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Query: UMLS:C0006142 (breast cancer)
 160,383 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The type 1 tyrosine kinase receptor HER2 (c-erbB2/neu) is associated with resistance to hormone therapy and poor survival in invasive breast cancer, whereas HER4 expression is associated with endocrine responsiveness. Patterns of tyrosine kinase receptor coexpression may aid prediction of recurrence risk after surgery for ductal carcinoma in situ (DCIS). Women who had undergone surgery for pure DCIS were studied. Out of 129 primary tumors, 39 had recurred and 90 had not recurred after 5 years of follow-up. Primary tumors were compared for HER2, HER3, and HER4, estrogen receptor, and Ki67 by immunohistochemistry. HER2 was expressed in 58%, HER3 in 49%, and HER4 in 63% of nonrecurrent DCIS, compared with HER2 expression in 82% (P = 0.008), HER3 expression in 71% (P = 0.04), and HER4 expression in 36% (P = 0.004) in DCIS that subsequently recurred. Dually expressing HER2/4 DCIS was more likely to be estrogen receptor positive than HER2-only-expressing DCIS (73% versus 53%; P = 0.05). HER2 expression was associated with a higher percentage and HER4 expression a significantly lower percentage of proliferating DCIS cells (median, 13.8% versus 8.4%; P = 0.001). Coexpression of HER2 with HER4 was associated with reduced recurrence compared with HER2-only positive DCIS (P = 0.003). This association remained significant when analyzing only high nuclear-grade DCIS (P = 0.015). Low nuclear grade, low proliferation rate and presence of HER4 expression were independent predictors of nonrecurrence. Potentially, HER4 expression may identify women who could avoid radiotherapy after breast-conserving surgery for DCIS.
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PMID:Absence of HER4 expression predicts recurrence of ductal carcinoma in situ of the breast. 1578 62

Breast cancers are a biologically heterogeneous group of mammary tumors with distinct natural histories and varied responses to established therapies. They have long been divided into those that are hormone sensitive [as defined by expression of the estrogen receptor alpha (ERalpha) and/or the progesterone receptor (PR)] and those that are not. Notably, only those breast cancers that express ERalpha and/or PR typically respond to hormonal therapy with tamoxifen, aromatase inhibitors, or the newer agent fulvestrant. More recently, the transmembrane tyrosine kinase receptor HER-2/neu was identified as an oncogene overexpressed by about 30% of breast cancers. These HER-2/neu-overexpressing breast cancers define a subset of breast tumors that are characteristically more aggressive, and women who develop them have a shorter survival. Trastuzumab (Herceptin), a humanized monoclonal antibody specific for HER-2/neu, has revolutionized the management of metastatic HER-2/neu-overexpressing breast cancers. As a single agent, it produces response rates similar to those of many single-agent chemotherapeutic agents active in metastatic breast cancer and has limited toxicity. Combining trastuzumab with chemotherapy can result in synergistic antitumor activity. The clear efficacy of trastuzumab against HER-2/neu-overexpressing metastatic breast cancer has led to a keen interest in testing its role in the management of early breast cancer, and multiple large clinical trials are currently in progress. This review summarizes the available clinical data on the use of trastuzumab in HER-neu-overexpressing breast cancer and briefly highlights emerging opportunities for innovative, trastuzumab-based breast cancer therapies.
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PMID:Trastuzumab: targeted therapy for the management of HER-2/neu-overexpressing metastatic breast cancer. 1589 Dec 69

