863 results on '"M, Dowsett"'
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2. Healing of a ruptured anterior cruciate ligament and patient-reported outcomes following non-surgical management with a novel bracing protocol
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S. Filbay, M. Dowsett, M. Chaker Jomaa, J. Rooney, J. Kazaglis, J. Merlino, M. Moran, M. Allwright, D. Kuah, R. Sabharwal, A. van den Heever, P. Lucas, G. Roger, M. Cross, and T. Cross
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Physical Therapy, Sports Therapy and Rehabilitation ,Orthopedics and Sports Medicine - Published
- 2022
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3. Abstract P2-05-02: Age-related genetic and epigenetic changes in estrogen-receptor positive breast cancer
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M Dowsett and EF Schuster
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Cancer Research ,Breast cancer ,Oncology ,business.industry ,Age related ,Cancer research ,Estrogen receptor ,Medicine ,Epigenetics ,business ,medicine.disease - Abstract
Background: Age is the main risk factor for developing breast cancer (BC) in women. The increase in incidence with age is dominated by estrogen receptor positive (ER+) BC despite the >90% reduction of estrogen levels during menopause and later life. Recent models suggest the lifetime risk of BC is correlated with the number of stem cell divisions with random mutations arising during each division and driving cancer development. However, only two genes are mutated in more than 20% of BC while several recurrent copy number alterations (CNAs) occur in more than 50%. New models of age-related risk factors need to be developed that incorporate mutations, CNAs, epigenetics, and other biological factors. As data of this type is limited in normal breast tissue, factors correlated with age of diagnosis in ER+ BC were identified to understand which variables changed with age and might impact risk of developing BC. Methods: In silico analysis of public databases was used to identify factors in ER+ primary BC and normal adjacent tissue (NT) that are correlated with age of diagnosis including DNA mutations, CNAs, DNA methylation and gene/protein expression (TCGA n=599ER+,113NT; METABRIC n=1435ER+,144NT). Results: DNA mutations accumulated with age in ER+ BC with the median mutation count below 28 in primary tumors diagnosis in patients 80yr. However, the two most frequently mutated genes (PIK3CA and TP53) showed no significant correlation with age. As previously reported, GATA3 mutation rate was nearly twice as high in younger patients (80yr=0.12). There was little evidence of a general accumulation of CNAs with age, but there were higher rates of gain in 16p (80yr=0.51) and loss of 1p (80yr=0.37) in older patients and lower rates of loss in 6q (80yr=0.24). The most significant correlations with age related to ESR1 including expression of ESR1 mRNA (rho=0.39,P=1.2e-23 Spearman), ERα protein (rho=0.35,P=1.7e-15 Spearman), and demethylation of ESR1 promoter (rho=-0.36,P=1.6e-13 Spearman). The levels of the activated form of ERα (pS118) also correlated with age but to a much lesser extent than total ERα (rho=0.12,P=0.01 Spearman). Demethylation and expression of ESR1 were highly correlated (rho=-0.50,P Conclusions: Analysis of DNA mutations and CNAs fit previous theoretical models with both the result of stochastic processes. In these models, the low impact on fitness from individual mutations allows the accumulation over time while the high fitness costs of CNAs prevent accumulation and are likely acquired in a single catastrophic event. The ability of ER+ BC to progress in the presence of very low postmenopausal estrogen levels may be partly explained by demethylation leading to higher ESR1 expression and maintenance of ERα activation. In theory, changes in expression and demethylation can be targeted to reduce the age-related increase in risk for developing BC. Citation Format: Schuster EF, Dowsett M. Age-related genetic and epigenetic changes in estrogen-receptor positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-05-02.
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- 2019
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4. PO-29: Coagulation and circulating tumour cells as pharmacodynamic biomarkers of response to aromatase inhibitors in breast cancer
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C.C. Kirwan, J. Castle, S. Pritchard, H. Tovey, N.J. Bundred, I. Smith, J. Robertson, J. Bliss, and M. Dowsett
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Hematology - Published
- 2022
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5. Abstract PL1: Genomic Profiling in Early Stage ER Positive Breast Cancers/Precision Medicine
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M Dowsett
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Cancer Research ,Oncology - Abstract
Genomic profiling has become mainstream for the management of early ER+ breast cancer and has become a favoured approach for research into pathways that govern prognosis and response and resistance to medical therapies.Management: Several commercial tests are available for the assessment of residual risk of recurrence of patients receiving hormonal therapies. We have compared several of these in postmenopausal patients treated with anastrozole or tamoxifen in the ATAC trial, including OncotypeDX (ODX), Prosigna (PAM50) and EndoPredict (EP). While PAM50 and EP provide estimates of risk that by design integrate tumour size and nodal status, estimates from ODX are also improved substantially by integration with clinicopathologic factors. The 3 tests include genes related to proliferation and to dependence on estrogen signalling with the ODX being dominated by the latter and PAM50 by the former. This may explain the better performance of the PAM50 than ODX at cessation of endocrine treatment after 5 years when the outcome for patients with high ER appears to worsen. While the tests have largely been validated in postmenopausal cases they are used in premenopausal cases as well. We found that while individual gene modules varied in expression across the menstrual cycle there was little systemic variability in the overall estimates of risk. Our recent work has indicated that mutations in TP53 add significant prognostic information to that from the commercial profiling tests.Research: We have conducted genomic analyses during presurgical therapy of ER+ breast cancer to determine the key pathways of endocrine resistance using change in Ki67 as the end-point of response. Very few tumours with low levels of ER by IHC ( Citation Format: M Dowsett. Genomic Profiling in Early Stage ER Positive Breast Cancers/Precision Medicine [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PL1.
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- 2022
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6. Abstract ES5-2: Clinical and molecular profiles to identify who is at risk?
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M Dowsett
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Oncology ,Cancer Research ,medicine.medical_specialty ,business.industry ,Internal medicine ,Medicine ,business - Abstract
The persistent risk of recurrence from ER-positive primary breast cancer has been known for many years. It was recently described in detail and in relation to baseline clinicopathologic factors in a meta-analysis by the EBCTCG. This involved nearly 63,000 patients that had been prescribed 5 years of endocrine therapy and had reached the end of that time recurrence-free (Pan et al, NEJM, 2017, 377, 1836). Among other things this revealed that even among patients with T1N0 disease 13% had a distant recurrence between years 5 and 20. Our group have previously created a Clinical Treatment Score (CTS) from nodal status, tumor size, grade, age and type of adjuvant endocrine treatment and validated this for estimating risk of distant recurrence from the time of diagnosis. Drawing on a training dataset of 4,735 patients from the ATAC trial and a validation set of 6,711 patients from the BIG1-98 trial we created the CTS5, a prognostic score of risk from year 5, that features the same factors as CTS other than type of endocrine treatment (Dowsett et al, JCO, 2018, 36, 1941). Of note, only 4/304 patients with one to three positive nodes that were categorized as low risk in the validation set had a distant recurrence between years 5 and 10. The CTS5 calculator can be accessed online at www.cts5-calculator.com. There are several commercially available molecular profiles that estimate the risk of recurrence over years 0-10 after diagnosis in endocrine-treated primary breast cancer. In the TransATAC study some of these, including the EPClin and PAM50-ROR, show similar prognostic information over years 5-10 (after 5 years of endocrine therapy) as they do over years 0-5 (during endocrine therapy). In contrast, while the Oncotype Recurrence Score (RS) showed similar prognostic information to EPClin and PAM50-ROR in years 0-5 its performance in years 5-10 was substantially worse. Examination of the time-dependent prognostic relationship of each of the individual genes and modules in the RS showed that those patients with higher ER signaling had good prognosis before year 5 but poorer after year 5, suggesting that the cessation of endocrine therapy may lead to this poorer post-5 year outcome (Dowsett et al Clin Cancer Res, 2015, 21, 2763). A broad-based assessment of gene expression in the TransATAC sample set found that there was limited potential to identify a prognostic profile that performed substantially better after 5 years (Buus et al, Breast Cancer Res, 2018, 20, 103). One test, the 7-gene Breast Cancer Index, has reported on a relatively small sample set that it can predict the benefit or not from extended adjuvant endocrine therapy. Further validation studies of this are warranted as well as other tests that provide the same predictive information. Citation Format: Dowsett M. Clinical and molecular profiles to identify who is at risk? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr ES5-2.
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- 2019
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7. A prospective study of endogenous serum hormone concentrations and breast cancer risk in premenopausal women on the island of Guernsey
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HV Thomas, TJ Key, DS Allen, JW Moore, M Dowsett, IS Fentiman, and DY Wang
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Cancer Research ,Estradiol ,Breast Neoplasms ,Guernsey ,Oncology ,Sex Hormone-Binding Globulin ,Odds Ratio ,Humans ,Female ,Testosterone ,Prospective Studies ,Menopause ,reproductive and urinary physiology ,hormones, hormone substitutes, and hormone antagonists ,Progesterone ,Research Article - Abstract
The associations between serum concentrations of oestradiol, progesterone, testosterone and sex hormone-binding globulin (SHBG) and risk of breast cancer in premenopausal women were investigated in a prospective study of breast cancer on the island of Guernsey. Sixty-two women diagnosed with breast cancer an average of 8 years subsequent to blood collection were matched for day of menstrual cycle, age and year of blood collection with 182 control subjects. Cases had a 12% higher mean oestradiol concentration over the whole menstrual cycle (P = 0.17) with a large difference at mid-cycle (75% higher, P = 0.04). Differences between cases and control subjects in progesterone (luteal phase), testosterone and SHBG were small and not statistically significant: luteal phase progesterone 9% lower in cases, P = 0.64; testosterone 4% higher, P = 0.57; SHBG 8% higher, P = 0.24. The small difference in oestradiol concentration could be aetiologically important, but larger prospective studies are needed.
