Biomedical subjects

E E Voest

Publications and source records attributed to E E Voest.

At least 19 recordsLinked to original sources

PubMed2006

Telephone consultation in palliative care for cancer patients: 5 years of experience in The Netherlands.

GOALS OF WORK: To analyze cancer patient-related consultations of a telephone helpdesk (TH) for palliative care over a period of 5 years in the region of Utrecht, The Netherlands. MATERIALS AND METHODS: A descriptive analysis was performed of consultations over a period of 5 years (2001-2006). The discipline and location of requesting professionals, patient characteristics, reasons for calling, symptoms, palliative care problems and needs for support were registered. MAIN RESULTS: A total of 1,794 consultations were analyzed. There was an increasing number of consultations during the study period. Of the patients, 51% were male and their median age was 65 years (range 0-104). Eighty-four percent were treated at home by their general practitioner. Two thirds of the patients had a life expectancy <4 weeks. Most questions referred to pain (49%), delirium (20%), nausea and vomiting (16%) and dyspnea (12%). The median number of symptoms was 1 (0-6). Of the questions, 54% were related to pharmacological problems, 19% to psychological problems and 21% to the organization of care. Of the requesting professionals, 17% asked for support for themselves. Of the consultations, 14% were related to end-of-life issues: palliative sedation (11%) and euthanasia (3%). CONCLUSION: After more than 5 years, the 24-h telephone consultation service fulfills a need for general practitioners dealing with daily dilemmas in palliative care treatment for cancer patients at home during the last period of their life.

Adolescent↗

PubMed2006

Phase I dose-finding and pharmacokinetic trial of orally administered indibulin (D-24851) to patients with solid tumors.

Indibulin is a synthetic small molecule which antitumor activity is based upon destabilization of microtubules. The primary study objectives were to determine the impact of fasted and fed condition on pharmacokinetic parameters, as well as the maximum tolerated dose of the oral drinking solution of indibulin administered once daily for 14 days every 3 weeks in patients with solid tumors. In the pilot food effect part, patients received a single dose of 20 mg indibulin on day-8 and -4, fasted or fed, in a randomized crossover design. In the dose-escalation part, patients received a single dose of indibulin on day-4. Three dose levels were evaluated: 20, 40 and 80 mg. After a washout period, patients received indibulin once daily for 14 days every 3 weeks (multiple dose part). Blood samples were collected in the pilot food effect- and in the dose escalation study. A total of 14 patients entered, of which 6 completed the food effect study. The ratio of indibulin (fed/fasted) in the food effect study for AUC(0-72) was estimated as 1.24 (P=0.082, 95%CI 0.96-1.41) and C(max) ratio was 0.89 (P=0.54, 95%CI 0.55-1.44). Interpatient variability was high. Higher peak plasma concentrations were reached under fasting conditions which was undesired regarding tolerability. Therefore the dose escalation study was continued under fed conditions. Dose limiting toxicities, nausea and vomiting, appeared to be related to the increased volume of the solvent lactic acid. This study is continued, evaluating indibulin administered as capsules on the recommended dose level of 60 mg daily for 14 days.

Acetamides↗

PubMed2006

Molecular subtypes of breast cancer and amplification of topoisomerase II alpha: predictive role in dose intensive adjuvant chemotherapy.

Benefit from chemotherapy treatment in breast cancer patients is determined by the molecular make-up of the tumour. In a retrospective analysis, we determined the molecular subtypes of breast cancer originally defined by expression microarrays by immunohistochemistry in tumours of patients who took part in a randomised study of adjuvant high-dose chemotherapy in breast cancer. In addition, the topoisomerase II alpha (TOP2A) amplification status was determined by fluorescence in situ hybridisation and chromogenic in situ hybridisation. 411 of the 753 tumours (55%) were classified as luminal-like, 137 (18%) as basal-like and 205 (27%) as human epithelial receptor type 2 (HER2) amplified. The basal-like tumours were defined as having no expression of ER and HER2; 98 of them did express epidermal growth factor receptor and/or cytokeratin 5/6. The luminal-like tumours had a significantly better recurrence free and overall survival than the other two groups. From the 194 HER2-positive tumours, 47 (24%) were shown to harbour an amplification of TOP2A. Patients with an HER2-amplified tumour randomised to the high-dose therapy arm did worse than those in the conventional treatment arm, possibly caused by the lower cumulative anthracycline dose in the high-dose arm. The tumours with a TOP2A amplification contributed hardly to this difference, suggesting that TOP2A amplification is not the cause of the steep dose-response curve for anthracyclines in breast cancer. Possibly, the difference of the cumulative dose of only 25% between the treatment arms was insufficient to yield a survival difference.

