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Martinez Saez O, Felip Falgas E, Cappelletti M, Tolosa P, Brasó-Maristany F, Sanfeliu Torres E, Pascual T, Chic N, Vidal M, Adamo B, Munoz M, Faull I, Odegaard J, Patel G, McEwen R, Carroll D, Ciruelos E, Generali D, Margeli Vila M, Prat A. 10P Survival according to early ctDNA dynamics in advanced breast cancer (ABC) treated with endocrine therapy (ET) and a CDK4/6 inhibitor (CDK4/6i). Ann Oncol 2022. [DOI: 10.1016/j.annonc.2022.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Bott RK, George G, McEwen R, Zylstra J, Knight WRC, Baker CR, Kelly M, Griffin N, McAddy N, Maisey N, Van Hemelrijck M, Gossage JA, Lagergren J, Davies AR. Predicting response to neoadjuvant chemotherapy in patients with oesophageal adenocarcinoma. Acta Oncol 2021; 60:1629-1636. [PMID: 34613874 DOI: 10.1080/0284186x.2021.1986228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BACKGROUND Neoadjuvant chemotherapy is often used prior to surgical resection for oesophageal adenocarcinoma but remains ineffective in a high proportion of patients. The histological Mandard tumour regression grade is used to determine chemoresponse but is not available at the time of treatment decision-making. The aim of this cohort study was to identify factors that predict chemotherapy response prior to surgery. METHODS A prospectively collected database of patients undergoing surgical resection for oesophageal adenocarcinoma from a high-volume UK institution was used. Patients were subcategorised using pathological tumour response into 'responders' (Mandard grade 1-3) and 'non-responders' (Mandard grade 4 and 5). Multivariable logistic regression analysis was performed to calculate crude and adjusted odds ratios (OR) with 95% confidence intervals (CI) for responder status adjusting for a variety of parameters. Receiver operating characteristic (ROC) curves were calculated. RESULTS Among 315 patients included, 102 (32%) were responders and 213 (68%) non-responders. A decrease in radiological tumour volume (OR 1.92 95%CI 1.02-3.62; p = 0.05), a 'partial response' RECIST score (OR 7.16 95%CI 1.49-34.36; p = 0.01), a clinically improved dysphagia score (OR 2.79 95%CI 1.05-7.04; p = 0.04) and lymphovascular invasion (OR 0.06 95%CI 0.02-0.13; p = 0.000) influenced responder status. ROC curve analysis for responder status utilising all available parameters had an area under the curve (AUC) of 0.86. CONCLUSION This study has highlighted the potential for using pre-defined factors to identify those patients who have responded to neoadjuvant chemotherapy, prior to surgical resection, potentially facilitating a more individualised therapeutic approach.
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Affiliation(s)
- Rebecca K. Bott
- Department of Upper Gastrointestinal and General Surgery, St Thomas’ Hospital, London, UK
- School of Cancer and Pharmaceutical Sciences, King’s College London, London, UK
| | - Gincy George
- School of Cancer and Pharmaceutical Sciences, Translational Oncology and Urology Research (TOUR), King’s College London, London, UK
| | - Ricardo McEwen
- Department of Upper Gastrointestinal and General Surgery, St Thomas’ Hospital, London, UK
| | - Janine Zylstra
- Department of Upper Gastrointestinal and General Surgery, St Thomas’ Hospital, London, UK
| | - William R. C. Knight
- Department of Upper Gastrointestinal and General Surgery, St Thomas’ Hospital, London, UK
- School of Cancer and Pharmaceutical Sciences, King’s College London, London, UK
| | - Cara R. Baker
- Department of Upper Gastrointestinal and General Surgery, St Thomas’ Hospital, London, UK