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- 2016
8. Communicating prognosis to patients with metastatic disease: what do they really want to know?
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Phyllis Butow, Rebecca Hagerty, Martin H.N. Tattersall, and Sharon M. Dowsett
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Adult ,Health Knowledge, Attitudes, Practice ,medicine.medical_specialty ,Breast Neoplasms ,Disease ,Audit ,Interviews as Topic ,Patient satisfaction ,medicine ,Humans ,Aged ,Aged, 80 and over ,Physician-Patient Relations ,Evidence-Based Medicine ,business.industry ,Communication ,Nursing research ,Public health ,Evidence-based medicine ,Middle Aged ,Prognosis ,Surgery ,Oncology ,Patient Satisfaction ,Family medicine ,Structured interview ,Women's Health ,Female ,business ,Qualitative research - Abstract
Clinical audits suggest that prognosis is often not discussed with cancer patients, and cancer patients often over- or underestimate their prognosis. Doctors wish to convey information honestly and sensitively, but are often unsure how best to achieve this. An evidence base and guidelines in this area are lacking. This study aimed to obtain patient and health professional views on optimal ways of presenting prognosis to patients with metastatic breast cancer. Qualitative methods were used to generate participant views and experiences. Seventeen patients and 13 health professionals working in cancer care participated in structured interviews, which were audio-taped and transcribed. Sampling was discontinued when informational redundancy was achieved. The transcribed interviews were content analysed by a trained assessor using the constant-comparative method. Seven primary themes were identified, including: communication within a caring, trusting, long-term relationship; open and repeated negotiations for patient preferences for information; clear, straightforward presentation of prognosis where desired; strategies to ensure patient understanding; encouragement of hope and a sense of control; consistency of communication within the multi-disciplinary team; communication with other members of the family. Communication about prognosis in a metastatic setting requires considerable resources from both patients and doctors. Nevertheless, a number of useful strategies were identified. A quantitative study obtaining feedback from a large and representative sample of patients with metastatic cancer is now in progress, to confirm patient preferences for the communication styles identified in this qualitative study.
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- 2002
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9. Selecting patients for extended adjuvant endocrine therapy
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M. Dowsett
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Oncology ,medicine.medical_specialty ,business.industry ,Internal medicine ,medicine.medical_treatment ,Endocrine therapy ,Medicine ,Surgery ,General Medicine ,business ,Adjuvant - Published
- 2017
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10. The AURORA initiative for metastatic breast cancer
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Aron Goldhirsch, Richard D. Gelber, Dimitrios Zardavas, K Engelen, J Baselga, Roberto Salgado, A. Di Leo, Larry Norton, G. von Minckwitz, Peter J. Campbell, Philippe Aftimos, Christos Sotiriou, David Cameron, P. Dinh, Alexandre Irrthum, Debora Fumagalli, Theodora Goulioti, Kamal S. Saini, M Dowsett, Martine Piccart, Michael Gnant, and Marion Maetens
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CA15-3 ,Oncology ,Breast Neoplasms -- blood -- diagnosis -- genetics ,Cancer Research ,medicine.medical_specialty ,Pathology ,molecular profiling ,Neoplasm Proteins -- blood -- genetics ,Breast Neoplasms ,Disease ,Breast cancer ,breast cancer ,Informed consent ,Internal medicine ,Biopsy ,medicine ,Humans ,Early Detection of Cancer ,next generation sequencing ,medicine.diagnostic_test ,business.industry ,Cancer ,Médecine pathologie humaine ,High-Throughput Nucleotide Sequencing ,Sciences bio-médicales et agricoles ,medicine.disease ,Prognosis ,Metastatic breast cancer ,Neoplasm Proteins ,3. Good health ,metastatic ,Clinical trial ,Cancérologie ,Female ,Minireview ,business ,targeted clinical trials - Abstract
Metastatic breast cancer is one of the leading causes of cancer-related mortality among women in the Western world. To date most research efforts have focused on the molecular analysis of the primary tumour to dissect the genotypes of the disease. However, accumulating evidence supports a molecular evolution of breast cancer during its life cycle, with metastatic lesions acquiring new molecular aberrations. Recognising this critical gap of knowledge, the Breast International Group is launching AURORA, a large, multinational, collaborative metastatic breast cancer molecular screening programme. Approximately 1300 patients with metastatic breast cancer who have received no more than one line of systemic treatment for advanced disease will, after giving informed consent, donate archived primary tumour tissue, as well as will donate tissue collected prospectively from the biopsy of metastatic lesions and blood. Both tumour tissue types, together with a blood sample, will then be subjected to next generation sequencing for a panel of cancer-related genes. The patients will be treated at the discretion of their treating physicians per standard local practice, and they will be followed for clinical outcome for 10 years. Alternatively, depending on the molecular profiles found, patients will be directed to innovative clinical trials assessing molecularly targeted agents. Samples of outlier patients considered as 'exceptional responders' or as 'rapid progressors' based on the clinical follow-up will be subjected to deeper molecular characterisation in order to identify new prognostic and predictive biomarkers. AURORA, through its innovative design, will shed light onto some of the unknown areas of metastatic breast cancer, helping to improve the clinical outcome of breast cancer patients., SCOPUS: re.j, info:eu-repo/semantics/published
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- 2014
11. Marker für die defekte homologe Rekombination beim sporadischen Mammakarzinom
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Christopher J. Lord, M Graeser, M Parton, H Gevensleben, I.E. Smith, Jorge S. Reis-Filho, Alan Ashworth, A McCarthy, M Dowsett, F Daley, Nicholas C. Turner, and N Orr
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Maternity and Midwifery ,Obstetrics and Gynecology - Published
- 2014
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12. Biomarker changes associated with the development of resistance to aromatase inhibitors (AIs) in estrogen receptor-positive breast cancer
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Ian E. Smith, Suzanne Drury, Jorge S. Reis-Filho, J. Salter, M. Dowsett, M Afentakis, Roger A'Hern, Margaret Hills, and Monica Arnedos
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Adult ,medicine.drug_class ,Receptor, ErbB-2 ,Estrogen receptor ,Breast Neoplasms ,Anastrozole ,Receptor, IGF Type 1 ,Progesterone receptor ,Nitriles ,Biomarkers, Tumor ,Medicine ,PTEN ,Humans ,Aromatase ,Insulin-like growth factor 1 receptor ,Aged ,Retrospective Studies ,Aged, 80 and over ,Aromatase inhibitor ,biology ,business.industry ,Aromatase Inhibitors ,PTEN Phosphohydrolase ,Hematology ,Original Articles ,Middle Aged ,Triazoles ,Androstadienes ,Tamoxifen ,Ki-67 Antigen ,Oncology ,Receptors, Estrogen ,Estrogen ,Drug Resistance, Neoplasm ,Letrozole ,Cancer research ,biology.protein ,Insulin Receptor Substrate Proteins ,Stathmin ,Female ,Neoplasm Recurrence, Local ,business ,Receptors, Progesterone ,medicine.drug - Abstract
The post-AI recurrence phenotype can be highly variable and reflect multiple mechanisms of resistance. In some cases, loss of ER occurs but there is also increased expression in other instances with evidence of persistent ER functioning, suggesting that further endocrine therapy may be appropriate in these patients. Cases of PTEN loss and HER2 gain also occur. Comprehensive molecular profiling of metastases will be required to direct subsequent targeted therapy with confidence.The purpose of this study was to identify any differences in key biomarkers associated with estrogen action between biopsies taken at diagnosis and at recurrence or progression during treatment with an aromatase inhibitor (AI). Patients were retrospectively identified from a clinical database as having relapsed or progressed during AI treatment. Immunohistochemistry was carried out against estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), insulin-like growth factor type-1 receptor (IGF1R), insulin receptor substrate-1 (IRS-1), stathmin, phosphatase and tensin homolog and Ki67. Fifty-five pairs of samples were identified with ER- and/or PgR-positive diseases. Four (7%) patients were ER-negative at progression. Overall, PgR levels were lower in the recurrence sample, but 35% of cases remained positive. IGF1R levels decreased significantly. There were no substantial changes in HER2, IRS-1 or stathmin levels to indicate a role in resistance. Higher Ki67 levels at resistance indicate more proliferative disease. The phenotype of AI-recurrent lesions shows high between-tumour heterogeneity. There is evidence of an increase in Ki67, a reduction in IGF1R and a loss of ER expression in some individuals and some activation of growth factor signalling pathways that may explain resistance in individuals and merit treatment targeted to those pathways. Biopsy at recurrence will be necessary to identify the relevant target for individuals.
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- 2014
13. The development of inhibitory control in preschool children: Effects of 'executive skills' training
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Sharon M. Dowsett and David J. Livesey
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Task switching ,Working memory ,Flexibility (personality) ,Executive functions ,Developmental psychology ,Task (project management) ,Behavioral Neuroscience ,Developmental Neuroscience ,Developmental and Educational Psychology ,Cognitive development ,Discrimination learning ,Psychology ,Cognitive load ,Developmental Biology ,Cognitive psychology - Abstract
As one of several processes involved in the executive functioning of the cognitive system, inhibitory control plays a significant role in determining how various mental processes work together in the successful performance of a task. Studies of response inhibition have shown that although 3-year-old children have the cognitive capacity to learn the rules required for response control, indicated by the correct verbal response, developmental constraints prevent them from withholding the correct response (Bell & Livesey, 1985; Livesey & Morgan, 1991). Some argue that these abulic dissociations are relative to children's ability to reflect on the rules required for response control (Zelazo, Reznick, & Pinon, 1995). The current study showed that repeated exposure to tasks facilitating the acquisition of increasingly complex rule structures could improve inhibitory control (as measured by a go/no-go discrimination learning task), even in children aged 3 years. These tasks included a variant of Diamond and Boyer's (1989) modified version of the Wisconsin Card Sort Task and a simplification of the change paradigm (Logan & Burkell, 1986). It is argued that experience with these tasks increased the acquisition of complex rules by placing demands on executive processes. This includes response control and other executive functions, such as representational flexibility, the ability to maintain information in working memory, the selective control of attention, and proficiency at error correction. The role of experiential variables in the development of inhibitory control is discussed in terms of the interaction between neural development and appropriate executive task experience in the early years.
