Genomic predictors of response to doxorubicin versus docetaxel in breast cancer
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Charles Perou
PROVIDER: E-GEOD-21997 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Results: In subjects who completed treatment and surgery, the pCR and near-complete response rates were 15.8% in HER2-negative and 50% in HER2-positive subjects. When stratified by genomic subtype, subjects of the HER2-enriched subtype had the best response (66.7%), the luminal A (11%) and B (4.8%) subtypes the poorest. Of 147 patients tested for p53 mutations using the AmpliChip test, 78 variants were detected; 55 were missense. The response rate among TP53 mutated patients was 30%, significantly higher than the rate in TP53 wild-type patients (10%, P = .0032). Concordance between AmpliChip mutation status versus IHC staining was 65%, with AmpliChip status being predictive of response and IHC status being not being predictive. Conclusion: Capecitabine plus docetaxel in HER2-negative subjects, and with trastuzumab in HER2-positive subjects, provided a good response rate with fewer cycles. p53 mutational analysis using the AmpliChip p53 assay, and genomic subtyping using the PAM50 assay, were promising predictive tests of response. reference x sample
2011-03-18 | E-GEOD-22358 | biostudies-arrayexpress
Project description:Breast cancer is no longer viewed as a homogenous disease, but rather a compilation of several distinct subtypes as defined by microarray or other large scale genomic analyses. Based on prior reports, we hypothesized that younger women’s breast tumors would be enriched for more aggressive subtypes (i.e. Basal-like) and higher grade, and that age-specific gene expression differences may be highly dependent on subtype classification and/or grade. Using two independent datasets, our current analysis shows that breast tumors arising in women aged = 45 years are enriched for the Basal-like subtype (and higher grade) while those aged = 65 years are enriched for Luminal tumors. Moreover, when evaluating gene expression differences between age-defined groups, sizable gene lists were identified which diminished to few, if any, age-specific genes when statistically correcting for significant clinical factors (i.e. subtype, grade, etc). Keywords: reference x sample 344 breast tumor samples hybridized with Stratagene common reference and profiled on Agilent microarrays.
2010-08-31 | E-GEOD-20624 | biostudies-arrayexpress
Project description:Metaplastic breast cancers (MBC) are aggressive, chemoresistant tumors characterized by lineage plasticity. To advance understanding of their pathogenesis and relatedness to other breast cancer subtypes, 28 MBCs were compared with common breast cancers using comparative genomic hybridization, transcriptional profiling, and reverse-phase protein arrays and by sequencing for common breast cancer mutations. MBCs showed unique DNA copy number aberrations compared with common breast cancers. PIK3CA mutations were detected in 9 of 19 MBCs (47.4%) versus 80 of 232 hormone receptor-positive cancers (34.5%; P = 0.32), 17 of 75 HER-2-positive samples (22.7%; P = 0.04), 20 of 240 basal-like cancers (8.3%; P < 0.0001), and 0 of 14 claudin-low tumors (P = 0.004). Of 7 phosphatidylinositol 3-kinase/AKT pathway phosphorylation sites, 6 were more highly phosphorylated in MBCs than in other breast tumor subtypes. The majority of MBCs displayed mRNA profiles different from those of the most common, including basal-like cancers. By transcriptional profiling, MBCs and the recently identified claudin-low breast cancer subset constitute related receptor-negative subgroups characterized by low expression of GATA3-regulated genes and of genes responsible for cell-cell adhesion with enrichment for markers linked to stem cell function and epithelial-to-mesenchymal transition (EMT). In contrast to other breast cancers, claudin-low tumors and most MBCs showed a significant similarity to a "tumorigenic" signature defined using CD44(+)/CD24(-) breast tumor-initiating stem cell-like cells. MBCs and claudin-low tumors are thus enriched in EMT and stem cell-like features, and may arise from an earlier, more chemoresistant breast epithelial precursor than basal-like or luminal cancers. PIK3CA mutations, EMT, and stem cell-like characteristics likely contribute to the poor outcomes of MBC and suggest novel therapeutic targets. Comparison of reference samples against treatment
2009-04-01 | E-GEOD-10885 | biostudies-arrayexpress
Project description:Our findings indicate that the integration of expression signatures and clinicopathological factors can better determine the individual risk of recurrence for newly diagnosed patients with lymph-node negative ER-positive breast cancer. Models incorporating other variables yet to be discovered will be needed to obtain robust prognostic models for ER-negative and HER2-positive breast cancer patients. A large data set was created by combining five different publicly available microarray datasets of node-negative breast cancer patients treated with local therapy only. The microarray gene expression data was combined using the batch effect adjustment by the Distance Weighted Discrimination method.
