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Query: UMLS:C0278488 (metastatic breast cancer)
 7,812 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Breast cancer is the most frequent tumor of women. The development of effective adjuvant therapy based on postoperative administration of short-term chemotherapy (4-6 months) or long-term hormone therapy (5 years) or both, significantly improved survival of patients. However, therapy of adjuvant/metastatic disease is still palliative with a very low probability to induce complete remission and definitive cure of disease. The relevant efforts of basic research to identify the key and selective molecular alterations, which sustain breast cancer growth and progression allowed the possibility to develop specific molecular target treatments. Trastuzumab, a humanized monoclonal antibody to HER-2, is the first molecular targeting agent approved for therapy of metastatic breast cancer, capable to significantly improve clinical outcome in combination with cytotoxic therapy. Recent preliminary data from randomized, prospective, clinical trials suggest that trastuzumab decreases the risk of early recurrence by 50% in patients with HER-2-positive disease. Other novel targeted treatments are in clinical evaluation, including antiangiogenic compounds (Bevacizumab, sunitinib, vatalanib, and others) and bi-functional drugs such as lapatinib (anti Her-2 and EGFR agent) showing promising activity. This review provides an updated overview of the status of development of targeted therapy in breast cancer, as well as the challenges related to the rational use of molecular targeting agents.
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PMID:Targeted therapy of breast cancer. 1734 46

ErbB/HER receptor or its signal transduction pathway is an attractive therapeutic target for breast cancer. Lapatinib, an orally administered dual inhibitor of ErbB1 (EGFR) and ErbB2 (HER2) receptor tyrosine kinases has shown promising results for metastatic breast cancer (MBC). Lapatinib exhibited activity against trastuzumab-refractory MBC and showed an acceptable adverse event profile such as transient mild rash, diarrhea and nausea. The addition of lapatinib to capecitabine resulted in significantly prolonged time to progression. Large randomized trials using lapatinib following chemotherapy and surgery are ongoing for early stage HER2-overexpressing breast cancer. Various combinations with agents such as paclitaxel, aromatase inhibitors, or other molecular targeted agents are currently being investigated in clinical trials. If these approaches overcome the limitations of trastuzumab, lapatinib will become an effective treatment option for breast cancer in the near future.
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PMID:Does lapatinib, a small-molecule tyrosine kinase inhibitor, constitute a breakthrough in the treatment of breast cancer? 1748

Aberrant activation of some members of human epidermal growth factor receptor (HER) family plays a key role in breast carcinogenesis. Lapatinib is an oral dual tyrosine kinase inhibitor selective for inhibition of epidermal growth factor receptor (EGFR/ErbB1) and HER2/ErbB2. Having more targets, probably its antitumor activity could be more efficient. Clinical data have shown that lapatinib is active in HER2-positive breast cancer as monotherapy, in combination with trastuzumab, and in trastuzumab-resistant patients. Phase I clinical trials have shown also that lapatinib is well tolerated, with mild diarrhea and skin rush as common toxic effects and low incidence of cardiotoxicity. Phase II and III clinical trials' data provide encouraging evidence of the clinical effectiveness of lapatinib in advanced or metastatic breast cancer and for its potential in patients with brain metastases. Interim results from the large, phase III trial in 392 patients showed that in combination with capecitabine lapatinib almost doubled time to progression when compared with capecitabine alone. Several clinical trials that explore the efficacy of lapatinib in combination with conventional chemotherapeutic agents [paclitaxel (Taxol), capecitabine and platinoids], hormonotherapy and other target therapies are ongoing in advanced breast cancer or in neo-adjuvant and adjuvant settings. Our improved understanding of the biology of breast cancer and the use of biomarkers for identification of specific subtypes are allowing us to bring patient-specific novel therapies such as lapatinib to the clinic.
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PMID:Lapatinib in breast cancer. 1759 27

Both HER-2 and EGFR are expressed in breast cancer and are implicated in its development and progression. The discovery of the association between HER-2 gene amplification and poor prognosis in breast cancer led to the development of HER-2 targeted therapies. Trastuzumab, a monoclonal antibody to HER-2, has significantly improved the prognosis for HER-2-positive breast cancer patients. It is now approved for the treatment of both HER-2-positive metastatic breast cancer and early stage HER-2-positive breast cancer. Recent results from trials of the dual HER-2 and EGFR tyrosine kinase inhibitor, lapatinib, also show very promising results in HER-2-positive breast cancer. A number of EGFR inhibitors have been tested in breast cancer clinical trials, but with limited effect. This may be due to difficulty in selecting the appropriate patient population, caused by the lack of definitive predictive markers for response to EGFR inhibition.
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PMID:EGFR and HER-2 antagonists in breast cancer. 1759 21

