Erythropoiesis-stimulating agents (ESAs) increase red blood cell (RBC) production in bone marrow by activating the erythropoietin receptor (EpoR) on erythrocytic-progenitor cells. ...Erythropoiesis-stimulating agents are approved in the United States and Europe for treating anaemia in cancer patients receiving chemotherapy based on randomised, placebo-controlled trials showing that ESAs reduce RBC transfusions. Erythropoiesis-stimulating agent-safety issues include thromboembolic events and concerns regarding whether ESAs increase disease progression and/or mortality in cancer patients. Several trials have reported an association between ESA use and increased disease progression and/or mortality, whereas other trials in the same tumour types have not provided similar findings. This review thoroughly examines available evidence regarding whether ESAs affect disease progression. Both clinical-trial data on ESAs and disease progression, and preclinical data on how ESAs could affect tumour growth are summarised. Preclinical topics include (i) whether tumour cells express EpoR and could be directly stimulated to grow by ESA exposure and (ii) whether endothelial cells express EpoR and could be stimulated by ESA exposure to undergo angiogenesis and indirectly promote tumour growth. Although assessment and definition of disease progression vary across studies, the current clinical data suggest that ESAs may have little effect on disease progression in chemotherapy patients, and preclinical data indicate a direct or indirect effect of ESAs on tumour growth is not strongly supported.
Genomic changes that occur in breast cancer during the course of disease have been informed by sequencing of primary and metastatic tumor tissue. For patients with relapsed and metastatic disease, ...evolution of the breast cancer genome highlights the importance of using a recent sample for genomic profiling to guide clinical decision-making. Obtaining a metastatic tissue biopsy can be challenging, and analysis of circulating tumor DNA (ctDNA) from blood may provide a minimally invasive alternative.
Hybrid capture-based genomic profiling was carried out on ctDNA from 254 female patients with estrogen receptor-positive breast cancer. Peripheral blood samples were submitted by clinicians in the course of routine clinical care between May 2016 and March 2017. Sequencing of 62 genes was carried out to a median unique coverage depth of 7503×. Genomic alterations (GAs) in ctDNA were evaluated and compared with matched tissue samples and genomic datasets of tissue from breast cancer.
At least 1GA was reported in 78% of samples. Frequently altered genes were TP53 (38%), ESR1 (31%) and PIK3CA (31%). Temporally matched ctDNA and tissue samples were available for 14 patients; 89% of mutations detected in tissue were also detected in ctDNA. Diverse ESR1 GAs including mutation, rearrangement and amplification, were observed. Multiple concurrent ESR1 GAs were observed in 40% of ESR1-altered cases, suggesting polyclonal origin; ESR1 compound mutations were also observed in two cases. ESR1-altered cases harbored co-occurring GAs in PIK3CA (35%), FGFR1 (16%), ERBB2 (8%), BRCA1/2 (5%), and AKT1 (4%).
GAs relevant to relapsed/metastatic breast cancer management were identified, including diverse ESR1 GAs. Genomic profiling of ctDNA demonstrated sensitive detection of mutations found in tissue. Detection of amplifications was associated with ctDNA fraction. Genomic profiling of ctDNA may provide a complementary and possibly alternative approach to tissue-based genomic testing for patients with estrogen receptor-positive metastatic breast cancer.
This phase II study evaluated the pharmacokinetics and safety of trastuzumab and paclitaxel given every 3 weeks to women with human epidermal growth factor receptor 2 (HER2)-overexpressing metastatic ...breast cancer.
Thirty-two patients received a loading dose of trastuzumab 8 mg/kg intravenously (day 1) and paclitaxel 175 mg/m2 (day 0). Thereafter, trastuzumab 6 mg/kg was administered on the same day as paclitaxel 175 mg/m2 every 3 weeks for seven cycles. In responding patients, trastuzumab monotherapy every 3 weeks was then continued until disease progression or patient withdrawal.
