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 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report here on the state of our knowledge of the target--namely, the epidermal growth factor (EGF) and its receptor--and the challenges related to the methods of determination of the epidermal growth factor receptor (EGFR) and associated molecular pathways. A critical review of the anti-EGFR therapeutic strategies is also outlined. The chimeric anti- EGFR monoclonal antibody cetuximab has been approved for EGFR-expressing colorectal tumors in patients who progress after irinotecan-based chemotherapy in combination with irinotecan and in squamous cell head and neck carcinomas for patients with locally advanced disease in combination with radiation therapy or after failure of platinum-based chemotherapy in recurrent or metastatic disease (FDA). Cetuximab has the potential to provide an improvement of clinical outcome also in other indications and tumor types, particularly when used as first-line therapy combined with standard chemotherapy for metastatic disease or in the adjuvant setting. Possible strategies to improve the effectiveness of anti-EGFR agents are suggested and include (i) the use of predictive tools capable of making a more rational selection of patients; (ii) the development of standardized predictive biomarkers as surrogates for early monitoring of drug efficacy; and (iii) adequate study design, statistical analysis and proper end points of efficacy to be applied in future prospective trials.
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PMID:The future of anti-EGFR therapy. 1752 May 86

Sarcomas are a heterogeneous group of malignant mesenchymal tumors of difficult classification. There is considerable variability in both histological appearance and responsiveness to therapy. Their overall poor clinical prognosis is reflected by the fact that >65% of patients suffering retroperitoneal soft tissue sarcoma die within 5 years [Heslin MJ, et al. Prognostic factors associated with long-term survival for retroperitoneal sarcoma: implications for management. J Clin Oncol 1997;15(8):2832-9]. A greater understanding of the biology of sarcomas is needed in order to increase the potential for identifying new therapeutic targets and strategies. Microarray analysis permits a global approach to gene expression analysis of thousands of genes at the same time and has proven to be useful for further molecular characterization of tumor tissue and cell lines. This article provides a comprehensive review of possible new biomarkers identified in gene expression studies of sarcomas. These markers give new insight into the pathogenesis of sarcomas, such as malignant fibrous histiocytoma [Lee YF, et al. Molecular classification of synovial sarcomas, leiomyosarcomas and malignant fibrous histiocytomas by gene expression profiling. Br J Cancer 2003;88(4):510-5], allow a further subclassifcation of tumors like calponin-positive and calponin-negative leiomyosarcoma, or may help to predict treatment responsiveness and prognosis in patients based on an individual gene expression pattern. In some studies candidate targets for possible new treatment strategies were identified. For instance newly identified markers such as ERBB2 [Allander SV, et al. Expression profiling of synovial sarcoma by cDNA microarrays: association of ERBB2, IGFBP2, and ELF3 with epithelial differentiation. Am J Pathol 2002;161(5):1587-95] and EGFR [Nielsen TO, et al. Molecular characterization of soft tissue tumours: a gene expression study. Lancet 2002;359(9314):1301-7] might lead to the possible therapeutic use of Trastuzumab, Gefitinib or Cetuximab in synovial sarcoma, comparable to the use of tyrosine kinase inhibitor STI (Gleevec) that is the standard treatment today of CD117-positive gastrointestinal stromal tumors.
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PMID:Gene expression profiling in sarcomas. 1755 81

The epidermal growth factor receptor, a transmembrane receptor tyrosine kinase of the erbB family, is expressed in 15-30% of all breast cancers. Anti-epidermal growth factor receptor agent cetuximab is an IgG1 chimeric monoclonal antibody with a potent antitumor activity. Cetuximab competes with ligand binding to the epidermal growth factor receptor ectodomain, resulting in an efficient blockade of tumor-promoting downstream signaling pathways. Large clinical studies recently demonstrated cetuximab synergy with radiotherapy and chemotherapy agent irinotecan. Studies in human breast cancer xenografts showed cetuximab synergy with paclitaxel, a potent mitosis spindle-cell stabilizer. In this report, combined paclitaxel and cetuximab achieved a major reduction of the skin metastases of a heavily pretreated patient with epidermal growth factor receptor-positive, estrogen receptor-negative, progesterone receptor-negative and human epidermal growth factor receptor-2-negative (triple-negative) invasive ductal breast carcinoma. Treatment was well-tolerated overall and response was not correlated with the appearance of major cetuximab-induced acneiform rash.
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PMID:Combined paclitaxel and cetuximab achieved a major response on the skin metastases of a patient with epidermal growth factor receptor-positive, estrogen receptor-negative, progesterone receptor-negative and human epidermal growth factor receptor-2-negative (triple-negative) breast cancer. 1758 8

