bluuebunny/crossref_metadata_2025_split huggingface dataset:
miRNA Profiling of Endocrine-Resistant Breast Tumours.
Authors: Larionov A. , Faratian D. , Caldwell H. , Sims A. , Fawkes A. , Murphy L. , Renshaw L. , Dixon J. , Dixon J. 
Published: December 2010

Abstract
RationalemiRNAs are a relatively recently discovered class of molecules with major implications in cellular biology, including tumorigenesis; yet little is known about their possible involvement in the development of endocrine resistance in breast cancer. The aim of this study was to identify sub-groups of endocrine-resistant tumours with distinctive miRNA profiles.Methods and ResultsFrozen biopsies were obtained from a series of 51 breast cancers, which were either progressing primary tumours, local recurrences or contra-lateral breast lesions developed while patients received endocrine treatment. Hormonal treatment included aromatase inhibitors or tamoxifen, most of the patients reached post-menopausal age, miRNA profiles were obtained using Illumina DASL® Sentrix Array Matrix.Un-supervised hierarchical clustering split 51 studied endocrine resistant tumours into two major groups, distinctive in their miRNA profiles. Several of miRNAs discriminating between the clusters have already been implemented in breast cancer (mir7, mir10a, mir205, mir206, mir 210). Most of the other miRNAs associated with the main tumour clusters are yet to be studied in relation to breast cancer biology (e.g. mir192, mir625, mir941, mir145 and mir512 among others). The miRNA-based tumour clusters were not clearly associated with a specific treatment or type of resistance. The miRNAs most clearly able to discriminate between tumours resistant to AIs and Tamoxifen included mir186, mir196a, mir196b and miR-594:9.1 (p&lt;0.05, fold change &gt;1.2).DiscussionThe results show heterogeneity of miRNA profiles in endocrine resistant breast cancers, for the first time suggesting that endocrine resistant tumours can be split into two major molecular sub-groups basing on their miRNA profiles. The results suggest that (i) miRNA-mediated gene expression regulation may be involved in the mechanisms of endocrine resistance and (ii) miRNA profiling allows different molecular sub-classes of endocrine-resistant tumours to be distinguished.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5130.
Src-Dependent Changes in Beta-Catenin Activity Promote a Migratory Phenotype in Endocrine-Resistant Breast Cancer Cells.
Authors: Wadhawan A. , Barrett-Lee P. , Smith C. , Nicholson R. , Hiscox S. 
Published: December 2010

Abstract
Background: Acquired resistance to endocrine therapies is associated with disease relapse and progression. In vitro, endocrine resistance is accompanied by increased Src activity and the development of a highly invasive and migratory phenotype. Here we have investigated the role of Src as a modulator of intercellular adhesion in endocrine-resistant breast cancer cells.Methods: Src and beta-catenin expression and activity were determined in endocrine-sensitive MCF7 and T47D cells and tamoxifen-resistant ('TamR') MCF7 cell variants at their basal level and following treatment with the Src inhibitor AZD0530 (0-2µM) using Western Blotting. Cell migration was assessed by seeding cells onto matrix-coated porous membranes in the presence or absence of AZD0530. After 24hrs, migratory cells were fixed, stained and counted. The effects of Src inhibition on beta-catenin association with E-cadherin was measured by immunoprecipitation whilst changes in cell morphology were determined using differential interference contrast microscopy.Results: In contrast to endocrine-sensitive MCF7 cells, tamoxifen-resistant ('TamR') variants displayed high levels of both activated Src kinase (Src phosphorylated at Y419) and tyrosine-phosphorylated beta-catenin (Y142 and Y654). Accompanying this was a decrease in the association of beta-catenin with E-cadherin; TamR cells also grew as dispersed cell colonies and displayed a greatly enhanced migratory phenotype compared to MCF7 cells. Inhibition of Src in TamR cells significantly reduced both Src activity and levels of beta-catenin (Y142 and Y654) whilst restoring beta-catenin association with E-cadherin and suppressing cell migration. Immunohistochemistry studies involving ER+ve breast cancer tissue (n=390 from the ABC trial) have revealed that higher nuclear levels of y142 phosphorylated beta-catenin correlate with increased levels of total beta-catenin in the nuclei, suggesting src activated beta-catenin may confer an aggressive breast cancer phenotype.Treatment of ER+ve, endocrine-sensitive MCF7 and T47D cells with tamoxifen in the short term promoted an increase in Src activity and an accompanying Src-dependent increase in tyrosine-phosphorylated Y142 and Y654 beta-catenin, No effect was seen following treatment with fulvestrant or upon oestrogen deprivation.Conclusion: Src-dependent changes in beta catenin phosphorylation status appear to play a central role in the development of the migratory nature accompanying tamoxifen resistance in breast cancer cells which may correlate with findings in clinical tissue. Importantly, Src-dependent changes in beta-catenin activity appear to be promoted by tamoxifen itself during the drug-responsive phase and can be suppressed by the concomitant use of Src inhibitors.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5143.
Cytochrome P450 (CYP) 2A6 Genetic Variation Predicts Letrozole Plasma Concentrations in Postmenopausal Women with Breast Cancer.
Authors: Desta Z. , Tyndale R. , Hoffmann E. , Kreutz Y. , Nguyen A. , Flockhart D. 
Published: December 2010

