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1.
ESMO Open ; 7(5): 100562, 2022 10.
Article in English | MEDLINE | ID: mdl-35987165

ABSTRACT

BACKGROUND: The anti-CD38 antibody isatuximab is approved for the treatment of relapsed/refractory multiple myeloma, but there are no data on its efficacy in solid tumors. This phase I/II study (NCT03637764) assessed the safety and activity of isatuximab plus atezolizumab (Isa + Atezo), an anti-programmed death-ligand 1 (PD-L1) antibody, in patients with immunotherapy-naive solid tumors: epithelial ovarian cancer (EOC), glioblastoma (GBM), hepatocellular carcinoma (HCC), and squamous cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS: Phase I assessed safety, tolerability, pharmacokinetics, pharmacodynamics, and the recommended phase II dose (RP2D) of isatuximab 10 mg/kg intravenously (i.v.) every week for 3 weeks followed by once every 3 weeks + atezolizumab 1200 mg i.v. every 3 weeks. Phase II used a Simon's two-stage design to assess the overall response rate or progression-free survival rate at 6 months (GBM cohort). Interim analysis was carried out at 6 months following first dose of the last enrolled patient in each cohort. Pharmacodynamic biomarkers were tested for CD38, PD-L1, tumor-infiltrating immune cells, and FOXP3+ regulatory T cells (Tregs) in the tumor microenvironment (TME). RESULTS: Overall, 107 patients were treated (EOC, n = 18; GBM, n = 33; HCC, n = 27; SCCHN, n = 29). In phase I, Isa + Atezo showed an acceptable safety profile, no dose-limiting toxicities were observed, and RP2D was confirmed. Most patients experienced ≥1 treatment-emergent adverse event (TEAE), with ≤48.5% being grade ≥3. The most frequent TEAE was infusion reactions. The study did not continue to stage 2 based on prespecified targets. Tumor-infiltrating CD38+ immune cells were reduced and almost cleared after treatment. Isa + Atezo did not significantly modulate Tregs or PD-L1 expression in the TME. CONCLUSIONS: Isa + Atezo had acceptable safety and tolerability. Clinical pharmacodynamic evaluation revealed efficient target engagement of isatuximab via treatment-mediated reduction of CD38+ immune cells in the TME. Based on clinical data, CD38 inhibition does not improve responsiveness to PD-L1 blockade in these patients.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Humans , B7-H1 Antigen/metabolism , Forkhead Transcription Factors , Tumor Microenvironment
2.
Health Serv Res Manag Epidemiol ; 9: 23333928221103107, 2022.
Article in English | MEDLINE | ID: mdl-35633832

ABSTRACT

Introduction: Previous research indicates that an increasing number of women who go to an emergency room for complications following an induced abortion are treated for a miscarriage, meaning their abortion is miscoded or concealed. Objective: To determine if the failure to identify a prior induced abortion during an ER visit is a risk factor for higher rates of subsequent hospitalization. Methods: Post hoc analysis of hospital admissions following an induced abortion and ER visit within 30 days: 4273 following surgical abortion and 408 following chemical abortion; abortion not miscoded versus miscoded or concealed at prior ER visit. Results: Chemical abortion patients whose abortions are misclassified as miscarriages during an ER visit subsequently experience on average 3.2 hospital admissions within 30 days. 86% of the patients ultimately have surgical removal of retained products of conception (RPOC). Chemical abortions are more likely than surgical abortions (OR 1.80, CL 1.38-2.35) to result in an RPOC admission, and chemical abortions concealed are more likely to result (OR 2.18, CL 1.65-2.88) in a subsequent RPOC admission than abortions without miscoding. Surgical abortions miscoded/concealed are similarly twice as likely to result in hospital admission than those without miscoding. Conclusion: Patient concealment and/or physician failure to identify a prior abortion during an ER visit is a significant risk factor for a subsequent hospital admission. Patients and ER personnel should be made aware of this risk.