Compelling experimental and clinical evidence suggests that epidermal growth factor receptor (EGFR) plays an important role in the pathogenesis of a variety of human cancers; thus, providing a strong rationale for the development of receptor antagonists as effective and specific therapeutic strategies for the treatment of EGFR-expressing cancers. Monoclonal antibodies (mAb), owing to their high specificity towards a given target, represent a unique class of novel cancer therapeutics. A number of anti-EGFR mAb are currently being developed in our clinic, including two that have been approved by the United States Food and Drug Administration for the treatment of refractory metastatic colorectal cancer (mCRC) and squamous cell carcinomas of the head and neck (SCCHN). Cetuximab (Erbitux, IMC-C225), an IgG1 mAb, has demonstrated significant antitumor activity, both as a single agent and in combination with chemotherapeutics and radiation, in patients with refractory mCRC and SCCHN, respectively. Panitumumab (Vectibix), an IgG2 mAb, has been approved as a single agent for the treatment of patients with refractory mCRC. These mAb, via blocking ligand/receptor interactions, exert their biological activity via multiple mechanisms, including inhibition of cell cycle progression, potentiation of cell apoptosis, inhibition of DNA repair, inhibition of angiogenesis, tumor cell invasion and metastasis and, potentially, induction of immunological effector mechanisms. Anti-EGFR antibodies have demonstrated good safety profiles and potent anticancer activity in our clinic and may prove to be efficacious agents in the treatment of a variety of human malignancies.
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PMID:Targeted cancer therapies based on antibodies directed against epidermal growth factor receptor: status and perspectives. 1772 81

New cancer-specific therapies are based on specific molecular alterations of malignant tumors which are targeted by small inhibitory molecules or specific antibodies. During the development of these agents potential molecular targets are characterized for their expression and importance for pathogenesis and clinical course of the disease. Frequently the assumption is made that the degree of expression of the target protein or the molecular alteration of the target gene allows a prediction if a certain patient will profit from the therapy against this specific protein or not. The first example was that breast cancer patients with overexpression and/or amplification of Her-2 respond to a Her-2-specific antibody (Herceptin) therapy. The expression or activation of the Epidermal Growth Factor Receptor (EGFR, Her-1) are altered in many epithelial tumours and clinical studies indicate that they have important roles in tumor aetiology and progression. Several EGFR-specific monoclonal antibodies and specific tyrosine kinase inhibitors were developed in the last years. Cetuximab is approved for the treatment of metastatic colorectal cancer and advanced squamous cell carcinoma of the head and neck and is investigated in numerous trials for other tumors. The expression of EGFR in the tumor was a prerequisite for the therapy in the first trials, giving the pathologist a central role in treatment decision. However, recent data clearly demonstrate that the degree of EGFR expression does not correlate with therapy response. Therefore a therapy should be not denied to a individual patient solely because of lack of EGFR expression in the tumor. Tyrosine kinase inhibitors (e. g. Gefitinib, Erlotinib) are effective in the treatment of non small cell lung cancer and also investigated in ongoing trials in many cancer types. The correlation of therapy response with both specific molecular alterations (EGFR tyrosine kinase domain mutations) and clinicopathological features (Asian ethnicity, women, non-smokers, bronchioloalveolar differentation) is a good example of the potential role of predictive molecular pathology in the future.
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PMID:[Role of predictive pathology in oncology--example of new therapies targeting EGFR]. 1786 89