Abstract
Background: The potent aromatase inhibitor (AI) letrozole is effective in the treatment of postmenopausal women with steroid-hormone-receptor–positive breast cancer (metastatic, neoadjuvant and adjuvant). The beneficial and adverse effects of letrozole vary widely among patients, and differences in pharmacokinetics may contribute to this variability. Letrozole is primarily cleared by hepatic metabolism. Since CYP2A6 has been implicated in letrozole metabolism in vitro, we tested the influence CYP2A6 genetic variants on plasma concentrations of letrozole in breast cancer patients. Methods: Postmenopausal women with early stage hormone receptor-positive breast cancer were recruited into an ongoing multicenter randomized clinical trial to study the pharmacogenomics of two AIs, exemestane (25 mg/day) and letrozole (2.5 mg/day) given orally. Total accrual to the trial is anticipated to be 250 in each arm. Three months plasma letrozole concentrations were measured by HPLC from 146 patients who were randomized to the letrozole arm and multiple CYP2A6 variants were genotyped from genomic DNA. Results: Plasma concentrations of letrozole showed wide variability among patients (16.6 ng/ml to 141.2 ng/ml; 8.5-fold difference). Genotypes were grouped based in to normal (*1/*1), intermediate (*1/*9 and *1/*12, n=23) and slow (*9/*12, *1/*2, *2/*9, *1/*35, *1/*4E; n=12) metabolizers based on genotyped predicted phenotype. A statistically significant difference in letrozole concentrations was observed among the patients with the different genotype groups (p&lt;0.0001; one-way ANOVA), with strong gene-dose effect relationship (r2=0.28; p&lt;0.0001). Letrozole plasma concentrations were significantly higher in patients with the slow or intermediate genotypes than those with normal genotype (p &lt; 0.0001; Dunn's post-test for multiple comparison correction).Conclusions: Polymorphisms in the CYP2A6 gene account for ∼28% of variability in letrozole concentrations in breast cancer patients. Prior genotyping for CYP2A6 variants may help to identify patients who benefit from letrozole and who experience adverse effects from the drug.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5160.
External Quality Assurance Schemes: The Impact of Participation in the UK Versus Rest of the World: 5 Year Data from the UK National External Quality Assurance Scheme.
Authors: Bartlett J. , Ibrahim M. , Jasani B. , Morgan J. , Ellis I. , Kay E. , Connolly Y. , Campbell F. , O'Grady A. , Starczynski J. , Di Palma S. , Hanby A. , Miller K. 
Published: December 2010

Abstract
The American Society of Clinical Oncology/College of American Pathologists guidelines highlighted the critical importance of quality assurance in diagnostic testing for HER2.Unstained formalin-fixed, paraffin-embedded human breast carcinoma cell line sections were circulated to scheme participants on 15 occasions over 5 years. “Reference laboratories” reported results for the HER2/chromosome 17 ratio and HER2 copy number for 5 years for each cell line. Results from the 5th years participants (3 runs 13, 14, 15) were assessed for the pass rate in UK versus rest of the world (EU, US, Asia, etc). The number of participants was 76-78 laboratories/run (UK 30-35, ROW 43-46).Results: The percentage of laboratories achieving “appropriate” results ranged from 78-82% overall. Significantly higher performance was observed over 3 runs for UK laboratories (91-97%, “appropriate” results) versus ROW laboratories (67-74% “appropriate” results), p = 0.004. All methods used by scheme participants in UK Laboratories had excellent performance rates (Pathvysion, PharmDx, Ventana SISH/Inform, Kreatech Posieden). However in the ROW there was evidence of poor performance, which may be related to the assay format, although numbers of comparisons are relatively small.Participation in external quality assurance schemes is a valuable mechanism for evaluation and benchmarking of performance between laboratories. It also serves to improve consistency of HER2 testing by in situ hybridization. Using data from the UK NEQAS scheme we identified that laboratories whose performance is monitored and linked to an intergrated corrective action component(UK laboratories) perform consistently better than laboratories where performance data alone is provided (ROW). In the UK both participation and adequate performance in a national EQA scheme is required for laboratory accreditation. Whilst, in the context of robust EQA there is no evidence that different methods affect performance, in the ROW implementation of some assays appears sub-optimal. This poor performance does not, however, identify fundamental flaws with these methods, which are currently very well controlled amongst UK users but suggests greater attention to EQA results and change to improve laboratory performance is required in the rest of the world.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6010.
PIK3CA Mutations Can Be Acquired during Tumor Progression in Breast Cancer.
Authors: Dupont J. , Dupont J. , Laenkholm A. , Laenkholm A. , Knoop A. , Knoop A. , Ewertz M. , Ewertz M. , Barrett C. , Hackl W. , Bandaru R. , Crowell T. , Rheinhardt J. , Liu W. , Gardner H. 
Published: December 2010

