Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0598934 (tumor growth)
 58,965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent trials have established the IFL combination (fluorouracil [5-FU], leucovorin, and irinotecan [CPT-11, Camptosar]) as a new standard first-line therapy for patients with metastatic colorectal cancer. Median survival for such patients treated with IFL still ranges from approximately 14 to 18 months, however, underscoring the need for new agents with novel mechanisms of action. Angiogenesis has become an attractive target for anticancer drug development, based on its important roles in tumor growth, invasion, and metastasis. A potent stimulus of angiogenesis is vascular endothelial growth factor (VEGF); two agents developed to inhibit VEGF activity, bevacizumab (Avastin) and SU5416, are in advanced clinical trials. Based on encouraging results in phase I and II trials with bevacizumab, a randomized trial of IFL with or without this monoclonal antibody is under way. Similarly, a randomized trial of 5-FU and leucovorin with or without the tyrosine kinase inhibitor SU5416 has recently completed accrual and results are pending. SU5416 is also being tested in a phase I/II trial combined with IFL. This article briefly reviews preclinical and clinical data leading to the current trials of these two agents in patients with colorectal cancer.
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PMID:Targeting vascular endothelial growth factor in colorectal cancer. 1219 27

Angiogenesis, or formation of new blood vessels from pre-existing ones, is essential for normal development and wound healing/reproductive functions in adults. Abnormal regulation of angiogenesis has been implicated in the pathogenesis of several disorders, including cancer. Vascular endothelial growth factor (VEGF)-A is a pivotal stimulator of angiogenesis because its binding to VEGF receptors has been shown to promote endothelial cell migration and proliferation, two key features required for the development of new blood vessels. In addition, VEGF-A increases vascular permeability, which may also contribute to angiogenesis and tumor growth. Recognition of the central role of VEGF-A in angiogenesis has led to the hypothesis that its inhibition may represent a novel and effective approach to the treatment of cancer and other conditions characterized by pathologic angiogenesis. Several lines of evidence support this idea, and early clinical experience with the humanized anti-VEGF-A monoclonal antibody bevacizumab (Avastin, rhuMAb-VEGF; Genentech, South San Francisco, CA) has been encouraging. Clinical efficacy of antiangiogenic therapy with bevacizumab is being evaluated in several phase 3 trials in various types of cancer, as well as in patients with age-related macular degeneration.
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PMID:Role of vascular endothelial growth factor in physiologic and pathologic angiogenesis: therapeutic implications. 1251 33

Angiogenesis is essential for tumor growth and metastasis and is a promising target in the search for new anti-neoplastic agents. Angiogenesis is a tightly regulated process dependent on the complex interplay between inhibitory and stimulatory angiogenic factors. Vascular endothelial growth factor is one of the best characterized of the pro-angiogenic growth factors, and multiple strategies have been developed to inhibit this pathway. Bevacizumab, a monoclonal antibody developed against vascular endothelial growth factor, has shown initial preclinical and clinical activity. This review will outline the conceptual basis of anti-angiogenic therapy, discuss the critical role of vascular endothelial growth factor, and summarize the available data on the use of bevacizumab in colorectal cancer.
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PMID:Inhibition of vascular endothelial growth factor in the treatment of colorectal cancer. 1280 94

Erlotinib (Tarceva) is an orally available selective small-molecule inhibitor of HER1/EGFR tyrosine kinase with a 50% inhibitory concentration of 2 nM for purified tyrosine kinase. This agent has been shown to produce stasis or regression of tumor growth in human cancer xenograft models, including non-small-cell lung cancer models. Ongoing preclinical investigations indicate that inhibition of the MAPK and Atk signaling pathways downstream of HER1/EGFR may be required for optimal antitumor effects. Erlotinib exhibits inhibition of MAPK and Atk kinases at concentrations higher than those required for HER1/EGFR tyrosine kinase inhibition; such findings suggest that maximal inhibition of HER1/EGFR, requiring high erlotinib doses, is necessary for optimum antitumor activity. These considerations are supported by tumor models, including non-small-cell lung cancer models, showing dose-related antitumor effects up to high doses of erlotinib. Erlotinib exhibits additive antitumor effects when combined with chemotherapeutic agents (cisplatin, doxorubicin, paclitaxel, gemcitabine [Gemzar], and capecitabine [Xeloda]), radiation therapy, and other targeted agents (e.g., bevacizumab [Avastin]). Recent studies indicate that erlotinib inhibits the EGFRvIII mutant at concentrations higher than those required for inhibition of wild-type receptor. Ongoing investigation will help to determine optimal dosing and dose frequency of erlotinib in various cancers in the clinical setting.
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PMID:Erlotinib: preclinical investigations. 1468 18

