Neu-overexpressing Breast Cancer Research Articles

An observational study on the incidence of HER-2/neu receptor over-expression and comparison of clinical presentation between HER-2/neu positive and HER-2/neu negative breast cancer

Background:Tumours that over express HER2/neu are less responsive to chemotherapy and patients with these tumours have a reduced survival compared with patients with normal levels of HER2/neu. The aim was to determine the frequency of HER-2/neu receptor over-expression in Breast cancer patients and its comparison to Her-2/neu negative breast cancer in respect to clinical presentation, risk factors, clinical staging, pathological staging.Methods: 50 patients who presented with Invasive ductal carcinoma of breast, meeting inclusion and exclusion criteria were included in the study. They were divided into two groups; according to Her-2/neu receptor over-expression (Yes/No).Incidence of Her-2-neu receptor over-expression was determined among the sample population. Both groups were compared on the basis of various parameters.Results: Young age at presentation, negative hormone receptor status (ER/PR), high grade of tumour, large sized tumour and increased axillary lymph nodes are more common in Her-2/neu over-expression patients. These parameters are statistically significant.Conclusions: Her-2/neu overexpressing breast cancers have increased invasive and metastatic capability and are less responsive to chemotherapy. They have increased risk of recurrence and patients with these tumours have a reduced survival compared with patients with normal levels of HER2/neu.

Transtuzumab induced organizing pneumonia: a case report

BackgroundPatients with metastatic breast cancer often have pulmonary symptoms with varying aetiologies. Transtuzumab is an extremely important drug used in the treatment of Her 2 neu over-expressing breast cancers. In this report we describe a case of organizing pneumonia associated with use of transtuzumab in metastatic breast cancer. Only three such cases have previously been reported.Case descriptionA 43 year old lady with Her 2 neu 3+, estrogen and progesterone receptor positive, metastatic breast cancer was started on weekly transtuzumab and albumen bound paclitaxel. She was admitted with an episode of bilateral pneumonitis after her fourth dose of therapy. It was managed conservatively with antibiotics. Subsequently, single agent transtuzumab was administered resulting in an anaphylactoid reaction followed by worsening dyspnoea requiring hospitalization and oxygen support for 3 days.Discussion and evaluationThe pneumonitis warranted further investigations including bronchoscopy which were performed. Bronchoscopic biopsy was consistent with a diagnosis of organizing pneumonia. Transtuzumab was stopped and she was started on steroids (dexamethasone). She improved remarkably and was discharged home on hormonal therapy, lapatinib and tapering doses of steroids.ConclusionOrganizing pneumonia closely mimics infection or progressive disease and can be difficult to diagnose in the setting of malignancy. Correct diagnosis is of paramount importance since delay in treatment can result in significantly adverse patient outcomes.

Reproductive Factors and Subtypes of Breast Cancer Defined by Estrogen Receptor, Progesterone Receptor, and Human Epidermal Growth Factor Receptor 2: A Register-Based Study From Korea

BackgroundThe relationship between reproductive breast risk factors and breast cancer survival in patients with different breast cancer subtypes is not well known. MethodsWe examined a large-sized, retrospective study of 23,882 subjects from the Korean Breast Cancer Registry. The breast cancer subtype was determined by immunohistochemical staining for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2). Information regarding reproductive factors, including breastfeeding, age at first birth (AFB), and parity, was gathered. Multivariate Cox regression analysis was used to estimate the association among breast cancer subtypes, such as luminal A, luminal B, Her-2/neu overexpressing, and triple negative breast cancer (TNBC), and breast cancer survival as dependent variables and adjusting for age and stage. ResultsHigh parity (≥ 5) increased the recurrence risk of luminal A and B breast cancer (hazard ratio [HR], 1.95; 95% confidence interval [CI], 0.96-3.97; P = .0055 and HR, 1.12; 95% CI, 0.42-3.02, respectively; P = .0073) in breast cancer–specific survival (BCSS), but 1 to 3 child births decreased the recurrence risk of luminal A breast cancer (HR, 0.56; 95% CI, 0.34-0.91; P = .0055) and luminal B breast cancer (HR, 0.32; 95% CI, 0.17-0.61; P = .0073) in BCSS. Early AFB (< 20 years) increased the recurrence risk of luminal A breast cancers (HR, 1.61; 95% CI, 0.62-4.26; P = .039) in BCSS and of TNBC (HR, 1.31; 95% CI, 0.78-2.21; P = .0006) in overall survival. Her-2/neu overexpressing breast cancer had no correlation with parity and AFB in breast cancer survival. ConclusionsHigh parity (≥ 5) and early AFB (< 20 years) were correlated with worse clinical outcomes in patients with luminal breast cancer, but not with other subtyped breast cancers.