Adult↗

PubMed2006

Interplay between VHL/HIF1alpha and Wnt/beta-catenin pathways during colorectal tumorigenesis.

Activation of the Wnt signaling pathway initiates the transformation of colorectal epithelial cells, although the transition to metastatic cancer requires angiogenesis. We have investigated the expression of the von Hippel-Lindau (VHL) tumor suppressor in the intestines from humans and mice. Here, we show that VHL expression is regulated by TCF4 and is restricted to the proliferative compartment at the bottom of intestinal crypts. Accordingly, VHL is completely absent from the proliferative intestinal pockets of Tcf4(-/-) perinatal mice. We observed complementary staining of the hypoxia-inducible factor (HIF) 1alpha to VHL in normal intestinal epithelium as well as in all stages of colorectal cancer (CRC). To the best of our knowledge, this is the first report demonstrating the presence of nuclear HIF1alpha in normoxic healthy adult tissue. Although we observed upregulated levels of VHL in very early CRC lesions from sporadic and familial adenomatous polyposis patients - presumably due to activated Wnt signaling - a clear reduction of VHL expression is observed in later stages of CRC progression, coinciding with stabilization of HIF1alpha. As loss of VHL in later stages of CRC progression results in stabilization of HIF, these data provide evidence that selection for VHL downregulation provides a proangiogenic impulse for CRC progression.

Adenocarcinoma↗

PubMed2006

[Better treatment for patients with colorectal liver metastases].

Three patients, 61, 58 and 63 years old, presented with non-resectable liver metastases from colorectal cancer. The first patient, a man, who had a solitary lesion in the liver and severe cardiovascular morbidity, was successfully treated with laser-induced interstitial thermotherapy. The second patient, a woman, had large multiple liver metastases and two concomitant isolated pulmonary metastases. Following chemotherapy with fluorouracil, leucovorin and oxaliplatin, all lesions were downsized and a hemihepatectomy and pulmonary wedge resections were able to be performed in two stages. At the last follow-up, both patients were disease-free after 12 and 24 months respectively. The third patient, a man, presenting with multiple synchronous liver metastases, showed a significant decrease of hepatic tumour involvement after six courses of capecitabine. At present he is in a good condition and his disease is stable. Surgical resection ofcolorectal liver metastases leads to a 5-year survival rate of up to 45% in selected patients. Unfortunately, only 10 to 20% of patients are amenable to surgical resection. In the remaining group, a combination of new treatment options using local tumour ablative therapies and novel chemotherapeutic regimens provide alternative strategies with the potential of long-term survival.

Antineoplastic Agents↗

PubMed2006

Efficacy of high-dose alkylating chemotherapy in HER2/neu-negative breast cancer.

BACKGROUND: High-dose chemotherapy in the adjuvant treatment of breast cancer has been abandoned by many. PATIENTS AND METHODS: 885 patients with stage III primary breast cancer and four or more axillary lymph node metastases were randomised to receive either five courses of FEC (fluorouracil, epirubicin and cyclophosphamide) followed by radiation therapy and tamoxifen, or the same treatment but with high-dose alkylating chemotherapy (cyclophosphamide, thiotepa and carboplatin) replacing the fifth course of FEC. Of these patients, 621 had HER2/neu-negative disease, as determined by immunohistochemistry and chromogenic in situ hybridisation. RESULTS: At a median follow-up of 84 months, a trend for a better relapse-free survival was observed in the high-dose arm: (hazard ratio (HR) 0.84, P = 0.076, two-sided). The 621 patients with HER2/neu-negative disease benefited from high-dose therapy, while patients with HER2/neu-positive disease did not (test for interaction, P = 0.006). There was a marked relapse-free survival benefit for patients with HER2/neu-negative disease (71.5% versus 59.1%, 5 years after randomisation; HR 0.68, P = 0.002) and also a survival benefit (78.2% versus 71.0% at 5 years; HR 0.72, P = 0.02). CONCLUSIONS: The findings from this subgroup analysis provide additional evidence that HER2/neu-positive breast cancer is relatively resistant to alkylating agents. For HER2/neu-negative tumours, however, high-dose chemotherapy should remain the subject of clinical studies.