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- 2000
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14. Communication styles in the cancer consultation: preferences for a patient-centred approach
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J. Dunsmore, Stewart M. Dunn, Michael Boyer, Sharon M. Dowsett, J.L. Saul, R. Findlow, and Phyllis Butow
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Sick role ,education ,Experimental and Cognitive Psychology ,medicine.disease ,Preference ,Style (sociolinguistics) ,Psychiatry and Mental health ,Breast cancer ,Patient satisfaction ,Oncology ,medicine ,Anxiety ,medicine.symptom ,Empirical evidence ,Psychology ,Curriculum ,Clinical psychology - Abstract
Objective: Although doctor–patient communication has been the focus of numerous studies, there is a lack of empirical evidence on which to base a curriculum for teaching effective communication skills for use in an oncology setting. Research within the general practice area identifies patient-centred and doctor-centred behaviours as the most important dimensions of doctor–patient communication. This study examined patients and their relatives/friends' preferences for and satisfaction with patient-centred and doctor-centred consulting styles. It was argued that by determining patient preferences for consulting styles, specific recommendations for improving communication in the oncology setting could be formulated. Participants and Methods: One hundred and thirteen women who had been treated for breast cancer and 48 of their relatives or friends watched videotaped scenarios of an oncology consultation, using professional actors. Viewers were randomly allocated to either a good prognosis or poor prognosis video, in which the oncologist discussed the patient's diagnosis, treatment and prognosis. These segments were presented in both styles to allow viewers to directly compare and contrast the patient-centred and doctor-centred approach. Outcomes included style preference and satisfaction. Demographic details, information and involvement preferences, anxiety and depression levels were also obtained. Results: Both patients and their relatives or friends significantly preferred a patient-centred consulting style across all aspects of the consultation (p
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- 2000
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15. Aromatase inhibitors: current status and future applications
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M Dowsett
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Cancer Research ,Endocrinology ,Oncology ,biology ,business.industry ,Endocrinology, Diabetes and Metabolism ,biology.protein ,Medicine ,Current (fluid) ,Aromatase ,business ,Bioinformatics - Published
- 1997
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16. Biological background to aromatase inhibition
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M. Dowsett
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Oncology ,medicine.medical_specialty ,Aromatase inhibition ,biology ,business.industry ,Advanced breast ,medicine.medical_treatment ,Cancer ,General Medicine ,medicine.disease ,Internal medicine ,medicine ,biology.protein ,Surgery ,Aromatase ,skin and connective tissue diseases ,Endocrine control ,business ,Adjuvant - Abstract
Highly specific and potent aromatase inhibitors are becoming available for the treatment of advanced breast cancer and trials of their use in the adjuvant setting have started. There is a good understanding of the role of aromatase in the determination of plasma oestrogen levels and (in premenopausal women) of its endocrine control. However, there is not a clear relationship between plasma oestrogens and oestrogen-dependent tumour growth and the role of intratumoural aromatase needs to be determined. To ensure optimal usage of the new aromatase inhibitors it is essential are improve our understanding of the intratumoural effects of these drugs.
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- 1996
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17. Electrochemical analysis of metallic heritage artefacts: time-lapse spectroelectrochemical techniques
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A. Adriaens and M. Dowsett
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Materials science ,Nanotechnology ,engineering.material ,Electrochemistry ,Electrochemical cell ,Corrosion ,Dielectric spectroscopy ,Metal ,Cultural heritage ,Coating ,visual_art ,visual_art.visual_art_medium ,Forensic engineering ,engineering - Abstract
This chapter discusses the evaluation of metal conservation treatments using a specialized electrochemical cell. The cell can be deployed in a synchrotron beam line to make in-situ , time-lapse measurements on heritage metal alloys undergoing processes based on electrochemical treatments/measurements. We focus on two specific projects: (1) the evaluation of currently used stabilization processes for cupreous objects recovered from marine environments, and (2) the development and testing of a coating to protect lead objects which is stable, reversible (i.e. easy to apply and to remove), protective against corrosion and aesthetically justified.
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- 2013
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18. HER2 staining intensity in HER2-positive disease: Relationship with FISH amplification and clinical outcome in the HERA trial of adjuvant trastuzumab
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Zabaglo, L. Stoss, O. Rüschoff, J. Zielinski, D. Salter, J. Arfi, M. Bradbury, I. Dafni, U. Piccart-Gebhart, M. Procter, M. Dowsett, M.
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skin and connective tissue diseases ,neoplasms - Abstract
Background: Trastuzumab treatment improves survival of HER2-positive primary breast cancer. HER2 staining intensity varies widely in HER2-positive tumours. Patients and methods: We investigated whether differences in immunohistochemical (IHC) staining intensity for HER2 in HER2-positive tumors (IHC 3+ or FISH ratio ≥2.0) was associated with prognosis or benefit from trastuzumab treatment in patients randomized to 1 year or no trastuzumab in the HERceptin Adjuvant (HERA) trial. Median follow-up was 2 years. The nested case-control analysis, included 425 patients (cases) with a disease-free survival (DFS) event and two matched controls (no DFS event) per case. Tissue sections stained for HER2 were assessed for HER2 staining intensity by image analysis. Results: HER2 staining intensity varied widely and correlated with HER2 gene copy number (Spearman, r = 0.498, P < 0.001) or less closely with HER2/CEP17 FISH ratio (r = 0.396, P < 0.001). We found no significant difference in DFS in the observation arm according to staining intensity (odds ratio [OR] change per 10 unit change in intensity: 1.015, 95% confidence interval [CI] 0.930-1.108) and no impact of staining intensity on benefit derived from 1-year trastuzumab (OR: 1.017, 95% CI 0.925-1.120). Conclusions: Variability in HER2 staining in HER2-positive tumours has no role in clinical management with adjuvant trastuzumab. © The Author 2013. Published by Oxford University Press on behalf of the European Society for Medical Oncology All rights reserved.
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- 2013
19. The Effects of ICI 182,780, a Pure Anti-Oestrogen, on the Hypothalamic-Pituitary-Gonadal Axis and on Endometrial Proliferation in Premenopausal Women
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M. Dowsett, E. J. Thomas, P. L. Walton, and N.M. Thomas
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medicine.medical_specialty ,Endocrinology ,business.industry ,Internal medicine ,medicine ,Obstetrics and Gynecology ,Hypothalamic–pituitary–gonadal axis ,General Medicine ,business - Published
- 1995
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20. Comparison of two methods of storing breast fine needle aspirates (FNAs) using oestrogen receptor immunocytochemical assay as a method of evaluating the storage methods
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M. Dowsett, S. A. Burton, and P.A. Trott
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Pathology ,medicine.medical_specialty ,Tissue Fixation ,Histology ,Cytospin Slide ,business.industry ,Biopsy, Needle ,Immunocytochemistry ,Breast Neoplasms ,General Medicine ,medicine.disease ,Immunohistochemistry ,Pathology and Forensic Medicine ,Staining ,Tissue culture ,Breast cancer ,Receptors, Estrogen ,medicine ,Humans ,Female ,Tissue Preservation ,Oestrogen receptor ,business ,Cells, Cultured - Abstract
Two methods of storing fine needle aspirates were compared in 14 patients with breast cancer. The methods of storage were: (1) as a Cytospin slide prepared immediately from the aspirated material and stored at -80 degrees C; (2) as a suspension of cells in tissue culture medium, stored at -80 degrees C. The effect of storage on the cells was assessed by means of an oestrogen receptor immunocytochemical assay (ER-ICA). An ER positivity of 100% was obtained by ER-ICA staining of cells after storage method 1, whilst all of the specimens stored by method 2 were ER-negative. The data demonstrate that cells stored in tissue culture medium at -80 degrees C are not suitable for ER measurement. The storage method of choice for specimens intended for ERICA is as a Cytospin slide. The ER status of cells deposited on Cytospin slides prepared immediately and stored at -80 degrees C for 2 years could be demonstrated despite the delay in processing the specimen.
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- 1994
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21. Endometriosis: Oestrogen and progesterone receptors in endometriosis: heterogeneity of different sites
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M. Dowsett, R.J. Howell, and D.K. Edmonds
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medicine.medical_specialty ,medicine.drug_class ,business.industry ,medicine.medical_treatment ,Rehabilitation ,Endometriosis ,Obstetrics and Gynecology ,Stimulation ,Endometrium ,medicine.disease ,Steroid hormone ,medicine.anatomical_structure ,Endocrinology ,Reproductive Medicine ,Estrogen ,Internal medicine ,medicine ,Immunohistochemistry ,business ,Receptor ,Hormone - Abstract
The expression of receptors for the ovarian steroid hormones oestrogen and progesterone was studied immunohistochemically using monoclonal antibodies in samples of endometriosis and endometrium in 22 patients. In nine patients samples of endometriosis from more than one site were studied. There was marked heterogeneity in expression of receptors in endometriosis, both when comparing lesions with the corresponding endometrium and also between samples of endometriosis collected from different sites within the same patient. It was suggested that local environmental factors related to the site, depth and degree of fibrosis of the lesions determine the amount of steroid hormone stimulation reaching the lesions and account for the observed difference between endometriosis and endometrium and between endometriosis lesions of different sites.
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- 1994
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22. Effect of tamoxifen or anastrozole on steroid sulfatase activity and serum androgen concentrations in postmenopausal women with breast cancer
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S J, Stanway, C, Palmieri, F Z, Stanczyk, E J, Folkerd, M, Dowsett, R, Ward, R C, Coombes, M J, Reed, and A, Purohit
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Postmenopause ,Tamoxifen ,Neoplasms, Hormone-Dependent ,Antineoplastic Agents, Hormonal ,Nitriles ,Androgens ,Humans ,Breast Neoplasms ,Female ,Steryl-Sulfatase ,Anastrozole ,Triazoles ,Gas Chromatography-Mass Spectrometry - Abstract
In postmenopausal women estrogens can be formed by the aromatase pathway, which gives rise to estrone, and the steroid sulfatase (STS) route which can result in the formation of estrogens and androstenediol, a steroid with potent estrogenic properties. Aromatase inhibitors, such as anastrozole, are now in clinical use whereas STS inhibitors, such as STX64, are still undergoing clinical evaluation. STX64 was recently shown to block STS activity and reduce serum androstenediol concentrations in postmenopausal women with breast cancer. In contrast, little is known about the effects of aromatase inhibitors or anti-estrogens on STS activity or serum androgen levels.Study 1: Blood was collected from ten postmenopausal women with breast cancer before and after two-week treatment with anastrozole and serum concentrations of androstenediol and other androgens and estrogens were assessed. Study 2: Blood samples were collected from 15 breast cancer patients before and after four-week treatment with anastrozole and 10 patients before and after four-week treatment with tamoxifen. Blood was used to assess STS activity in peripheral blood lymphocytes (PBLs) and serum dehydroepiandrosterone sulfate and dehydroepiandrosterone levels.Neither anastrozole nor tamoxifen had any significant effect on STS activity as measured in PBLs. Anastrozole did not affect serum androstenediol concentrations.Anastrozole and tamoxifen did not inhibit STS activity and serum androstenediol concentrations were not reduced by aromatase inhibition. As androstenediol has estrogenic properties, it is possible that the combination of an aromatase inhibitor and STS inhibitor may give a therapeutic advantage over the use of either agent alone.