Inhibition of cell growth by BrMC through inactivation of Akt in HER-2/neu-overexpressing breast cancer cells.

We previously reported that chrysin (ChR) and its analogs induced cell cycle arrest and apoptosis in human estrogen receptor-positive/-negative breast cancer cells. However, it was unknown whether 8-bromo-7-methoxychrysin (BrMC), a novel synthetic ChR analog, inhibited the cell growth of human epidermal growth factor receptor 2 (HER-2)/neu-overexpressing breast cancers. In the present study, it was demonstrated that BrMC preferentially inhibited the cell viability of HER-2/neu-overexpressing MDA-MB-453 and BT-474 cells. Western blot analysis revealed that HER-2/neu expression and tyrosine phosphorylation were inhibited by BrMC in a concentration-dependent manner; whereas the proteasome inhibitor, MG-132, significantly prevented BrMC-induced HER-2/neu depletion and cell death in MDA-MB-453 cells. This directly indicated that BrMC-induced HER-2/neu depletion and cell growth inhibition was mediated by a proteasomal pathway. BrMC significantly downregulated the expression of cyclin D1, cyclin E and CDK4, followed by the suppression of protein kinase B phosphorylation and downstream effectors, GSK-3β and β-catenin. A colony formation assay also confirmed the growth-inhibitory effects of BrMC. Thus, these findings clearly demonstrate the anticancer activity of BrMC against human HER-2/neu-overexpressing breast cancer cells. Thus, these findings clearly demonstrate the anticancer activity of BrMC against human HER 2/neu-overexpressing breast cancer cells, and highlight BrMC as a promising candidate for breast cancer therapy.

Immunologically active cryogels for breast cancer therapy (P4329)

Abstract Passive immunotherapy has become an effective adjunct for the treatment of HER2/neu-overexpressing breast cancers, as patients can respond well to monoclonal antibodies such as trastuzumab (anti-HER-2/neu antibody therapy). However, patients with late-stage disease, who often become immunosuppressed are unlikely to respond, motivating the development of new prophylactic vaccines. To this end, we have developed an injectable, polymer-based cryogel vaccine containing living, attenuated HER-2/neu-overexpressing breast cancer cells. The cryogel-based vaccine mimics key aspects of bacterial infection and directly controls immune-cell trafficking and activation in the body. This system provides a sustained release of GM-CSF to recruit host dendritic cells (DCs) to the porous material, and subsequently presents breast cancer antigens and TLR9 ligand CpG oligonucleotides to activate the resident DCs. Subcutaneous injection of the cryogel vaccines provide potent prophylactic protection against mammary cancer in mice, consistent with significantly higher titers of Her-2/neu-specific antibodies compared to the humoral responses induced by bolus injection of irradiated GM-CSF-secreting breast tumor cells. The cryogel-based vaccines induced a 70-fold increase in antibody production compared to untreated mice and 100% survival was achieved in vaccinated mice. The cryogel-based vaccines represent a promising tool for the development of novel active immunotherapeutic approaches to cancer.

Enzymatic Discovery of a HER-2/neu Epitope That Generates Cross-Reactive T Cells

Patients with HER-2/neu-expressing breast cancer remain at risk for relapse following standard therapy. Vaccines targeting HER-2/neu to prevent relapse are in various phases of clinical testing. Many vaccines incorporate the HER-2/neu HLA-A2-binding peptide p369-377 (KIFGSLAFL), because it has been shown that CTLs specific for this epitope can directly kill HER-2/neu-overexpressing breast cancer cells. Thus, understanding how tumors process this epitope may be important for identifying those patients who would benefit from immunization. Proteasome preparations were used to determine if p369-377 was processed from larger HER-2/neu-derived fragments. HPLC, mass spectrometry, cytotoxicity assays, IFN-γ ELISPOT, and human breast cancer cell lines were used to assess the proteolytic fragments. Processing of p369-377 was not detected by purified 20S proteasome and immunoproteasome, indicating that tumor cells may not be capable of processing this Ag from the HER-2/neu protein and presenting it in the context of HLA class I. Instead, we show that other extracellular domain HER-2/neu peptide sequences are consistently processed by the proteasomes. One of these sequences, p373-382 (SLAFLPESFD), bound HLA-A2 stronger than did p369-377. CTLs specific for p373-382 recognized both p373-382 and p369-377 complexed with HLA-A2. CTLs specific for p373-382 also killed human breast cancer cell lines at higher levels than did CTLs specific for p369-377. Conversely, CTLs specific for p369-377 recognized p373-382. Peptide p373-382 is a candidate epitope for breast cancer vaccines, as it is processed by proteasomes and binds HLA-A2.

