25 research outputs found
The role of bevacizumab in solid tumours: A literature based meta-analysis of randomised trials
BACKGROUND:
Bevacizumab is a humanised monoclonal antibody which blocks the binding of circulating vascular endothelial growth factor to its receptors. To date, the Food and Drug Administration has approved bevacizumab for the treatment of several solid tumours. To assess the impact of bevacizumab-based regimens on outcome in these advanced solid tumour types, we performed a meta-analysis. We included all of the randomised trials (phase II or III) where bevacizumab was tested in the first line setting compared with a control arm, including chemotherapy, placebo or other anti-neoplastic agents.
METHODS:
A literature-based meta-analysis of randomised controlled trials (RCTs) in accordance with the preferences for reported items in systematic reviews and meta-analyses guidelines were undertaken. The primary end-point considered was overall survival (OS). The secondary end-points were progression-free survival (PFS) time, response rate and safety. A subgroup analysis was performed to highlight any differences between studies in different tumour types for all end-points.
RESULTS:
The pooled analysis from RCTs on bevacizumab-based regimens revealed significantly increased OS (hazard ratio [HR] for death 0.92, 95% confidence interval [CI]: 0.88-0.95; P < 0.0001), PFS (HR: 0.72, 95% CI: 0.67-0.78; P < 0.00001) and response rate (risk ratio: 1.38, 95% CI: 1.27-1.50; P < 0.00001) compared to control arm in solid tumours overall and in colorectal, lung, ovarian and renal cancer as single indications. However, notably, no effect on survival was seen in breast cancer.
CONCLUSION:
This study confirmed that bevacizumab-based regimens result in a significant effect on survival and response in advanced colorectal, lung, ovarian and kidney cancer. In cancers where bevacizumab failed overall as in breast cancer, a dedicated biomarkers analysis is warranted to select the proper subgroup of patient that might have the adequate clinical benefi
Structured and shared CT radiological report of gastric cancer: a consensus proposal by the Italian Research Group for Gastric Cancer (GIRCG) and the Italian Society of Medical and Interventional Radiology (SIRM)
Objectives Written radiological report remains the most important means of communication between radiologist and referring medical/surgical doctor, even though CT reports are frequently just descriptive, unclear, and unstructured. The Italian Society of Medical and Interventional Radiology (SIRM) and the Italian Research Group for Gastric Cancer (GIRCG) promoted a critical shared discussion between 10 skilled radiologists and 10 surgical oncologists, by means of multi-round consensus-building Delphi survey, to develop a structured reporting template for CT of GC patients. Methods Twenty-four items were organized according to the broad categories of a structured report as suggested by the European Society of Radiology (clinical referral, technique, findings, conclusion, and advice) and grouped into three "CT report sections" depending on the diagnostic phase of the radiological assessment for the oncologic patient (staging, restaging, and follow-up). Results In the final round, 23 out of 24 items obtained agreement ( >= 8) and consensus ( 0.05). Conclusions The structured report obtained, shared by surgical and medical oncologists and radiologists, allows an appropriate, clearer, and focused CT report essential to high-quality patient care in GC, avoiding the exclusion of key radiological information useful for multidisciplinary decision-making
Performance Analysis of Anti-Collision Protocols for RFID Systems
Recently RFID technology has made its way into end-user applications, enabling automatic item identification without requiring line of sight. In particular passive tags provide a promising, low cost and energy-efficient solution for inventory applications. However, their large-scale adoption strictly depends on the efficiency of the identification process. A major challenge is how to arbitrate channel access so that all tags are able to answer the reader inquiries and identify themselves over time. This paper stems from the observation that a variety of anti-collision protocols for RFIDs have been proposed in the literature. However, a thorough simulation comparison among them and a clear identification of the mechanisms resulting in better end- to-end performance is lacking. The objective of our work has been to fill this gap. This paper presents the results of a detailed ns2-based comparative evaluation of representatives of all the classes of anti-collision protocols so far proposed. Simulation results show that end-to-end performance of the different classes of protocols in terms of metrics such as the time needed for tags identification differ significantly over what previously found by experiments which only focused on the number of reading cycles for tag identification. Our thorough performance evaluation has highlighted that different solutions are to be used in different application scenarios and that decreasing the collisions (rather than idle times) is the way to go to further improve anti-collision protocols performance
Low-cost standard signatures in wireless sensor networks: a case for reviving pre-computation techniques?