Advanced colorectal cancer remains an urgent health concern, despite improvements in systemic chemotherapy. Targeted therapeutics promise effective tumor therapy with minimal side effects. Angiogenesis (the formation of new blood vessels) is essential for tumor growth and metastasis and may be an ideal target in the search for new antineoplastic agents. Vascular endothelial growth factor is one of the best characterized of the proangiogenic growth factors that regulate angiogenesis and is a logical target in colorectal cancer therapy. Bevacizumab (Avastin; Genentech Inc.; South San Francisco, CA), a humanized murine monoclonal antibody directed at vascular endothelial growth factor, is being evaluated in the treatment of various types of cancer. It has shown promising efficacy in phase II clinical trials in patients with metastatic colorectal cancer. Addition of bevacizumab at a dose of 5 mg/kg to chemotherapy (5-fluorouracil plus leucovorin) resulted in a higher objective response rate (40% versus 17%), longer time to disease progression (9.0 versus 5.2 months), and longer median survival time (21.5 versus 13.8 months). Hypertension and thrombosis were the principal safety concerns, but were manageable. Further phase II/III studies of bevacizumab, administered with 5-fluorouracil plus leucovorin, with or without irinotecan and/or oxaliplatin, in colorectal cancer, are under way.
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PMID:Targeted therapy of colorectal cancer: clinical experience with bevacizumab. 1517 11

Angiogenesis, the formation of blood vessels, is a vital process in tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is a potential target for antiangiogenic therapy because its overexpression has been associated with tumor vascularity, poor prognosis, and aggressive disease in many malignancies, including colorectal cancer (CRC). Bevacizumab is a recombinant humanized monoclonal antibody against VEGF. It is the first angiogenesis inhibitor to show significant activity in patients and, when combined with chemotherapy, leads to a significant survival benefit in CRC. This monoclonal antibody has been approved for first-line therapy in combination with intravenous 5-fluorouracil-containing regimens in patients with metastatic CRC. Vatalanib (PTK787/ZK222584) is an oral antiangiogenic tyrosine kinase inhibitor of the VEGF receptor. Currently, it is being evaluated in combination with FOLFOX (5-fluorouracil/leucovorin/oxaliplatin) in metastatic CRC. This article reviews the process of angiogenesis and the successful translation of antiangiogenic agents into the clinic. Specifically, studies evaluating VEGF-targeted agents in combination with oxaliplatin-containing regimens in CRC are discussed.
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PMID:Combining anti-VEGF approaches with oxaliplatin in advanced colorectal cancer. 1547 83

Angiogenesis plays an important role in tumor growth and development. Vascular endothelial growth factor (VEGF) is one of the most potent proangiogenic factors and therefore is an ideal target in colorectal cancer therapy. Bevacizumab (Avastin, Genentech, Inc., South San Francisco, CA) is a humanized monoclonal antibody, designed to directly target VEGF. The agent has shown promising activity in preclinical and phase I and II studies and is well tolerated compared with conventional cytotoxic chemotherapy. The U.S. Food and Drug Administration recently approved bevacizumab in combination with 5-fluorouracil-based chemotherapy as first-line therapy for patients with metastatic colorectal cancer. The approval was based on phase III data demonstrating that patients treated with bevacizumab plus chemotherapy survived approximately five months longer compared with patients treated with chemotherapy alone. This article will focus on the role of VEGF in tumorigenesis and summarize the available data on the use of bevacizumab in the treatment of metastatic colorectal cancer.
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PMID:Antivascular endothelial growth factor monoclonal antibody therapy: a promising paradigm in colorectal cancer. 1575 99