- Published
- 2011
23. International expert consensus on primary systemic therapy in the management of early breast cancer: highlights of the fourth symposium on primary systemic therapy in the management of operable breast cancer, cremona, Italy (2010)
- Author
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A. Berruti, D. Generali, M. Kaufmann, L. Puztai, G. Curigliano, M. Aglietta, L. Gianni, W. R. Miller, M. Untch, C. Sotiriou, M. Daidone, P. Conte, D. Kennedy, G. Damia, P. Petronini, S. Di Cosimo, P. Bruzzi, M. Dowsett, C. Desmedt, R. E. Mansel, L. Olivetti, C. Tondini, A. Sapino, P. Fenaroli, G. Tortora, H. Thorne, F. Bertolini, F. Ferrozzi, M. Danova, E. Tagliabue, E. de Azambuja, A. Makris, M. Tampellini, G. Dontu, L. Van't Veer, A. L. Harris, S. B. Fox, L. Dogliotti, A. Bottini, Berruti, Alfredo, Generali, Daniele, Kaufmann, Manfred, Puztai, Lajo, Curigliano, Giuseppe, Aglietta, Massimo, Gianni, Luca, Miller, William R., Untch, Michael, Sotiriou, Christo, Daidone, Mariagrazia, Conte, Pierfranco, Kennedy, Derek, Damia, Giovanna, Petronini, Piergiorgio, Di Cosimo, Serena, Bruzzi, Paolo, Dowsett, Mitch, Desmedt, Christine, Mansel, Robert E., Olivetti, Lucio, Tondini, Carlo, Sapino, Anna, Fenaroli, Privato, Tortora, Gianpaolo, Thorne, Hather, Bertolini, Francesco, Ferrozzi, Francesco, Danova, Marco, Tagliabue, Elda, de Azambuja, Evandro, Makris, Andrea, Tampellini, Marco, Dontu, Gabriela, Veer, Laura Van't, Harris, Adrian L., Fox, Stephen B., Dogliotti, Luigi, and Bottini, Alberto
- Subjects
Cancer Research ,Antineoplastic Agents, Hormonal ,Receptor, ErbB-2 ,Biopsy ,Antineoplastic Agents ,Breast Neoplasms ,Antineoplastic Agent ,ErbB-2 ,Meta-Analysis as Topic ,Antineoplastic Combined Chemotherapy Protocols ,Biomarkers, Tumor ,Chemotherapy ,Humans ,Chemotherapy, Adjuvant ,Clinical Trials as Topic ,Female ,Ki-67 Antigen ,Palpation ,Remission Induction ,Treatment Outcome ,Ultrasonography, Mammary ,Neoadjuvant Therapy ,Oncology ,Adjuvant ,Operable breast cancer ,Ultrasonography ,Mammary ,Antineoplastic Combined Chemotherapy Protocol ,Tumor ,Hormonal ,fungi ,food and beverages ,General Medicine ,Breast Neoplasm ,Biomarkers ,Human ,Receptor - Abstract
A panel of international breast cancer experts formulated a declaration of consensus regarding many key issues in the use of primary systemic therapy (PST) either in clinical routine or research practice. The attainment of pathological complete response (pCR), defined as no residual invasive tumor in the surgical specimens both in breast and in axillary nodes, is one of the main goals of PST, and pCR can be used as the primary objective in prospective clinical trials. However, pCR is not a reliable endpoint with all treatment approaches, and alternatives such as Ki67 index of the residual invasive disease or after 2 weeks of PST are also potential endpoints. PST has several advantages: breast conservation and the unique opportunity to obtain information on the interaction between treatment and tumor biology. Changes in tumor biology after PST are an early phenomenon; so, an additional core biopsy performed after 14 days from treatment start should be considered in clinical trials.
- Published
- 2011
24. Current Perspectives on Neoadjuvant Treatment of ER-Positive BC
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M. Dowsett, D. A. Cameron, N. Parry, and I. A. Mayer
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Oncology ,medicine.medical_specialty ,business.industry ,Neoadjuvant treatment ,Internal medicine ,Medicine ,Current (fluid) ,business - Published
- 2014
- Full Text
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25. Comparison of Four Immunochemical Methods For the Measurement of Oestrogen Receptor Levels In Breast Cancer
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J. A. McKINNA, M. Dowsett, H. Minasian, N. King, C. M. Ryde, D. Smith, K. Maclennan, and P.A. Trott
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Pathology ,medicine.medical_specialty ,Histology ,Concordance ,Breast Neoplasms ,Pathology and Forensic Medicine ,Immunoenzyme Techniques ,Breast cancer ,Freezing ,medicine ,Humans ,Oestrogen receptor ,Frozen section procedure ,medicine.diagnostic_test ,business.industry ,Biopsy, Needle ,Significant difference ,General Medicine ,medicine.disease ,Immunohistochemistry ,Staining ,Receptors, Estrogen ,Immunoassay ,Female ,Primary breast cancer ,business - Abstract
Four methods of assessing oestrogen receptor (ER) status were compared in 33 patients with operable primary breast cancer. the methods used to assess the ER status were immunocyto-chemical assay (ER-ICA) of frozen sections, fine needle aspirates and imprint material and enzyme immunoassay (ER-EIA) of tumour tissue. A mean overall ER positivity of 45% (15 out of 33), 41 % (13 out of 32) and 21 % (six out of 29) was obtained by immunocytochemical (ER-ICA) staining of frozen sections, fine needle aspirates and tumour imprints, respectively, and a mean overall ER positivity of 42% (14 out of 33) was obtained by ER-EIA. the concordance of ER positivity in pairs of data obtained from different method combinations was found to range between 72 and 91%. However, statistically there was no significant difference between the four methods on the basis of the data obtained. Good comparability has been shown between the three tissue analyses and therefore the method of choice is technically not immediately apparent.
- Published
- 1992
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- View/download PDF
26. POTENCY AND SELECTIVITY OF THE NON-STEROIDAL AROMATASE INHIBITOR CGS 16949A IN POSTMENOPAUSAL BREAST CANCER PATIENTS
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A. Mehta, M. Dowsett, Robert Stein, and R. C. Coombes
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medicine.medical_specialty ,Estrone ,medicine.drug_class ,Endocrinology, Diabetes and Metabolism ,Antineoplastic Agents ,Breast Neoplasms ,chemistry.chemical_compound ,Endocrinology ,Sex hormone-binding globulin ,Internal medicine ,Nitriles ,medicine ,Humans ,Potency ,Androstenedione ,Neoplasm Metastasis ,Aromatase ,Gonadal Steroid Hormones ,Testosterone ,Aged ,Randomized Controlled Trials as Topic ,Aged, 80 and over ,Aromatase inhibitor ,Dose-Response Relationship, Drug ,Estradiol ,Fadrozole ,biology ,Estrogen Antagonists ,Imidazoles ,Estrogens ,Middle Aged ,chemistry ,biology.protein ,Female ,Menopause ,medicine.drug - Abstract
A selective inhibitor of aromatase is widely sought for the treatment of postmenopausal women with breast cancer. CGS 16949A has been shown to be a highly selective, potent inhibitor of aromatase in vitro. Its potency as an oestrogen suppressant and its selectivity were examined by treating 24 postmenopausal patients with advanced breast cancer for 4 weeks with doses of 0.3, 1.0 and 2.0 mg twice daily. The study was conducted in two parts which compared the two lower doses and the two higher doses separately in a cross-over design protocol. All doses significantly suppressed serum oestradiol and oestrone levels below pretreatment levels. Cross-over analysis indicated that the 2.0 mg twice daily dose achieved significantly greater suppression of oestradiol levels than 0.1 mg twice daily but there was no significant differences between any of the doses in the suppression of oestrone. No significant effects were noted on serum levels of LH, FSH, SHBG, prolactin, testosterone, androstenedione, 17-hydroxyprogesterone or cortisol. For the four steroids this was true both for basal samples and those collected after Synacthen stimulation. However, serum aldosterone levels were significantly suppressed by 1.0 mg twice daily CGS 16949A and further suppressed by 2.0 mg twice daily. It is concluded that CGS 16949A is a potent oestrogen suppressant in postmenopausal patients but that its effect is not totally selective.
- Published
- 1990
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27. Oestrogen receptor (ER) analysis in B-cell chronic lymphocytic leukemia: Correlation of biochemical and immunocytochemical methods
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M. Dowsett, Estela Matutes, Daniel Catovsky, Ricardo Morilla, Aaron Polliack, N. Melo, and C. Hobday
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Adult ,Male ,Cancer Research ,Pathology ,medicine.medical_specialty ,medicine.drug_class ,Chronic lymphocytic leukemia ,Immunocytochemistry ,Centrifugation ,Biology ,Monoclonal antibody ,Immunoenzyme Techniques ,medicine ,Humans ,Lymphocytes ,Aged ,Aged, 80 and over ,Estradiol ,Hematology ,Middle Aged ,medicine.disease ,Immunohistochemistry ,Leukemia, Lymphocytic, Chronic, B-Cell ,Staining ,Leukemia ,Receptors, Estrogen ,Oncology ,Cancer research ,Female ,Tamoxifen ,Immunostaining ,medicine.drug - Abstract
Oestrogen receptors (ER) are present in neoplastic lymphoid cells and have been considered a physiological marker of growth rate or differentiation. Tamoxifen, an oestrogen antagonist, has been given in some patients with CLL and Hodgkin's disease, with dramatic response in single cases. Until now, ER status has been assessed using a steroid binding assay (SBA) which has many inherent problems. Recently, the development of monoclonal antibodies directed against ER has been applied to the study of breast carcinomas and results obtained show good correlation with the quantitative SBA. We studied 49 cases of B-cell chronic lymphocytic leukemia (CLL) using immunostaining of cytospin preparations. In 30 of these cases ER enzyme immunoassay (ER-EIA) was also performed. Cultured MCF-7 cells, derived from a pleural effusion of a breast cancer patient, known to contain high levels of ER were used as a positive control (40-48% ER positive cells by immunocytochemistry; 200 fmol/mg protein by EIA). All of the CLL cases except two (96%) were negative for ER (less than 1% staining; less than 4 fmol/mg protein). The two positive cases expressed granular ER staining over the nucleus (9.2 and 12.1% positive cells) and were positive by EIA and SBA. It is concluded that (i) patients with CLL rarely express ER and (ii) immunocytochemical staining of cytospin preparations is a valid technique for the measurement of ER. It is of interest that one of the positive cases was diagnosed as CLL with Richter's transformation confirming earlier findings.