2010-10-25 | E-GEOD-15393 | biostudies-arrayexpress
Project description:Results When compared with each other, primary tumors and regional metastases showed statistically indistinguishable gene expression patterns. Supervised analyses comparing patients with distant metastases versus primary tumors or regional metastases showed that the distant metastases were distinct and distinguished by the lack of expression of fibroblast/mesenchymal genes, and by the high expression of a 13-gene profile (that is, the âvascular endothelial growth factor (VEGF) profileâ) that included VEGF, ANGPTL4, ADM and the monocarboxylic acid transporter SLC16A3. At least 8 out of 13 of these genes contained HIF1α binding sites, many are known to be HIF1α-regulated, and expression of the VEGF profile correlated with HIF1α IHC positivity. The VEGF profile also showed prognostic significance on tests of sets of patients with breast and lung cancer and glioblastomas, and was an independent predictor of outcomes in primary breast cancers when tested in models that contained other prognostic gene expression profiles and clinical variables. Conclusions These data identify a compact in vivo hypoxia signature that tends to be present in distant metastasis samples, and which portends a poor outcome in multiple tumor types. Microarrays and immunohistochemistry were used to analyze primary breast tumors, regional (lymph node) metastases, and distant metastases in order to identify biological features associated with distant metastases.
2009-03-31 | E-GEOD-3521 | biostudies-arrayexpress
Project description:Breast cancers can be classified using whole genome expression into distinct subtypes that show differences in patient prognosis. One of these groups, the basal-like carcinomas, are poorly differentiated, highly metastatic, and genomically unstable. These tumors also contain specific genetic alterations with one example being frequent p53 mutations. The loss of the tumor suppressor gene encoded by the retinoblastoma (RB1) locus is a well-characterized occurrence in many tumor types, however, its role in breast cancer is less clear with many reports demonstrating a Loss of Heterozygosity (LOH) that does not correlate with loss of RB1 protein expression. Here we report that LOH of the RB1 locus was observed at a high frequency in basal-like and luminal B tumors. These tumors also concurrently have low expression of RB1 mRNA as assessed by DNA microarray. As in previous reports, we also did not see a significant correlation between RB1 LOH and protein expression as measured by immunohistochemistry (IHC). p16INK4a, however, was highly expressed both by microarray and IHC, in basal-like tumors only presumably due to a previously reported feedback loop caused by RB1 loss. These results suggest that the functional loss of RB1 is a common event in the progression of basal-like and luminal B breast tumors, which may play a key role in dictating therapeutic responses Keywords: reference x sample Comparison of reference samples against treatment
2010-06-25 | E-GEOD-10884 | biostudies-arrayexpress
Project description:Purpose: The biological subtypes of breast cancer designated as Luminal A, Luminal B, HER2+/ER-, and Basal-like are clinically important for prognosis and planning treatment strategies. Recognizing that there is a continuum in both the spectrum of breast cancer disease and the risk of survival, we sought to develop a clinical test for the biological subtypes using a supervised risk classier.Methods: Microarray and real-time quantitative RT-PCR (qRT-PCR) data from 189 samples, procured as fresh-frozen and formalin-fixed, paraffin-embedded tissues, were used to statistically select prototypical samples and genes for the biological subtypes of breast cancer. Predictions for biological subtype and risk of recurrence were determined for different stages of disease, treatments, and across analytical platforms. Results: The biological subtype predictions on a large combined microarray test set showed prognostic significance across all patients (1244 subjects; p<0.0001), on node negative patients with no adjuvant systemic therapy (738 subjects; p<0.0001), and on patients treated with endocrine therapy (404 subjects; p=0.001). Analysis of a neoadjuvant chemotherapy study revealed a high pathologic complete response (pCR) rate in HER2+/ER- and Basal-like patients. The subtype and risk predications were also highly significant when using the qRT-PCR assay from archived FFPE breast cancers. Conclusion: Our risk predictor based on distance to biological subtype centroids provides a continuous risk score that applies to all stages of breast cancer given current therapies. The assay can be performed using archived breast tissues and a real-time qRT-PCR assay, thus facilitating application to retrospective cohorts and clinical samples. Keywords: reference x sample Comparison of reference samples against treatment