Trastuzumab trough levels were more than 20 mug/mL by the end of cycle 1. The half-life of trastuzumab was estimated to be 18 to 27 days, although this may be an underestimate. The combination of paclitaxel and trastuzumab was generally well tolerated, with no unexpected toxicities and no pharmacokinetic interaction. The most common adverse events were myalgia, paresthesias, alopecia, arthralgia, and fatigue. Events associated with trastuzumab included infusion-related reactions and cardiac dysfunction. Ten patients had a > or = 15% decrease in ejection fraction, but only one had symptomatic heart failure. The investigator-assessed objective response rate was 59% (four complete and 15 partial responses) and seven patients (22%) had stable disease. The median duration of response was 10.5 months and median time to progression was 12.2 months.
Additional investigation of trastuzumab administered every 3 weeks is warranted. In combination with paclitaxel, it is generally well tolerated. Plasma trastuzumab trough levels and clinical response rates compare favorably with those achieved with the standard weekly trastuzumab regimen plus chemotherapy. The presence of trastuzumab does not alter exposure to paclitaxel.
Estrogen receptor-positive (ER-positive) metastatic breast cancer is often intractable due to endocrine therapy resistance. Although ESR1 promoter switching events have been associated with ...endocrine-therapy resistance, recurrent ESR1 fusion proteins have yet to be identified in advanced breast cancer.
To identify genomic structural rearrangements (REs) including gene fusions in acquired resistance, we undertook a multimodal sequencing effort in three breast cancer patient cohorts: (i) mate-pair and/or RNAseq in 6 patient-matched primary-metastatic tumors and 51 metastases, (ii) high coverage (>500×) comprehensive genomic profiling of 287–395 cancer-related genes across 9542 solid tumors (5216 from metastatic disease), and (iii) ultra-high coverage (>5000×) genomic profiling of 62 cancer-related genes in 254 ctDNA samples. In addition to traditional gene fusion detection methods (i.e. discordant reads, split reads), ESR1 REs were detected from targeted sequencing data by applying a novel algorithm (copyshift) that identifies major copy number shifts at rearrangement hotspots.
We identify 88 ESR1 REs across 83 unique patients with direct confirmation of 9 ESR1 fusion proteins (including 2 via immunoblot). ESR1 REs are highly enriched in ER-positive, metastatic disease and co-occur with known ESR1 missense alterations, suggestive of polyclonal resistance. Importantly, all fusions result from a breakpoint in or near ESR1 intron 6 and therefore lack an intact ligand binding domain (LBD). In vitro characterization of three fusions reveals ligand-independence and hyperactivity dependent upon the 3′ partner gene. Our lower-bound estimate of ESR1 fusions is at least 1% of metastatic solid breast cancers, the prevalence in ctDNA is at least 10× enriched. We postulate this enrichment may represent secondary resistance to more aggressive endocrine therapies applied to patients with ESR1 LBD missense alterations.
Collectively, these data indicate that N-terminal ESR1 fusions involving exons 6–7 are a recurrent driver of endocrine therapy resistance and are impervious to ER-targeted therapies.
Targeting basal-like breast cancers Dey, Nandini; Smith, Brian R; Leyland-Jones, B
Current drug targets,
11/2012, Letnik:
13, Številka:
12
Journal Article
Recenzirano
Basal-like breast tumors and triple negative breast tumors are high-risk breast cancers that typically carry the poorest prognoses compared with HR (Hormone Receptor)-positive tumors and HER2 (Human ...Epidermal growth factor Receptor 2)-amplified tumors for known therapies. These subsets of breast cancers exhibit aggressive clinical behavior, pushing margins of invasion, poor clinical outcome, and derive limited benefit from current therapy. This clinical situation is contributed and further aggravated by their less known biology, lack of obvious molecular targets, absence of favorable biomarkers, and their limited response to single-drug therapy. In 2010, Oakman et al., remarked that current therapy fails to curtail the innate aggressive behavior of TNBC (Triple Negative Breast Cancer) in the majority of patients. The poor prognosis coupled with a lack of targeted use of therapies is responsible for the high mortality in this subtype. The present review will examine the existing literature and scrutinize the difficulties that have, to date, limited the understanding of the biology of these tumor cells, and provide a rationale for the development of the concept of combining subtype-specific and pathway-specific drug targets for the therapeutic intervention of the disease.