The HER2 gene, located on 17q, encodes a 185-kD transmembrane tyrosine kinase receptor. Amplification of this gene with overexpression of the gene product occurs in about 30% of cases of breast cancer and is considered to be a poor prognostic indicator for this tumor. Results for HER2 expression in osteosarcoma are controversial, with some studies reporting up to 61% of positive cases and others reporting only negative results. Further, expression of HER2 is reported to be a favorable prognostic indicator by some groups and unfavorable by others. The present study used tissue microarrays containing 34 samples of osteosarcoma from 18 patients to analyze HER2 expression by immunohistochemistry and gene copy number by chromogenic in situ hybridization. The microarray included 13 pretreatment biopsies, 11 posttreatment resection specimens, and 10 resected metastases and comprised 18 osteoblastic, 6 chondroblastic, 5 fibroblastic, and 5 mixed subtypes. HER2 protein expression was seen in 4 of 34 (12%) tumor samples that originated from 2 of 18 patients (11%). The staining pattern was consistently weak and focal, and immunohistochemical overexpression of the HER2 protein, defined as complete membrane positivity, was never observed. Further, the presence of HER2 gene amplification was not detected in any osteosarcoma by chromogenic in situ hybridization. Therefore, therapies based on antibodies directed against the HER2 protein are unlikely to have much value in the treatment of pediatric osteosarcomas. From a technical standpoint, this study also demonstrates the value of tissue microarrays in screening tumors at the protein and gene levels using conventional light microscopy.
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PMID:HER2 amplification and overexpression is not present in pediatric osteosarcoma: a tissue microarray study. 1621 48

The erbB-2 gene encodes tyrosine kinase receptor p185(neu). Overexpression of erbB-2 plays a key role in tumorigenesis and the progression of tumors such as breast cancer and ovarian cancer. Our investigation suggests that the anti-inflammatory agent N-(4-ethoxyphenol)-2-hydroxy-acid amide (SUCI02) reversibly represses tyrosine phosphorylation of erbB-2 in a dose-dependent manner, with half maximal inhibition occurring at a concentration of 21.05 micromol/L without reduced erbB-2 receptor expression. Activation of mitogen-activated protein kinase and protein kinase B, downstream molecules of the erbB-2-mediated signal transduction pathway, was inhibited following exposure to SUCI02. In contrast, tyrosine phosphorylation of epidermal growth factor receptor (EGFR) was relatively unaffected by SUCI02. Proliferation of erbB-2-overexpressing BT474 cells was inhibited to a greater extent than proliferation of EGFR-overexpressing A431 cells following exposure to SUCI02. SUCI02 induced cell cycle arrest in G(1) phase with upregulation of p27 and downregulation of pRb phosphorylation. Systemic administration of SUCI02 in nude mice resulted in inhibition of erbB-2 tyrosine kinase phosphorylation of subcutaneous human breast cancer BT474 xenografts. We conclude that SUCI02 inhibits erbB-2 tyrosine kinase phosphorylation in vitro and in vivo, shuts down the erbB-2 downstream pathway and induces cell cycle arrest in G(1) phase. These results suggest that SUCI02 is a potential novel anticancer agent that deserves further investigation. (Cancer Sci 2006; 97: 84-89).
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PMID:SUCI02 inhibits the erbB-2 tyrosine kinase receptor signaling pathway and arrests the cell cycle in G1 phase in breast cancer cells. 1636 26

Tumor cell contamination might induce relapse after autologous transplantation in breast cancer patients. We used an ex vivo purging strategy to decrease the number of contaminating breast tumor cells in leukaphereses without altering the engraftment potential of the hemopoietic progenitor cells. This method is based on immunoselection of CD34+ cells derived from mobilized peripheral blood of patients with metastatic breast cancer and expansion in the presence of flt3 ligand, stem cell factor, interleukin 6, and thrombopoietin. Tumor contamination before and after culture was monitored by mammaglobin messenger RNA amplification by quantitative polymerase chain reaction. We analyzed both adherent and suspended cells obtained after 2 weeks of culture. Hemopoietic progenitors were increased among suspended cells. In this fraction, tumor cell contamination was decreased, whereas it increased within the adherent cell fraction. Experimental models using CD34+ cells from healthy donors spiked with breast cancer cells were also constructed to investigate whether treatment with anti-ErbB-receptor drugs could further reduce the tumor load without affecting the clonogenic potential of hemopoietic cells. For this purpose, we successfully assayed trastuzumab, a monoclonal antibody against ErbB-2, and gefitinib, an epidermal growth factor receptor tyrosine kinase receptor inhibitor. These results suggest that positively selected CD34+ cells from cancer patients contain tumor cells and that ex vivo expansion can reduce the tumor load of the suspended fraction. Target-based agents against ErbB-2, epidermal growth factor receptor, or both--such as trastuzumab or gefitinib--might increase the efficiency of purging.
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PMID:Tumor cell purging by ex vivo expansion of hemopoietic stem cells from breast cancer patients combined with targeting ErbB receptors. 1639 70