Inhibition of Cell Growth and Induction of Apoptosis by Antrodia camphorata in HER-2/neu-Overexpressing Breast Cancer Cells through the Induction of ROS, Depletion of HER-2/neu, and Disruption of the PI3K/Akt Signaling Pathway.

Previously, we demonstrated that a submerged fermentation culture of Antrodia camphorata (AC) promotes cell-cycle arrest and apoptosis in human estrogen receptor-positive/negative breast cancer cells. However, whether AC is effective against HER-2/neu-overexpressing breast cancers has not been thoroughly elucidated. In the present study, we showed that AC exhibited a significant cytotoxic effect against HER-2/neu-overexpressing MDA-MB-453 and BT-474 cells. Immunoblot analysis demonstrated that HER-2/neu and their tyrosine phosphorylation were inhibited by AC in a dose-dependent manner. An increase in intracellular reactive oxygen species (ROS) was observed in AC-treated cells, whereas antioxidant N-acetylcysteine (NAC) significantly prevented AC induced HER-2/neu depletion and cell death, which directly indicates that AC-induced HER-2/neu depletion and cell death was mediated by ROS generation. Also, AC significantly downregulated the expression of cyclin D1, cyclin E, and CDK4 followed by the suppression of PI3K/Akt, and their downstream effectors GSK-3β and β-catenin. Notably, AC-treatment induced apoptotic cell death, which was associated with sub-G1 accumulation, DNA fragmentation, mitochondrial dysfunction, cytochrome c release, caspase-3/-9 activation, PARP degradation, and Bcl-2/Bax dysregulation. Assays for colony formation also confirmed the growth-inhibitory effects of AC. This is the first report confirming the anticancer activity of this potentially beneficial mushroom against human HER-2/neu-overexpressing breast cancers.

P3-10-01: Alternative Dosing Regimens with the EGFr Inhibitors (Gefitinib and Lapatinib) in Mammary Cancer Models: Prevention and Therapeutic Efficacy.

Abstract The EGFR inhibitors are effective in treatment of lung and pancreatic cancers (erlotinib, gefitinib) and Neu overexpressing breast cancer (lapatinib) in humans; as well as preventing multiple cancers in animal models. However, the development of toxicities (Iressa, skin rashes; Lapatinib, diarrhea) limit their potential use in prevention; and perhaps even in an adjuvant setting. We examined whether alternative dosing regimens which might reduce toxicity would still achieve preventive and therapeutic efficacy. Female Sprague-Dawley rats were administered a single IV dose of methylnitrosourea (MNU) at 50 days of age. In a prevention study, MNU treated rats administered Gefitinib daily (10 mg/kg BW/day, 7x/week) or Gefitinib (70 mg/kg BW, 1x/week) beginning 5 days after MNU resulted in 94 and 75% reductions, respectively, in cancer multiplicity. Simultaneous measurements of tumor load (number of tumors x tumor weight) showed that both regimens resulted in greater than a 90% decrease. In the therapeutic study (initiating treatment when animals developed a small palpable cancer), both regimens were again highly effective. A prevention study was also performed with Lapatinib (75 mg/kg BW/day, 7x/week or 525 mg/kg BW, 1x/week). While the daily dose reduced cancer multiplicity 90%, the weekly dose caused a 70% reduction. Finally, we examined the effects of daily or weekly dosing with Iressa (100 mg/kg BW/day, 5x/week or 500 or 250 mg/kg BW, 1x/week) in an ER− mouse model (using MMTV-Neu; p53+/− mice). This study showed that while daily dosing with Iressa decreased tumor multiplicity roughly 80%, weekly dosing at either dose caused roughly a 50% decrease. These data show that even a significant alteration in the dosing of Gefitinib (EGFR 1) or Lapatinib (EGFR 2/1) still resulted in a large reduction in mammary cancers. The important clinical question will be whether this altered dosing will diminish the toxicities associated with these agents. We cannot determine this in animal models since, at the effective doses employed, the typical toxicities observed in humans are not observed. Supported by NCI contract number HHSN261200433001C. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-10-01.

Abstract A80: Modified dosing schedules with the EGFr inhibitors gefitinib and lapatinib in rodent models of mammary and urinary bladder cancer: Preventive and therapeutic effects.