- Published
- 1990
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28. PG 8.02 Neoadjuvant endocrine therapy: patient selection, treatment duration and surrogate endpoints
- Author
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M. Dowsett
- Subjects
Surgery ,General Medicine - Published
- 2015
- Full Text
- View/download PDF
29. Consensus statement. Workshop on therapeutic resistance in breast cancer: impact of growth factor signaling pathways and implications for future treatment
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J M W, Gee, A, Howell, W J, Gullick, C C, Benz, R L, Sutherland, R J, Santen, L-A, Martin, F, Ciardiello, W R, Miller, M, Dowsett, P, Barrett-Lee, J F R, Robertson, S R, Johnston, H E, Jones, A E, Wakeling, R, Duncan, R I, Nicholson, Gee, Jm, Howell, A, Gullick, Wj, Benz, Cc, Sutherland, Rl, Santen, Rj, Martin, La, Ciardiello, Fortunato, Miller, Wr, Dowsett, M, Barrett Lee, P, Robertson, Jf, Johnston, Sr, Jones, He, Wakeling, Ae, Duncan, R, and Nicholson, Ri
- Subjects
Hormone Antagonists ,Drug Resistance, Neoplasm ,Humans ,Breast Neoplasms ,Drug Therapy, Combination ,Female ,Growth Inhibitors ,Signal Transduction - Abstract
Anti-hormones (notably tamoxifen), chemotherapy and modern radiotherapeutic approaches are invaluable in the management of breast cancer, and collectively have contributed substantially to the improved survival in this disease. Moreover, there is promise that these successes will continue with the emergence of other endocrine agents (for example, aromatase inhibitors and pure anti-oestrogens). However, de novo and acquired resistance comprises a significant problem with all treatment approaches examined to date. This Workshop aimed to evaluate the contribution made by growth factor signalling pathways in the various resistant states, primarily focusing on resistance to anti-hormonal strategies and spanning experimental models and, where possible, clinical breast cancer data. The successes and limitations of therapeutic targeting of these pathways with various signal transduction inhibitors (STIs) were evaluated in model systems and from emerging clinical trials (including epidermal growth factor receptor inhibitors such as gefitinib). It was concluded that growth factor signalling is an important contributor in the development of endocrine resistance in breast cancer and that use of STIs provides a promising therapeutic strategy for this disease. However, the cancer cell is clearly able to harness alternative growth factor signalling pathways for growth and cell survival in the presence of STI monotherapy and, as a consequence, the efficacy of STIs is likely to be limited by the acquisition of resistance. A number of strategies were proposed from studies in model systems that appeared to enhance anti-tumour actions of existing STI monotherapy, notably including combination therapies targeting multiple pathways. With the increased availability of diverse STIs and improved drug delivery, there is much hope that the more complex therapeutic strategies proposed may ultimately be achievable in clinical practice.
- Published
- 2005
30. SP003 Pathology challenges for biology-driven trials: The Ki67 experience
- Author
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M. Dowsett
- Subjects
Cancer Research ,medicine.medical_specialty ,Oncology ,medicine ,Medical physics ,Biology - Published
- 2013
- Full Text
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31. Apoptosis-its role in tumour growth and therapy
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P. A. Ellis, M. Dowsett, and I. E. Smith
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Histology ,Apoptosis ,business.industry ,Neoplasms ,Cancer research ,Humans ,Medicine ,General Medicine ,business ,Cell Division ,Pathology and Forensic Medicine - Published
- 1996
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32. Body mass index, serum sex hormones, and breast cancer risk in postmenopausal women
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T J, Key, P N, Appleby, G K, Reeves, A, Roddam, J F, Dorgan, C, Longcope, F Z, Stanczyk, H E, Stephenson, R T, Falk, R, Miller, A, Schatzkin, D S, Allen, I S, Fentiman, D Y, Wang, M, Dowsett, H V, Thomas, S E, Hankinson, P, Toniolo, A, Akhmedkhanov, K, Koenig, R E, Shore, A, Zeleniuch-Jacquotte, F, Berrino, P, Muti, A, Micheli, V, Krogh, S, Sieri, V, Pala, E, Venturelli, G, Secreto, E, Barrett-Connor, G A, Laughlin, M, Kabuto, S, Akiba, R G, Stevens, K, Neriishi, C E, Land, J A, Cauley, L H, Kuller, S R, Cummings, K J, Helzlsouer, A J, Alberg, T L, Bush, G W, Comstock, G B, Gordon, and S R, Miller
- Subjects
Cancer Research ,medicine.medical_specialty ,Estrone ,Breast Neoplasms ,Risk Assessment ,Body Mass Index ,chemistry.chemical_compound ,Dehydroepiandrosterone sulfate ,Sex hormone-binding globulin ,Breast cancer ,Estrone sulfate ,Risk Factors ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Gonadal Steroid Hormones ,Testosterone ,Aged ,biology ,Estradiol ,business.industry ,Middle Aged ,medicine.disease ,Postmenopause ,Endocrinology ,Logistic Models ,Oncology ,chemistry ,Relative risk ,Case-Control Studies ,biology.protein ,Female ,business ,Body mass index - Abstract
Body mass index, serum sex hormones, and breast cancer risk in postmenopausal women. Background: Obesity is associated with increased breast cancer risk among postmenopausal women. We examined whether this association could be explained by the relationship of body mass index (BMI) with serum sex hormone concentrations. Methods: We analyzed individual data from eight prospective studies of postmenopausal women. Data on BMI and prediagnostic estradiol levels were available for 624 case subjects and 1669 control subjects; data on the other sex hormones were available for fewer subjects. The relative risks (RRs) with 95% confidence intervals (CIs) of breast cancer associated with increasing BMI were estimated by conditional logistic regression on case- control sets, matched within each study for age and recruitment date, and adjusted for parity. All statistical tests were two- sided. Results: Breast cancer risk increased with increasing BMI (P-trend = .002), and this increase in RR was substantially reduced by adjustment for serum estrogen concentrations. Adjusting for free estradiol reduced the RR for breast cancer associated with a 5 kg/m(2) increase in BMI from 1.19 (95% CI = 1.05 to 1.34) to 1.02 (95% CI = 0.89 to 1.17). The increased risk was also substantially reduced after adjusting for other estrogens (total estradiol, non-sex hormone-binding globulin- bound estradiol, estrone, and estrone sulfate), and moderately reduced after adjusting for sex hormone-binding globulin, whereas adjustment for the androgens (androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate, and testosterone) had little effect on the excess risk. Conclusion: The results are compatible with the hypothesis that the increase in breast cancer risk with increasing BMI among postmenopausal women is largely the result of the associated increase in estrogens, particularly bioavailable estradiol.
- Published
- 2003
33. Response
- Author
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J. M. Rae, D. F. Hayes, J. Cuzick, I. Sestak, and M. Dowsett
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Cancer Research ,Oncology - Published
- 2012
- Full Text
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34. Characterisation of ultra-shallow junctions using advanced SIMS, SRP and HRTEM techniques
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Adrian Murrell, Tao Wang, Majeed A. Foad, G. De Cock, E.J.H. Collart, T. Cullis, D. Elliner, and M. Dowsett
- Subjects
Materials science ,Ion implantation ,Dopant ,Doping ,Resolution (electron density) ,Analytical chemistry ,Wafer ,Classification of discontinuities ,High-resolution transmission electron microscopy ,Ion - Abstract
B+/1 keV implants have been studied using SIMS, looking in detail at the as-implanted depth profile, to distinguish the true dopant distribution from measurement artefacts. Different SIMS machines and ion energies have been compared, and wafer pre-processing before analysis used to examine the low concentration profile tail. Annealed samples have also been studied, and high depth resolution analysis carried out of the near surface fine structure. The data has been compared with SRP and HRTEM, and used to assign peaks and discontinuities in the profile to dopant states and interfaces.