Angiopoietin (Ang) is a ligand for the endothelium-specific tyrosine kinase receptor Tie-2, while a shift in the Ang-1:Ang-2 expression ratio in favor of Ang-2 was found to be associated with tumor angiogenesis. In the present study, we analyzed the immunohistochemical expression of Ang-2 in a series of 198 breast cancers, in which VEGF expression and microvessel density (MVD) were previously determined. Ang-2 expression was negative in 24 (12%), positive in 50 (25%) and strongly positive in 124 (63%) of 198 cases. A significant correlation was found between Ang-2 and VEGF expressions (p=0.0004) and between Ang-2 expression and MVD (p=0.0006), while a high MVD was found in 10 (77%) of 13 tumors with a strongly positive VEGF and positive Ang-2 expression and in 40 (71%) of 56 tumors with a strongly positive VEGF and strongly positive Ang-2 expression. Although there was no difference in the disease free survival (DFS) stratified according to Ang-2 expression alone, the 69 patients with a strongly positive VEGF and a strongly positive or positive Ang-2 expression had a significantly (p=0.0316) worse DFS than those with other combinations of VEGF and Ang-2 expressions. A multivariate analysis indicated lymph node metastasis and MVD to be independently significant prognostic factors for DFS, while the combination of VEGF and Ang-2 expressions was not a significant factor for DFS. In conclusion, the Ang-2 expression was found to be closely correlated with VEGF expression and MVD in breast cancer, while a high MVD was frequently found in tumors with a high expression of both VEGF and Ang-2. The survival analysis demonstrated a high MVD, which was induced by a high expression of both VEGF and Ang-2, to therefore have a strong prognostic significance in breast cancer.
Breast Cancer Res Treat 2006 Aug
PMID:Angiopoietin 2 expression in invasive ductal carcinoma of the breast: its relationship to the VEGF expression and microvessel density. 1653 28

The advent of targeted therapies has allowed treatment to be directed at signaling pathways integral to tumor growth and survival. Sunitinib (SU11248, sunitinib malate; Pfizer Inc., New York, NY, USA) is a novel oral small-molecule multitargeted receptor tyrosine kinase inhibitor that has demonstrated direct antitumor activity and antiangiogenic action. It targets the vascular endothelial growth factor receptor (VEGFR), platelet derived growth factor receptor (PDGFR), stem-cell factor receptor and Fms-like tyrosine kinase receptor 3 receptor tyrosine-kinases. In January 2006, sunitinib malate was granted approval by the U.S. Food and Drug Administration for the treatment of gastrointestinal stromal tumor after disease progression on, or intolerance to, imatinib mesylate, as well as for the treatment of metastatic renal cell cancer. This review will discuss the development of sunitinib, particularly in acute myeloid leukemia, imatinib-resistant gastrointestinal stromal tumors and renal cell cancer. The review will also discuss ongoing trials with sunitinib in other malignancies such as neuroendocrine tumors and breast cancer, as well as its potential future development in combination therapy with other agents and in other malignancies.
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PMID:Sunitinib: a newly approved small-molecule inhibitor of angiogenesis. 1684 42