Abstract
Background: Activation of the PI3K pathway by somatic mutations in the PI3KCA oncogene plays an important role in breast cancer. Mutations in PI3KCA have been described in approximately 30 % of breast carcinomas. Dysregulation of the PI3K pathway may have a significant impact on primary or acquired resistance towards endocrine and anti HER2 targeted therapy. The objective of this study was to assess changes in mutations in PI3KCA between the primary tumor and corresponding later metastatic lesions.Material: Formalin-fixed paraffin-embedded tumor blocks were available from 104 paired samples from primary tumors and corresponding distant metastases. In 99 patients paired PI3KCA mutation results were obtained.Methods: H&E sections were generated from each formalin-fixed paraffin-embedded tumor block, and thus guided two 1mm cores were obtained for Tumour microarray (TMA) preparation and DNA extraction for mutational analysis. In samples with scant tumor tissue macrodissection was made. Mutations in exon 9 (E542K, E545K) and in exon 20 (H1047L, H1047R) in the helical and the kinase domains of the PIK3CA gene encoding the catalytic p110 subunit of PI3K were analyzed by primer extension methodology using the SNaPshot Multiplex kit from ABI.Results: The PIK3CA mutations were detected in 36 % (37/102 patients) of the primary tumors or axillary nodes, with 14 % exon 9 mutations (E542K, E545K) and 25 % exon 20 mutations (H1047R, H1047L). In metastatic lesions there were mutations in 45 % (46/103), with 13 % exon 9 mutations (E542K, E545K) and 36 % exon 20 mutations (H1047R, H1047L). There was a clear increase in Exon 20 mutations in metastases (P = 0.07) suggesting that mutations in PIK3CA can be acquired during tumor progression. Exon 20 mutations were acquired in 21 % of the patients in the metastatic setting compared with the primary tumor. There was no significant change in exon 9 mutations between primary tumor and metastatic lesion. Expression analysis of other markers of interest: HER2, PTEN, p-AKT, pS6, p-ERK, KI67, cyclin D1 are being made.Conclusion: These data suggest that PI3KCA mutations can be acquired during tumor progression, indicating an increase in the activation of the PI3K pathway. Our data show that approximately half of the tumors at relapse are addicted to the PI3K pathway. The study confirms the necessity of performing tumor marker expression analysis in the metastatic lesion when it comes to treatment decision making. Correlations between the mutations, other markers of the pathway, and clinical data will be presented at the meeting.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6023.
GP88 Serum Level Is Increased in Breast Cancer Patients with Disease Progression.
Authors: Serrero G. , Serrero G. , Tkaczuk K. , Yue B. , Kamimura S. , Tait N. , Zhan M. , Ecklund D. 
Published: December 2010