- Published
- 2002
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35. Highlights and Future Directions in AI Clinical Research
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M. Cunningham and M. Dowsett
- Subjects
Clinical research ,Engineering ethics ,Psychology - Published
- 2014
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36. HER-2 amplification impedes the antiproliferative effects of hormone therapy in estrogen receptor-positive primary breast cancer
- Author
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M, Dowsett, C, Harper-Wynne, I, Boeddinghaus, J, Salter, M, Hills, M, Dixon, S, Ebbs, G, Gui, N, Sacks, and I, Smith
- Subjects
Antineoplastic Agents, Hormonal ,Receptor, ErbB-2 ,Gene Amplification ,Breast Neoplasms ,Anastrozole ,Triazoles ,Immunohistochemistry ,Tamoxifen ,Ki-67 Antigen ,Receptors, Estrogen ,Nitriles ,Humans ,Multicenter Studies as Topic ,Female ,Cell Division ,Randomized Controlled Trials as Topic - Abstract
In experimental models, human epidermal growth factor receptor-2 (HER-2) amplification leads to estrogen independence and tamoxifen resistance in estrogen receptor (ER)-positive human breast cancer cells. Some but not all reports suggest an association between HER-2 positivity and hormone independence in breast cancer patients. This study aimed to evaluate the antiproliferative effects of endocrine therapy in HER-2-positive/ER-positive primary human breast cancer. The effect on proliferation (Ki67) of hormone therapy was assessed at 2 weeks and/or 12 weeks in biopsies from 115 primary breast cancers with ER-positive tumors. The patients took part in one of 3 neoadjuvant trials of hormonal therapy with a SERM (tamoxifen or idoxifene) or an aromatase inhibitor (anastrozole or vorozole). HER-2 status was assessed by immunocytochemistry and fluorescence in situ hybridization (FISH). Fifteen patients were defined as HER-2 positive by both immunohistochemistry and FISH, with the remaining 100 patients HER-2 negative. Geometric mean Ki67 levels were substantially higher in HER-2-positive than HER-2-negative tumors (27.7% versus 11.5%, respectively; P = 0.003). In HER-2-negative patients, Ki67 was reduced by 62 and 71% at 2 and 12 weeks, respectively (P0.0001 for both), but HER-2-positive patients showed no significant fall. The proportional change in Ki67 was significantly different between HER-2-positive and -negative patients (P = 0.014 at 2 weeks; P = 0.047 at 12 weeks). Mean ER levels were lower in the HER-2-positive patients (P = 0.06) but the change in Ki67 was impeded even in those with high ER. Apoptotic index was reduced by 30% at 2 weeks in the HER-2-negative group. However, there were no statistically significant differences in apoptotic index between the groups. It is concluded that ER-positive/HER-2-positive primary breast carcinomas show an impeded antiproliferative response to endocrine therapy that nonetheless may vary between individual treatments. This together with high baseline proliferation is likely to translate to poor clinical response.
- Published
- 2001
37. Effect of raloxifene on breast cancer cell Ki67 and apoptosis: a double-blind, placebo-controlled, randomized clinical trial in postmenopausal patients
- Author
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M, Dowsett, N J, Bundred, A, Decensi, R C, Sainsbury, Y, Lu, M J, Hills, F J, Cohen, P, Veronesi, M E, O'Brien, T, Scott, and D B, Muchmore
- Subjects
Adult ,Aged, 80 and over ,Selective Estrogen Receptor Modulators ,Apoptosis ,Breast Neoplasms ,Middle Aged ,Immunohistochemistry ,Drug Administration Schedule ,Postmenopause ,Ki-67 Antigen ,Double-Blind Method ,Italy ,Receptors, Estrogen ,Raloxifene Hydrochloride ,Tumor Cells, Cultured ,Humans ,Female ,Aged - Abstract
Raloxifene is a selective estrogen receptor (ER) modulator approved for prevention and treatment of postmenopausal osteoporosis. This is an exploratory study of raloxifene in primary breast cancer patients.Postmenopausal women (50-80 years of age), with histological or cytological diagnosis of stage I or II primary breast cancer, were randomly assigned to 14 days of placebo, 60 mg/day raloxifene, or 300 mg twice daily (600 mg/day) of raloxifene. A core biopsy of the primary tumor was obtained before therapy, and a representative sample of the excised tumor was obtained from the operative specimen after treatment. Paired baseline and endpoint biopsies from each patient were analyzed for Ki67, apoptosis, and estrogen and progesterone receptors. Treatment group differences in efficacy measurements were primarily evaluated for baseline-to-endpoint change and percentage change using a one-way ANOVA with treatment as the fixed effect.Of 167 enrolled patients, 143 had evaluable efficacy data. Most breast cancer cases were invasive (98.6%), stage I (76.6%), and ER-positive (83.2%). In patients with ER-positive tumors, Ki67 increased 7% from baseline on placebo and decreased by 21% on 60 mg/day raloxifene (P = 0.015 versus placebo) and by 14% on 600 mg/day raloxifene (P = 0.064 versus placebo). Raloxifene did not affect apoptosis. ER decreased significantly with 60 mg/day or 600 mg/day raloxifene compared with placebo (P0.01 for each comparison). Raloxifene had no statistically significant effects on Ki67 among patients with ER-negative tumors. There were no treatment differences in adverse events.In this exploratory trial, 60 mg/day raloxifene showed a significant antiproliferative effect in ER-positive breast cancer, demonstrated by the decrease in Ki67, with no effect in ER-negative cancer. This provides support for raloxifene having a breast cancer preventive effect in postmenopausal women.
- Published
- 2001
38. Attitudes to randomized clinical trials amongst out-patients attending a medical oncology clinic
- Author
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Martin H.N. Tattersall, Peter M. Ellis, Sharon M. Dowsett, and Phyllis Butow
- Subjects
Oncology ,medicine.medical_specialty ,business.industry ,Public Health, Environmental and Occupational Health ,Alternative medicine ,Mean age ,Teaching hospital ,Out patients ,law.invention ,Clinical trial ,Randomized controlled trial ,Interquartile range ,law ,Family medicine ,Internal medicine ,Physical therapy ,Medicine ,Original Article ,Patient participation ,business - Abstract
Objective To assess the understanding of and attitudes towards randomized clinical trials amongst patients attending oncology out-patient clinics. Design Cross-sectional survey. Subjects Patients attending medical oncology out-patient clinics at a Sydney teaching hospital. Main outcome Patients' willingness to participate in a randomized clinical trial. Results Sixty consecutive patients were surveyed. The mean age was 55.2 (SD 14) years. Eighty-eight per cent of respondents thought that patients should be asked to participate in trials testing new treatments, however, only a third would consider participating in a randomized trial themselves. If a trial was endorsed by an independent cancer information service such as the NSW Cancer Council, 72% of respondents would be more likely to participate. Knowledge about randomized trials was not high. Respondents scored a median of 3 out of 7 (interquartile range, 2–4) correct answers to a series of questions about randomized trials. Patients willing to participate in a randomized trial were more likely to perceive the doctor favourably (P = 0.05), less likely to perceive trials as experimental (P = 0.05) and less likely to perceive trials as representing an inconvenience or loss of control (P = 0.09). Conclusions Understanding amongst patients of the need for and mechanisms of randomized clinical trials is not good. This may contribute to the difficulties investigators face in seeking consent for clinical trials. Evaluation of new strategies to educate the public and patients about randomized trials is needed. Involvement of consumers in the design and conduct of clinical trials and evaluation of strategies to improve doctors' communication of clinical trial information is also required.
- Published
- 2001
39. BCAR1/p130Cas expression in untreated and acquired tamoxifen-resistant human breast carcinomas
- Author
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S, van der Flier, C M, Chan, A, Brinkman, M, Smid, S R, Johnston, L C, Dorssers, and M, Dowsett
- Subjects
Adult ,Aged, 80 and over ,Retinoblastoma-Like Protein p130 ,Estrogen Antagonists ,Proteins ,Breast Neoplasms ,Middle Aged ,Phosphoproteins ,Tamoxifen ,Crk-Associated Substrate Protein ,Receptors, Estrogen ,Drug Resistance, Neoplasm ,Humans ,Female ,Aged - Abstract
High BCAR1/p130Cas expression in primary breast tumour cytosol predicts a poor chance of response recurrent disease to tamoxifen treatment in patients with oestrogen receptor (ER)-positive breast carcinomas. In this study, we assessed whether BCAR1/p130Cas expression is altered during acquisition of anti-oestrogen resistance. BCAR1/p130Cas protein was quantitatively measured by chemiluminescent Western blot analysis in the cytosol of 34 predominantly ER(+) carcinomas that initially responded to primary tamoxifen treatment and subsequently progressed (n = 22 ) or developed during adjuvant tamoxifen treatment (n = 12) and compared to 54 untreated ER(+) human breast carcinomas. We did not detect significant differences in the level of BCAR1/p130Cas protein in untreated and acquired tamoxifen-resistant carcinomas. Our results indicate that in tumour progression towards tamoxifen resistance, increase of BCAR1/p130Cas may be only one of the molecular mechanisms. Thus, high BCAR1/p130Cas protein levels appear to be a hallmark for intrinsic resistance to tamoxifen in breast carcinomas.
- Published
- 2000
40. Antiproliferative effects of idoxifene in a placebo-controlled trial in primary human breast cancer
- Author
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M, Dowsett, J M, Dixon, K, Horgan, J, Salter, M, Hills, and E, Harvey
- Subjects
Time Factors ,Biopsy ,Estrogen Antagonists ,Apoptosis ,Breast Neoplasms ,Middle Aged ,Immunohistochemistry ,Placebos ,Postmenopause ,Tamoxifen ,Ki-67 Antigen ,Double-Blind Method ,Receptors, Estrogen ,Humans ,Female ,Receptors, Progesterone ,Biomarkers ,Cell Division ,Aged - Abstract
Idoxifene is a novel selective estrogen receptor modulator. It has reduced agonist activity on breast and uterine cells compared with tamoxifen and antiproliferative effects in tamoxifen-resistant breast cancer cells. Previous studies have shown that a short course of treatment with other antiestrogens prior to surgery caused a significant reduction of the growth fraction when measured by immunohistological staining using the mouse monoclonal antibody Ki67. In this study, we assessed the effect of idoxifene on biological markers of cell proliferation (Ki67) and apoptosis (TdT-mediated dUTP-biotin nick end labeling), and estrogen and progesterone receptor (ER/PR) expression was also evaluated. Core-cut biopsies were obtained in 77 postmenopausal patients with primary breast cancer at diagnosis. Patients were randomized to 40 mg/day idoxifene or placebo for 14-21 days prior to obtaining a second biopsy sample at surgical resection. The percentage of Ki67-positive cells fell from a mean 19.7 +/- 2.7% (SE) to 13.4 +/- 3.4% in idoxifene-treated ER-positive tumors (n = 30; P = 0.0043), but there was no significant effect in placebo-treated ER-positive tumors (n = 27). No effect was seen on ER-negative tumors in either group. Idoxifene had no significant effect on apoptotic index but produced a statistically significant fall in idoxifene-treated ER immunohistochemical score and a small increase in PR that did not reach statistical significance (0.05P0.10). Idoxifene was well tolerated in all patients. Idoxifene has an antiproliferative effect in ER-positive but not ER-negative breast cancers, and no significant effect on apoptosis in the short-term.