Hyperactivation of ErbB signaling is implicated in metastatic breast cancer. However, the mechanisms that cause dysregulated ErbB signaling and promote breast carcinoma cell invasion remain poorly understood. One pathway leading to ErbB activation that remains unexplored in breast carcinoma cell invasion involves transactivation by G-protein-coupled receptors (GPCRs). Protease-activated receptor-1 (PAR1), a GPCR activated by extracellular proteases, is overexpressed in invasive breast cancer. PAR1 is also proposed to function in breast cancer invasion and metastasis, but how PAR1 contributes to these processes is not known. In this study, we report that proteolytic activation of PAR1 by thrombin induces persistent transactivation of EGFR and ErbB2/HER2 in invasive breast carcinoma, but not in normal mammary epithelial cells. PAR1-stimulated EGFR and ErbB2 transactivation leads to prolonged extracellular signal-regulated kinase-1 and -2 signaling and promotes breast carcinoma cell invasion. We also show that PAR1 signaling through Galpha(i/o) and metalloprotease activity is critical for ErbB transactivation and cellular invasion. Finally, we demonstrate that PAR1 expression in invasive breast carcinoma is essential for tumor growth in vivo assessed by mammary fat pad xenografts. These studies reveal a critical role for PAR1, a receptor activated by tumor-generated proteases, in hyperactivation of ErbB signaling that promotes breast carcinoma cell invasion.
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PMID:Persistent transactivation of EGFR and ErbB2/HER2 by protease-activated receptor-1 promotes breast carcinoma cell invasion. 1837 13

Breast cancer is the most common female malignancy in many industrialized countries. Approximately one fourth of all women diagnosed with early breast cancer present with tumors that are characterized by erbB2 amplification. While the associated Her-2/neu receptor overexpression results in a high risk of relapse and poor prognosis, these tumors also represent a target for a selective monoclonal antibody therapy with trastuzumab (Herceptin). The combination of trastuzumab with chemotherapy has led to a considerable reduction of recurrences and to a significant reduction in breast cancer mortality both in the adjuvant and metastatic setting. Unfortunately, despite Her-2/neu overexpression, not all patients equally benefit from trastuzumab treatment, and almost all women with metastatic breast cancer eventually progress during antibody therapy. Moreover, trastuzumab is burdened with cardiotoxicity, thus increasing the risk of symptomatic congestive heart failure. In addition, the marginal costs for a 1 year therapy of trastuzumab-based therapy, which is currently considered to be the most effective treatment regimen in the adjuvant setting, may amount for up to US$ 40.000. Testing for erbB2 oncogene amplification by fluorescence in situ hybridization (FISH) and chromogenic in situ hybridization (CISH), respectively, and staining for Her-2/neu receptor overexpression by immunohistochemistry (IHC) represent the current standard for determining patient eligibility for trastuzumab-based therapy. However, while the negative predictive value of these assays for predicting the absence of benefit from trastuzumab-based therapy is sufficiently high, their positive predictive value remains insufficient, i.e. only a proportion of patients selected by these tests substantially benefit from trastuzumab-containing regimen. Accordingly, over the last years a number of biomarkers have been evaluated in their potential to predict response to trastuzumab-based therapies. These include markers auf activation of Her-2/neu (e.g., tyrosine phosphorylated Her-2/neu in tissue and cleaved Her-2/neu extracellular domain in serum) and its dimerization partners (e.g., EGFR), respectively, but also components of Her-2/neu-induced downstream signaling pathways that are crucial for the growth inhibitory effects of trastuzumab (e.g., PTEN and PI3K). Other parameters, such as topoisomerase-II alpha and c-myc co-amplifications, have also been identified as potentially useful predictors of response to trastuzumab-based chemotherapy regimen. While the benefit of these predictive biomarkers in the metastatic setting is currently explored, their usefulness in the adjuvant setting is still largely unknown. It is, however, undisputable that, within the group of Her-2/neu overexpressing tumors, further response predictors are needed in order to minimize trastuzumab-associated side effects, and to reduce the considerable societal costs that are associated with trastuzumab-based treatment regimen.
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PMID:Predicting the efficacy of trastuzumab-based therapy in breast cancer: current standards and future strategies. 1837 8

Targeting the human epidermal growth factor receptor type 2 (HER2) in breast cancer patients whose tumors overexpress HER2 has been clearly demonstrated to be effective in clinical trials with the monoclonal antibody trastuzumab. Not all patients, however, respond to trastuzumab therapy. Lapatinib is an oral receptor tyrosine kinase inhibitor that targets HER2 and the EGFR. Preclinical data reveal that lapatinib has activity in trastuzumab-resistant cell lines as well as synergistic activity with trastuzumab. In a pivotal phase III trial, a combination of lapatinib and capecitabine significantly decreased the risk of disease progression relative to capecitabine alone in women with HER2-positive advanced or metastatic breast cancer previously treated with anthracyclines, taxanes, and trastuzumab. Other trials are evaluating lapatinib in inflammatory breast cancer--for which encouraging data have been reported--in combination with hormone therapy, in combination with trastuzumab, and as an adjunct to adjuvant therapy for early-stage disease. Notably, lapatinib has not been associated with serious or symptomatic cardiotoxicity in clinical trials. It can cross the blood-brain barrier and might therefore have a role in preventing central-nervous-system progression. These features make lapatinib an ideal agent to evaluate more fully in HER2-positive metastatic and early-stage breast cancer.
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PMID:Drug Insight: intracellular inhibitors of HER2--clinical development of lapatinib in breast cancer. 1859 99