Antineoplastic Agents, Alkylating↗

PubMed2006

Interleukin-8 CSF levels predict survival in patients with leptomeningeal metastases.

Median survival of patients with leptomeningeal metastases (LM) is 4 to 6 months, with a few long-term survivors. Current prognostic factors for survival have limited value. The authors measured the CSF levels of nine inflammatory proteins in 57 patients with LM and determined their prognostic value. High interleukin (IL)-8 CSF levels predicted short-term survival independently. The data indicate that IL-8 CSF levels may serve as a prognosticator in patients with LM, but prospective validation is needed.

Adult↗

PubMed2005

CSF levels of angiogenesis-related proteins in patients with leptomeningeal metastases.

The authors determined the levels of vascular endothelial growth factor (VEGF) and urokinase-type plasminogen activator (uPA) in the CSF of patients with leptomeningeal metastases (LM; n = 53), cancer patients without LM (n = 18), and subjects without malignancy (n = 25). Median levels of uPA and VEGF were significantly higher in patients with LM, supporting the hypothesis that angiogenesis contributes to LM. VEGF was negatively correlated with survival in patients with LM, suggesting its use as a prognostic factor.

Adult↗

PubMed2005

Early endostatin treatment inhibits metastatic seeding of murine colorectal cancer cells in the liver and their adhesion to endothelial cells.

Endostatin, a carboxy-terminal fragment of collagen XVIII, potently inhibits angiogenesis and tumour growth, presumably through induction of apoptosis in endothelial cells and/or inhibition of their migration. Here we have tested how the timing of recombinant human endostatin (rh-E) administration affects its antitumour activity in a liver metastasis model of mouse C26 colorectal carcinoma cells. The effects of rh-E treatment on hepatic tumour load and on early tumour cell seeding were evaluated. Recombinant human endostatin was most effective in reducing intrahepatic tumour growth when administered prior to tumour cell inoculation. Analysis of early tumour cell seeding by using [(125)I]iododeoxyuridine-labelled C26 cells or by in vivo microscopy showed that rh-E reduced tumour cell seeding in the liver sinusoids. Recombinant human endostatin did not inhibit tumour growth when administered later than 4 days after tumour injection. Pretreatment of human umbilical vein endothelial cells with rh-E in vitro reduced C26 tumour cell adhesion under flow conditions two-fold as assessed by video microscopy and multiphoton laser scanning microscopy. Our results show that rh-E, in addition to antiangiogenic effects, reduces tumour cell adhesion in the liver sinusoids during the very early phases of metastasis formation. These data point towards a previously unknown mode of action of endostatin, that is, its ability to interfere with tumour cell seeding. Such insights may be helpful in the design of trials to improve (surgical) treatment of colorectal carcinoma and liver metastases.

Animals↗

PubMed2005

Amyloid-beta-stimulated plasminogen activation by tissue-type plasminogen activator results in processing of neuroendocrine factors.

