods

Seven days after a single injection of herceptin (2 mg/kg; i.p.), left ventricular pressure volume loops were measured in HeN compotent (TLR4^+/+) and HeJ mutant (TLR4^-/-) treated with trastuzumab and control mice. Immunofluorescent staining for monocyte infiltration and analyses of plasma by (ELISAs) for different chemokines including: MCP-1and tumor necrosis factor-α (TNF-α), Western immunoblotting assay for ICAM-1, and used troponin I for cardiac injury marker.

Results

Trastuzumab injection resulted in an impairment of left ventricular function in TLR-4 competent (HeN), in contrast TLR4^-/^- trastuzumab mice showed improved left ventricular function EF%, CO; p < 0.05, attenuation of mononuclear cell infiltration in TLR4 ^-/-; p < 0.05 vs.TLR-4 competent (HeN), reduced level of cytokines TNF-α, MCP-1 and ICAM-1 expression in TLR4^-/-, marked reduction of myocardial troponin-I levels in TLR4-deficient mice. Data are presented as means ± SE; n = 8 in each group p < 0.05 vs.TLR-4 competent (HeN).

Conclusions

Treatment with trastuzumab induces an inflammatory response that contributes to myocardial tissue TLR4 mediates chemokine expression (TNF-α, MCP-1and ICAM-1), so in experimental animals TLR4 deficiency improves left ventricular function and attenuates pathophysiological key mechanisms in trastuzumab induced cardiomyopathy.

The important molecular markers on chromosome 17 and their clinical impact in breast cancer

Abnormalities of chromosome 17 are important molecular genetic events in human breast cancers. Several famous oncogenes (HER2, TOP2A and TAU), tumor suppressor genes (p53, BRCA1 and HIC-1) or DNA double-strand break repair gene (RDM1) are located on chromosome 17. We searched the literature on HER2, TOP2A, TAU, RDM1, p53, BRCA1 and HIC-1 on the Pubmed database. The association of genes with chromosome 17, biological functions and potential significance are reviewed. In breast cancer, the polysomy 17 (three or more) is the predominant numerical aberration. HER2 amplification is widely utilized as molecular markers for trastuzumab target treatment. Amplified TOP2A, TAU and RDM1 genes are related to a significant response to anthracycline-based chemotherapy, taxane or cisplatin, respectively. In contrast, p53, BRCA1 and HIC-1 are important tumor suppressor genes related to breast carcinogenesis. This review focused on several crucial molecular markers residing on chromosome 17. The authors consider the somatic aberrations of chromosome 17 and associated genes in breast cancer.

Activity and resistance of trastuzumab according to different clinical settings

Trastuzumab, a humanized monoclonal antibody directed against HER2, has shown efficacy in breast cancers; however many patients do not respond to this reagent. Here, we discuss the potential mechanisms of trastuzumab efficacy and resistance in different clinical settings as a step toward optimizing the appropriate application of this antibody. The three major antitumor mechanisms of trastuzumab, i.e., inhibition of proliferation, antibody-dependent cell cytotoxicity (ADCC) and inhibition of DNA repair, appear to be differentially operative in different clinical settings. ADCC appears to be the prevalent mechanism in trastuzumab neoadjuvant monotherapy, whereas in neoadjuvant, adjuvant or metastatic settings in which trastuzumab is combined with chemotherapy, the relative role of ADCC is probably small, considering the compromising effects of chemotherapy on the immune cells that mediate this mechanism. In neoadjuvant and adjuvant settings involving concomitant use of trastuzumab and chemotherapy, the primary mechanism at play is presumably inhibition of DNA repair by the antibody, while in sequential protocols, the antibody acts mostly by exerting cytostatic activity through inhibition of HER2-mediated tumor cell proliferation. According to the ability of the antibody to induce cytotoxic or cytostatic antitumor effects depending on the clinical setting, different criteria, i.e., RECIST for cytotoxic effect, OS, and DFS for cytostatic, must be considered in accurately estimating antibody efficacy. Moreover, since trastuzumab resistance likely depends directly on the mechanisms responsible for its antitumor activity, resistance mechanisms must also be considered with respect to the different clinical settings.