- School of Cancer and Pharmaceutical Sciences, King’s College London, London, UK
| | - Mark Kelly
- Department of Upper Gastrointestinal and General Surgery, St Thomas’ Hospital, London, UK
- School of Cancer and Pharmaceutical Sciences, King’s College London, London, UK
| | - Nyree Griffin
- Department of Radiology, St Thomas’ Hospital, London, UK
| | - Naami McAddy
- Department of Radiology, St Thomas’ Hospital, London, UK
| | - Nick Maisey
- Department of Medical Oncology, Guy’s Hospital London, London, UK
| | - Mieke Van Hemelrijck
- School of Cancer and Pharmaceutical Sciences, Translational Oncology and Urology Research (TOUR), King’s College London, London, UK
| | - James A. Gossage
- Department of Upper Gastrointestinal and General Surgery, St Thomas’ Hospital, London, UK
- School of Cancer and Pharmaceutical Sciences, King’s College London, London, UK
| | - Jesper Lagergren
- School of Cancer and Pharmaceutical Sciences, King’s College London, London, UK
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Andrew R. Davies
- Department of Upper Gastrointestinal and General Surgery, St Thomas’ Hospital, London, UK
- School of Cancer and Pharmaceutical Sciences, King’s College London, London, UK
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Knight WRC, McEwen R, Byrne BE, Habib W, Bott R, Zylstra J, Mahadeva U, Gossage JA. Endoscopic tumour morphology impacts survival in adenocarcinoma of the oesophagus. Eur J Surg Oncol 2020; 46:2257-2261. [PMID: 32814680 DOI: 10.1016/j.ejso.2020.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/03/2020] [Accepted: 07/01/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND Prognostication in oesophageal cancer on the basis of preoperative variables is challenging. Many of the accepted predictors of survival are only derived after surgical treatment and may be influenced by neoadjuvant therapy. This study aims to explore the relationship between pre-treatment endoscopic tumour morphology and postoperative survival. METHODS Patients with endoscopic descriptions of tumours were identified from the prospectively managed databases including the OCCAMS database. Tumours were classified as exophytic, ulcerating or stenosing. Kaplan Meier survival analysis and multivariable Cox regression analyses were performed to determine hazard ratios (HR) with 95% confidence intervals. RESULTS 262 patients with oesophageal adenocarcinoma undergoing potentially curative resection were pooled from St Thomas' Hospital (161) and the OCCAMS database (101). There were 70 ulcerating, 114 exophytic and 78 stenosing oesophageal adenocarcinomas. Initial tumour staging was similar across all groups (T3/4 tumours 71.4%, 70.2%, 74.4%). Median survival was 55 months, 51 months and 36 months respectively (p < 0.001). Rates of lymphovascular invasion (P = 0.0176), pathological nodal status (P = 0.0195) and pathological T stage (P = 0.0007) increased from ulcerating to exophytic to stenosing lesions. Resection margin positivity was 21.4% in ulcerating tumours compared to 54% in stenosing tumours (p < 0.001). When compared to stenosing lesions, exophytic and ulcerating lesions demonstrated a significant survival advantage on multivariable analysis (HR 0.56 95% CI 0.31-0.93, HR 0.42 95% CI 0.21-0.82). CONCLUSION This study demonstrates that endoscopic morphology may be an important pre-treatment prognostic factor in oesophageal cancer. Ulcerating, exophytic and stenosing tumours may represent different pathological processes and tumour biology.
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Affiliation(s)
- William R C Knight
- Department of Surgery, Guy's & St Thomas' Oesophago-gastric Centre, London, United Kingdom.
