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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The long-term effort in investigating chemical methods to eliminate only cancer cells has improved our knowledge and has led to the development of new drugs. The targets for cancer treatment may be large polymeric molecules such as DNA or microtubules as well as regulatory pathways for tumor development and cell survival preservation or tyrosine kinase activity. Examples of new agents are: trastuzumab (Herceptin), a humanized monoclonal antibody that blocks the HER-2/neu proto-oncogene in combination with cytotoxic agents, is used in a percentage of breast cancer patients; signal transduction inhibitor of abl tyrosine kinase STI 571 (Glivec) has been shown to be an active treatment for chronic myeloid leukemia and GISTs; epidermal growth factor receptors in certain tumors have been targeted with agents such as C225 (Cetuximab) and ZD 1839 (IRESSA); an adenosine deaminase analogue of deoxyadenosine, Cladribine (2-chloro-2 deoxy-adenosine) has shown high effectiveness in hairy-cell leukemia and the multitargeted antifolate (Premetrexed) and several vaccines have been studied and are in clinical trials for resistant cancers. These new drug developments represent a promising field for future cancer management.
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PMID:Molecular characterization as a target for cancer therapy in relation to orphan status disorders (Review). 1237 30

Although treatment of advanced non-small-cell lung cancer has been improved with the availability of such new agents as the taxanes, topoisomerase inhibitors, vinorelbine (Navelbine), and gemcitabine (Gemzar), platinum-based combination therapy has appeared to reach a threshold of therapeutic effectiveness. A paradigm shift in approach to non-small-cell lung cancer and other tumors may be heralded by the development of agents targeting specific biologic pathways in tumor development. Such new agents include antibody epithelial growth factor receptor (EGFR) inhibitors (eg, the monoclonal antibodies trastuzumab [Herceptin] and cetuximab [IMC-C225, Erbitux]) and EGFR tyrosine kinase inhibitors (eg, ZD1839 [Iressa] and OSI-774), angiogenesis inhibitors (eg, matrix metalloproteinase inhibitors), vascular endothelial growth factor (VEGF) inhibitors (eg, monoclonal antibody to VEGF ligand and small-molecule tyrosine kinase), and signal transduction inhibitors (eg, ISIS-3521, an antisense oligonucleotide to protein kinase C-alpha). A number of these agents have entered advanced-phase clinical investigation. It is likely that targeted therapy will have applications in combination with cytotoxic chemotherapy or radiation therapy at all stages of treatment, including maintenance therapy. It is even possible that these new biologic therapies will be used together as rational combinations (based on pathologic diagnosis) for advanced non-small-cell lung cancer.
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PMID:Targeted therapy in non-small-cell lung cancer. 1237 97

In the past few years, new agents based on monoclonal antibodies have been developed in Oncology. Indeed in some case tumor cells express antigenic targets at higher levels than normal cells. There are 2 main types of monoclonal antibodies that can be either conjugated to cytotoxic drugs or radio-active compounds or be non-conjugated. Among the last category, some are currently used in the treatment of patients, including 2 monoclonal antibodies targeting receptors with tyrosine kinase activity (HER2: Herceptin (DCI: trastuzumab), EGFr: Erbitux (DCI: cetuximab). A third monoclonal antibody is commonly used in cancer treatment, which targets CD20, a transmembrane marker of B lymphoma (MabThera (DCI: rituximab). Both Herceptin and MabThera have been associated with improved survival in patients with breast carcinoma and lymphoma, respectively. New promising agents are under investigation such anti EGFr in colon and head and neck carcinoma or new compounds such as anti-VEGF. These examples outline the importance of the recent progress in selectively targeting tumor antigen and the potential impact of these approaches in Oncology.
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PMID:[Principal therapeutic uses of monoclonal antibodies in oncology]. 1258 79