A meta-analysis of trials of ESA use in patients with breast cancer receiving chemotherapy was conducted. Nine studies were analyzed (ESAn = 2346; controln = 2367). The overall stratified ...random-effects odds ratio (95% CI) was 1.17 (0.99–1.39) for death and 1.01 (0.87–1.16) for disease progression-related end points. Odds ratios remain consistent with prior data after including recent results.
New data on erythropoiesis-stimulating agents (ESAs) regarding overall survival and disease progression-related outcomes in patients with breast cancer receiving chemotherapy are presented in a meta-analysis of controlled trials of ESA use (epoetin &agr;, epoetin &bgr;, darbepoetin &agr;, biosimilars).
A literature search identified reports from January 1997 through March 2014. We used company databases for Amgen, Inc., or Janssen studies and published data for other studies. Random-effects odds ratios (ORs) were calculated to compare results for patients randomized to ESA with those randomized to control.
Deaths were reported for 571 of 2346 patients (24%) in the ESA groups and 523 of 2367 patients (22%) in the control groups OR, 1.20; 95% confidence interval (CI) 1.03–1.40. Sensitivity analyses were conducted to explore the effects of individual studies and exclusion of one study (BEST) resulted in an OR for death of 1.12 (95% CI 0.94–1.34). In seven studies reporting progression-related end points (N = 4197; ESAn = 2088; controln = 2109), the OR was 1.01 (95% CI 0.87–1.16) for ESA compared with control.
After incorporating recent results of ESA use in patients with breast cancer, risks of survival and progression-free survival remain consistent with previously published data.
The expression of side-population (SP) cells and their relation to tumour-initiating cells (T-ICs) have been insufficiently studied in breast cancer (BC). We therefore evaluated primary cell cultures ...derived from patients and a panel of human BC cell lines with luminal- or basal-molecular signatures for the presence of SP and BC stem cell markers.
The SPs from luminal-type BC were analysed for BC T-IC characteristics, including human epidermal growth factor receptor 2 (HER2), ERalpha, IGFBP7 expression and their ability to initiate tumours in non-obese diabetic severe combined immunodeficiency (NOD/SCID) mice. Pharmacological modulators were used to assess the effects of HER2 signalling and breast cancer-resistance protein (BCRP) expression on SPs.
The SP was more prevalent in the luminal subtype of BC compared with the basal subtype. HER2 expression was significantly correlated with the occurrence of an SP (r(2)=0.75, P=0.0003). Disappearance of SP in the presence of Ko143, a specific inhibitor of the ATP-binding cassette transporter BCRP, suggests that BCRP is the predominant transporter expressed in this population. The SP also decreased in the presence of HER2 signalling inhibitors AG825 or trastuzumab, strengthening the notion that HER2 contributed to the SP phenotype, likely through downstream AKT signalling. The SP cells from luminal-type MCF-7 cells with enforced expression of HER2, and primary cells with luminal-like properties from a BC patient, displayed enrichment in cells capable of repopulating tumours in NOD/SCID mice. Engraftment of SP cells was inhibited by pretreatment with AG825 or by in vivo treatment with trastuzumab.
Our findings indicate an important role of HER2 in regulating SP and hence T-ICs in BC, which may account for the poor responsiveness of HER2-positive BCs to chemotherapy, as well as their aggressiveness.
The clinical experience recently reported with epidermal growth factor receptor (EGFR)-targeting drugs confirms the synergistic interactions observed between these compounds and conventional ...cytotoxic agents, which were previously established at the preclinical stage. There are, however, examples of major gaps between the bench and the bedside. Particularly demonstrative is the failure of the tyrosine kinase inhibitors (TKIs) (gefitinib and erlotinib) combined with chemotherapy in pretreated nonsmall cell lung cancer patients. These discrepancies can be due to several factors such as the methodology used to evaluate TKI plus cytotoxic agent combinations in preclinical models and the insufficient consideration given to the importance of the drug sequences for the tested combinations. Recent advances in understanding the biologic basis of acquired resistance to these agents have great potential to improve their clinical effectiveness. The purpose of this review is to critically examine the experimental conditions of the preclinical background for anti-EGFR drug-cytotoxic agent combinations and to attempt to explain the gap between clinical observations and preclinical data.
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