Abstract The EGFR inhibitors are approved for treatment of lung and pancreatic cancers (Erlotinib, Gefitinib) and Neu overexpressing breast cancer (Lapatinib) in humans; as well as preventing multiple cancers in animal models. However, the development of toxicities (Iressa, skin rashes; Lapatinib, diarrhea) limit their potential use in prevention; and perhaps even in an adjuvant setting. We examined whether alternative dosing regimens which might reduce toxicity would still achieve preventive and therapeutic efficacy. Female Sprague-Dawley rats were administered a single IV dose of methylnitrosourea (MNU) at 50 days of age. In a prevention study, MNU treated rats administered Gefitinib daily (10 mg/kg BW/day, 7×/week) or Gefitinib (70 mg/kg BW, 1×/week) beginning 5 days after MNU resulted in 94 and 75% reductions, respectively, in cancer multiplicity. Simultaneous measurements of tumor load (number of tumors × tumor weight) showed that both regimens resulted in greater than a 90% decrease. In the therapeutic study (initiating treatment when animals developed a small palpable cancer), both regimens were again highly effective. A prevention study was also performed with Lapatinib (75 mg/kg BW/day, 7×/week or 525 mg/kg BW, 1×/week). While the daily dose reduced cancer multiplicity 90%, the weekly dose caused a 70% reduction. Finally, we examined the effects of daily or weekly dosing with Iressa (100 mg/kg BW/day, 5×/week or 500 or 250 mg/kg BW, 1×/week) in an ER− mouse model (using MMTV/Neu; p53+/− mice). This study showed that while daily dosing with Iressa decreased tumor multiplicity approximately 80%, weekly dosing at either dose caused roughly a 50% decrease. These data show that even a significant alteration in the dosing of Gefitinib (EGFR 1) or Lapatinib (EGFR 2/1) still resulted in a large reduction in mammary cancers. We similarly tested Lapatinib (weekly, 525 mg; or daily, 75 mg/kg/day) in a delayed preventive/therapeutic setting in an OH-BBN model of urinary bladder cancer. We found that although daily dosing was most effective weekly dosing was still relatively effective. The important clinical question will be whether this altered dosing will diminish the toxicities associated with these agents. We cannot determine this in animal models since, at the effective doses employed, the typical toxicities observed in humans are not observed. Supported by NCI contract number HHSN261200433001C. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A80.

The tumor suppressor RECK interferes with HER-2/Neu dimerization and attenuates its oncogenic signaling

Our previous study demonstrates that HER-2/Neu oncogene inhibits a matrix metalloproteinase inhibitor and tumor metastasis suppressor RECK to promote metastasis. Conversely, the effect of RECK on the oncogenic function of HER-2/Neu is unknown. Ectopic expression of RECK in 293T cells and HER-2/Neu-overexpressing breast cancer cells shows that RECK and HER-2/Neu are co-localized and these two proteins can be co-immunoprecipitated. RECK inhibits HER-2/Neu receptor dimerization and autophosphorylation, which causes reduction of ERK and AKT kinase activity and down-regulation of HER-2/Neu target genes. RECK expression is reduced in 58.8% of breast cancer tissues and is associated with lymph node invasion supporting its anti-metastatic role. Collectively, we provide the first evidence that RECK can negatively regulate oncogenic activity of HER-2/Neu by inhibiting receptor dimerization. Structured summary HER-2/Neu physically interacts with HER-2/Neu by blue native page ( View interaction) HER-2/Neu physically interacts with RECK by coimmunoprecipitation ( View interaction) HER-2/Neu and RECK colocalize by fluorescence microscopy (View Interaction 1, 2) HER-2/Neu physically interacts with RECK by anti bait coimmunoprecipitation ( View interaction)