This study evaluated the role of EGF and the effects of EGF-targeting drugs (Cetuximab, AEE 788) on growth, apoptosis, and autocrine VEGF-secretion of thyroid cancer (TC) cells. Autocrine activation of the epidermal growth factor receptor (EGF-R) is commonly regarded to contribute to the malignant phenotype of TC cells and may therefore represent a rational therapeutic target. Out of a number of TC cell lines two anaplastic (Hth74, C643), one follicular (FTC133), and one papillary thyroid cancer cell line (TPC1) were analyzed in depth for VEGF-R-and EGF-R-expression, basal and EGF-stimulated (1-100 ng/ml) VEGF protein secretion and proliferation. Subsequently the antiprolifereative and antiangiogenic effect of cetuximab (Erbitux), a monoclonal antibody that blocks the EGF-R and AEE 788, a novel dual-kinase inhibitor of EGF-R and VEGF-R were assessed, and the downstream EGF-R signal transduction was analyzed by means of detecting phosphorylated pEGF-R, pVEGF-R, pAkt, and p-MAPK. EGF stimulated VEGF-mRNA expression and protein secretion in all TC cell lines. The EGF-R antagonist Cetuximab consistently decreased VEGF secretion in all TC cell lines (min. 15%, n.s. in C643 cells and max. 90% in Hth74 cells, P < 0.05), but did not affect tumor cell proliferation in vitro. In contrast, the EGF-R- and VEGF-R-kinase inhibitor AEE 788 not only reduced VEGF secretion (min. 55%, P < 0.05 in C643 and max. 75%, P < 0.05, in FTC133), but also exhibited a dose-dependent inhibition of tumor cell proliferation (min. 75%, P < 0.05 in C643 and max. 95%, P < 0.05 in Hth74) and was a potent inductor of apoptosis in two of four TC cell lines. These effects were always accompanied by reduced levels of pEGF-R, pVEGF-R, pAkt, and pMAPK. Although inhibition of the EGF-receptor by Cetuximab potently disrupts autocrine secretion of VEGF, only the concurrent inhibition of the VEGF- and EGF receptor, e.g., by AEE 788 induces reduced proliferation and apoptosis in vitro. This suggests a particular rationale for the use of tyrosine kinase inhibitors with dual modes of action such as AEE 788 in thyroid cancer.
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PMID:Differential effects of cetuximab and AEE 788 on epidermal growth factor receptor (EGF-R) and vascular endothelial growth factor receptor (VEGF-R) in thyroid cancer cell lines. 1787 19

Epidermal growth factor receptor (EGFR) and vascular endothelial growth factor (VEGF) are often overexpressed in colorectal cancer and are associated with inferior outcomes. Based on successful randomized phase III trials, anti-EGFR and anti-VEGF therapeutics have entered clinical practice. Cetuximab (Erbitux), an EGFR-specific antibody, is currently approved in the United States in combination with irinotecan (Camptosar) for patients with metastatic colorectal cancer refractory to irinotecan or as a single agent for patients unable to tolerate irinotecan-based therapy. In retrospective analyses, patients with EGFR-expressing rectal cancer undergoing neoadjuvant radiation therapy had a significantly inferior disease-free survival and lower rates of achieving pathologic complete response. Based on the positive data in metastatic colorectal cancer and synergy with radiation therapy seen in preclinical models, there is a strong rationale to combine cetuximab with neoadjuvant radiation therapy and chemotherapy in rectal cancer. Bevacizumab (Avastin), a VEGF-specific antibody, was the first antiangiogenic agent to be approved in the United States for use in combination with standard chemotherapy in the first- and second-line of treatment in metastatic colorectal cancer. VEGF-targeted therapy may lead to indirect killing of cancer cells by damaging tumor blood vessels, and may increase the radiosensitivity of tumor-associated endothelial cells. VEGF blockade can also "normalize" tumor vasculature, thereby leading to greater tumor oxygenation and drug penetration. This review will address completed and ongoing trials that have established and continue to clarify the effects of these agents in rectal cancer.
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PMID:Targeted therapy in rectal cancer. 1791 Mar 11

JNJ-28871063 is a potent and highly selective pan-ErbB kinase inhibitor from a novel aminopyrimidine oxime structural class that blocks the proliferation of epidermal growth factor receptor (EGFR; ErbB1)- and ErbB2-overexpressing cells but does not affect the growth of non-ErbB-overexpressing cells. Treatment of human cancer cells with JNJ-28871063 inhibited phosphorylation of functionally important tyrosine residues in both EGFR and ErbB2 and blocked downstream signal transduction pathways responsible for proliferation and survival. A single dose of compound reduced phosphorylation of ErbB2 receptors in tumor-bearing mice, demonstrating target suppression in vivo. Tissue distribution studies show that JNJ-28871063 crosses the blood-brain barrier and penetrates into tumors, where it is able to accumulate to higher levels than those found in the plasma. JNJ-28871063 showed oral antitumor activity in human tumor xenograft models that overexpress EGFR and ErbB2. In an intracranial ErbB2-overexpressing tumor model, JNJ-28871063 extended survival relative to untreated animals. The brain is a primary site of metastasis for EGFR-overexpressing lung cancers and ErbB2-overexpressing breast cancers. Therefore, the ability to penetrate into the brain could be an advantage over existing therapies such as trastuzumab (Herceptin) and cetuximab (Erbitux), which are antibodies and do not cross the blood-brain barrier. These results show that JNJ-28871063 is orally bioavailable, has activity against EGFR and ErbB2-dependent tumor xenografts, and can penetrate into the brain and inhibit ErbB2-overexpressing tumor growth.
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PMID:Cellular and in vivo activity of JNJ-28871063, a nonquinazoline pan-ErbB kinase inhibitor that crosses the blood-brain barrier and displays efficacy against intracranial tumors. 1798 94