3.
AJNR Am J Neuroradiol ; 43(5): 675-681, 2022 05.
Article in English | MEDLINE | ID: mdl-35483906

ABSTRACT

BACKGROUND AND PURPOSE: Imaging assessment of an immunotherapy response in glioblastoma is challenging due to overlap in the appearance of treatment-related changes with tumor progression. Our purpose was to determine whether MR imaging radiomics-based machine learning can predict progression-free survival and overall survival in patients with glioblastoma on programmed death-ligand 1 inhibition immunotherapy. MATERIALS AND METHODS: Post hoc analysis was performed of a multicenter trial on the efficacy of durvalumab in glioblastoma (n = 113). Radiomics tumor features on pretreatment and first on-treatment time point MR imaging were extracted. The random survival forest algorithm was applied to clinical and radiomics features from pretreatment and first on-treatment MR imaging from a subset of trial sites (n = 60-74) to train a model to predict long overall survival and progression-free survival and was tested externally on data from the remaining sites (n = 29-43). Model performance was assessed using the concordance index and dynamic area under the curve from different time points. RESULTS: The mean age was 55.2 (SD, 11.5) years, and 69% of patients were male. Pretreatment MR imaging features had a poor predictive value for overall survival and progression-free survival (concordance index = 0.472-0.524). First on-treatment MR imaging features had high predictive value for overall survival (concordance index = 0.692-0.750) and progression-free survival (concordance index = 0.680-0.715). CONCLUSIONS: A radiomics-based machine learning model from first on-treatment MR imaging predicts survival in patients with glioblastoma on programmed death-ligand 1 inhibition immunotherapy.


Subject(s)
Glioblastoma , B7-H1 Antigen , Female , Glioblastoma/diagnostic imaging , Glioblastoma/drug therapy , Humans , Immunotherapy , Machine Learning , Magnetic Resonance Imaging/methods , Male , Middle Aged , Retrospective Studies
4.
Crit Rev Oncol Hematol ; 111: 60-65, 2017 Mar.
Article in English | MEDLINE | ID: mdl-28259296

ABSTRACT

Since 2005, the standard of care for patients with newly diagnosed glioblastoma (GBM) has consisted of maximal resection followed by radiotherapy plus daily temozolomide (TMZ), followed by maintenance TMZ. In patients selected for clinical trials, median overall survival (OS) and progression-free survival (PFS) with this regimen is 15-17 months and 6-7 months, respectively. There have been various, largely unsuccessful attempts to improve on this standard of care. With the FDA approval of the tumor-treating fields (TTFields) device, Optune, for recurrent GBM (2011), and the more recent EF-14 interim trial results and approval for newly diagnosed GBM patients, several questions have arisen. A roundtable of experts was convened at the 2015 ASCO meeting to engage in an open conversation and debate of the EF-14 results presented at that meeting and their implications for neuro-oncology practice and clinical research. In October 2015, subsequent to the roundtable discussion, TTFields received FDA approval for newly diagnosed GBM.


Subject(s)
Brain Neoplasms/therapy , Glioblastoma/therapy , Medical Oncology/standards , Adult , Aged , Antineoplastic Agents, Alkylating/therapeutic use , Brain Neoplasms/drug therapy , Brain Neoplasms/radiotherapy , Dacarbazine/analogs & derivatives , Dacarbazine/therapeutic use , Disease-Free Survival , Female , Glioblastoma/drug therapy , Glioblastoma/radiotherapy , Humans , Male , Middle Aged , Randomized Controlled Trials as Topic , Standard of Care , Temozolomide
5.
Science ; 349(6255): 1522-5, 2015 Sep 25.
Article in English | MEDLINE | ID: mdl-26404832

ABSTRACT

Gravitational waves are expected to be radiated by supermassive black hole binaries formed during galaxy mergers. A stochastic superposition of gravitational waves from all such binary systems would modulate the arrival times of pulses from radio pulsars. Using observations of millisecond pulsars obtained with the Parkes radio telescope, we constrained the characteristic amplitude of this background, A(c,yr), to be <1.0 × 10(-15) with 95% confidence. This limit excludes predicted ranges for A(c,yr) from current models with 91 to 99.7% probability. We conclude that binary evolution is either stalled or dramatically accelerated by galactic-center environments and that higher-cadence and shorter-wavelength observations would be more sensitive to gravitational waves.