Abstract
GP88 (progranulin) is an 88-kDa glycoprotein autocrine growth factor that plays a critical role in breast tumorigenesis. GP88 is expressed in human BC tumors in a positive correlation with their tumorigenicity. In estrogen receptor positive (ER+) cells, GP88 expression is low and is stimulated by estradiol whereas in ER negative (ER-) cells, it is constitutively overexpressed. In ER+ cells, increased GP88 expression was found to be associated with resistance to anti-estrogen therapy. In Her-2 overexpressing breast tumors, increased GP88 expression was associated with Herceptin resistance. Inhibition of GP88 expression in human breast adenocarcinoma cells resulted in a drastic reduction of tumor incidence and tumor growth in nude mice. Immunohistochemical studies carried out with 206 paraffin-embedded human breast biopsies have shown that GP88 is expressed in invasive ductal carcinomas in correlation with expression of markers of poor prognosis whereas normal tissues and benign breast lesions were negative. Importantly, high GP88 expression in tissue biopsies was accompanied by decreased disease-free and overall survival. Since GP88 contains a signal peptide for secretion, we have shown that GP88 can be found in serum. An IRB approve blood sampling study of 189 patients (Race: Caucasian- 91, African American-92, Asian-6; median age- 51 with a range from 26 to 81) established at the University of Maryland demonstrated that GP88 was measurable in serum and that GP88 serum level was statistically elevated in breast cancer patients when compared to healthy individuals. Median level of GP88 was 40.7 ng/ml (range 6.4-80) in early stage (stage 1 –3) BC pts (p- value = 0.007) and 45.3 ng/ml (range 9.8 to 158.4) in stage 4 metastatic BC patients (p-value= 0.0007). Statistically significant increase in circulating GP88 level was found in early stages as well as in metastatic disease when compared to healthy individuals.Since we have shown that GP88 tissue expression was associated with increased disease recurrence, the present study was focused on examining whether GP88 serum level was also increased in disease progression and could be used to monitor disease recurrence. Our data show that patients with disease recurrence or progression presented a 5 to 10 fold increase in their GP88 serum levels.This study identifies GP88 as a measurable biomarker for recurrence or disease progression not only at the tissue but also at the serum level.This study is supported by grants from MIPS, the Avon Foundation and from the National Cancer Institute.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6040.
Prognostic Significance of Nodal and PgR Status on Early Relapse in Operable HER-2 Positive Breast Cancer from the Pre-Trastuzumab Era.
Authors: Cho H. , Van Belle V. , Vandorpe T. , Wildiers H. , Janssen H. , Leunen K. , Amant F. , Vergote I. , Berteloot P. , Smeets A. , Van Limbergen E. , Weltens C. , Paridaens R. , Van Huffel S. , Christiaens M. , Neven P. 
Published: December 2010

Abstract
Background: Over the last decade, trastuzumab has become a standard adjuvant treatment option in HER-2 positive breast cancers. However, with a mainly 'on-treatment' effect only, the economic burden and adverse effects incurred from its routine use for 1 year following completion of chemotherapy, there emerges a need to identify a group of HER-2 positive breast cancers at low-risk for relapse. We, therefore, investigated potential prognostic factors in a cohort of HER-2 positive breast cancers in the era before trastuzumab, especially focusing on hormonal status.Methods: We retrospectively reviewed the data of 240 trastuzumab-naïve patients with a HER-2 FISH-positive breast cancer who had primary surgery at University Hospitals Leuven between January 2000 and December 2005. We collected data including age at diagnosis, menopausal status, histologic type, tumor size, grade, lymph node involvement, estrogen receptor (ER) /progesterone receptor (PgR) status, and disease-free survival (DFS) outcome. A multivariate Cox hazard model was used to identify prognostic factors and the cumulative DFS rate was determined using the Kaplan-Meier method.Results: After a median follow-up of 57.5 months there were 50 breast cancer related events meaning that 5-year DFS rate was 78.4% for the entire cohort. Median time to first event was 20 months and ranged from 4 to 96 months. Cox model revealed that only PgR status and lymph node involvement were independent prognostic factors for disease relapse. (p = 0.03 and p &lt; 0.01 respectively). In Kaplan-Meier analysis, patients with PgR+ showed better DFS rate than those with PgR- (figure 1; 83.8% vs. 73.1%, p = 0.02) while ER status didn't reach statistical significance (p = 0.154).Nodal involvement ≥4 was strongly associated with poor DFS rate compared with node negativity. (p = 0.00). Of note, a subgroup of patients with PgR+ and LN-. presented no relapse within the first two years after surgery (figure 2).Conclusions: In this series of HER-2 positive breast cancers, PgR and nodal status were strong prognostic factors for early breast cancer relapse. Patients with a PgR+/LN- phenotype were unlikely to relapse within the first two years of surgery. We propose to evaluate the added benefit of adjuvant trastuzumab to chemotherapy in women with this phenotype as such data are yet not available from the major adjuvant trastuzumab trials.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6046.
Value ER, PR and HER Status as Independent Prognostic Factor of Local Recurrence after Breast Conserving Surgery.
Authors: Ostapenko V. , Bruzas S. , Mudenas A. , Sabonis J. , Kurtinaitis J. , Jackevicius A. , Ostapenko A. 
Published: December 2010

