[Show abstract][Hide abstract] ABSTRACT: Background
Variations in single nucleotide polymorphisms (SNPs) have been associated with enhanced drug efficacy and toxicity in cancer therapy. SNP variations in the ErbB2 gene have been identified that alter the protein sequence of the HER2-neu protein, but how these polymorphisms affect prognosis and response to HER2 targeted therapy is unknown. We examined eleven ErbB2 SNPs that alter the HER2-neu amino acid sequence to determine whether any of these particular polymorphisms were associated with increased trastuzumab cardiotoxicity in a case–control study.
140 subjects were enrolled from a single institution under Weill Cornell Medical College IRB protocol #0804009734. Patients were eligible if they had histologically or cytologically proven HER2-neu positive breast cancer and more than 3 months of trastuzumab therapy. Cases had either symptomatic CHF or a decline in LVEF of 15% (or if the LVEF <55%, a decline in LVEF of 10%) that resulted in at least temporary discontinuation of trastuzumab, whereas controls had no decline in their LVEF. Eleven ErbB2 single gene SNPs that resulted in an alteration in the HER2-neu protein amino acid sequence were studied. Single gene SNP analysis was carried out using SNP genotyping assays from genomic DNA obtained from peripheral blood or buccal swab.
Only two of the ErbB2 SNPs (Ile 655 Val and Pro 1170 Ala) were found to have variation. There was no association between codon 665 and cardiotoxicity; however the proline variant of amino acid 1170 was more likely than the alanine variant to be found in cases with trastuzumab cardiotoxicity (35% of case patients as compared to 17% of controls, p = 0.04). This association remained significant in multivariable analysis taking into account age, race, and history of hypertension (adjusted OR = 2.60, 95% CI = 1.02, 6.62, p = 0.046).
The Her2/neu Pro 1170 Ala polymorphism can be used to identify a subset of patients who are at increased risk of cardiotoxicity from trastuzumab therapy. Her2/neu single nucleotide polymorphisms may be useful in conjunction with other biomarkers to risk stratify patients in order to optimize clinical management.
BMC Cancer 04/2015; 15(1). DOI:10.1186/s12885-015-1298-6 · 3.32 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Data from two phase 3 studies of eribulin were pooled in analyses initially requested by the European Medicines Agency to assess whether specific patient subgroups, previously treated with an anthracycline and a taxane, benefited from eribulin. Study 305/EMBRACE included women after two-to-five lines of chemotherapy for advanced breast cancer who were randomized to eribulin mesylate (1.4 mg/m2 on days 1 and 8 every 21 days) or treatment of physician’s choice. In Study 301, patients who had received up to two prior chemotherapy regimens for advanced disease were randomized to eribulin (as above) or capecitabine (1.25 g/m2 b.i.d. on days 1–14 every 21 days). In the pooled population, overall survival (OS), progression-free survival and response rates were analysed in the intent-to-treat population and selected subgroups. Overall, 1,062 patients were randomized to eribulin and 802 patients to control. Median OS was 15.2 months with eribulin versus 12.8 months with control (hazard ratio [HR] 0.85; 95 % CI 0.77, 0.95; P = 0.003). In all subgroups assessed, OS data favoured eribulin; significant improvements occurred in some subgroups, notably in women with human epidermal growth factor receptor 2 (HER2)-negative disease (HR 0.82; P = 0.002), although the effect in those with HER2-negative but hormone-receptor-positive disease did not reach statistical significance; benefits were also seen, among others, in those with estrogen-receptor-negative and triple-negative disease. Eribulin improves OS in various patient subgroups with advanced/metastatic breast cancer who had previously received an anthracycline and a taxane. Women with HER2-negative disease are among those who may obtain benefit from eribulin.
Electronic supplementary material
The online version of this article (doi:10.1007/s10549-014-3144-y) contains supplementary material, which is available to authorized users.
Breast Cancer Research and Treatment 11/2014; 149(1). DOI:10.1007/s10549-014-3144-y · 4.20 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Glycoprotein NMB (gpNMB), a novel transmembrane protein overexpressed in 40% to 60% of breast cancers, promotes metastases in animal models and is a prognostic marker of a poor outcome in patients. The antibody-drug conjugate glembatumumab vedotin consists of a fully human anti-gpNMB monoclonal antibody, conjugated via a cleavable linker to monomethyl auristatin E. Glembatumumab vedotin is generally well tolerated, with observed objective responses in advanced melanoma. This is, to our knowledge, the first study of glembatumumab vedotin in breast cancer.