Tumor-targeted drug delivery is an attractive strategy in cancer treatment. We have previously reported a paclitaxel model conjugate using a bombesin receptor-recognizing peptide in which the drug cytotoxicity against H1299 human nonsmall cell lung cancer was enhanced compared to unconjugated taxol. In an effort to expand the development of tumor-recognizing taxanes, paclitaxel (PTX, taxol) was conjugated to the anti-epidermal growth factor receptor (anti-EGFR) monoclonal antibody (MAb) Erbitux (C225) to serve as a model MAb-mediated drug delivery compound. Thus, paclitaxel was derivatized at its 2'-hydroxy function by introduction of a succinate linker, and the carboxyl group of the latter was covalently attached to C225 through amide bond formation. The final product conjugate (PTXC225) was analyzed mass spectrometrically for assessment of the drug-to-antibody ratios. Cytotoxicity screening of the drug-antibody conjugate against A431, UM-SCC-1, and UM-SCC-6 cells indicated an enhancement in cytocidal effect of paclitaxel as compared to those of the free drug, the intact antibody, and a physical mixture of the two (the controls). In A431 cells, the conjugate showed 25.2% +/- 2.2% of apoptosis induction as compared to little or no apoptosis caused by the controls. Biodistribution analysis of the PTXC225 in tumor-implanted nude mice and a tyrosine-kinase assay showed that conjugation of the drug did not interfere with the immunoreactivity of the antibody. The 24-h tumor uptake of C225 and PTXC225 were 11.7% +/- 6.0% and 7.1% +/- 3.6% of the injected dose per gram of tissue (%ID/g), respectively, which were not significantly different. Also, in A431-implanted nude mice, the conjugate and C225 showed tumor growth inhibition effects of 57.2% and 41.2%, respectively, against a saline-treated control, which were not significantly different from each other. This lack of difference in the in vivo antitumor activity of the MAb-delivered drug and free PTX may be due to either a relatively low dose of the antibody-delivered drug (346 microg/kg), or an untimely release of it, or both. The tumor growth inhibition pattern of the conjugate, however, was identical to that of C225, indicating that the attachment of PTX did not affect the antigen-binding and growth inhibitory features of the MAb. These preliminary results demonstrate the potential of tumor-targeted delivery of taxol as a promising strategy in cancer treatment and warrant further work to develop more suitable drug-MAb linkers as well as improved dosage and treatment protocols.
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PMID:Synthesis and biological evaluation of paclitaxel-C225 conjugate as a model for targeted drug delivery. 1264 40

Overexpression of epidermal growth factor receptor (EGFR) in epithelial tumors, including head and neck, lung, breast, colon and other solid tumors, has frequently been correlated with poor prognosis, thus stimulating efforts to develop new cancer therapies that target EGFR. Monoclonal antibodies and tyrosine kinase inhibitors specifically targeting EGFR are the most well-studied and hold substantial promise of success. Several compounds of monoclonal antibodies and tyrosine kinase inhibitors targeting EGFR have been studied and clinical trials are now underway to test the safety and efficacy of these targeting strategies in several human tumors. This review will address each of these agents alone or in combination with radiation or chemotherapy and highlight some of these promising developments. Cetuximab (Erbitux) is being evaluated in combination with radiation or chemotherapy in Phase III trials. Other compounds such as h-R3, ABX-EGF, EMD-55900 and ICR-62 have proved to be effective in targeting malignant cells alone or in combination with traditional therapies. Tyrosine kinase inhibitors targeting the intracellular domain of EGFR, including ZD-1839 (gefitinib, Iressa), OSI-774 (Erlotinib/Tarceva), PD-153053, PD-168393 and CI-1033, have been studied in clinical setting alone or in combination with radiation or chemotherapy. ZD-1839 is being studied in a Phase III trial in patients with advanced non-small cell lung cancer. EGFR targeted treatment by monoclonal antibodies and tyrosine kinase inhibitors have been proven to sensitize tumor cells to the effects of chemotherapy and radiation therapy. The synergistic activities and nonoverlapping toxicities of these compounds allow concomitant administration with cytotoxic therapy. Challenges of evaluating EGFR targeted agents exist in selecting the optimal dosages and determining long-term toxicity.
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PMID:Targeting epidermal growth factor receptor: novel therapeutics in the management of cancer. 1282 Jul 79