6.
Br J Cancer ; 107(9): 1481-7, 2012 Oct 23.
Article in English | MEDLINE | ID: mdl-23037712

ABSTRACT

BACKGROUND: Bevacizumab improves outcome for most recurrent glioblastoma patients, but the duration of benefit is limited and survival after initial bevacizumab progression is poor. We evaluated bevacizumab continuation beyond initial progression among recurrent glioblastoma patients as it is a common, yet unsupported practice in some countries. METHODS: We analysed outcome among all patients (n=99) who received subsequent therapy after progression on one of five consecutive, single-arm, phase II clinical trials evaluating bevacizumab regimens for recurrent glioblastoma. Of note, the five trials contained similar eligibility, treatment and assessment criteria, and achieved comparable outcome. RESULTS: The median overall survival (OS) and OS at 6 months for patients who continued bevacizumab therapy (n=55) were 5.9 months (95% confidence interval (CI): 4.4, 7.6) and 49.2% (95% CI: 35.2, 61.8), compared with 4.0 months (95% CI: 2.1, 5.4) and 29.5% (95% CI: 17.0, 43.2) for patients treated with a non-bevacizumab regimen (n=44; P=0.014). Bevacizumab continuation was an independent predictor of improved OS (hazard ratio=0.64; P=0.04). CONCLUSION: The results of our retrospective pooled analysis suggest that bevacizumab continuation beyond initial progression modestly improves survival compared with available non-bevacizumab therapy for recurrent glioblastoma patients require evaluation in an appropriately randomised, prospective trial.


Subject(s)
Angiogenesis Inhibitors/administration & dosage , Antibodies, Monoclonal, Humanized/administration & dosage , Brain Neoplasms/drug therapy , Glioblastoma/drug therapy , Neoplasm Recurrence, Local/drug therapy , Adult , Aged , Angiogenesis Inhibitors/adverse effects , Antibodies, Monoclonal, Humanized/adverse effects , Bevacizumab , Disease Progression , Drug Administration Schedule , Humans , Middle Aged , Retrospective Studies , Survival Analysis , Treatment Outcome , Young Adult
7.
Lancet Oncol ; 12(6): 583-93, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21474379

ABSTRACT

Although low-grade gliomas (LGG) have a less aggressive course than do high-grade gliomas, the outcome of these tumours is ultimately fatal in most patients. Both the tumour and its treatment can cause disabling morbidity, particularly of cognitive functions. Because many patients present with seizures only, with no other signs and symptoms, maintenance of quality of life and function constitutes a particular challenge in LGG. The slow growth pattern of most LGG, and the rare radiological true responses despite a favourable clinical response to treatment, interferes with the use of progression-free survival as the primary endpoint in trials. Overall survival as an endpoint brings logistical challenges, and is sensitive to other non-investigational salvage therapies. Clinical trials for LGG need to consider other measures of patient benefit such as cognition, symptom burden, and seizure activity, to establish whether improved survival is reflected in prolonged wellbeing. This Review investigates clinical and imaging endpoints in trials of LGG, and provides response assessment in neuro-oncology (RANO) criteria for non-enhancing tumours. Additionally, other measures for patients with brain tumours that assess outcome are described. Similar considerations are relevant for trials of high-grade gliomas, although for these tumours survival is shorter and survival endpoints generally have more value than they do for LGG.


Subject(s)
Brain Neoplasms/therapy , Glioma/therapy , Brain Neoplasms/mortality , Brain Neoplasms/pathology , Clinical Trials as Topic , Disease Progression , Glioma/mortality , Glioma/pathology , Humans , Magnetic Resonance Imaging , Positron-Emission Tomography , Treatment Outcome
8.
Br J Radiol ; 84(1000): 327-33, 2011 Apr.
Article in English | MEDLINE | ID: mdl-20959370

ABSTRACT

OBJECTIVE: The aim of this study was to determine the prognostic significance of the volume and intensity of abnormal (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET) accumulation within areas of contrast enhancement on post-therapeutic volumetric MRI. METHODS: A total of 10 patients with Grade III or IV glioma were treated with resection followed by intracavitary radiation therapy with (131)I-labelled antitenascin monoclonal antibody. Patients underwent serial FDG-PET and 1.5 T MR imaging. For each patient, MR and FDG-PET image volumes at each time point were aligned using a rigid-body normalised mutual information algorithm. Contrast-enhancing regions of interest (ROIs) were defined using a semi-automated k-means clustering technique. Activity within the ROI on the co-registered PET scan was calculated as a ratio (mean activity ratio; MAR) to activity in contralateral normal-appearing white matter (NAWM). The PET lesion was defined as the portion of the ROI associated with activity greater than two standard deviations above the mean in NAWM. Survival was assessed using the logrank test. RESULTS: Larger contrast-enhancing ROIs were strongly associated with an increased MAR (r = 0.51; p<0.002). Enhancing lesions with an MAR >1.2 were associated with decreased survival (p<0.016). In nine patients who died, the MAR on PET correlated inversely with survival duration (r = -0.43; p<0.01), whereas PET lesion volume did not. CONCLUSION: Following intracavitary radiation therapy, the development of contrast-enhancing lesions that are associated with high mean FDG-PET accumulation suggests poor prognosis.