Abstract
Aim : Evaluate value ER, PR and HER2 status as independent prognostic factor of local recurrence after breast conserving surgery Methods and materials: The retrospective study of 537 breast cancer patients stage I,II,III which were combined treated in Institute Oncology, Vilnius University in 2005-2006.was made The surgery treatment was used as primarily selection criteria, the data on vital status of all patients was summarized by December, 2008. The median follow-up time was 33 month. Pts age was from 29 years to 76 years. Premenopausal pts (&lt;50 years) - 181 pts, postmenopausal – 356 pts. All pts underwent Breast conserving surgery, irradiation and chemohormono therapy. Distribution of pts according pathological tumor size "pT" was pT0 - 5 pts (1,0%), pT1 - 312 pts (58,1%), pT2 - 208 pts (38,7%), pT3 - 12 pts (2,2%). Distribution of pts according to nodal status "pN" was: "N0" - 333 pts (62,1%), "N1"- 172 pts (32%), "N2" - 30 pts (5,8%), "N3" - 2 pts (0,3%). Distribution of pts according differentiation degree "G" was “G1"- 100 (18,6%), "G2"- 266 (49,7%), "G3" - 171 (31,7%). Pts distribution according ER receptors positive tumors was ER strong (score &gt;=10) - 166 pts (30,9%), medium (score 6-9) - 146 pts (27,2%), week (scrore &lt;=5) - 72 pts (13,4%), no reaction - 148 pts (27,6%). Pts distribution according PR receptors positive tumors was PR strong (score &gt;=10) - 141 pts (26,6%), medium (score 6-9) - 125 pts (23,3%), week (scrore &lt;=5) - 84 pts (15,6%), no reaction - 182 pts (33,9%). Pts distribution according HER2 receptors (3+) - 117 pts (21,8%), HER2 receptors (2+) - 116 pts (21,8%), HER2 receptors (1+) - 188 pts (35,0%), HER2 receptors no reaction - 110 pts (20,5%).Results: Local recurrence rate was calculated according Nelson-Aalen cumulative hazard estimate (analysis time 4 years) and was equal to 8 %.Local recurrence rate according ER-, PR-, HER2 0 vs ER+, PR+, HER2 3+ was equal to 14% vs 4,5%.In 63,5% of all local recurrence ER, PR were negative “0 “,in 40.9% of all local recurrences HER2 was positive (3+) Conclusion: According to our preliminary results ER, PR and HER2 status are independent prognostic factor of local recurrence after breast.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6047.
Clinical and Nutritional Correlates of Survival in Breast Cancer.
Authors: Lis C. , Gupta D. , Dahlk S. , Vashi P. , Lammersfeld C. 
Published: December 2010

Abstract
Background: Malnutrition can be a frequent manifestation of breast cancer and its treatment. Several nutritional assessment tools have varying levels of association with survival, and have been tested individually with different patient populations, sometimes making it difficult to assess the impact of one tool relative to the others. We therefore conducted a single-institution multivariate analysis of 3 most commonly used nutritional tools - Body Mass Index (BMI), Subjective Global Assessment (SGA) and bioimpedance-derived phase angle (PA).Material and Methods: A case series of 234 breast cancer patients treated at Cancer Treatment Centers of America. Using SGA, patients were classified as well nourished (SGA A), moderately malnourished (SGA B) or severely malnourished (SGA C). Cox proportional hazard models were used to evaluate the independent prognostic effects of SGA, PA and BMI after controlling for each other, stage at diagnosis and prior treatment history (newly diagnosed versus previously treated).Results: Of 234 patients, 74 were newly diagnosed while 160 had received prior treatment. 159 had early stage (I/II) disease at diagnosis, while 75 had late stage (III/IV). The median age at presentation was 52.8 years (range 25-75 years). The mean PA and BMI scores were 5.5 (std. dev = 1.1) and 28.7 (std. dev = 6.2) respectively. 171 patients were well-nourished (SGA A) while 63 were malnourished (SGA B/C). Multivariate Cox modeling, after adjusting for stage at diagnosis, prior treatment history and other nutritional variables, found that malnourished status (SGA B/C) was associated with a relative risk (RR) of 2.4 (95% CI: 1.5-3.9, p &lt; 0.001). Late stage at diagnosis was associated with a RR of 2.0 (95% CI: 1.3-3.2; p = 0.003) and previously treated category was associated with a RR of 7.9 (95% CI: 3.9-15.8; p &lt; 0.001). PA and BMI were found to be statistically non-significant.Discussion: We found that SGA A (well-nourished status) versus SGA B/C (moderate to severe malnourished status) identified patients with better survival outcomes independent of BMI, PA, stage at diagnosis and prior treatment history. Among the nutritional assessment tools evaluated, SGA emerged as the strongest predictor of survival in breast cancer.
Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6048.