Vascular Endothelial Growth Factor in the Circulation in Cancer Patients May Not Be a Relevant Biomarker

Levels of circulating vascular endothelial growth factor (VEGF) have widely been used as biomarker for angiogenic activity in cancer. For this purpose, non-standardized measurements in plasma and serum were used, without correction for artificial VEGF release by platelets activated ex vivo. We hypothesize that "true" circulating (c)VEGF levels in most cancer patients are low and unrelated to cancer load or tumour angiogenesis. We determined VEGF levels in PECT, a medium that contains platelet activation inhibitors, in citrate plasma, and in isolated platelets in 16 healthy subjects, 18 patients with metastatic non-renal cancer (non-RCC) and 12 patients with renal cell carcinoma (RCC). In non-RCC patients, circulating plasma VEGF levels were low and similar to VEGF levels in controls if platelet activation was minimized during the harvest procedure by PECT medium. In citrate plasma, VEGF levels were elevated in non-RCC patients, but this could be explained by a combination of increased platelet activation during blood harvesting, and by a two-fold increase in VEGF content of individual platelets (controls: 3.4 IU/10(6), non-RCC: 6.2 IU/10(6) platelets, p = 0.001). In contrast, cVEGF levels in RCC patients were elevated (PECT plasma: 64 pg/ml vs. 21 pg/ml, RCC vs. non-RCC, p<0.0001), and not related to platelet VEGF concentration. Our findings suggest that "true" freely cVEGF levels are not elevated in the majority of cancer patients. Previously reported elevated plasma VEGF levels in cancer appear to be due to artificial release from activated platelets, which in cancer have an increased VEGF content, during the blood harvest procedure. Only in patients with RCC, which is characterized by excessive VEGF production due to a specific genetic defect, were cVEGF levels elevated. This observation may be related to limited and selective success of anti-VEGF agents, such as bevacizumab and sorafenib, as monotherapy in RCC compared to other forms of cance

UvA-DARE (Digital Academic Repository) Vascular Endothelial Growth Factor in the Circulation in Cancer Patients May Not Be a Relevant Biomarker

Abstract Background: Levels of circulating vascular endothelial growth factor (VEGF) have widely been used as biomarker for angiogenic activity in cancer. For this purpose, non-standardized measurements in plasma and serum were used, without correction for artificial VEGF release by platelets activated ex vivo. We hypothesize that &apos;&apos;true&apos;&apos; circulating (c)VEGF levels in most cancer patients are low and unrelated to cancer load or tumour angiogenesis

Understanding Palliative Cancer Chemotherapy: About Shared Decisions and Shared Trajectories

Most models of patient-physician communication take decision-making as a central concept. However, we found that often the treatment course of metastatic cancer patients is not easy to describe in straightforward terms used in decision-making models but is instead frequently more erratic. Our aim was to analyse these processes as trajectories. We used a longitudinal case study of 13 patients with metastatic colorectal and pancreatic cancer for whom palliative chemotherapy was a treatment option, and analysed 65 semi-structured interviews. We analysed three characteristics of the treatment course that contributed to the ‘erraticness’ of the course: (1) The treatment (with or without chemotherapy) contained many options; (2) these options were not stable entities to be decided upon, but changed identity over the course of treatment, and (3) contrary to the closure (option X means no option Y, Z, etc.) a decision implies, the treatment course was a continuous process in which options instead remained open. When the treatment course is characterised by these many and changeable options that do not result in closure, the shared decision-making model should take these into account. More attention needs to be paid to the erratic character of the process in which the doctor has to provide continuous information that is related to the changing situation of the patient; also, flexibility in dealing with protocols is warranted, as is vigilance about the overall direction of the process

Radiofrequency and Microwave Ablation Compared to Systemic Chemotherapy and to Partial Hepatectomy in the Treatment of Colorectal Liver Metastases:A Systematic Review and Meta-Analysis

To assess safety and outcome of radiofrequency ablation (RFA) and microwave ablation (MWA) as compared to systemic chemotherapy and partial hepatectomy (PH) in the treatment of colorectal liver metastases (CRLM). MEDLINE, Embase and the Cochrane Library were searched. Randomized trials and comparative observational studies with multivariate analysis and/or matching were included. Guidelines from National Guideline Clearinghouse and Guidelines International Network were assessed using the AGREE II instrument. The search revealed 3530 records; 328 were selected for full-text review; 48 were included: 8 systematic reviews, 2 randomized studies, 26 comparative observational studies, 2 guideline-articles and 10 case series; in addition 13 guidelines were evaluated. Literature to assess the effectiveness of ablation was limited. RFA + systemic chemotherapy was superior to chemotherapy alone. PH was superior to RFA alone but not to RFA + PH or to MWA. Compared to PH, RFA showed fewer complications, MWA did not. Outcomes were subject to residual confounding since ablation was only employed for unresectable disease. The results from the EORTC-CLOCC trial, the comparable survival for ablation + PH versus PH alone, the potential to induce long-term disease control and the low complication rate argue in favour of ablation over chemotherapy alone. Further randomized comparisons of ablation to current-day chemotherapy alone should therefore be considered unethical. Hence, the highest achievable level of evidence for unresectable CRLM seems reached. The apparent selection bias from previous studies and the superior safety profile mandate the setup of randomized controlled trials comparing ablation to surgery

LPS signal transduction: The picture is becoming more complex

Lipopolysaccharide (LPS) is the principal initiator of septic shock and it is to a large extent responsible for post-operative mortality. The use Of antibiotics is still the most successful therapy against infection that may lead to sepsis and septic shock. With the advent of antibiotic resistant strains like MRSA the usefulness of conventional antibiotics is declining and new treatment strategies for LPS-mediated septic shock are called for. In this review we discuss the molecular mechanisms that are involved in the recognition of LPS and in the initiation of an immune response. Furthermore, we also review the recent insights in the signal transduction including receptor Clustering and signalosome activation. Further insight into LPS-dependent signal transduction will assist the development of novel rational therap

Cost issues in new disease-modifying treatments for advanced cancer: in-depth interviews with physicians

BACKGROUND: The high costs of new disease-modifying, but non-curative, treatments in advanced cancer are increasingly regarded as problematic. Little is known about oncologists' beliefs regarding their ethical obligations for cost considerations about these types of treatments. PARTICIPANTS AND METHODS: This study used in-depth interviews to explore how physicians in The Netherlands view their role regarding the cost of potentially beneficial but expensive drugs, especially for new disease-modifying treatments in advanced cancer. Thirty-six physicians, 19 physicians caring for patients with advanced cancer and 17 physicians participating in four national oncology guideline committees, were interviewed. RESULTS: Physicians identified cost considerations on three levels: individual patient care, hospital policies and national guideline development. Generally, physicians were reluctant to consider costs in individual patient care, believing this compromised their ethical obligations. They did consider costs relevant at the level of hospital policies regarding coverage for drugs. They were divided regarding the role of cost considerations in national practice guideline development. CONCLUSIONS: The distinctive levels of decision-making were understood to be morally relevant as physicians separated their role as direct care provider from that of taking part in decisions about coverage. Because of the fundamental tension between the physician obligation to act in the best interest of the individual patient, the vulnerability of having a life-threatening illness and the inevitability of sharing resources in modern health care, cost considerations will always be problematic for physicians. The roles physicians play at different levels, especially at the levels of hospital policies and national practice guidelines, should further be developed and explicate