Therapeutic Breast Cancer Vaccines

Treatment of breast cancer in the adjuvant setting has changed rapidly over the last few years. In addition to improvements in chemotherapy, radiation, hormone manipulation, and surgery, immunotherapy has emerged as an effective adjunct for the treatment of breast cancer. Passive immunotherapeutic agents such as trastuzumab have been widely adopted as the standard of care for HER-2/neu overexpressing breast cancer. Vaccine therapy in the metastatic setting has yet to demonstrate clinical significance in a phase III testing. This may be due to the enhanced immunosuppressive effects demonstrated in the tumor microenvironment. Lack of co-stimulatory molecules, activation of the cytotoxic T-lymphocyte antigen-4 (CTLA-4), increased T regulatory cells as well as soluble immunosuppressive factors produced by the tumor contribute to the ineffectiveness of vaccine therapy. Based on these observations, there has been a shift towards treating patients with minimal residual disease and a high risk of relapse. In this adjuvant setting, immune mechanisms of tumor evasion are less formidable, and the use of vaccine therapy in these patients may offer a higher chance of clinical benefit. There are several different vaccine approaches, including the use of cell-based vaccines (autologous, allogeneic, or dendritic cell-based), tumor-associated peptide or protein vaccines, DNA vaccines, heat shock proteins, and recombinant technology using viral or bacterial vectors to enhance immunogenicity of vaccine preparations. This review summarizes principles involving vaccine formulation and antigen selection, followed by a brief synopsis of therapeutic vaccines given in the metastatic setting and possible reasons for their lack of efficacy. The current literature regarding vaccine development for the treatment of breast cancer in the adjuvant setting is also reviewed.

Quercetin‐induced ubiquitination and down‐regulation of Her‐2/neu

Her-2/neu (ErbB2) is a transmembrane tyrosine kinase and acts as a co-receptor for the other EGFR family members. It is well known that high expression of Her-2/neu is associated with a poor prognosis in breast cancer. Quercetin, a flavonoid present in many vegetables and fruits, has been studied extensively as a chemoprevention agent in several cancer models. In this study, we observed that quercetin decreased the level of Her-2/neu protein in time- and dose-dependent manners and also inhibited the downstream survival PI3K-Akt signaling pathway in Her-2/neu-overexpressing breast cancer SK-Br3 cells. We also observed that quercetin induced polyubiquitination of Her-2/neu. When the proteasome pathway was blocked by MG-132 during quercetin treatment, accumulation of the NP-40 insoluble form of Her-2/neu occurred. Interestingly, data from immunocomplex studies revealed that quercetin promoted interaction between Her-2/neu and Hsp90 which is a molecular chaperone involved in stabilization of Her-2/neu. In this condition, inhibition of Hsp90 activity by a specific inhibitor, geldanamycin (GA), or intracellular ATP depletion caused dissociation of Hsp90 from Her-2/neu and promoted ubiquitination and down-regulation of Her-2/neu protein. In addition, the carboxyl terminus of Hsc70-interacting protein (CHIP), a chaperone-dependent E3 ubiquitin ligase, played a crucial role in the quercetin-induced ubiquitination of Her-2/neu. Inhibition of tyrosine kinase activity of Her-2/neu by quercetin could indicate an lateration in the Her-2/neu structure which promotes CHIP recruitments and down-regulation of Her-2/neu. We believe that by using quercetin, new therapeutic strategies can be developed to treat Her-2/neu overexpressing cancers.

Level of HER-2/neu protein expression in breast cancer may affect the development of endogenous HER-2/neu-specific immunity

We questioned whether the incidence or magnitude of the humoral or cellular immune response to the self-tumor antigen HER-2/neu is influenced by the level of HER-2/neu protein overexpression as defined by immunohistochemical staining of tumors in breast cancer patients. We obtained peripheral blood from 104 women with stage II, III, and IV pathologically confirmed HER-2/neu-overexpressing breast cancer. Patients were categorized with +1 (n = 14), +2 (n = 20), or +3 (n = 70) HER-2/neu overexpression by institutional pathologic report. Circulating antibodies to HER-2/neu were evaluated using ELISA. T-cell responses to HER-2/neu were measured using an antigen-specific tritiated thymidine incorporation assay. Eighty-two percent of subjects with HER-2/neu antibodies were +3 overexpressors compared with 18% +2 overexpressors and 0% +1 overexpressors, a highly significant difference (P < 0.001), and there were significant differences in the magnitude of the HER-2/neu-specific antibodies between groups with varying HER-2/neu protein expression (P = 0.022). In addition, 65% of subjects with HER-2/neu-specific T cells were +3 overexpressors compared with 16% +2 overexpressors and 19% +1 overexpressors (P = 0.001). Data presented here indicate that endogenous HER-2/neu-specific humoral and T-cell immunity is greater in patients with +3 protein overexpression in their tumors than in patients with lower levels of HER-2/neu expression. Overexpression of a self-tumor-associated protein is a potential mechanism by which immunogenicity is enhanced and may aid in the identification of biologically relevant proteins to target for immune-based molecular cancer therapies.

