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

Metastatic breast cancer (MBC) may present de novo but more commonly develops in women initially presenting with early breast cancer despite the widespread use of adjuvant hormonal and cytotoxic chemotherapy. MBC is incurable. Hormone sensitive MBC eventually becomes resistant to endocrine therapy in most women. Anthracyclines are the agents of choice in the treatment of endocrine resistant MBC. With the widespread use of anthracyclines in the adjuvant setting, taxanes have become the agents of choice for many patients. Recently capecitabine has become established as a standard of care for patients pretreated with anthracyclines and taxanes. However, a range of agents have activity as third line treatment. These include gemcitabine, vinorelbine and platinum analogues. The sequential use of non-cross resistant single agents rather than combination therapy is preferable in most women with MBC. Even though combination therapy can improve response rates and increase progression free interval, there is no robust evidence to indicate an advantage in terms of overall survival. Moreover, combination therapy is associated with a higher toxicity rate and poor quality of life. There is no role for dose-intense therapy, high dose therapy or maintenance chemotherapy outside the context of a clinical trial. The introduction of trastuzumab, monoclonal antibody targeting growth factor receptors, has improved the therapeutic options for women with tumours overexpressing HER2/neu. DNA micro-array profiles of tumours can potentially help to individualise therapy in future. Molecular targeted therapy has the potential to revolutionise the management of MBC.
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PMID:Management of endocrine resistant breast cancer. 1510 7

Elevated levels of the extracellular domain of HER-2/neu in serum (sHER-2/neu) have been shown to be of prognostic importance. In this phase II study with weekly paclitaxel in metastatic breast cancer, we investigated the predictive quality of this serum oncoprotein by correlating the outcome of therapy to sHER-2/neu levels. Paclitaxel (90 mg/m2 weekly x6, q9w) was administered to 35 patients with complete outcome assessment and biochemical follow-up. sHER-2/neu was measured using standardized enzyme-linked immunoassays. We found that 62.9% (22/35) of the patients had elevated levels (> or = 15 ng/ml) of sHER-2/neu. The overall response rate (RR) to weekly paclitaxel was 40.0% (14/35). There was no difference in RR between sHER-2/neu-positive patients (40.9%) and sHER-2/neu-negative patients (38.5%; p = 0.4). The progression-free interval was longer for sHER-2/neu-negative patients (53.2 weeks) in comparison to sHER-2/neu-positive patients (31.2 weeks; p = 0.098). Responses were significantly more durable in sHER-2/neu-negative patients (65.2 weeks) than in the sHER-2/neu-positive subgroup (25.7 weeks; p = 0.042). Introducing hypothetical cut-offs into the sHER-2/neu-positive subset, we found that in patients with a sHER-2/neu level of greater than 22 ng/ml, the progression-free survival decreased significantly with increasing sHER-2/neu levels (p < or = 0.022). Considering the high impact of progression-free survival and duration of response as outcome parameters, the sHER-2/neu status is a predictive indicator for benefit from paclitaxel chemotherapy.
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PMID:Serum HER-2/neu as a prediction and monitoring parameter in a phase II study with weekly paclitaxel in metastatic breast cancer. 1516 Oct 43

The HER2/neu oncoprotein is a major target for the development of new cancer therapies and is similar to the estrogen receptor, which guides hormone therapy. The HER2/neu status is used to guide therapy decisions in patients with HER2/neu-overexpressing breast cancer tumors. The HER2/neu oncogene, or c-erbB-2, encodes a transmembrane receptor protein that is expressed on normal epithelial cells and can be overexpressed in breast cancer cells. Studies have shown that the extracellular domain (ECD) of the HER2/neu oncoprotein is released from the cell and can be measured in the circulation of women with breast cancer. Enzyme-linked immunosorbent assay methods used to measure the circulating HER2/neu ECD have shown that the prevalence of elevated ECD levels is approximately 18.1% in women with primary breast cancer and approximately 45.6% in women with metastatic breast cancer (MBC). Many studies have monitored the circulating ECD levels after surgery and indicate that increasing ECD levels can indicate recurrence of breast cancer earlier than clinical diagnosis. Studies in women with MBC showed that serial changes in circulating HER2/neu ECD levels paralleled the clinical course of disease, regardless of the treatment regimen. Several studies identified a subgroup of patients with MBC who had HER2/neu-negative disease by tissue testing but developed elevated ECD levels with MBC. In contrast to tissue testing, which is a one-time event, monitoring the circulating levels of the HER2/neu ECD in patients with breast cancer provides a real-time assessment of the HER2/neu status and provides important information for managing the therapy of patients with MBC.
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PMID:Monitoring the circulating levels of the HER2/neu oncoprotein in breast cancer. 1524 13