In the past few years many encouraging advancements have been made in understanding the molecular mechanisms underlying carcinogenesis and tumor progression. These improvements have led to the identification of promising new targets for cancer therapy. There has been much success with the HER2 targeting antibody trastuzumab (Herceptin) in the treatment of early stage and metastatic breast cancer. Consequently, several antibodies inhibiting cellular signaling of VEGF and EGFR were tested with respect to their efficacy in breast cancer. In phase II and III clinical trials the humanized anti-VEGF antibody bevacizumab (Avastin) alone or in combination with capecitabine exhibited responses in patients with metastatic breast cancer. Recent developments focus on small molecules interfering with different signal transduction pathways in tumor cells. Numerous inhibitors of EGF and VEGF receptor tyrosine kinases and farnesyl transferases are in early stages of clinical development for breast cancer. Another promising approach is the targeting of endothelins and their two G-protein coupled receptors (ET(A)R und ET(B)R). In this article, we will shortly outline well established targeted treatments and discuss the current development of novel agents to be utilized for molecular targeted breast cancer therapy. Due to the heterogeneity of disease and varying response to conventional systemic therapies, these new perceptions may lead to substantial patient benefit and provide a promising basis for future clinical application.
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PMID:Targeted therapies in breast cancer: established drugs and recent developments. 1869 Aug 83

Breast cancer is the second leading cause of cancer death in women. Treatment options for advanced-stage disease, although numerous, remain suboptimal. Lapatinib and ixabepilone are two new agents approved by the United States Food and Drug Administration (FDA) in 2007 for the treatment of locally advanced breast cancer (LABC) or metastatic breast cancer (MBC). When added to the existing endocrine therapies-single--agent cytotoxic therapies and combination chemotherapy regimens--lapatinib and ixabepilone offer potential treatment strategies for disease that has become resistant to trastuzumab and the taxanes, respectively. Lapatinib is an oral dual tyrosine kinase inhibitor against members of the human epidermal growth factor receptor (HER) family (HER1 or epidermal growth factor receptor [EGFR], and HER2). It is indicated for combination therapy with capecitabine for the treatment of patients with HER2-overexpressing LABC or MBC whose disease has progressed after receiving previous treatment with an anthracycline, a taxane, and trastuzumab. Of note, lapatinib is the first FDA-approved tyrosine kinase inhibitor indicated for use in MBC. Ixabepilone, the first FDA-approved analog of the antimicrotubule agent epothilone B, is indicated as monotherapy for the treatment of LABC or MBC in patients whose tumors are refractory or resistant to anthracyclines, taxanes, and capecitabine. It is also indicated in combination with capecitabine for treatment of LABC or MBC that is resistant to anthracycline and taxane. Both lapatinib and ixabepilone are fairly well tolerated. The most common toxicities with lapatinib are diarrhea (65%) and hand-and-foot syndrome (53%), whereas peripheral neuropathy (62%), fatigue (56%), and neutropenia (54%) are most common with ixabepilone. Though the conventional standard end point of overall survival has not yet been assessed in clinical trials, these agents have been shown to improve surrogate markers of clinical benefit: progression-free survival and the related time to progression. Future clinical trials should focus on elucidation of optimal combination or sequential therapies, as well as patient-specific therapies based on tumor characteristics, such as biomarkers and tumor subtypes.
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PMID:Lapatinib and ixabepilone for the treatment of metastatic breast cancer. 1882 21

ErbBs signalling is always associated with the development of the majority of solid cancers via both the MAPK pathway leading to cell cycle progression and the PI3K pathway causing cell survival. As a consequence, many ErbB antagonists have been developed and patented for cancer treatment purposes. These antagonists belong to two drug classes: monoclonal antibodies (mAbs) and small molecules competing with ATP and inhibiting the tyrosine kinase domain (TKIs). Three patented mAbs are currently approved in clinical cancer treatment: Trastuzumab (Herceptin) directed against HER2 and used to treat breast cancer, Cetuximab and Panitumumab which are anti-EGFR antibodies approved for colorectal cancer treatment. Unfortunately, these mAbs are facing cancer resistance mediated by paracrine activation of other ErbB members or compensatory ErbB signalling factors. In parallel, three TKIs have been approved to treat cancer: Gefitinib (Iressa), Erlotinib (Tarceva) inhibiting specifically EGFR and approved to treat non small cell lung cancer and Lapatinib (Tykerb) which has the dual specificity EGFR/HER2 and recently approved to treat metastatic breast cancer. These TKIs are also facing resistance mutations within the TK domain which increase its affinity to ATP. Resistance problems are leading to the adoption of a new strategy based on the combination of different therapies and this is likely to be the most promising future of cancer treatments.
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PMID:ErbB antagonists patenting: "playing chess with cancer". 1907 65


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