Subject(s)
Brain Neoplasms/diagnosis , Glioma/diagnosis , Magnetic Resonance Imaging/methods , Positron-Emission Tomography/methods , Adult , Aged , Brain Neoplasms/diagnostic imaging , Female , Fluorodeoxyglucose F18 , Glioma/diagnostic imaging , Humans , Male , Middle Aged , Prognosis , Radiopharmaceuticals
9.
Br J Cancer ; 101(12): 1986-94, 2009 Dec 15.
Article in English | MEDLINE | ID: mdl-19920819

ABSTRACT

BACKGROUND: We evaluated bevacizumab with metronomic etoposide among recurrent malignant glioma patients in a phase 2, open-label trial. METHODS: A total of 59 patients, including 27 with glioblastoma (GBM) and 32 with grade 3 malignant glioma, received 10 mg kg(-1) bevacizumab biweekly and 50 mg m(-2) etoposide daily for 21 consecutive days each month. The primary end point was a 6-month progression-free survival, and secondary end points included safety and overall survival. Vascular endothelial growth factor (VEGF), VEGFR-2, carbonic anhydrase 9 (CA9) and hypoxia-inducible factor-2alpha (HIF-2alpha) were assessed semiquantitatively in archival tumours using immunohistochemistry and were correlated with outcome. RESULTS: Among grade 3 and GBM patients, the 6-month progression-free survivals were 40.6% and 44.4%, the radiographic response rates were 22% and 37% and the median survivals were 63.1 and 44.4 weeks, respectively. Hypertension predicted better outcome among both grade 3 and GBM patients, whereas high CA9 and low VEGF were associated with poorer progression-free survival (PFS) among those with GBM. The most common grade > or = 3 adverse events included neutropaenia (24%), thrombosis (12%), infection (8%) and hypertension (3%). Two patients had asymptomatic, grade 1 intracranial haemorrhage and one on-study death occurred because of pulmonary embolism. CONCLUSION: Bevacizumab with metronomic etoposide has increased toxicity compared with previous reports of bevacizumab monotherapy. Its anti-tumour activity is similar to that of bevacizumab monotherapy or bevacizumab plus irinotecan. (ClinicalTrials.gov: NCT00612430).


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Brain Neoplasms/drug therapy , Glioma/drug therapy , Neoplasm Recurrence, Local/drug therapy , Administration, Oral , Adult , Aged , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal, Humanized , Bevacizumab , Biomarkers, Tumor/analysis , Brain Neoplasms/mortality , Etoposide/administration & dosage , Etoposide/adverse effects , Female , Glioma/mortality , Humans , Male , Middle Aged , Treatment Failure , Vascular Endothelial Growth Factor A/antagonists & inhibitors
10.
Br J Cancer ; 101(12): 1995-2004, 2009 Dec 15.
Article in English | MEDLINE | ID: mdl-19904263