The U.S. Gastrointestinal Intergroup (GI Intergroup), including the National Cancer Institute of Canada, has created a portfolio of clinical trials for patients with stage II and III colon and rectal cancer, integrating therapeutic strategies from recent advanced disease trials. Fluoropyrimidine-based combination therapy for metastatic disease, with either irinotecan or oxaliplatin plus bevacizumab, has resulted in significant improvement in response and disease-free and overall survival. Cetuximab and irinotecan have produced intriguing response and progression-free survival data from randomized phase II trials. Although patients with stage II and III rectal cancer are uniformly included in individual clinical trials, the GI Intergroup conducts separate trials in patients with stage II and III colon cancer, with the exception of the National Surgical Adjuvant Breast and Bowel Project (NSABP), which continues to merge both stages in their statistical designs. The U.S. chemotherapy platform for adjuvant therapy clinical trials is based on the positive adjuvant data from NSABP C-07 [FLOX with bolus 5-fluorouracil (5-FU)] and the MOSAIC trial (FOLFOX with infusional 5-FU). Three irinotecan-based adjuvant trials (one U.S. and two European) did not reach designated statistical end points. In addition, the GI Intergroup has consistently integrated molecular biological and other laboratory projects as important components of past and current trials. NSABP has recently completed accrual of patients to C-08, which is evaluating FOLFOX with or without bevacizumab in stage II/III colon cancer. E5202, the largest U.S. stage II colon cancer trial, determines patient risk by the initial evaluation of tumor 18q loss of heterozygosity and microsatellite instability status. Low-risk patients are observed, whereas high-risk patients are randomized to FOLFOX with or without bevacizumab. N0147 evaluates FOLFOX with or without cetuximab in patients with stage III disease. Two large rectal cancer trials have begun to accrue patients. NSABP R-04 compares neoadjuvant radiation with either continuous infusion 5-FU with or without oxaliplatin versus capecitabine with or without oxaliplatin. E5204 is the adjuvant comparison of FOLFOX with or without bevacizumab and is also available to NSABP R-04 patients.
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PMID:New approaches to assessing and treating early-stage colon and rectal cancers: cooperative group strategies for assessing optimal approaches in early-stage disease. 1800

Several molecular pathways have been shown to play key roles in the development and progression of colorectal cancer (CRC). This enhanced understanding of tumor biology has provided the rationale for the design and development of novel agents that are directed against important targets, including growth factors, receptors, and tumor-specific/tumor-selective antigens. The epidermal growth factor receptor (EGFR) signaling pathway has received much attention over the past 5-10 years because it is overexpressed in more than 85% of tumors from patients with metastatic CRC. Cetuximab and panitumumab are monoclonal antibodies presently approved for use by the FDA in the refractory disease setting, and they have provided significant advances in the treatment of advanced CRC. However, much focus has shifted toward using these biologic therapies in combination with cytotoxic chemotherapy in up-front settings, such as first-line therapy and in the neoadjuvant therapy of liver-limited disease. The clinical studies conducted to date suggest that cetuximab can be safely and effectively combined with oxaliplatin- and irinotecan-based chemotherapy in the first-line treatment of metastatic CRC. Moreover, the results of the CRYSTAL phase III study provide support for the use of the combination of FOLFIRI (5-fluorouracil/leucovorin/irinotecan) and cetuximab in the neoadjuvant setting and allow for R0 surgical resection with curative intent. Much work continues to investigate the critical molecular biomarkers that can be used to predict clinical response to chemotherapy and/or targeted therapies as well as to identify which patients might be at increased risk for developing drug-specific side effects.
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PMID:First-line use of anti-epidermal growth factor receptor monoclonal antibodies in metastatic colorectal cancer. 1802 86


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