The HER-2/neu transmembrane tyrosine kinase receptor is both a prognostic marker and a therapeutic target for breast cancer. Accurate determination of HER-2/neu status is a prerequisite for selecting breast tumors for HER-2/neu immunotherapy or for taxan based chemotherapy. Unfortunately, there is no consensus concerning how this determination should be reached. We compared assessment of HER-2/neu status using Multiplex ligation-dependent probe amplification (MLPA) and immunohistochemistry (IHC). The patient group comprised 60 Indonesian breast cancers patients. IHC was performed on paraffin sections using the CB11 antibody from Novocastra. Results were scored according to the Hercept test. For MLPA, DNA was extracted from frozen samples, PCR amplified with a probe set containing three hemi-primer sets for the HER-2 locus and another nine control probes spread over chromosome 17 and other chromosomes, and analyzed on a gene scanner. A ratio above two for at least two HER-2 locus probes compared to the control probes was regarded as amplification. IHC for HER-2/neu was negative in 36 cases, and 24 cases (40%) showed expression. Seven, eight and nine of the latter cases were 1+, 2+ and 3+ positive, respectively. Forty-seven cases showed no amplification by MLPA, and 13 cases (22%) were amplified. Comparison of IHC and MPLA showed that none of the 36 IHC-negative or seven IHC 1+ cases was amplified. Five of the eight (63%) 2+ cases were amplified, and eight of nine (89%) of the IHC 3+ tumors showed gene amplification by MLPA assay. For HER-2/neu, there is a good correlation between gene amplification detected by MLPA and overexpression by IHC in invasive breast cancer. It appears that MLPA can detect the HER-2 amplified cases in the IHC 2+ class. Because MLPA is quick and inexpensive, it is an attractive method for detecting HER-2/neu amplification in daily laboratory practice.
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PMID:Comparison of multiplex ligation dependent probe amplification to immunohistochemistry for assessing HER-2/neu amplification in invasive breast cancer. 1690 32

Neuropilin-1 (NRP-1), a non-tyrosine kinase receptor of vascular endothelial growth factor-165 (VEGF165), was found expressed on endothelial and some tumor cells. Since its overexpression is correlated with tumor angiogenesis and progression, the targeting of NRP-1 could be a potential anti-cancer strategy. To explore this hypothesis, we identified a peptide inhibiting the VEGF165 binding to NRP-1 and we tested whether it was able to inhibit tumor growth and angiogenesis. To prove the target of peptide action, we assessed its effects on binding of radiolabeled VEGF165 to recombinant receptors and to cultured cells expressing only VEGFR-2 (KDR) or NRP-1. Antiangiogenic activity of the peptide was tested in vitro in tubulogenesis assays and in vivo in nude mice xenotransplanted in fat-pad with breast cancer MDA-MB-231 cells. Tumor volumes, vascularity and proliferation indices were determined. The selected peptide, ATWLPPR, inhibited the VEGF165 binding to NRP-1 but not to tyrosine kinase receptors, VEGFR-1 (flt-1) and KDR; nor did it bind to heparin. It diminished the VEGF-induced human umbilical vein endothelial cell proliferation and tubular formation on Matrigel and in co-culture with fibroblasts. Administration of ATWLPPR to nude mice inhibited the growth of MDA-MB-231 xenografts, and reduced blood vessel density and endothelial cell area but did not alter the proliferation indices of the tumor. In conclusion, ATWLPPR, a previously identified KDR-interacting peptide, was shown to inhibit the VEGF165 interactions with NRP-1 but not with KDR and to decrease the tumor angiogenesis and growth, thus validating, in vivo, NRP-1 as a possible target for antiangiogenic and antitumor agents.
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PMID:Antiangiogenic and antitumor activities of peptide inhibiting the vascular endothelial growth factor binding to neuropilin-1. 1695 72

Trastuzumab is a monoclonal antibody targeted against the HER2 tyrosine kinase receptor. The majority of patients with metastatic breast cancer who initially respond to trastuzumab develop resistance within one year of treatment initiation, and in the adjuvant setting 15% of patients still relapse despite trastuzumab-based therapy. In this review, we discuss potential mechanisms of antitumor activity by trastuzumab, and how these mechanisms become altered to promote therapeutic resistance. We also discuss novel therapies that may improve the efficacy of trastuzumab, and that offer hope that the survival of breast cancer patients with HER2-overexpressing tumors can be vastly improved.
Breast Cancer Res 2006
PMID:HER2 therapy: molecular mechanisms of trastuzumab resistance. 1709 62


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