| | - Ricardo McEwen
- Department of Surgery, Guy's & St Thomas' Oesophago-gastric Centre, London, United Kingdom
| | - Ben E Byrne
- Department of Surgery, Guy's & St Thomas' Oesophago-gastric Centre, London, United Kingdom; Centre for Surgical Research, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK
| | - Wais Habib
- Department of Surgery, Guy's & St Thomas' Oesophago-gastric Centre, London, United Kingdom
| | - Rebecca Bott
- Department of Surgery, Guy's & St Thomas' Oesophago-gastric Centre, London, United Kingdom
| | - Janine Zylstra
- Department of Surgery, Guy's & St Thomas' Oesophago-gastric Centre, London, United Kingdom
| | - Ula Mahadeva
- Department of Histopathology, Guy's & St Thomas', London, United Kingdom
| | - James A Gossage
- Department of Surgery, Guy's & St Thomas' Oesophago-gastric Centre, London, United Kingdom; School of Cancer and Pharmaceutical Sciences, King's College London, UK; Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institute, Stockholm, Sweden
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Hrebien S, Citi V, Garcia-Murillas I, Cutts R, Fenwick K, Kozarewa I, McEwen R, Ratnayake J, Maudsley R, Carr TH, de Bruin EC, Schiavon G, Oliveira M, Turner N. Early ctDNA dynamics as a surrogate for progression-free survival in advanced breast cancer in the BEECH trial. Ann Oncol 2020; 30:945-952. [PMID: 30860573 PMCID: PMC6594458 DOI: 10.1093/annonc/mdz085] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Background Dynamic changes in circulating tumour DNA (ctDNA) levels may predict long-term outcome. We utilised samples from a phase I/II randomised trial (BEECH) to assess ctDNA dynamics as a surrogate for progression-free survival (PFS) and early predictor of drug efficacy. Patients and methods Patients with estrogen receptor-positive advanced metastatic breast cancer (ER+ mBC) in the BEECH study, paclitaxel plus placebo versus paclitaxel plus AKT inhibitor capivasertib, had plasma samples collected for ctDNA analysis at baseline and at multiple time points in the development cohort (safety run-in, part A) and validation cohort (randomised, part B). Baseline sample ctDNA sequencing identified mutations for longitudinal analysis and mutation-specific digital droplet PCR (ddPCR) assays were utilised to assess change in ctDNA abundance (allele fraction) between baseline and 872 on-treatment samples. Primary objective was to assess whether early suppression of ctDNA, based on pre-defined criteria from the development cohort, independently predicted outcome in the validation cohort. Results In the development cohort, suppression of ctDNA was apparent after 8 days of treatment (P = 0.014), with cycle 2 day 1 (4 weeks) identified as the optimal time point to predict PFS from early ctDNA dynamics. In the validation cohort, median PFS was 11.1 months in patients with suppressed ctDNA at 4 weeks and 6.4 months in patients with high ctDNA (hazard ratio = 0.20, 95% confidence interval 0.083–0.50, P < 0.0001). There was no difference in the level of ctDNA suppression between patients randomised to capivasertib or placebo overall (P = 0.904) nor in the PIK3CA mutant subpopulation (P = 0.071). Clonal haematopoiesis of indeterminate potential (CHIP) was evident in 30% (18/59) baseline samples, although CHIP had no effect on tolerance of chemotherapy nor on PFS. Conclusion Early on-treatment ctDNA dynamics are a surrogate for PFS. Dynamic ctDNA assessment has the potential to substantially enhance early drug development. Clinical registration number NCT01625286.
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Affiliation(s)
- S Hrebien
- Breast Cancer Now Research Centre, The Institute of Cancer Research, London, UK
| | - V Citi
- Breast Cancer Now Research Centre, The Institute of Cancer Research, London, UK; Clinical Pharmacology and Pharmacogenetics Unit, Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - I Garcia-Murillas
- Breast Cancer Now Research Centre, The Institute of Cancer Research, London, UK
| | - R Cutts
- Breast Cancer Now Research Centre, The Institute of Cancer Research, London, UK
| | - K Fenwick
- Breast Cancer Now Research Centre, The Institute of Cancer Research, London, UK
| | - I Kozarewa
- Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | - R McEwen
- Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | - J Ratnayake
- Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | - R Maudsley
- Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | - T H Carr
- Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | - E C de Bruin
- Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | - G Schiavon
- Oncology, IMED Biotech Unit, AstraZeneca, Cambridge, UK
| | - M Oliveira
- Vall d'Hebron University Hospital and Vall d'Hebron Institute of Oncology (VHIO), Barcelona, Spain
| | - N Turner
- Breast Cancer Now Research Centre, The Institute of Cancer Research, London, UK; Breast Unit, Royal Marsden Hospital, London, UK.