- Published
- 2000
41. Communication styles in the cancer consultation: preferences for a patient-centred approach
- Author
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S M, Dowsett, J L, Saul, P N, Butow, S M, Dunn, M J, Boyer, R, Findlow, and J, Dunsmore
- Subjects
Adult ,Physician-Patient Relations ,Patient Satisfaction ,Communication ,Adaptation, Psychological ,Sick Role ,Humans ,Breast Neoplasms ,Female ,Middle Aged ,Prognosis ,Referral and Consultation ,Aged - Abstract
Although doctor-patient communication has been the focus of numerous studies, there is a lack of empirical evidence on which to base a curriculum for teaching effective communication skills for use in an oncology setting. Research within the general practice area identifies patient-centred and doctor-centred behaviours as the most important dimensions of doctor-patient communication. This study examined patients and their relatives/friends' preferences for and satisfaction with patient-centred and doctor-centred consulting styles. It was argued that by determining patient preferences for consulting styles, specific recommendations for improving communication in the oncology setting could be formulated.One hundred and thirteen women who had been treated for breast cancer and 48 of their relatives or friends watched videotaped scenarios of an oncology consultation, using professional actors. Viewers were randomly allocated to either a good prognosis or poor prognosis video, in which the oncologist discussed the patient's diagnosis, treatment and prognosis. These segments were presented in both styles to allow viewers to directly compare and contrast the patient-centred and doctor-centred approach. Outcomes included style preference and satisfaction. Demographic details, information and involvement preferences, anxiety and depression levels were also obtained.Both patients and their relatives or friends significantly preferred a patient-centred consulting style across all aspects of the consultation (p0.0001), except within the treatment segment of the good prognosis video where there was no significant difference. One third of the viewers preferred a doctor-centred style for the treatment and prognosis segments. Predictors of a patient-centred style preference in the treatment and prognosis segments included watching a poor prognosis video (OR=2.45, 95% CI 1.04-5.81, p=0.04; OR=3.22, 95% CI 1.22-8.50, p=0.02, respectively), and being employed in a professional occupation (OR=2.38, 95% CI 1.02-5.53, p=0.04 for the treatment segment only). Satisfaction ratings varied within and across videos.Despite some methodological limitations, this study provides empirical data indicating that patients and their relatives or friends prefer a patient-centred approach to the consultation, particularly when the patient has a poor prognosis. The fact that a substantial minority of patients preferred a doctor-centred style emphasizes the need to enhance physicians' abilities to recognize different patient needs throughout the consultation.
- Published
- 2000
42. Assessment of HER2 status in breast cancer: why, when and how?
- Author
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M, Dowsett, T, Cooke, I, Ellis, W J, Gullick, B, Gusterson, E, Mallon, and R, Walker
- Subjects
Receptor, ErbB-2 ,Biomarkers, Tumor ,Humans ,Breast Neoplasms ,Female ,Immunohistochemistry ,Proto-Oncogene Mas ,Neoplasm Proteins - Abstract
Human epidermal growth factor receptor 2 (HER2) is overexpressed, usually as a result of HER2 proto-oncogene amplification, in 20-30% of breast cancers. A HER2-positive status is generally associated with more aggressive disease and a worse prognosis. Furthermore, a positive HER2 status may predict the likelihood of resistance to some conventional therapies, as well as probably being predictive of sensitivity to anthracycline dose intensification. In addition to this prognostic/predictive value, HER2 is a target for specific therapy, with anti-HER2 monoclonal antibody therapy available in the USA. This article reviews the different assays used to determine HER2 status, discussing their relative advantages/disadvantages and the need for their standardisation before integration alongside other pathological indices into the clinical management of breast cancer.
- Published
- 2000
43. Prediction of clinical outcome from primary tamoxifen by expression of biologic markers in breast cancer patients
- Author
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J, Chang, T J, Powles, D C, Allred, S E, Ashley, A, Makris, R K, Gregory, C K, Osborne, and M, Dowsett
- Subjects
Aged, 80 and over ,Ploidies ,Antineoplastic Agents, Hormonal ,Biopsy, Needle ,Breast Neoplasms ,Prognosis ,Disease-Free Survival ,S Phase ,Tamoxifen ,Ki-67 Antigen ,Treatment Outcome ,Receptors, Estrogen ,Predictive Value of Tests ,Recurrence ,Biomarkers, Tumor ,Disease Progression ,Humans ,Female ,Receptors, Progesterone ,Aged - Abstract
The aim of this study was to evaluate pretreatment clinical features and biological markers together with changes in these factors as predictors of response and relapse in patients receiving tamoxifen for primary breast cancer. Fine-needle aspiration cytology of the primary breast cancer was performed before tamoxifen treatment in 54 patients and repeated after therapy on day 14, day 60, or on both days in a subset of 35 patients. These samples were evaluated for estrogen receptor (ER), progesterone receptor (PgR), Ki67, S-phase fraction and ploidy. The overall response to tamoxifen was 57% (31 of 54 patients). Pretreatment ER and PgR significantly predicted for response by univariate analysis (P0.0001 and P0.003, respectively). By multivariate analysis, ER expression was the only independent predictor of response, and it was associated with 27 times the likelihood of response (95% confidence interval, 6-136). Increase in PgR and decrease in Ki67 on day 14 significantly predicted for response to tamoxifen (P0.03 and P0.04, respectively). Lack of ER, clinical node-positive disease, and failure to decrease Ki67 on day 14 were significantly associated with increased risk of relapse (P0.05). By multivariate analysis, ER expression was the only independent predictor of relapse (P0.005). Pretreatment and early changes in molecular marker expression may assist in the prediction of response and clinical outcome in primary breast cancer patients receiving tamoxifen.
- Published
- 2000
44. The development of inhibitory control in preschool children: effects of 'executive skills' training
- Author
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S M, Dowsett and D J, Livesey
- Subjects
Discrimination Learning ,Male ,Inhibition, Psychological ,Child Development ,Cognition ,Child, Preschool ,Child Behavior ,Humans ,Attention ,Female ,Cues ,Child - Abstract
As one of several processes involved in the executive functioning of the cognitive system, inhibitory control plays a significant role in determining how various mental processes work together in the successful performance of a task. Studies of response inhibition have shown that although 3-year-old children have the cognitive capacity to learn the rules required for response control, indicated by the correct verbal response, developmental constraints prevent them from withholding the correct response (BellLivesey, 1985; LiveseyMorgan, 1991). Some argue that these abulic dissociations are relative to children's ability to reflect on the rules required for response control (Zelazo, Reznick,Pinon, 1995). The current study showed that repeated exposure to tasks facilitating the acquisition of increasingly complex rule structures could improve inhibitory control (as measured by a go/no-go discrimination learning task), even in children aged 3 years. These tasks included a variant of Diamond and Boyer's (1989) modified version of the Wisconsin Card Sort Task and a simplification of the change paradigm (LoganBurkell, 1986). It is argued that experience with these tasks increased the acquisition of complex rules by placing demands on executive processes. This includes response control and other executive functions, such as representational flexibility, the ability to maintain information in working memory, the selective control of attention, and proficiency at error correction. The role of experiential variables in the development of inhibitory control is discussed in terms of the interaction between neural development and appropriate executive task experience in the early years.
- Published
- 2000
45. Expression of nuclear receptor interacting proteins TIF-1, SUG-1, receptor interacting protein 140, and corepressor SMRT in tamoxifen-resistant breast cancer
- Author
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C M, Chan, A E, Lykkesfeldt, M G, Parker, and M, Dowsett
- Subjects
Proteasome Endopeptidase Complex ,Antineoplastic Agents, Hormonal ,Transcription, Genetic ,Intracellular Signaling Peptides and Proteins ,Nuclear Proteins ,Receptors, Cytoplasmic and Nuclear ,Breast Neoplasms ,LIM Domain Proteins ,Nuclear Receptor Interacting Protein 1 ,Gene Expression Regulation, Neoplastic ,Postmenopause ,Tamoxifen ,Premenopause ,Receptors, Estrogen ,Drug Resistance, Neoplasm ,Tumor Cells, Cultured ,ATPases Associated with Diverse Cellular Activities ,Humans ,Female ,RNA, Messenger ,Carrier Proteins ,Adaptor Proteins, Signal Transducing ,Transcription Factors - Abstract
Regulation of gene transcription as a consequence of steroid receptor-DNA interaction is mediated via nuclear receptor interacting proteins (RIPs), including coactivator or corepressor proteins, which interact with both the receptor and components of the basic transcriptional unit and vary between cell types. The aim of this study was to test the hypothesis that resistance of some breast carcinomas to tamoxifen was associated with inappropriate expression of some of these RIPs. Using Northern analysis, we observed no significant difference between the amount of either TIF-1 or SUG-1 mRNA expressed in parental MCF-7 and MCF-7 tamoxifen-resistant cell lines. However, the expression of RIP140 mRNA was lower in the resistant cell line and in the presence of estradiol, the level of RIP140 mRNA was higher in the resistant cells but not in the parental cells. In a cohort of 19 tamoxifen-resistant breast tumor samples, there was no significant difference in the level of the RIP140 and TIF-1 and corepressor SMRT mRNA compared with tamoxifen-treated tumors (n = 6) or untreated tumors (n = 21). However, SUG-1 mRNA was lower in resistant breast tumors. These data provide no support for increased expression of these RIPs or decreased expression of corepressor SMRT for being a mechanism for resistance of breast tumors to tamoxifen.