Alzheimer's disease brain is characterized by the abundant presence of amyloid deposits. Accumulation of the major constituent of these deposits, amyloid-beta (Abeta), has been associated with decreased neurotransmission, increased neuronal cell death, and with cognitive decline. The mechanisms underlying these phenomena have not yet been fully elucidated. We have previously shown that amyloid peptides like Abeta bind tissue-type plasminogen activator (tPA) and cause enhanced plasmin production. Here we describe the identification of five major neuronal cell-produced Abeta-associated proteins and how Abeta-stimulated plasmin formation affects their processing. These five proteins are all neuroendocrine factors (NEFs): chromogranins A, B and C; truncated chromogranin B; and VGF. Plasminogen caused processing of Abeta-bound (but not soluble) tPA, chromogranin B and VGF and the degradation products were released from Abeta. Processing of the neuroendocrine factors was dependent on tPA as it was largely abrogated in tPA-/- cells or in the presence of a specific tPA-inhibitor. If plasmin indeed produces NEF-derived peptides in vivo, some of these peptides may have biological activity, for instance in regulating neurotransmitter release that may affect the pathology of Alzheimer's disease.

Amino Acid Sequence↗

PubMed2004

Phase I and pharmacokinetic study of the combination of topotecan and ifosfamide administered intravenously every 3 weeks.

To determine the maximum-tolerated dose (MTD), dose-limiting toxicities, and pharmacokinetics of topotecan administered as a 30-min intravenous (i.v.) infusion over 5 days in combination with a 1-h i.v. infusion of ifosfamide (IF) for 3 consecutive days every 3 weeks. Patients with advanced malignancies refractory to standard therapy were entered into the study. The starting dose of topotecan was 0.4 mg x m(-2) day(-1) x 5 days. Ifosfamide was administered at a fixed dose of 1.2 g x m(-2) day(-1) x 3 days. In all, 36 patients received 144 treatment courses. Owing to toxicities, the schedule of topotecan administration was reduced from 5 to 3 days. The MTD was reached at topotecan 1.2 mg x m(-2) day(-1) x 3 days with IF 1.2 g x m(-2) day(-1) x 3 days. Haematological toxicities were dose limiting. Neutropenia was the major toxicity. Thrombocytopenia and anaemia were rare. Nonhaematological toxicities were relatively mild. Partial responses were documented in three patients with ovarian cancer dosed below the MTD. Topotecan and IF did not appear to interact pharmacokinetically. The relationships between the exposure to topotecan lactone and total topotecan, and the decrease in absolute neutrophil count and the decrease in thrombocytes, were described with sigmoidal-E(max) models. The combination of 1.0 mg m(-2) day(-1) topotecan administered as a 30-min i.v. infusion daily times three with 1.2 g x m(-2) day(-1) IF administered as a 1-h i.v. infusion daily times three every 3 weeks was feasible. However, the combination schedule of topotecan and IF did result in considerable haematological toxicity and in conjunction with previously reported pronounced nonhaematological toxicities and treatment related deaths, it may be concluded that this is not a favourable combination.

Adult↗

PubMed2004

Are tumours angiogenesis-dependent?

The final proof of principle that cancer patients can be effectively treated with angiogenesis inhibitors is eagerly awaited. Various preclinical in vivo experiments have proven that most tumours need new vessel formation in order to grow and to form metastases. First of all, tumours do not grow in avascular corneas until new blood vessels reach the implant. Secondly, the introduction of only one angiogenic gene can cause a switch from tumour dormancy to progressive tumour growth. Thirdly, tumour growth can be inhibited and sometimes tumour regression can be obtained just by attacking the vascular compartment with specific angiogenesis inhibitors. These three examples of preclinical experiments and many others have led to the conclusion that, in general, tumours are angiogenesis-dependent. Supported by disappointing clinical results, the angiogenesis dependency of tumours has been questioned, mainly because of the immaturity and the presumed lack of a functional blood supply (oxygen delivery and discarding of waste products) from a newly formed tumour vasculature. However, human tumours are highly heterogeneous in vascular architecture, differentiation, and functional blood supply. Vascular immaturity is a natural consequence of a genetically based unlimited expansion of tumour cells, compared to the well-regulated growth of different organs during embryonic development, for example. Unlimited tumour expansion and therefore the continuous stimulation of vessel outgrowth prevent endothelial cells from generating a mature vasculature, but instead continuously stimulate them to expand the vascular compartment of the growing tumour. In this review, the translation of angiogenesis inhibitors as a treatment for cancer from preclinical experiments to the clinic is evaluated. The preclinical evidence that tumours are angiogenesis-dependent is summarized and explanations are put forward for why the clinical results so far are not as exciting as was expected from preclinical studies. Reviewing the translation, one may conclude that human tumours are heterogeneous in their vascular architecture and function and that tumour-induced angiogenesis in humans is a more complex (multifactorially regulated) process compared with angiogenesis in preclinical cancer models.