HER-2/neu transcriptionally activates Jab1 expression via the AKT/β-catenin pathway in breast cancer cells

Jab1 is a co-activator of activating protein-1 (AP-1) transcription factor and the fifth subunit of the constitutive photomorphogenesis 9 (COP9) signalosome, which has been shown to mediate nuclear exportation and ubiquitin-dependent degradation of the tumor suppressor p27(Kip1). Jab1 is overexpressed in several types of human cancer. However, de-regulation of Jab1 gene expression in cancer cells is largely unclear. In this study, we reported that expression of Jab1 was stimulated by HER-2/neu oncogene via transcriptional activation. Promoter deletion and mutation analysis indicated that HER-2/neu stimulated Jab1 via the T cell factor (TCF) binding site located at the -380/-368 region of the human Jab1 promoter. DNA affinity precipitation assay and chromatin immunoprecipitation assay verified that binding of beta-catenin and TCF-4 to this consensus site was increased by HER-2/neu. In addition, dominant-negative mutant of TCF significantly attenuated the stimulatory effect of HER-2/neu. We also demonstrated that HER-2/neu increased beta-catenin/TCF-mediated Jab1 expression via the AKT signaling pathway because chemical inhibitor or dominant-negative mutant of AKT effectively attenuated the stimulatory action of HER-2/neu. IGF-I, which is a well-known AKT activator, also up-regulated the expression of Jab1 in NIH/3T3 and MCF-7 cells. Knockdown of Jab1 by small interfering RNA (siRNA) preferentially inhibited proliferation of HER-2/neu-overexpressing breast cancer cells. Taken together, our results suggest that HER-2/neu transcriptionally activates Jab1 expression to promote proliferation of breast cancer cells.

Adjuvant trastuzumab in the treatment of her-2-positive early breast cancer: a meta-analysis of published randomized trials.

BackgroundBreast cancer is the most common cancer in women in the U.S. and Western Europe. Amplification of the her-2/neu gene occurs in approximately 25% of invasive ductal carcinomas of the breast. The first HER-2/neu-targeted approach to reach the clinic was trastuzumab, a humanized monoclonal antibody directed against the extracellular domain of the HER-2/neu protein. Trastuzumab therapy prolongs the survival of patients with metastático HER-2/neu-overexpressing breast cancer when combined with chemotherapy and has recently been demonstrated to lead to dramatic improvements in disease-free survival when used in the adjuvant therapy setting in combination with or following chemotherapy. Here, we performed a meta-analysis of completed clinical trials of adjuvant trastuzumab in the adjuvant setting. Survival, recurrence, brain metastases, cardiotoxicity and directions for future research are discussed.MethodsA meta-analysis of randomized controlled trials (RCT) was performed comparing adjuvant trastuzumab treatment for HER2-positive early breast cancer (EBC) to observation. The MEDLINE, EMBASE, CANCERLIT and Cochrane Library databases, and abstracts published in the annual proceedings were systematically searched for evidence. Relevant reports were reviewed by two reviewers independently and the references from these reports were searched for additional trials, using guidelines set by QUOROM statement criteria.ResultsPooled results from that five randomized trials of adjuvant Trastuzumab showed a significant reduction of mortality (p < 0.00001), recurrence (p < 0.00001), metastases rates (p < 0.00001) and second tumors other than breast cancer (p = 0.007) as compared to no adjuvant Trastuzumab patients. There were more grade III or IV cardiac toxicity after trastuzumab (203/4555 = 4.5%) versus no trastuzumab (86/4562 = 1.8%). The likelihood of cardiac toxicity was 2.45-fold higher (95% CI 1.89 – 3.16) in trastuzumab arms, however that result was associated with heterogeneity. The likelihood of brain metastases was 1.82-fold higher (95% CI 1.16 – 2.85) in patients who received trastuzumab.ConclusionThe results from this meta-analysis are sufficiently compelling to consider 1 year of adjuvant trastuzumab treatment for women with HER-2-positive EBC based on the risk: benefit ratio demonstrated in these studies. Adequate assessment of HER-2/neu status is critical, and careful cardiac monitoring is warranted because of cardiac toxicity. Clinical trials should be designed to answer unsolved questions.