[Show abstract][Hide abstract] ABSTRACT: The development of breast cancer metastasis is accompanied by dynamic transcriptome changes and dramatic alterations in nuclear and chromatin structure. The basis of these changes is incompletely understood. The DNA methylome of primary breast cancers contribute to transcriptomic heterogeneity and different metastatic behavior. Therefore we sought to characterize methylome remodeling during regional metastasis. We profiled the DNA methylome and transcriptome of 44 matched primary breast tumors and regional metastases. Striking subtype-specific patterns of metastasis-associated methylome remodeling were observed, which reflected the molecular heterogeneity of breast cancers. These divergent changes occurred primarily in CpG island (CGI)-poor areas. Regions of methylome reorganization shared by the subtypes were also observed, and we were able to identify a metastasis-specific methylation signature that was present across the breast cancer subclasses. These alterations also occurred outside of CGIs and promoters, including sequences flanking CGIs and intergenic sequences. Integrated analysis of methylation and gene expression identified genes whose expression correlated with metastasis-specific methylation. Together, these findings significantly enhance our understanding of the epigenetic reorganization that occurs during regional breast cancer metastasis across the major breast cancer subtypes and reveal the nature of methylome remodeling during this process.
PLoS ONE 08/2014; 9(8):e103896. DOI:10.1371/journal.pone.0103896 · 3.23 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Background
We sought to define the clinical and ultrastructure effects of ixabepilone (Ix), a microtubule-stabilizing chemotherapy agent on cutaneous sensory nerves and to investigate a potential mitochondrial toxicity mechanism.Methods
Ten breast cancer patients receiving Ix underwent total neuropathy score clinical (TNSc) assessment, distal leg skin biopsies at cycle (Cy) 3 (80–90 mg/m2), Cy5 (160–190 mg/m2), and Cy7 (>200 mg/m2) and were compared to 5 controls. Skin blocks were processed for EM and ultrastructural morphometry of Remak axons done.ResultsAt baseline, Ix-treated subjects had higher TNSc values (4.5 ± 0.8 vs. 0.0 ± 0.0), greater percentage of empty (denervated) Schwann cells (29% vs. 12%), altered axonal diameter (422.9 ± 17 vs. 354.9 ± 14.8 nm, P = 0.01), and axon profiles without mitochondria tended to increase compared to control subjects (71% vs. 70%). With increasing cumulative Ix exposure, an increase in TNSc values (Cy3: 5.4 ± 1.2, Cy7: 10 ± 4, P < 0.001), empty Schwann cells (39% by Cy7), and dilated axons (in nm, Cy3: 506.3 ± 22.1, Cy5: 534.8 ± 33, Cy7: 527.8 ± 24.4; P < 0.001) was observed. In addition, axon profiles without mitochondria (Cy3:74%, Cy7:78%) and mitochondria with abnormal morphology (grade 3 or 4) increased from 24% to 79%. Schwann cells with atypical mitochondria and perineuronal macrophage infiltration in dermis were noted.InterpretationThis study provides functional and structural evidence that Ix exposure induces a dose-dependent toxicity on small sensory fibers with an increase in TNSc scores and progressive axonal loss. Mitochondria appear to bear the cumulative toxic effect and chemotherapy-induced toxicity can be monitored through serial skin biopsy-based analysis.
[Show abstract][Hide abstract] ABSTRACT: Eribulin mesylate, a novel non-taxane microtubule dynamics inhibitor, is approved for treatment of metastatic breast cancer (MBC) in patients who have previously received at least 2 chemotherapeutic regimens for MBC that should have included an anthracycline and a taxane in the adjuvant or metastatic setting. This phase 2 study evaluated efficacy and safety of eribulin as first-line therapy for human epidermal growth factor receptor 2-negative (HER2-negative) MBC. Patients with measurable HER2-negative locally recurrent breast cancer or MBC with ≥12 months since prior neoadjuvant or adjuvant (neo/adjuvant) chemotherapy received eribulin mesylate 1.4 mg/m(2) IV on days 1 and 8 of each 3-week cycle. Endpoints included objective response rate (ORR) per RECIST v1.1 (primary), safety, progression-free survival (PFS), clinical benefit rate (ORR + stable disease ≥6 months; CBR), and duration of response (DOR). Fifty-six patients were enrolled and received eribulin; 38 (68 %) had prior neo/adjuvant therapy, including 33 who had anthracycline and/or taxane-containing chemotherapy; 41 (73 %) had estrogen receptor-positive disease, and 12 (21 %) had estrogen receptor-negative, progesterone receptor-negative, and HER2-negative (triple-negative) disease. Patients received a median of 7 cycles (range 1-43); 6 (11 %) received treatment for ≥12 months. ORR was 29 % (95 % CI 17.3-42.2), CBR was 52 %, and median DOR was 5.8 months. Median PFS was 6.8 months. Thirty-six patients (64 %) had grade 3/4 treatment-related adverse events; most common were neutropenia (50 %), leukopenia (21 %), and peripheral neuropathy (21 %). These results demonstrate that eribulin has substantial antitumor activity as first-line treatment for HER2-negative MBC with acceptable safety.
Breast Cancer Research and Treatment 04/2014; 146(2). DOI:10.1007/s10549-014-2923-9 · 4.20 Impact Factor