The improved understanding of the molecular biology of urothelial malignancies is helping to define the role of new targets and prognostic indices that can direct the most appropriate choice of treatment for advanced disease. Many human tumors express high levels of growth factors and their receptors that can be used as potential therapeutical targets. Tyrosine-kinase receptors, including many growth factor receptors such the receptors for epidermal growth factor (EGF), vascular endothelial growth factor (VEGF), and Her2/neu, have been found overexpressed in urothelial tumors. For many of these growth factor receptors, the degree of expression has been associated with the progression of cancer and a poor prognosis. Among the best studied growth factor receptors are the two members of EGF receptor familiy EGFr (ErbB-1), and Her2/neu (ErbB-2). Several preclinical studies in bladder cancer models, have confirmed that systemic administration of growth factor inhibitors inhibits the growth and metastasis of human transitional cell carcinoma established in the bladder wall of athymic nude mice. Additional studies indicate that therapy with EGFR inhibitors enhances the activity of conventional cytoreductive chemotherapeutic agents, in part by inhibiting tumor cell proliferation, angiogenesis, and inducing apoptosis. Novel targeted therapy hold promise to improve the current results of bladder cancer treatment. Based on the success seen with anti-HER2 monoclonal antibodies (Herceptin) and the promising results with EGFR targeted agents (IMC-C225 Cetuximab, ZD1389 Iressa, OSI-774 Tarceva, GW 57016) in other tumor types, and based on the results obtained in preclinical models, there is a great interest in assessing these agents in patients with bladder cancer. Several trials are now ongoing testing these new agents alone or in combination with chemotherapy in bladder cancer patients. The integration of these newer biologic agents, probably to supplement rather than to supplant chemotherapeutic drugs, should be a primary direction of research with the objective to interfere with multiple aspects of bladder cancer progression. However, the value of integration of biologically targeted agents into combined modality treatment for patients with bladder cancer has still to be proven.
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PMID:Novel approaches with targeted therapies in bladder cancer. Therapy of bladder cancer by blockade of the epidermal growth factor receptor family. 1285 May 30

Rash is a class effect of HER1/epidermal growth factor receptor (EGFR)-targeted agents, and has occurred with high frequency and in a dose-dependent manner in clinical trials of these agents in cancer patients. Analysis of phase II trials of erlotinib (Tarceva) in non-small-cell lung cancer, head and neck cancer, and ovarian cancer shows a significant association between rash severity and objective tumor response. Rash severity was highly significantly associated with survival in patients with non-small-cell lung cancer receiving erlotinib; median survival in patients with no rash was 46.5 days, compared with 257 days in those with grade 1 rash (P < .0001) and 597 days in those with grade 2/3 rash (P < .0001). Similarly, for the combined non-small-cell lung cancer, head and neck cancer, and ovarian cancer studies, median survival in patients with no rash was 103 days, compared with 191 days in those with grade 1 rash (P = .0001) and 266 days in those with grade 2/3/4 rash (P = .0001). Similar findings have been made with cetuximab (Erbitux) and in some settings with gefitinib (Iressa). The strong association of rash severity with response/survival suggests that rash may serve as a marker of response to erlotinib treatment and may be used to guide treatment to obtain optimal response. Dosing erlotinib at the maximum tolerated dose, which is associated with more frequent and more severe rash, may improve response rates and survival durations. Further study of the potentially important association between rash and outcome of treatment with EGFR-targeted agents is needed.
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PMID:Can rash associated with HER1/EGFR inhibition be used as a marker of treatment outcome? 1468 20