Angiogenesis Inducing Agents↗

PubMed2004

Increased levels of viable circulating endothelial cells are an indicator of progressive disease in cancer patients.

BACKGROUND: There is accumulating evidence from preclinical studies that circulating endothelial cells (CECs) play an important role in neovascularization and tumor growth. The role of CECs in human cancer progression is sparsely investigated. We therefore analyzed CECs in peripheral blood of cancer patients. In addition, we correlated CEC levels in these patients with plasma levels of cytokines that are known to mobilize CECs in experimental models. PATIENTS AND METHODS: Viable CECs were isolated, quantified and cultured from cancer patients' whole blood by using magnetic beads coupled to an antibody directed against CD146, a pan-endothelial marker. Viable cells were visualized by calceinAM staining. Positive staining for specific endothelial cell markers [i.e. von Willebrand factor, CD31, vascular endothelial cell growth factor (VEGF) receptor-2] was used to confirm the endothelial phenotype. RESULTS: Cancer patients with progressive disease (95 patients) had on average 3.6-fold more CECs than healthy subjects (46 patients, P <0.001). Patients (17) with stable disease had CEC numbers equal to that circulating in healthy subjects (P = 0.69). A subset of in vitro cultured CECs incorporated into endothelial layers and formed colonies. Plasma levels of cytokines that are thought to mobilize CECs from the bone marrow [VEGF, placental growth factor, stromal cell derived factor 1alpha and stem cell factor (71 patients)] did not correlate with CEC amounts. The levels of viable CECs in cancer patients were modified by granulocyte colony-stimulating factor treatment and chemotherapy. CONCLUSION: In progressive cancer patients, the amount of CECs is increased. These CECs are viable and may contribute to vessel formation. The number of CECs is influenced by anticancer treatment.

Angiogenesis Inhibitors↗

PubMed2004

Simultaneous radio- and chemotherapy for squamous cell carcinoma of the head and neck in daily clinical practice: 5 years experience in a University Hospital.

Several randomized studies and meta-analyses have shown that simultaneous radio- and chemotherapy prolongs survival in patients with unresectable squamous cell carcinoma of the head and neck as compared with conventional radiotherapy. We assessed the feasibility and effectiveness of simultaneous radiotherapy (35 x 2 Gy) and chemotherapy [cisplatinum 100 mg/m(2) or carboplatin (AUC 6) on days 1, 22 and 43] in daily clinical practice in a cohort of 87 patients treated at our institute between 1998 and 2002. Eighty patients completed radiotherapy according to schedule. Eighty patients received two courses of chemotherapy and 50 patients three courses. Nephrotoxity, bone marrow suppression and ototoxicity were the most frequent side-effects. Median weight loss was 8.5%. Median survival was 15 months and 44% of the patients were alive at 2 years. Patients receiving three courses of chemotherapy had a better survival than patients receiving two or less courses. Treatment with simultaneous radio- and chemotherapy for advanced head and neck cancer is a demanding, but feasible treatment in daily clinical practice. Survival seems to be comparable with the results achieved in patients selected for clinical trials.

Adult↗

PubMed2004

Tumor growth and metastasis are not affected in thrombin-activatable fibrinolysis inhibitor-deficient mice.

Many studies have indicated that the plasminogen activation system may have a prominent role in cancer. Activation of the zymogen plasminogen into the serine protease plasmin by plasminogen activator is mediated by carboxyterminal basic amino acids in fibrin, including lysines and arginines. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a circulating carboxypeptidase B-type proenzyme that, after activation, removes carboxyterminal lysine or arginine residues in fibrin, resulting in decreased plasminogen activation and attenuated fibrinolysis. To determine directly whether TAFI is involved in primary tumor growth and metastasis formation, we examined the effects of TAFI deficiency on subcutaneous growth and experimentally or spontaneously induced pulmonary metastasis formation of different tumor cell types in mice. In all tumor models TAFI deficiency did not affect the formation and growth of primary and metastasized tumors.