Angiogenesis, the process of new blood vessel formation, is an essential step in tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is a key mediator in this process, and elevated levels of this cytokine are observed in solid tumors and are correlated with worse clinical outcomes. Research has therefore focused on developing agents that target angiogenic factors such as VEGF in order to inhibit tumor growth. One such agent is bevacizumab, a humanized monoclonal antibody generated by engineering the VEGF-binding residues of a murine neutralizing antibody into the framework of a normal human immunoglobulin G. Bevacizumab recognizes VEGF receptors 1 and 2 and thus can neutralize the biologically active forms of VEGF that interact with these receptors. In addition, bevacizumab has shown antiangiogenic and antitumor activity in several cancer types, recently gaining approval from the FDA for use in combination with fluorouracil-based chemotherapy as a first-line treatment for metastatic cancer of the colon or rectum.
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PMID:Bevacizumab: antiangiogenic cancer therapy. 1575 67

Angiogenesis is a strongly regulated process, which is dependent upon a complex interplay between inhibitory and stimulatory angiogenic factors. It is essential for tumor growth and metastasis: increased angiogenesis is correlated with poor prognosis in cancer patients. Many novel compounds that potently inhibit formation of neoplastic blood vessels have been recently developed. Major categories of angiogenesis antagonists include protease inhibitors, direct inhibitors of endothelial cell proliferation and migration, angiogenic growth factor suppressors, inhibitors of endothelial-specific integrin/survival signalling, copper chelators, and inhibitors with other specific mechanisms. There is increasing interest in developing angio-suppressive agents for colorectal cancer treatment. Some 20 direct and indirect antiangiogenesis drugs are currently being evaluated in clinical trials in colorectal cancer (CRC). Promising results have been reported. These include an increase in overall survival and reduction in the risk of death (Bevacizumab), reversal of cellular resistance (Cetuximab) and activity as second-line therapy in patients who have exhausted other available treatment options (Cetuximab, ABX-EGF, PTK-787, Gefitinib, Erlotinib). This review will outline the mechanisms of action of the principal antiangiogenic drugs, summarize the available data on the use of these new drugs in colorectal cancer, discuss their impact in clinical practice and offer a glimpse into how antiangiogenetic therapy will be integrated into the future care of patients with gastrointestinal cancers.
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PMID:Colorectal cancer and antiangiogenic therapy: what can be expected in clinical practice? 1589 May 25

The improved survival associated with adding the anti-vascular endothelial growth factor (VEGF) monoclonal antibody bevacizumab (Avastin) to chemotherapy for the treatment of patients with metastatic colorectal cancer demonstrates the importance of targeting collateral cells involved in tumor growth, progression, and metastatic spread. Based on the Gompertzian model of tumor growth, adding anti-VEGF agents to standard chemotherapy may be especially effective in early stages of cancer. By improving chemotherapy delivery to the tumor and inhibiting regrowth between treatment cycles, anti-VEGF agents may alter the growth pattern of a tumor such that it is more susceptible to eradication. These concepts also suggest that anti-VEGF agents could enhance the effectiveness of chemotherapy given conventionally or in a dose-dense fashion. As such, it is possible that the effectiveness of chemotherapy could be maintained or improved, even at lower cumulative doses, which may improve its tolerability. Additionally, the effects of anti-VEGF agents on metronomic chemotherapy, which is reported to have antiangiogenic properties on its own, warrant further evaluation. Preclinical data demonstrate that cytostatic angiogenesis inhibitors are potent complementary agents to metronomic chemotherapy, producing sustained complete regressions in some models of human cancer. Dose-dense and metronomic chemotherapy have in common a shortened dosing interval and resultant increased and/or prolonged exposure of tumor cells to chemotherapy in vivo. Optimizing the use of anti-VEGF agents in the clinic demands further investigation of the most appropriate way to combine them with chemotherapy, particularly regimens designed to exploit known tumor growth patterns and those designed to target the endothelial cells involved in neovascularization with multiple agents.
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PMID:Clinical implications of antiangiogenic therapies. 1593


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