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Oelmann E, Michaloglou C, Crafter C, Siersbaek R, Delpuech O, Curven J, Carnevalli L, Staniszweska A, Polanska U, Cheraghchi-Bashi A, Lawson M, Chernukhin I, McEwen R, Carroll J, Cosulich S. Abstract PD4-04: Combined inhibition of mTOR and CDK4/6 is required for optimal blockade of E2F function and long term growth inhibition in estrogen receptor positive breast cancer. Cancer Res 2018. [DOI: 10.1158/1538-7445.sabcs17-pd4-04] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
The cyclin dependent kinase (CDK) –retinoblastoma (RB) -E2F pathway plays a critical role in the control of cell cycle in estrogen receptor positive (ER+) breast cancer. Small molecule inhibitors of CDK4/6 have shown promise in this tumour type in combination with hormonal therapies, reflecting the particular dependence of this subtype of cancer on cyclin D1 and E2F transcription factors. mTOR inhibitors have also shown potential in clinical trials in this disease setting. Recent data has suggested cooperation between the phosphatidylinositol 3-kinase (PI3K) pathway and CDK4/6 inhibition in preventing early adaptation and eliciting growth arrest, but the mechanisms of the interplay between these pathways have not been fully elucidated. Here we show that profound and durable inhibition of ER+ breast cancer growth is likely to require multiple hits on E2F mediated transcription. We demonstrate that inhibition of mTOR using the mTORC1/2 inhibitor vistusertib at 300nM causes a >50% decrease in cyclin D1 protein levels and RB phosphorylation in three cell lines. At these concentrations, vistusertib treatment also elicits marked effects on E2F mediated transcription, causing changes in the mRNA levels of 28 out of 43 (65%) of a selected set of E2F target genes.Combined inhibition of mTOR, CDK4/6 and ER delivers profound and durable regressions in breast cancer cell lines and xenografts (110.2% tumour growth inhibition at day 48). In vivo data show, that over a period of 58 days, tumours failed to re-grow in the presence of the triplet combination compared to either agent alone, suggesting, that the triplet is necessary to maintain growth inhibition. Furthermore, we show that CDK4/6 inhibitor resistant cell lines re-activate the CDK-RB-E2F pathway, but remain sensitive to mTOR inhibition (EC50 52.7 nM in parental cells vs 39.6-73.3 nM in a number of palbociclib resistant cell populations), suggesting that mTORC1/2 inhibitors may represent an option for patients that have relapsed on CDK4/6 therapy. A Phase I study (PASTOR) combining the dual TOR kinase inhibitor Vistusertib with Palbociclib, and Fulvestrant is underway to explore safety and efficacy of the triplet combination in patients with metastatic breast cancer.
Citation Format: Oelmann E, Michaloglou C, Crafter C, Siersbaek R, Delpuech O, Curven J, Carnevalli L, Staniszweska A, Polanska U, Cheraghchi-Bashi A, Lawson M, Chernukhin I, McEwen R, Carroll J, Cosulich S. Combined inhibition of mTOR and CDK4/6 is required for optimal blockade of E2F function and long term growth inhibition in estrogen receptor positive breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr PD4-04.
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Affiliation(s)
- E Oelmann
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - C Michaloglou
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - C Crafter
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - R Siersbaek
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - O Delpuech
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - J Curven
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - L Carnevalli
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - A Staniszweska
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - U Polanska
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - A Cheraghchi-Bashi
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - M Lawson
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - I Chernukhin
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - R McEwen
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - J Carroll
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