2010-06-24 | E-GEOD-10886 | biostudies-arrayexpress
Project description:Introduction: A gene expression signature indicative of active wound responses is common to more than 90% of non-neoplastic tissues adjacent to breast cancer, but these tissues also show substantial heterogeneity, suggesting different microenvironmental subtypes. Genomic variation in the extratumoral microenvironment has received limited study. Methods: Gene expression analysis from 72 patient-derived samples adjacent to invasive breast cancer or ductal carcinoma in situ was evaluated. Unsupervised clustering identified two distinct gene expression subgroups that differed substantially in expression of genes associated with epithelial-to-mesenchymal transition (EMT). We evaluated the prognostic and biological relevance of this extratumoral EMT-like signature using clinical and experimental approaches. Results: We found that the extratumoral EMT-like signature was not significantly associated with overall survival among all patients [Hazard Ratio (HR) = 1.4, 95% CI 0.6 - 2.8, p=0.337], but there was a strong association with overall survival among estrogen receptor (ER)-positive patients [HR = 2.5, 95% CI 0.9 – 6.7, p=0.062] or hormone-treated patients [HR=2.6, 95% CI 1.0 – 7.0, p=0.045]. In addition, co-culturing of ER-positive MCF-7 cells with cells undergoing EMT increased migration of MCF7 cells in a TGF-β1 dependent manner. Conclusion: Together, these results suggest that the presence of an EMT-like signature in the cancer-adjacent extratumoral microenvironment may influence the aggressiveness of the ER-positive tumors and that ER-positive patients with these extratumoral signatures may require additional treatments or more aggressive surgeries. Reference vs. test sample. 74 test samples (12 breast tumors, 62 normal tissue adjacent to breast tumor) from 72 patients.
2011-12-31 | E-GEOD-31589 | biostudies-arrayexpress
Project description:Cancer progression is mediated by processes that are also important in wound repair. As a result, cancers have been conceptualized as overhealing wounds or "wounds that do not heal," and gene expression signatures reflective of wound repair have shown value as predictors of breast cancer survival. Despite the widespread acknowledgment of commonalities between host responses to wounds and host responses to cancer, the gene expression responses of normal tissue adjacent to cancers have not been well characterized. Using RNA extracted from histologically normal breast tissue from 105 patients, 121 arrays were performed, including 72 arrays representing 58 reduction mammoplasty patients and 49 arrays representing 47 cancer patients, we measured whole genome expression profiles and identified a gene expression signature that is induced in response to breast cancer.
2010-01-06 | E-GEOD-16113 | biostudies-arrayexpress
Project description:The basal-like breast cancer subtype portends a poor clinical prognosis, and a defining feature of this subtype is the high expression of genes in the âproliferation signatureâ. B-Myb, a member of the MYB protein family of transcription factors, is highly expressed in the proliferation signature and is amplified and overexpressed in a variety of tumor types, including breast. In this report we demonstrated that B-Myb is highly expressed in basal-like breast cancer relative to the other subtypes, and B-Myb expression alone is prognostic. We also identified an association between a nonsynonymous B-Myb germline variant (S427G, rs2070235) and an increased risk of having a basal-like breast cancer among patients with breast cancer. The expression of B-Myb, or the S427G variant, was manipulated in vitro and we observed that in hTERT-immortalized normal Human Mammary Epithelial Cells, but not basal-like tumor-derived lines, cells ectopically expressing B-Myb showed increased sensitivity to DNA topoisomerase II inhibitors, but not other chemotherapeutics; in addition, microarray analyses of B-Myb overexpressing cells identified many G2/M targets as being preferentially induced. These results again suggest that B-Myb is involved in G2/M cell cycle control and that dysregulation of B-Myb may contribute to an increased sensitivity to a specific class of chemotherapeutic agents in vitro, and potentially in vivo. These data provide insight into the influence of B-Myb in human breast cancer, which is of potential clinical importance for determining disease risk and for guiding treatment. Experiment Overall Design: Reference VS. Samples
2009-01-18 | E-GEOD-11429 | biostudies-arrayexpress