ABSTRACT

BACKGROUND: We evaluated the efficacy of imatinib mesylate in addition to hydroxyurea in patients with recurrent glioblastoma (GBM) who were either on or not on enzyme-inducing anti-epileptic drugs (EIAEDs). METHODS: A total of 231 patients with GBM at first recurrence from 21 institutions in 10 countries were enrolled. All patients received 500 mg of hydroxyurea twice a day. Imatinib was administered at 600 mg per day for patients not on EIAEDs and at 500 mg twice a day if on EIAEDs. The primary end point was radiographic response rate and secondary end points were safety, progression-free survival at 6 months (PFS-6), and overall survival (OS). RESULTS: The radiographic response rate after centralised review was 3.4%. Progression-free survival at 6 months and median OS were 10.6% and 26.0 weeks, respectively. Outcome did not appear to differ based on EIAED status. The most common grade 3 or greater adverse events were fatigue (7%), neutropaenia (7%), and thrombocytopaenia (7%). CONCLUSIONS: Imatinib in addition to hydroxyurea was well tolerated among patients with recurrent GBM but did not show clinically meaningful anti-tumour activity.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Brain Neoplasms/drug therapy , Glioblastoma/drug therapy , Adolescent , Adrenal Cortex Hormones/administration & dosage , Adult , Aged , Benzamides , Biomarkers, Tumor/analysis , Female , Glioblastoma/mortality , Humans , Hydroxyurea/administration & dosage , Hydroxyurea/adverse effects , Hydroxyurea/pharmacokinetics , Imatinib Mesylate , Male , Middle Aged , Piperazines/administration & dosage , Piperazines/adverse effects , Piperazines/pharmacokinetics , Proto-Oncogene Proteins c-kit/genetics , Pyrimidines/administration & dosage , Pyrimidines/adverse effects , Pyrimidines/pharmacokinetics , Survival Rate
12.
J Med Ethics ; 32(8): 435-8, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16877620

ABSTRACT

OBJECTIVE: To study the preferences of patients for information related to elective procedures. METHODS: A survey was carried out using a sample of 187 women. The majority of whom were on a low-income, who obtained obstetric or gynaecological services at St Joseph Regional Medical Center in Milwaukee, Wisconsin, while they were in a waiting room. RESULTS: Many of the complications, including those that are uncommon and less serious, were considered to be relevant to the medical decisions of most patients. Average seriousness ratings associated with complications of various elective procedures were in the range of moderate to high. A frequency of complications of 1:100 or higher would factor into most women's elective treatment decisions. Women indicated a preference for receiving as much or more information pertaining to complications associated with particular elective obstetric or gynaecological procedures as other elective procedures. CONCLUSION: Most women wish to be informed of risks and treatment alternatives, rate many complications as serious, and are likely to use information provided to make elective treatment decisions.


Subject(s)
Patient Care/psychology , Patient Education as Topic , Patient Participation/psychology , Women/psychology , Adolescent , Adult , Attitude to Health , Decision Making , Female , Genital Diseases, Female/complications , Genital Diseases, Female/psychology , Genital Diseases, Female/therapy , Health Care Surveys/methods , Humans , Middle Aged , Pregnancy , Pregnancy Complications/psychology , Pregnancy Complications/therapy , Risk Assessment/methods , Risk Factors
13.
Internet resource in English | LIS -Health Information Locator | ID: lis-10746

ABSTRACT

It examines and responds to an assertion that librarians are knowledge managers, and suggests that the content of "real" knowledge management courses should be developed by the Schools of Information Science.


Subject(s)
Organization and Administration , Knowledge Management , Information Management
16.
Biol Blood Marrow Transplant ; 7(5): 284-93, 2001.
Article in English | MEDLINE | ID: mdl-11400951

ABSTRACT

We evaluated the feasibility of tandem-cycle high-dose chemotherapy (HDCT) with cisplatin, melphalan, and peripheral blood progenitor cells (PBPCs). Fifty patients with high-risk primary (n = 17) or stage IV breast cancer (n = 29) or other malignancies (n = 4) received 2 cycles of intravenous melphalan, 20 to 151.8 mg/m2, and cisplatin, 200 mg/m2, followed by granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF. Starting at 40 mg/m2 of melphalan, patients also received PBPCs. Delayed platelet recovery defined the maximum tolerated dose (MTD) for melphalan at 101.2 mg/m2 per cycle. There were no treatment-related deaths. Cycle 2 was delivered at a median of 1.7 months after cycle 1; 72% of patients treated at the MTD received both cycles. Cycle 2 was omitted when patients refused it or had disease progression or toxicities, primarily prolonged thrombocytopenia. Complete response rates in stage IV breast cancer patients increased from 28% pre-HDCT to 55% after cycle 2. At a median follow-up of 4.6 years (range, 1.5-8.1 years), 11 of 29 patients with stage IV breast carcinoma were alive with 5-year projected progression-free and overall survival rates of 19% (95% confidence interval [CI], 7%-41%) and 39% (95% CI, 20%-62%), respectively. Five-year projected progression-free and overall survival rates for patients with stage IV breast cancer in complete response following HDCT versus all others were 35% (95% CI, 15%-70%) versus 0% (P = .01) and 61% (95% CI, 35%-91%) versus 10% (95% CI, 2%-60%) (P = .003; log-rank test), respectively. Estrogen-receptor positivity was predictive of reduced risk of progression (relative risk [RR], 0.25; 95% CI, 0.10-0.65; P = .003) and death (RR, 0.27; 95% CI, 0.10-0.72; P = .009) after adjusting for response status. Five-year projected relapse-free and overall survival rates were 71% (95% CI, 43%-96%) and 82% (95% CI, 56%-100%), respectively, for the 17 patients with high-risk primary breast cancer. Tandem-cycle high-dose melphalan and cisplatin with PBPCs is feasible. Preliminary data suggest significant activity in selected patients with stage IV responding breast carcinoma.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Breast Neoplasms/therapy , Hematopoietic Stem Cell Transplantation , Adult , Antineoplastic Combined Chemotherapy Protocols/toxicity , Breast Neoplasms/complications , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Cisplatin/administration & dosage , Cisplatin/toxicity , Disease-Free Survival , Feasibility Studies , Female , Follow-Up Studies , Graft Survival , Granulocyte Colony-Stimulating Factor/administration & dosage , Humans , Maximum Tolerated Dose , Melphalan/administration & dosage , Melphalan/toxicity , Middle Aged , Neoplasm Staging , Survival Analysis , Treatment Outcome
17.
Br J Cancer ; 84(12): 1591-8, 2001 Jun 15.
Article in English | MEDLINE | ID: mdl-11401310