SRL172, non-specific immunological adjuvant downregulates interleukin-4, upregulates interleukin-2 production, switching towards a T-helper-1 response, induces an increase in natural killer cells and activates antigen presenting cells. The human epidermal growth factor receptor 2 gene amplification is frequently observed in a number of primary tumors, suggesting that the overexpression of this growth factor receptor may contribute to transformation and tumorigenesis. Gene amplification occurs in approximately 15-20% of human breast cancers Amplification is associated with aggressive tumor behavior and shortened survival. Trastuzumab, humanized anti-HER-2 antibody targets the HER-2 protein with high affinity. Trastuzumab when used alone or in combination with cytotoxic chemotherapy can induce reasonably durable remissions in a significant percentage of women with metastatic breast cancer whose tumors demonstrate Her-2/neu gene amplification. One of the proposed mechanisms of trastuzumab antitumor action is through antibody dependent cellular cytotoxocity. Pivotal study showed that Trastuzumab+IL-2 resulted in NK cell expansion with enhanced in vitro targeted killing of HER-2-expressing cells. SRL172 by increasing IL-2 production and number of natural killer cells may augment the efficacy of trastuzumab in metastatic breast cancer patients. SRL 172 increases IL-2 production and the number of NK cells in vivo. Based on these data, a clinical trial can be performed to test whether SRL 172 added to trastuzumab is safe and more efficacious.
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PMID:SRL172 (killed Mycobacterium vaccae) may augment the efficacy of trastuzumab in metastatic breast cancer patients. 1560 48

Although HER2 gene status determines the eligibility of breast cancer patients to trastuzumab therapy, only a fraction of HER2 gene-amplified cancers are actually responsive, indicating that complex genotypical profiles might sustain HER2-targeted therapy responsiveness. To identify genetic factors modulating the response to HER2-targeted therapy, the numerical status of chromosome 17 was evaluated in HER2 gene-amplified tumor specimens from 43 patients who received trastuzumab-based treatment for advanced breast cancer, and in 60 unamplified breast carcinomas. Archival tumor specimens were analyzed by interphase fluorescence in situ hybridization (FISH) using a centromeric probe for chromosome 17 simultaneously with the HER2/neu human gene-specific probe. In the 43 patients who received trastuzumab-based treatment, response rate and time to progression (TTP) were compared between subgroups according to chromosome 17 status. Numerical aberrations of chromosome 17 were found in 65% of HER2-amplified tumors (single centromeric signal, 44%; >3 centromeric signals, 21%) and 60% of unamplified cancers (single centromeric signal, 43%; >3 centromeric, 17%). In the 43 treated metastatic breast cancer patients, trastuzumab was combined with docetaxel (35 patients), paclitaxel (2 patients), or vinorelbine (6 patients). Response rate was 92% in patients with >2 centromeric signals (chromosome 17 eusomy/polysomy), and 53% in patients whose tumor showed a single signal (chromosome 17 monosomy) (p=0.005). Chromosome 17 numerical status was not found to affect TTP. Multivariate logistic regression analysis confirmed that the effect of chromosome 17 monosomy on tumor response was independent of other potential clinical variables. Our findings suggest that 17 monosomy defines a subgroup of HER2 gene-amplified breast cancer characterized by reduced responsiveness to trastuzumab-based treatment. Further studies on the imbalance between the amplified HER2 gene and functionally antagonist gene(s) on chromosome 17 are warranted.
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PMID:HER2 gene-amplified breast cancers with monosomy of chromosome 17 are poorly responsive to trastuzumab-based treatment. 1564 16

Trastuzumab has shown significant single-agent activity in patients with Her-2/neu overexpressing metastatic breast cancer, and increased response rates, progression-free and overall survival when added to standard chemotherapy. Despite higher response rates, the combination with chemotherapy has higher toxicity and it remains unknown whether single-agent trastuzumab is equally effective as the combined treatment in terms of progression-free and overall survival. We therefore carried out a retrospective multivariate analysis of 117 patients with Her-2/neu overexpressing metastatic breast cancer who were treated with trastuzumab with or without chemotherapy at a single institution between November 1999 and December 2003. Response rates tended to be higher in patients receiving trastuzumab in combination with chemotherapy (34 versus 8%, p=0.060). However, this did not translate into a benefit in progression-free survival: median (95% confidence interval) progression-free survival was 6.2 (4.45-7.95) months in patients receiving trastuzumab plus chemotherapy versus 4.2 (1.77-6.63) months in those receiving single-agent trastuzumab (p=0.560). Likewise, no significant difference in overall survival was observed: 27.0 (19.9-34.0) versus 23.1 (16.2-30.0) months (p=0.809). We conclude that in the absence of extensive visceral involvement necessitating a higher response rate, single-agent trastuzumab may be a safe and less-toxic alternative to its combined use with other chemotherapy agents. This needs to be confirmed in prospective randomized trials.
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PMID:Single-agent trastuzumab versus trastuzumab plus cytotoxic chemotherapy in metastatic breast cancer: a single-institution experience. 1565 16