Structure-based and ligand-based drug design for HER 2 receptor

Human epidermal growth factor receptor 2, HER2, is a commonly over-expressed tyrosine kinase receptor found in many types of carcinoma. Despite that there are several HER2 inhibitors, namely Iressa, Tarceva and Tykerb, currently in clinical trials, all can cause several side effects. In this study, both structure-based and ligand-based drug design were employed to design novel HER2 inhibitors from traditional Chinese medicine (TCM). The HER2 structure model was built in homology modeling based on known receptors of the same family. Docking and de novo evolution experiments were performed to identify candidates and to build derivatives. A training set of 32 compounds with inhibitory activities to HER2 was used to formulate the pharmacophore hypotheses that were subsequently used to examine candidates obtained from the docking study. Hydrogen bond interactions, salt-bridge formations and pi-stacking were observed between the ligands and Phe731, Lys753, Asp863 and Asp808 of HER2 protein. Combining results from both docking and pharmacophore mapping analysis, CLC015-5, CLC604-11 and CLC604-18 were well accepted and consistent in both approaches and were considered as the most potential HER2 inhibitors.

Estrogen/progesterone receptor negativity and HER2 positivity predict locoregional recurrence in patients with T1a,bN0 breast cancer

PURPOSE

Data have suggested that the molecular features of breast cancer are important determinants of outcome; however, few studies have correlated these features with locoregional recurrence (LRR). In the present study, we evaluated estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) as predictors of LRR in patients with lymph node-negative disease and tumors < or = 1cm, because these patients often do not receive adjuvant chemotherapy or trastuzumab.

METHODS AND MATERIALS

The data from 911 patients with stage T1a,bN0 breast cancer who had received definitive treatment at our institution between 1997 and 2002 were retrospectively reviewed. We prospectively analyzed ER/PR/HER2 expression from the archival tissue blocks of 756 patients. These 756 patients represented the cohort for the present study.

RESULTS

With a median follow-up of 6.0 years, the 5- and 8-year Kaplan-Meier LRR rate was 1.6% and 5.9%, respectively, with no difference noted in those who underwent breast conservation therapy vs. mastectomy (p=.347). The 8-year LRR rates were greater in the patients with ER-negative (10.6% vs. 4.2%, p=.016), PR-negative (9.0% vs. 4.2%, p=.009), or HER2-positive (17.5% vs. 3.9%, p=0.009) tumors. On multivariate analysis, ER-negative and PR-negative disease (hazard ratio, 2.37; p=.046) and HER2-positive disease (hazard ratio, 3.13, p=.016) independently predicted for LRR.

CONCLUSION

Patients with ER/PR-negative or HER2-positive T1a,bN0 breast cancer had a greater risk of LRR. Therapeutic strategies, such as the use of chemotherapy and/or anti-HER2 therapies, should be considered for future clinical trials for these patients.

Therapeutic antibodies, vaccines and antibodyomes

The potential for antibodies to act as "magic bullets" for treatment of human disease was recognized a century ago, but its full realization has began to occur only during the last decade. A key to their current success is the ability to make libraries of antibodies/B cells, isolate a single species, and engineer it to be safe, efficacious and of high quality. Despite this progress, major challenges to the effective prevention, diagnosis and treatment of a vast majority of diseases remain. Limited success in the development of effective vaccines against diseases such as AIDS and cancer reflects our incomplete understanding of how antibodies are generated and function. Only a miniscule number of antibodies are characterized out of the universe of antibodies generated by the immune system. Knowledge of antibodyomes-the complete sets of antibodies-could help solve these and other challenges.

Adjuvant systemic therapy of early stage breast cancer

Az adjuváns gyógyszeres terápia sikeres alkalmazásával elsősorban a távoli metasztázisok kialakulásának esélye csökkenthető, a diagnózis idején fennálló mikrometasztázisok megszüntetése révén. Célkitűzés: A korai emlőrák posztoperatív szisztémás gyógyszeres kezelési lehetőségeinek áttekintése. Módszer: A szerző az irodalmi adatok és saját tapasztalata alapján összefoglalja a korai emlőrák műtéti megoldását követő szisztémás terápia legfontosabb szempontjait. Eredmények: Az adjuváns kezelés során citotoxikus kezelés, hormonterápia és HER2 receptort célzó biológiai terápia, illetve ezek kombinációja kerül alkalmazásra. Az endokrin kezelésben fontos szerepe van a tamoxifenterápiának, amelyet mind a premenopauzális, mind a posztmenopauzális emlőrák kezelésében alkalmaznak. Premenopauzában az elfogadott standard hormonterápiát az LH-RH analóggal végzett petefészek-szuppresszió és/vagy tamoxifenkezelés képezi. Posztmenopauzában az adjuváns endokrin kezelésben ma már a harmadik generációs aromatázgátlók is szerepet kapnak, bár még nem tisztázott, hogy az iniciális, a szekvenciális vagy a meghosszabbított terápia jelenti-e az optimális stratégiát. Az adjuváns polikemoterápia elsősorban a nyirokcsomóáttétes esetekben kerül alkalmazásra, emellett a magas rizikójú nyirokcsomó-negatív betegek posztoperatív kezelésében is egyre gyakrabban alkalmazzák. Az alkilálók és antraciklinek mellett a taxánok (docetaxel és paclitaxel) bevezetése komoly előrehaladást hozott az adjuváns kemoterápiában. Ma már biológiai célzott terápia, a trastuzumabterápia is fontos részét képezi a műtét utáni kezelésnek, amelynek időtartama a jelenlegi szakmai ajánlások alapján egy év. Következtetések: Az elmúlt években bevezetett taxántartalmú kemoterápiák, a posztmenopauzális emlőrákban alkalmazott harmadik generációs aromatázgátlók és az adjuváns trastuzumab alkalmazása mind lényegesen hozzájárulnak a korai emlőrákban szenvedő betegek gyógyulási esélyeihez.