ABSTRACT

We assessed the feasibility and pharmacokinetics of high-dose infusional paclitaxel in combination with doxorubicin, cyclophosphamide, and peripheral blood progenitor cell rescue. Between October 1995 and June 1998, 63 patients with high-risk primary [stage II with >or= 10 axillary nodes involved, stage IIIA or stage IIIB inflammatory carcinoma (n = 53)] or with stage IV responsive breast cancer (n = 10) received paclitaxel 150-775 mg/m(2)infused over 24 hours, doxorubicin 165 mg/m(2)as a continuous infusion over 96 hours, and cyclophosphamide 100 mg kg(-1). There were no treatment-related deaths. Dose-limiting toxicity was reversible, predominantly sensory neuropathy following administration of paclitaxel at the 775 mg/m(2) dose level. Paclitaxel pharmacokinetics were non-linear at higher dose levels; higher paclitaxel dose level, AUC, and peak concentrations were associated with increased incidence of paraesthesias. No correlation between stomatitis, haematopoietic toxicities, and paclitaxel dose or pharmacokinetics was found. Kaplan-Meier estimates of 30-month event-free and overall survival for patients with primary breast carcinoma are 65% (95% CI; 51-83%) and 77% (95% CI; 64-93%). Paclitaxel up to 725 mg/m(2) infused over 24 hours in combination with with doxorubicin 165 mg/m(2) and cyclophosphamide 100 mg kg(-1) is tolerable. A randomized study testing this regimen against high-dose carboplatin, thiotepa and cyclophosphamide (STAMP V) is currently ongoing.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Carcinoma, Ductal, Breast/drug therapy , Hematopoietic Stem Cell Transplantation , Paclitaxel/adverse effects , Adult , Area Under Curve , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/pathology , Cyclophosphamide/administration & dosage , Disease-Free Survival , Dose-Response Relationship, Drug , Doxorubicin/administration & dosage , Female , Humans , Lymphatic Metastasis , Middle Aged , Neoplasm Staging , Paclitaxel/pharmacokinetics , Peripheral Nervous System Diseases/chemically induced , Treatment Outcome
19.
J Natl Cancer Inst ; 93(12): 921-9, 2001 Jun 20.
Article in English | MEDLINE | ID: mdl-11416113