| | - S Cosulich
- AstraZeneca, Cambridge, Cambridgeshire, United Kingdom; CRUK Cambridge Institute, Cambridge, Cambridgeshire, United Kingdom; University of Bradford, Bradford, Cheshire, United Kingdom
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Fleischmann R, van Vollenhoven RF, Smolen J, Emery P, Florentinus S, Rathmann S, Kupper H, Kavanaugh A, Taylor P, Genovese M, Keystone EC, Drescher E, Berclaz PY, Lee C, Fidelus-Gort R, Schlichting D, Beattie S, Luchi M, Macias W, Kavanaugh A, Emery P, van Vollenhoven RF, Dikranian AH, Alten R, Klearman M, Musselman D, Agarwal S, Green J, Gabay C, Weinblatt ME, Schiff MH, Fleischmann R, Valente R, van der Heijde D, Citera G, Zhao C, Maldonado MA, Rakieh C, Nam JL, Hunt L, Villeneuve E, Bissell LA, Das S, Conaghan P, McGonagle D, Wakefield RJ, Emery P, Wright HL, Thomas HB, Moots R, Edwards SW, Hamann P, Heward J, McHugh N, Lindsay MA, Haroon M, Giles JT, Winchester R, FitzGerald O, Karaderi T, Cohen CJ, Keidel S, Appleton LH, Macfarlane GJ, Siebert S, Evans D, Paul Wordsworth B, Plant D, Bowes J, Orozco G, Morgan AW, Wilson AG, Isaacs J, Barton A, Williams FM, Livshits G, Spector T, MacGregor A, Williams FM, Scollen S, Cao D, Memari Y, Hyde CL, Zhang B, Sidders B, Ziemek D, Shi Y, Harris J, Harrow I, Dougherty B, Malarstig A, McEwen R, Stephens JL, Patel K, Shin SY, Surdulescu G, He W, Jin X, McMahon SB, Soranzo N, John S, Wang J, Spector TD, Baker J, Litherland GJ, Rowan AD, Kite KA, Bayley R, Yang P, Smith JP, Williams J, Harper L, Kitas GD, Buckley C, Young SP, Fitzpatrick MA, Young SP, McGettrick HM, Filer A, Raza K, Nash G, Buckley C, Muthana M, Davies H, Khetan S, Adeleke G, Hawtree S, Tazzyman S, Morrow F, Ciani B, Wilson G, Quirke AM, Lugli E, Wegner N, Charles P, Hamilton B, Chowdhury M, Ytterberg J, Potempa J, Fisher B, Thiele G, Mikuls T, Venables P, Adebajo AO, Kavanaugh A, Mease P, Gomez-Reino JJ, Wollenhaupt J, Hu C, Stevens R, Sieper J, van der Heijde D, Dougados M, Van den Bosch F, Goupille P, Rathmann SS, Pangan AL, van der Heijde D, Sieper J, Maksymowych WP, Brown MA, Rathmann S, Pangan AL, Sieper J, van der Heijde D, Elewaut D, Pangan AL, Anderson J, Haroon M, Ramasamy P, O'Rourke M, Murphy C, Fitzgerald O, Jani M, Moore S, Mirjafari H, Macphie E, Chinoy H, Rao C, McLoughlin Y, Preeti S. Oral Abstracts 7: RA Clinical * O37. Long-Term Outcomes of Early RA Patients Initiated with Adalimumab Plus Methotrexate Compared with Methotrexate Alone Following a Targeted Treatment Approach. Rheumatology (Oxford) 2013. [DOI: 10.1093/rheumatology/ket198] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Rosli N, McGoldrick C, McEwen R, Laing R, Mackenzie A, Douglas J. Bacteraemias in injecting drug users – the Grampian experience. J Infect 2007. [DOI: 10.1016/j.jinf.2007.04.096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Talmadge JE, Talmadge CB, Zbar B, McEwen R, Meeker AK, Tribble H. In vivo immunologic selection of class I major histocompatibility complex gene deletion variants from the B16-BL6 melanoma. J Natl Cancer Inst 1987; 78:1215-21. [PMID: 3473258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The mechanism by which tumor allografts escape host immunologic attack was investigated. B16-BL6 cells (the bladder 6 subline of the B16 melanoma) (H-2b) were transfected with a gene (Dd) encoding an allogeneic class I major histocompatibility complex antigen. Clones that expressed Dd antigen were injected into the footpads of nonimmune syngeneic mice, syngeneic immune mice, and nude mice. Under conditions of immunologic selection a clone that contained multiple copies of the transfected gene formed variants that lacked the transfected gene. Primary tumors and pulmonary metastases of immunized mice and pulmonary metastases of nonimmunized mice had lost the Dd gene and, in most cases, all of the associated plasmid. In contrast, in immunodeficient nude mice, primary tumors and pulmonary metastases retained the Dd gene and the associated plasmid. Deletion of genes encoding cell surface antigens may be one of the mechanisms by which allogeneic tumors escape immunologic attack.
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