Animals↗

PubMed2003

[The clinical perspective of angiogenesis inhibitors].

An important development in the treatment of cancer is the recognition that the tumour's microenvironment, notably its vasculature, may be an attractive target for therapy. In the eighties of the last century, the concept of angiogenesis (the formation of new blood vessels from existing vasculature) was developed. Angiogenesis is the driving force behind tumour growth and metastasis. Recent angiogenesis research has elucidated the role of growth factors (vascular endothelial growth factor (VEGF), epidermal growth factor), metalloproteinases and endogenous proteins such as angiostatin and endostatin. This new knowledge has led to the rapid development of several angiogenesis inhibiting strategies. Although these new strategies showed very promising results in preclinical animal studies, early clinical studies with individual angiogenesis inhibitors have shown no antitumour effect so far. However, in recent studies blocking VEGF in addition to conventional chemotherapy has led to an increase in disease-free survival time and in response rate to chemotherapy. Angiogenesis research has contributed to the knowledge of the biology of cancer, the design of modified clinical studies and the development of surrogate markers that can be used as pharmacodynamic end points in future studies.

Angiogenesis Inducing Agents↗

PubMed2003

Plasminogen mediates liver regeneration and angiogenesis after experimental partial hepatectomy.

BACKGROUND: Plasmin system components are upregulated after partial hepatectomy, but their contribution to surgery-induced hepatic angiogenesis and regeneration is unclear. Liver regeneration and angiogenesis after partial hepatectomy were examined in mice lacking plasminogen or urokinase plasminogen activator (uPA). METHODS: Mice with a single-gene deletion of plasminogen or uPA were subjected to 70 per cent partial hepatectomy. Liver regeneration was measured as relative liver weight and cell proliferation index. Angiogenesis was quantified by determining hepatic microvessel density after staining for sinusoidal endothelial cells. RESULTS: The liver remnant weight was significantly reduced in mice lacking plasminogen or uPA compared with that in wild-type mice on days 2 and 7 after partial hepatectomy. This correlated with impaired cell proliferation. In wild-type mice, regeneration was accompanied by a significant increase in microvessel density after hepatectomy; this increase was impaired in plasminogen-deficient mice. CONCLUSION: Plasminogen and uPA are essential for optimal liver regeneration. In addition, plasminogen appears to be a major determinant in regeneration-associated hepatic angiogenesis.

Animals↗

PubMed2003

Angiostatin prolongs the survival of mice with leptomeningeal metastases.

BACKGROUND: As a result of the more effective treatment of primary tumours, the incidence of leptomeningeal metastases (LM) is increasing. Current treatment modalities have little effect on the survival of patients with LM. We investigated whether antiangiogenic treatment inhibits the progression of leptomeningeal tumours. MATERIALS AND METHODS: To assess the role of angiogenesis in leptomeningeal tumours, we inoculated melanoma cells in the subarachnoid space in balb/c mice. At different stages, the mice were sacrificed and the microvessel density was determined. Human specimens of LM were compared with the mouse model. For the intervention studies, the mice were treated with the angiogenesis inhibitor angiostatin. Survival was the endpoint in these studies. RESULTS: Tumour seeding in the early disease stages was concentrated around the pre-existent arachnoid vasculature. In the more advanced stages, the tumour masses covered larger areas of the leptomeninges. Arachnoidal microvessel density in this advanced stage was increased compared with control mice. Systemic treatment of the mice with LM with angiostatin (100 mg kg-1 day-1) resulted in prolonged survival compared with mice treated with vehicle and with approximately one-fifth of the long-term survivors of the angiostatin-treated group. CONCLUSIONS: This study shows that neovascularization is important in the growth of LM in mice. Systemic targeting of the vascular compartment may be a useful approach in novel therapeutic strategies for patients with LM.

Angiogenesis Inhibitors↗