Presence of HER4 associates with increased sensitivity to Herceptin in patients with metastatic breast cancer

INTRODUCTION

HER2 overexpression, or rather HER2 gene amplification, is indicative for Herceptin therapy in both metastatic and pre-metastatic breast cancer patients. Patient's individual sensitivity to Herceptin treatment, however, varies enormously and spans from effectual responsiveness over acquired insensitivity to complete resistance from the outset. Thus no predictive information can be deduced from HER2 determination so that molecular biomarkers indicative for Herceptin sensitivity or resistance need to be identified. Both ErbB receptor-dependent signalling molecules as well as HER2-related ErbB receptor tyrosine kinases, known to mutually interact and to cross-regulate each other are prime candidates to be involved in cellular susceptibility to Herceptin.

METHODS

Using immunohistochemistry and fluorescence in situ hybridisation, we retrospectively investigated primary breast cancer tissues from 48 patients who were under Herceptin treatment. We quantified the gene copy numbers of all HER receptors and evaluated their coexpression profile. Moreover the HER2 phosphorylation state, the ratio of native to truncated HER2, p27(kip1) and PTEN expression were objects of this study.

RESULTS

Above all markers investigated in this study Kaplan-Meier and Cox regression analysis revealed a significant positive impact of HER4 (co-)expression on overall survival from beginning of antibody therapy. Both HER4 expression and HER4 gene amplification emerged as independent prognostic markers in Herceptin-treated breast cancer patients and responsiveness to Herceptin turned out to be more efficient if tumour cells show HER4 expression.

CONCLUSIONS

Although HER4 is known to potentially exert a tumour cell killing activity and in turn to have a favourable impact in breast cancer patients we demonstrate here the first time that HER4 expression prolongs overall survival in Herceptin-treated patients. Elucidating HER4 receptor function in the context of Herceptin treatment will advance the design of highly efficient receptor targeting. By then we need to extend the analysis of breast cancer by allowing for HER2/HER4 coexpression by which valuable additional prognostic and predictive information might possibly be revealed.

Recommendations for research priorities in breast cancer by the Coalition of Cancer Cooperative Groups Scientific Leadership Council: systemic therapy and therapeutic individualization

Over 9,000 women with breast cancer are enrolled annually on clinical trials sponsored by the National Cancer Institute (NCI), accounting for about one-third of all patients enrolled on NCI-sponsored trials. Thousands are also enrolled on pharmaceutical-sponsored studies. Although breast cancer mortality rates have recently declined for the first time in part due to systemic therapeutic advances, coordinated efforts will be necessary to maintain this trend. The Coalition of Cancer Cooperative Groups convened the Scientific Leadership Council in breast cancer (BC), an expert panel, to identify priorities for future research and current trials with greatest practice-changing potential. Panelists formed a consensus on research priorities for chemoprevention, development and application of molecular markers for predicting therapeutic benefit and toxicity, intermediate markers predictive of therapeutic effect, pathogenesis-based therapeutic approaches, utilization of adaptive designs requiring fewer patients to achieve objectives, special and minority populations, and effects of BC and treatment on patients and families. Panelists identified 13 ongoing studies as High Priority and identified gaps in the current trial portfolio. We propose priorities for current and future clinical breast cancer research evaluating systemic therapies that may serve to improve the efficiency of clinical trials, identify individuals most likely to derive therapeutic benefit, and prioritize therapeutic strategies.