This review highlights three examples of novel targeted therapeutics for solid tumors that are currently approved in Japan: 1) Trastuzumab (Herceptin) for patients with metastatic breast cancer that demonstrates overexpression of HER2/neu; 2) Imatinib mesylate (Glivec) for patients with gastrointestinal tumors, of which tumor cells express c-Kit; and 3) Gefitini (Iressa) for patients with advanced non-small cell lung cancers, which response to gefitinib is recently suggested to be associated with EGFR mutation. In these molecular targeted therapies, diagnostic tools to verify the presence of an appropriate molecular target is crucial to the success, and thus the methods and its interpretation are discussed in this review.
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PMID:[Molecular diagnosis of solid tumors]. 1577 42

Trastuzumab (Herceptin) is a humanized antibody directed against the extracellular domain of the tyrosine kinase orphan receptor Her-2/neu (erbB-2) that has shown therapeutic efficacy against Her-2/neu-overexpressing breast tumors. However, less than 35% of patients with Her-2/neu-overexpressing metastatic breast cancer respond to trastuzumab as a single agent, whereas the remaining cases do not demonstrate tumor regression. Furthermore, the majority of patients who achieve an initial response generally acquire resistance within one year. Therefore, the identification of the potential mechanisms of resistance to trastuzumab can be very helpful for the development of new compounds, which might overcome that resistance and/or have additive/synergistic antitumor effect when given in association with trastuzumab. Recent studies in breast cancer cells have revealed a bi-directional connection between Her-2/neu and fatty acid synthase (FAS), a major lipogenic enzyme catalyzing the synthesis of long-chain saturated fatty acids from the 2-carbon donors malonyl-CoA and acetyl-CoA. Her-2/neu overexpression stimulates the FAS promoter and ultimately mediates increased endogenous fatty synthesis, and this Her-2/neu-mediated induction of breast cancer-associated FAS is inhibitable by trastuzumab. On the other hand, chemical FAS inhibitors as well as RNA interference-mediated silencing of FAS gene repress Her-2/neu gene expression at the transcriptional level. Moreover, specific FAS blockade synergistically sensitizes breast cancer cells carrying Her-2/neu-oncogene amplification and/or overexpression to trastuzumab-induced cell growth inhibition and apoptotic cell death. Strikingly, FAS inhibition synergistically interacts with trastuzumab in Her-2/neu-negative breast cancer cells engineered to overexpress Her-2/neu, thus suggesting that the molecular linkage between FAS activity and functioning of Her-2/neu cannot be explained only on the basis of a transcriptional repression of Her-2/neu gene promoter. Interestingly, while in liver and adipose tissue FAS produces fat from excess carbon consumed as carbohydrates, which is ultimately stored as triglycerides, in epithelial cancer cells, FAS activity is mainly involved in the production of phospholipids partitioning into detergent-resistant membrane microdomains (lipid raft-aggregates), which point to an active role of FAS in the deregulation of membrane functioning in tumor cells. Importantly, clusters of Her-2/neu and EGFR (erbB-1) co-localize with lipid rafts and the lipid environment in the cell membrane of breast cancer cells profoundly influences their association properties and biological functions. We hypothesize that pharmacological or small interference RNA-induced inhibition of breast cancer-associated FAS will result in major changes in the synthesis of phospholipids which, in turn, should impair a correct cellular localization of Her-2/neu at the cellular membrane of breast cancer cells. In this working model, FAS inhibition could induce a shift in the equilibrium between transport of Her-2/neu to and from the membrane favoring an increased Her-2/neu internalization followed by intracellular degradation, thus enhancing the mechanism of action of the anti-Her-2/neu antibody trastuzumab. Moreover, the inhibition of FAS-driven lipid rafts will also negatively affect EGFR-Her-2/neu cross-talk, an important mechanism of trastuzumab resistance. In summary, the specific blockade of a novel molecular linkage between FAS-regulated membrane composition and functioning of transmembrane growth factor receptors EGFR and Her-2/neu may represent a previously unrecognized therapeutic approach circumventing trastuzumab resistance in breast carcinomas.
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PMID:Targeting fatty acid synthase-driven lipid rafts: a novel strategy to overcome trastuzumab resistance in breast cancer cells. 1578 Apr 99

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

Clinical trial data indicate that epirubicin-based adjuvant treatment of breast cancer is associated with marked improvement in relapse-free and overall survival compared with traditional cyclophosphamide/methotrexate/5-fluorouracil. The outcomes are comparable to those achieved with sequential use of doxorubicin/cyclophosphamide and paclitaxel. Dose intensification of epirubicin is feasible, with tolerable side effects and no increased risk of cardiotoxicity beyond that expected. Clinical trial data coupled with pharmacokinetic evidence provide a strong foundation and rationale for current and future investigation of epirubicin in combination with the taxanes in the adjuvant setting. An ongoing German study is evaluating epirubicin/cyclophosphamide in combination with trastuzumab as first-line therapy of metastatic breast cancer in patients whose tumors overexpress HER2/neu protein. These results, particularly the tolerability of this regimen, will form the basis for future adjuvant and neoadjuvant studies of epirubicin/trastuzumab-based regimens.
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PMID:Overview of epirubicin-based adjuvant therapy in breast cancer. 1595 41


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