Prognostic value of HER-2/neu overexpression for the development of brain metastasis after treatment of early breast cancer

21044 Background: Several studies have addressed the incidence of brain metastasis in HER-2/neu-overexpressing metastatic breast cancer. However, the relevance of HER-2/neu overexpression as a risk factor for brain metastases in breast cancer has not yet been clearly defined. The aim of this study is to analyze the risk of brain metastasis in HER-2/neu-positive early breast cancer patients in comparison with HER-2/neu-negative patients. Methods: We used tissue microarray to examine HER- 2/neu overexpression by immunohistochemistry (IHC) in 773 consecutive patients diagnosed with breast carcinoma who underwent surgery between January 1993 and December 1998. Patients were considered HER-2/neu-positive if they were 3+ on IHC testing. A total of 194 (25.1%) patients with HER-2/neu-overexpressing newly diagnosed breast cancer were identified in our study. The medical records and pathologic data of all 773 patients were reviewed retrospectively. Results: During a median follow-up period of 8.1 years, brain metastasis were identified in 7.2% (14 patients) with 194 HER-2/neu-overexpressing breast cancer compared with 2.6% (15 patients) in 597 HER-2/neu-negative patients (hazard ratio 2.924 [1.385–6.175], P=0.005). More HER-2/neu-overexpressing patients developed distant metastasis (33.5% vs. 18.8%, P=0.0001). The 8-year overall survival was 76.1% for HER-2/neu-negative patients versus 56.4% for HER-2/neu-positive patients (P&lt;0.00001). By multivariate analysis, HER-2/neu overexpression, tumor size larger than 2 cm, at least one positive node, and progesterone receptor (PR)-negativity were independent risk factors for the development of brain metastases. Conclusions: Our data show that HER-2/neu overexpressing early breast cancer patients are at significantly increased risk for brain metastases. Also, our results demonstrate that HER-2/neu overexpression is an important independent prognostic factor of early breast cancer, and suggest that more aggressive adjuvant chemotherapy and radiologic screening to detect brain metastases should be considered in this population. No significant financial relationships to disclose.

Silk fibroin mediated delivery of liposomal emodin to breast cancer cells

The efficacy of a drug is dependent on its mode of delivery and its potency at the tumor site. In this study, the drug delivery and efficacy of silk fibroin coated liposomes (SF-ELP), encapsulating a receptor tyrosine kinase inhibitor, emodin, on Her2/ neu over-expressing breast cancer cells, was investigated. This study demonstrates that SF-ELP was more efficacious in suppressing the growth of Her2/ neu over-expressing breast cancer cells MDA-MB-453 and BT-474 as compared to uncoated emodin loaded liposomes (ELP). Reduced levels of phosphorylated Her2/ neu correlated with growth inhibition observed in the MDA-MB-453 cells, treated with both ELP and SF-ELP. ELP treatment of MDA-MB-453 breast cancer cells resulted in inhibition of the PI3K pathway whereas SF-ELP treatment inhibited both the PI3K and MAPK pathways, which contributed to the enhanced growth inhibitory effects of Her2/ neu over-expressing breast cancer cells. Coating of ELP with silk fibroin did not alter the target specificity of emodin, on the other hand the emodin efficacy was enhanced. Higher uptake of emodin delivered by SF-ELP lead to increased cell death as compared to emodin delivery via ELP. Silk fibroin coating around the liposome imparts an extra layer that emodin has to extravasate in order to release from the encapsulating liposome. This increases retention of the drug in the cell for a longer time and protects emodin from quick release and metabolism. Longer intracellular retention may lead to the longer availability of emodin for down-modulation of various Her2/ neu pathways. This study demonstrates that silk fibroin coating enhanced emodin delivery in Her2/ neu over-expressing breast cancer cells thereby increasing the overall efficacy of the drug.

European Organization for Research and Treatment of Cancer – Breast Cancer Group (EORTC BCG)

This section provides current contact details and a summary of recent or ongoing clinical trials being coordinated by European Organization for Research and Treatment of Cancer – Breast Cancer Group (EORTC BCG). Clinical trials include: Postoperative adjuvant chemotherapy followed by adjuvant tamoxifen versus nil for node-negative and node-positive patients with operable breast cancer. EORTC Study No. 10901Randomized phase III study comparing short, intensive preoperative combination chemotherapy with similar therapy given postoperatively. EORTC Trial No. 10902Phase III randomized trial investigating the role of internal mammary and medial supraclavicular (IM-MS) lymph node chain irradiation in stage I–III breast cancer (joint study of the EORTC Radiotherapy Cooperative Group and the EORTC Breast Cancer Cooperative Group). EORTC Study No. 10925/22922A survey of the Breast International Group (BIG) to assess the attitude of patients aged &lt;35 years, with early breast cancer, toward the risk of loss of fertility related to adjuvant therapies. BIG 3-98/EORTC 10002LAMANOMA: Conservative local treatment versus mastectomy after induction chemotherapy in locally advanced breast cancer: a randomized phase III study. BIG 2-00/EORTC Study No. 10974/22002p53 study: First prospective intergroup translational research trial assessing the potential predictive value of p53 using a functional assay in yeast in patients with locally advanced/inflammatory or large operable breast cancer, prospectively randomized to a taxane versus non-taxane regimen. BIG 1-00/EORTC 10994After mapping of the axilla: radiotherapy or surgery AMAROS. EORTC 10981/22023A randomized phase II–III trial evaluating the efficacy of capecitabine and vinorelbine in anthracycline and taxane pretreated metastatic breast cancer. EORTC 10001/160010Phase I study of lonafarnib (SCH 66336) in combination with Herceptin plus paclitaxel in HER-2 neu overexpressing breast cancer. EORTC 10051/16023MINDACT trial: A prospective, randomized study comparing the Amsterdam 70-gene expression signature (Mammaprint) with common clinical pathological criteria in selecting patients for adjuvant chemotherapy in node-negative breast cancer. BIG 3-04/EORTC 10041