- Published
- 1999
46. Biologic markers as predictors of clinical outcome from systemic therapy for primary operable breast cancer
- Author
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Gary M. Clark, Jenny C. Chang, C K Osborne, L. Assersohn, M. Dowsett, T. J. Powles, R. K. Gregory, S. E. Ashley, A. Makris, and D. C. Allred
- Subjects
Oncology ,Adult ,Cancer Research ,medicine.medical_specialty ,Pathology ,medicine.medical_treatment ,Estrogen receptor ,Breast Neoplasms ,Breast cancer ,Predictive Value of Tests ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Biomarkers, Tumor ,Humans ,Genes, Tumor Suppressor ,Neoadjuvant therapy ,Aged ,Biologic marker ,Ploidies ,business.industry ,Cancer ,DNA, Neoplasm ,Middle Aged ,medicine.disease ,Prognosis ,Minimal residual disease ,Neoadjuvant Therapy ,Radiation therapy ,Tamoxifen ,Methotrexate ,Treatment Outcome ,Receptors, Estrogen ,Lymphatic Metastasis ,Female ,Mitoxantrone ,business ,Receptors, Progesterone ,medicine.drug - Abstract
PURPOSE: To determine whether pretreatment clinical features and molecular markers, together with changes in these factors, can predict treatment response and survival in patients with primary operable breast cancer who receive neoadjuvant therapy. PATIENTS AND METHODS: Mitoxantrone, methotrexate (with or without mitomycin), and tamoxifen chemoendocrine therapy was administered to 158 patients before surgery. Clinical response was assessed after four cycles of treatment. Fine-needle aspiration cytology for estrogen receptor (ER), progesterone receptor (PgR), c-erbB-2, p53, bcl-2, Ki67, S-phase fraction (SPF), and ploidy were performed pretreatment and repeated on day 10 or day 21 after the first cycle of treatment. RESULTS: Good clinical response (GCR, defined as complete response or minimal residual disease) was achieved in 31% of patients (49 of 158). Tumor size, nodal disease, response, ER, PgR, c-erbB-2, p53, bcl-2, Ki67, SPF, and ploidy were analyzed as predictors of survival. By univariate analysis, node-positive disease (P = .05), lack of ER (P CONCLUSION: Molecular markers may be used to predict the likelihood of achieving GCR, which seems to be a valid surrogate marker for survival.
- Published
- 1999
47. Impact of tamoxifen on the pharmacokinetics and endocrine effects of the aromatase inhibitor letrozole in postmenopausal women with breast cancer
- Author
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M, Dowsett, C, Pfister, S R, Johnston, D W, Miles, S J, Houston, J A, Verbeek, H, Gundacker, A, Sioufi, and I E, Smith
- Subjects
Adult ,Aged, 80 and over ,Antineoplastic Agents, Hormonal ,Aromatase Inhibitors ,Antineoplastic Agents ,Breast Neoplasms ,Middle Aged ,Triazoles ,Postmenopause ,Tamoxifen ,Antineoplastic Combined Chemotherapy Protocols ,Letrozole ,Nitriles ,Humans ,Female ,Enzyme Inhibitors ,Aged - Abstract
This study examined whether the addition of tamoxifen to the treatment regimen of patients with advanced breast cancer being treated with the aromatase inhibitor letrozole led to any pharmacokinetic or pharmacodynamic interaction. Twelve of 17 patients completed the core period of the trial in which 2.5 mg/day letrozole was administered alone for 6 weeks and in combination with 20 mg/day tamoxifen for the subsequent 6 weeks. Patients responding to treatment continued on the combination until progression of disease or any other reason for discontinuation. Plasma levels of letrozole were measured at the end of the 6-week periods of treatment with letrozole alone and the combination and once more between 4 and 8 months on combination therapy. No further measurements were done thereafter. Hormone levels were measured at 2-week intervals throughout the core period. Marked suppression of estradiol, estrone, and estrone sulfate occurred with letrozole treatment, and this was not significantly affected by the addition of tamoxifen. However, plasma levels of letrozole were reduced by a mean 37.6% during combination therapy (P0.0001), and this reduction persisted after 4-8 months of combination therapy. Letrozole is the first drug to be described in which this pharmacokinetic interaction occurs with tamoxifen. The mechanism is likely to be a consequence of an induction of letrozole-metabolizing enzymes by tamoxifen but was not further addressed in this study. It is possible that the antitumor efficacy of letrozole may be affected. Thus, sequential therapy may be preferable with these two drugs. It is not known whether tamoxifen interacts with other members of this class of drugs or with other drugs in combination.
- Published
- 1999
48. Double-blind, randomised, multicentre endocrine trial comparing two letrozole doses, in postmenopausal breast cancer patients
- Author
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E, Bajetta, N, Zilembo, M, Dowsett, L, Guillevin, A, Di Leo, L, Celio, A, Martinetti, A, Marchianò, P, Pozzi, S, Stani, and E, Bichisao
- Subjects
Adult ,Aged, 80 and over ,Dose-Response Relationship, Drug ,Aromatase Inhibitors ,Breast Neoplasms ,Middle Aged ,Triazoles ,Postmenopause ,Aromatase ,Double-Blind Method ,Letrozole ,Nitriles ,Humans ,Female ,Aged - Abstract
Letrozole is an orally competitive aromatase inhibitor. This double-blind, randomised, multicentre trial was carried out to evaluate the endocrine effects of two doses of letrozole, 0.5 mg versus 2.5 mg orally daily, in postmenopausal advanced breast cancer patients progressing after tamoxifen. The pharmacokinetics of letrozole was also assessed. 46 patients entered the trial, 22 on letrozole 0.5 mg and 24 on 2.5 mg. A significant suppression of oestrone and oestradiol levels was achieved by both letrozole doses. Neither letrozole dose induced any changes in cortisol and aldosterone production at rest or after Synacthen stimulation. Androstenedione, testosterone, 17 alpha-OH progesterone, triiodothyronine (T3) thyroxine, (T4) and thyroid-stimulating hormone (TSH) plasma levels did not show any significant changes. Sex hormone binding globulin (SHBG), follicle-stimulating hormone (FSH) and luteinising hormone (LH) levels increased significantly over time. Plasma letrozole concentrations increased until reaching steady-state values after 1 month at the dose of 0.5 mg and after 2 months at 2.5 mg. In conclusion, both letrozole doses suppressed oestrogen levels without affecting adrenal activity.
- Published
- 1999
49. Evaluation of tamoxifen plus letrozole with assessment of pharmacokinetic interaction in postmenopausal women with metastatic breast cancer
- Author
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J N, Ingle, V J, Suman, P A, Johnson, J E, Krook, J A, Mailliard, R H, Wheeler, C L, Loprinzi, E A, Perez, V C, Jordan, and M, Dowsett
- Subjects
Adult ,Aged, 80 and over ,Antineoplastic Agents, Hormonal ,Breast Neoplasms ,Middle Aged ,Triazoles ,Postmenopause ,Tamoxifen ,Endocrinology ,Treatment Outcome ,Antineoplastic Combined Chemotherapy Protocols ,Letrozole ,Nitriles ,Humans ,Drug Interactions ,Female ,Aged - Abstract
The goals of this clinical trial involving postmenopausal women with metastatic breast cancer were to: (a) examine the effects of letrozole on tamoxifen (TAM) pharmacokinetics; (b) examine estrogen suppression in patients receiving TAM plus letrozole; and (c) evaluate tolerability, toxicity, objective response, and time to progression for the combination. Postmenopausal women with measurable or evaluable metastatic breast cancer received TAM (20 mg daily) for 6 weeks, and then letrozole (2.5 mg daily) was added. To examine for any effect of letrozole on the levels of TAM and two metabolites [N-desmethyl-TAM and 4-hydroxy-TAM], serum samples were obtained at 6, 12, 18, and 24 weeks. To examine for aromatase inhibition, serum samples were obtained before treatment and at 6, 12, 18, and 24 weeks for estradiol, estrone (E1) E1 sulfate, and sex hormone-binding globulin. A total of 34 patients were entered on this trial, and 23 patients were still on study at week 24, 18 of whom had blood samples available at both week 6 and week 24. The 95% confidence interval for the mean difference between levels at week 24 and levels at week 6 was -34 to 15 ng/ml for TAM, -35 to 45 ng/ml for N-desmethyl-TAM, and -1 to 2 for 4-hydroxy-TAM. For estradiol, a significant decrease (median, 88.5%; range, 73.7-95.2%) was identified after 6 weeks of letrozole, which was maintained for an additional 12 weeks. Similar significant reductions were identified for E1. E1 sulfate levels increased after 6 weeks of TAM alone but then decreased significantly after the addition of letrozole. Sex hormone-binding globulin levels were significantly elevated after 6 weeks of TAM alone and remained elevated after the addition of letrozole. Six of the 34 patients (17.6%) achieved an objective response (95% confidence interval, 6.8-34.5%), with a median time to disease progression of 7.6 months. There was no indication of a systematic decrease in TAM, N-desmethyl-TAM, or 4-hydroxy-TAM after the additional of letrozole. Estrogen suppression induced by letrozole was substantial despite the concomitant administration of TAM. The antitumor effect of TAM plus letrozole was less than expected.
- Published
- 1999
50. Reduction in angiogenesis after neoadjuvant chemoendocrine therapy in patients with operable breast carcinoma
- Author
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A, Makris, T J, Powles, S, Kakolyris, M, Dowsett, S E, Ashley, and A L, Harris
- Subjects
Adult ,Tamoxifen ,Neovascularization, Pathologic ,Antineoplastic Combined Chemotherapy Protocols ,Humans ,Breast Neoplasms ,Female ,Middle Aged ,Prognosis ,Immunohistochemistry ,Mastectomy ,Neoadjuvant Therapy ,Aged - Abstract
The intensity of angiogenesis, as measured by microvessel density, is a strong independent predictor of survival in breast carcinoma patients. The impact of chemotherapy and/or endocrine therapy on this process is unknown.Histologic samples from patients randomized to a trial of neoadjuvant (NEO) versus adjuvant (ADJ) chemoendocrine therapy for operable breast carcinoma were obtained. Samples from 195 patients (90 NEO samples and 105 ADJ samples) were analyzed. Immunostaining was performed with the CD34 monoclonal antibody and the scoring of microvessels was performed using the Chalkley method.The median score of the NEO patients was 5.7 (95% confidence interval [CI], 5.3-6.0) and the median score of the ADJ patients was 6.3 (95% CI, 6-6.7) (P=0.025). Using previously validated scoring categories, there were fewer samples with a poor prognosis (scoreor =7) in the NEO group (26%) compared with the ADJ group (32%) (P=0.04).The results of the current study suggest that NEO chemoendocrine therapy causes a reduction in microvessel density in primary breast carcinomas, which could be secondary to tumor regression or due to a direct effect on angiogenesis.
- Published
- 1999
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