ABSTRACT

BACKGROUND: Exposure of human cancer cells to ionizing radiation activates the epidermal growth factor receptor (EGFR), which, in turn, mediates a cytoprotective response that reduces the cells' sensitivity to ionizing radiation. Overexpression of a dominant-negative EGFR mutant, EGFR-CD533, disrupts the cytoprotective response by preventing radiation-induced activation of the receptor and its downstream effectors. To investigate whether gene therapy with EGFR-CD533 has the potential to increase tumor cell radiosensitivity, we introduced an adenoviral vector containing EGFR-CD533 into xenograft tumors in nude mice and evaluated the tumor response to ionizing radiation. METHODS: Xenograft tumors established from the human mammary carcinoma cell line MDA-MB-231 were transduced via infusion with the adenoviral vector Ad-EGFR-CD533 or a control vector containing the beta-galactosidase gene, Ad-LacZ. The transduced tumors were then exposed to radiation in the therapeutic dose range, and radiation-induced EGFR activation was assessed by examining the tyrosine phosphorylation of immunoprecipitated EGFR. Radiosensitization was determined in vitro by colony-formation assays. All statistical tests were two-sided. RESULTS: The transduction efficiency of MDA-MB-231 tumors by Ad-LacZ was 44%. Expression of EGFR-CD533 in tumors reduced radiation-induced EGFR activation by 2.94-fold (95% confidence interval [CI] = 2.23 to 4.14). The radiosensitivity of Ad-EGFR-CD533-transduced tumors was statistically significantly higher (46%; P<.001) than that of Ad-LacZ-transduced tumors, yielding a dose-enhancement ratio of 1.85 (95% CI = 1.54 to 2.51). CONCLUSIONS: Transduction of MDA-MB-231 xenograft tumors with Ad-EGFR-CD533 conferred a dominant-negative EGFR phenotype and induced tumor radiosensitization. Therefore, disruption of EGFR function through overexpression of EGFR-CD533 may hold promise as a gene therapeutic approach to enhance the sensitivity of tumor cells to ionizing radiation.


Subject(s)
Breast Neoplasms/therapy , ErbB Receptors/physiology , Genetic Therapy , Animals , Breast Neoplasms/pathology , Breast Neoplasms/radiotherapy , Cell Survival/drug effects , Cell Survival/radiation effects , Dose-Response Relationship, Radiation , Doxycycline/toxicity , ErbB Receptors/genetics , ErbB Receptors/radiation effects , Female , Gene Expression Regulation, Neoplastic/radiation effects , Humans , Mice , Mice, Nude , Radiation Tolerance , Transplantation, Heterologous , Tumor Cells, Cultured , Tumor Stem Cell Assay
20.
Oncogene ; 20(11): 1388-97, 2001 Mar 15.
Article in English | MEDLINE | ID: mdl-11313882

ABSTRACT

Activation of the epidermal growth receptor (ErbB1) occurs within minutes of a radiation exposure. Immediate downstream consequences of this activation are currently indistinguishable from those obtained with growth factors (GF), e.g. stimulation of the pro-proliferative mitogen-activated protein kinase (MAPK). To identify potential differences, the effects of GFs and radiation on other members of the ErbB family have been compared in mammary carcinoma cell lines differing in their ErbB expression profiles. Treatment of cells with EGF (ErbB1-specific) or heregulin (ErbB4-specific) resulted in a hierarchic transactivations of ErbB2 and ErbB3 dependent on GF binding specificity. In contrast, radiation indiscriminately activated all ErbB species with the activation profile reflecting that cell's ErbB expression profile. Downstream consequences of these ErbB interactions were examined with MAPK after specifically inhibiting ErbB1 (or 4) with tyrphostin AG1478 or ErbB2 with tyrphostin AG825. MAPK activation by GFs or radiation was completely inhibited by AG1478 indicating total dependance on ErbB1 (or 4) depending on which ErbB is expressed. Inhibiting ErbB2 caused an enhanced MAPK response simulating an amplified ErbB1 (or 4) response. Thus ErbB2 is a modulator of ErbB1 (or 4) function leading to different MAPK response profiles to GF or radiation exposure.


Subject(s)
Breast Neoplasms/radiotherapy , Carcinoma/radiotherapy , Genes, erbB , Radiation, Ionizing , Receptor Protein-Tyrosine Kinases/radiation effects , Autocrine Communication , Benzothiazoles , Epidermal Growth Factor/pharmacology , ErbB Receptors/metabolism , ErbB Receptors/radiation effects , Female , Growth Substances/pharmacology , Humans , Neuregulin-1/pharmacology , Quinazolines , Receptor Protein-Tyrosine Kinases/metabolism , Receptor, ErbB-2/metabolism , Receptor, ErbB-2/radiation effects , Receptor, ErbB-3/metabolism , Receptor, ErbB-3/radiation effects , Receptor, ErbB-4 , Signal Transduction , Tumor Cells, Cultured , Tyrphostins/pharmacology
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