The tumor-killing mechanisms available to monoclonal antibodies (mAbs; e.g., antagonism of growth factor receptors, antibody-dependent cell-mediated cytotoxicity) limit efficacy. Previous studies suggested that i.v. beta-glucan might function as an adjuvant for antitumor mAbs. beta- Glucan had been shown to function via the iC3b-receptor complement receptor 3 (CR3; CD11b/CD18) thereby enhancing leukocyte killing of tumor cells coated with iC3b via naturally occurring antitumor antibodies. Therapy with beta-glucans was limited by levels of natural antibodies and by tumor escape through elimination of antigen-positive cells. Accordingly, it was hypothesized that beta-glucan responses could be improved by combined administration with antitumor mAbs. Five tumor models were explored in BALB/c or C57Bl/6 mice using tumors that expressed either high levels of naturally occurring antigens (e.g., G(D2) ganglioside) or recombinant human MUC1. In comparison with antitumor mAb or beta-glucan alone, combined treatment with mAb plus beta-glucan produced significantly greater tumor regression in all models that included mammary, s.c., and hepatic tumors. Tumor-free survival only occurred in models that incorporated stable expression of the target antigen. beta-Glucan enhancement of the mAb tumoricidal response did not occur in mice deficient in either leukocyte CR3 (CD11b(-/-)) or serum C3, confirming the requirement for CR3 on leukocytes and iC3b on tumors. Granulocytes appeared to be primarily responsible for tumoricidal activity, because beta-glucan therapeutic responses did not occur in granulocyte-depleted mice. These data suggest that the therapeutic efficacy of mAbs known to activate complement (e.g., Herceptin, Rituxan, and Erbitux) could be significantly enhanced if they were combined with beta-glucan.
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PMID:Beta-glucan functions as an adjuvant for monoclonal antibody immunotherapy by recruiting tumoricidal granulocytes as killer cells. 1469 21

Colorectal cancers (CRC) express the epidermal growth factor receptor (EGF-R), a type I transmembrane receptor with tyrosine kinase activity. EGF-R signaling inhibition is a promising target for cancer therapy. ZD1839 (Iressa, AstraZeneca) and OSI-774 (Tarceva, Roche) are small molecular weight molecules with selective and reversible tyrosine kinase inhibition properties directed to EGF-R. Orally administered, these molecules induce sustained tumor stabilizations in previously treated metastatic CRC patients. The most frequent treatment-related toxicities are fatigue, diarrhea and acne-like follicular rash. The addition in the clinic of 5-FU, lOHP or CPT-11 to ZD1839 or OSI-774 does not seem to increase the own toxicity of each cytotoxic agents. Cetuximab (Erbitux, Merck) is an intravenously administered humanized monoclonal antibody which bind with high affinity with the extracellular domain of the EGF-R. The most frequent treatment-related toxicities are diarrhea, fatigue, nausea and cutaneous toxicity (allergic or acne-like follicular rashes, folliculitis). Most, if not all of these adverse events are mild. Partial responses were observed with cetuximab either alone (RR: 10%) or in combination with CPT-11 (RR: 22%) in patients with CPT-11 refractory advanced CRC which expressed EGF-R. The combination of cetuximab to folinic acid, 5-FU and CPT-11 seems tolerable at the cost of a slight increase of severe diarrhea and neutropenia. Finally, the promising activity of these EGF-R inhibitors has to be confirmed throughout randomized studies.
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PMID:[Inhibitors of epidermal growth factor receptor and colorectal cancer]. 1476 44

The treatment of aerodigestive tract tumors remains difficult despite improved techniques in detection, surgery, radiation, and chemotherapy. Therefore, strategies to improve efficacy in accord with safety are needed. The epidermal growth factor receptor has become a target of increasing interest. Cetuximab is a monoclonal antibody targeting this receptor. A series of phase I and II studies of cetuximab in combination with radiotherapy or chemotherapy have been conducted initially to determine the optimal biological dose (ie, tumor epidermal growth factor receptor-saturating dose) and to establish a safety profile with cetuximab in combination with other antitumor agents. Ultimately, these therapies may become valuable contributors in the treatment of head and neck cancer and lung cancer. This report will focus specifically on the epidermal growth factor receptor and cetuximab.
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PMID:Cetuximab in cancers of the lung and head & neck. 1498 82


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