Adjuvant Therapy with Trastuzumab for HER-2/neu-Positive Breast Cancer

Breast cancer is the most common cancer in women in the U.S. and western Europe. Amplification of the her-2/neu gene occurs in approximately 25% of invasive ductal carcinomas of the breast. In experimental models, transfection of the her-2/neu gene results in transformation of mammary epithelial cells. In human breast cancer, amplification of the her-2/neu gene results in protein over expression and poor prognosis. Patients whose tumors have her-2/neu gene amplification have a shorter disease-free survival time than patients whose tumors exhibit a normal her-2/neu gene copy number. her-2/ neu gene amplification identifies a biologically unique subset of aggressive breast tumors that are sensitive to growth inhibition and apoptosis induced by anti-HER-2/neu-targeted therapies. The first HER-2/neu-targeted approach to reach the clinic was trastuzumab, a humanized monoclonal antibody directed against the extracellular domain of the HER-2/neu protein. Trastuzumab therapy prolongs the survival of patients with metastatic HER-2/neu-overexpressing breast cancer when combined with chemotherapy and has recently been demonstrated to lead to dramatic improvements in disease-free survival when used in the adjuvant therapy setting in combination with or following chemotherapy. However, potential cardiotoxicity requires careful patient selection. Here, we review the recently completed clinical trials of adjuvant trastuzumab in the adjuvant setting. HER-2/neu testing, patient selection, cardiotoxicity, duration of therapy, and directions for future research are discussed.

Trastuzumab mimotope vaccination of HER-2/neu transgenic mice results in prolonged tumor-free survival and reduced tumor load

12510 Background: Passive immunotherapy with the humanized monoclonal antibody trastuzumab (Herceptin) to date is the most effective treatment for patients with HER-2/neu overexpressing breast cancer. In previous studies we could show that active immunization with peptide mimotopes, i.e. structural mimics of the epitope recognized by trastuzumab, leads to formation of antibodies again recognizing HER-2/neu in mice. Functional in vitro analyses of the induced antibodies demonstrated “trastuzumab-like” properties, such as receptor internalization, inhibition of signaling, and antibody-mediated cytotoxicity against HER-2/neu overexpressing breast cancer cells. The aim of the present study was to test the effects of trastuzumab mimotope vaccination in vivo, namely in a HER-2/neu transgenic mouse model. Methods: We used BALB-neuT mice, which carry the activated neu oncogene on the BALB/c background. These mice constitute the most aggressive animal model for HER-2/neu driven carcinogenesis, as all females uniformly develop mammary carcinomas at the age of 12 weeks. One group of mice was immunized with the previously described trastuzumab mimotope - KLH conjugate, a control group with the carrier protein KLH alone, and a further control group was left naïve. Mice were palpated weekly to monitor tumor development and size, and blood samples were taken at regular intervals to follow up the induced immune responses. Results: Trastuzumab mimotope immunizations lead to delayed tumor development and thus to an increase in tumor-free survival. When tumors occurred, they were smaller and grew more slowly than in the control mice. In contrast, control KLH immunizations did not affect tumor growth kinetics as compared to the naïve mice. Serum analysis demonstrated that all immunized animals had mounted an anti-KLH immune response, so we accredit the observed tumor-inhibitory effects in the mimotope group to the biologic properties of induced anti-HER-2/neu antibodies. Conclusion: These results indicate that epitope-specific vaccination with mimotopes elicits trastuzumab-like antibodies that are effective in vivo against HER-2/neu overexpressing tumor cells also in HER-2/neu expressing organisms. [Table: see text]