Effective pre-computation techniques have been proposed
almost 15 years ago for trimming the cost of modular
exponentiations at the basis of several standard signature and
key management schemes, such as the (Elliptic Curve) Digital
Signature Algorithm or Diffie-Hellman key exchange. Despite
their promises, the actual application of such techniques in the
wireless sensor security arena has been apparently overlooked,
and most of the research effort has rather focused on the
identification of alternative lightweight constructions. However,
modern sensor are equipped with relatively large flash memories
which make memory consumption a less critical requirement,
and emerging energy harvesting technologies provide occasional
energy peaks which could be exploited for anticipating otherwise
costly computational tasks. These trends push for a reconsideration
of pre-computation techniques, which are explored in this
paper as follows: (1) we further optimize prior pre-computation
techniques by exploiting more recent results on Cayley graph
expanders, (2) we implement an ECDSA scheme relying on
pre-computations over two different wireless sensor node platforms
(TelosB and MICA2), and (3) we experimentally assess
the relevant performance and energy costs. In the traditional
scenario of wireless sensor networks without energy harvesting,
our prototype ECDSA implementation, despite still not fully
optimized, outperforms prior work by almost 50%, and achieves
an efficiency superior to NTRU signatures, natural candidates for
low-power devices. Finally, (4) we quantitatively discuss ways to
exploit harvested energy peaks to further improve efficiency
AGREE: exploiting energy harvesting to support data-centric access control in WSNs
This work is motivated by a general question: can energy harvesting capabilities embedded in modern sensor nodes be exploited so as to support security mechanisms which otherwise would be too demanding and hardly viable? More specifically, in this work we focus on the support of extremely powerful, but complex, fine-grained data-centric access control mechanisms based on multi-authority Ciphertext Policy Attribute Based Encryption (CP-ABE). By integrating access control policies into the (encrypted) data, such mechanisms do not require any server-based access control infrastructure and are thus highly desirable in many wireless sensor network scenarios. However, as concretely shown by a proof-of-concept implementation first carried out in this paper on TelosB and MicaZ motes, computational complexity and energy toll of state-of-the-art multi-authority CP-ABE schemes is still critical. We thus show how to mitigate the relatively large energy consumption of the CP-ABE cryptographic operations by proposing AGREE (Access control for GREEn wireless sensor networks), a framework that exploits energy harvesting opportunities to pre-compute and cache suitably chosen CP-ABE-encrypted keys, so as to minimize the need to perform CP-ABE encryptions when no energy from harvesting is available. We assess the performance of AGREE by means of simulation and actual implementation, validating its operation with real-world energy-harvesting traces collected indoors by TelosB motes equipped with photovoltaic cells, as well as public available traces of radiant light energy. Our results show that complex security mechanisms may become significantly less demanding when implemented so as to take advantage of energy harvesting opportunities. © 2013 Elsevier B.V. All rights reserved
AGREE: Exploiting energy harvesting to support data-centric access control in WSNs
This work is motivated by a general question: can energy harvesting capabilities embedded in modern sensor nodes be exploited so as to support security mechanisms which otherwise would be too demanding and hardly viable? More specifically, in this work we focus on the support of extremely powerful, but complex, fine-grained data-centric access control mechanisms based on multi-authority Ciphertext Policy Attribute Based Encryption (CP-ABE). By integrating access control policies into the (encrypted) data, such mechanisms do not require any server-based access control infrastructure and are thus highly desirable in many wireless sensor network scenarios. However, as concretely shown by a proof-of-concept implementation first carried out in this paper on TelosB and MicaZ motes, computational complexity and energy toll of state-of-the-art multi-authority CP-ABE schemes is still critical. We thus show how to mitigate the relatively large energy consumption of the CP-ABE cryptographic operations by proposing AGREE (Access control for GREEn wireless sensor networks), a framework that exploits energy harvesting opportunities to pre-compute and cache suitably chosen CP-ABE-encrypted keys, so as to minimize the need to perform CP-ABE encryptions when no energy from harvesting is available. We assess the performance of AGREE by means of simulation and actual implementation, validating its operation with real-world energy-harvesting traces collected indoors by TelosB motes equipped with photovoltaic cells, as well as public available traces of radiant light energy. Our results show that complex security mechanisms may become significantly less demanding when implemented so as to take advantage of energy harvesting opportunities. © 2013 Elsevier B.V. All rights reserved
Low-cost Standard Signatures in Wireless Sensor Networks: A Case for Reviving Pre-computation Techniques?
Effective pre-computation techniques have been proposed
almost 15 years ago for trimming the cost of modular
exponentiations at the basis of several standard signature and
key management schemes, such as the (Elliptic Curve) Digital
Signature Algorithm or Diffie-Hellman key exchange. Despite
their promises, the actual application of such techniques in the
wireless sensor security arena has been apparently overlooked,
and most of the research effort has rather focused on the
identification of alternative lightweight constructions. However,
modern sensor are equipped with relatively large flash memories
which make memory consumption a less critical requirement,
and emerging energy harvesting technologies provide occasional
energy peaks which could be exploited for anticipating otherwise
costly computational tasks. These trends push for a reconsideration
of pre-computation techniques, which are explored in this
paper as follows: (1) we further optimize prior pre-computation
techniques by exploiting more recent results on Cayley graph
expanders, (2) we implement an ECDSA scheme relying on
pre-computations over two different wireless sensor node platforms
(TelosB and MICA2), and (3) we experimentally assess
the relevant performance and energy costs. In the traditional
scenario of wireless sensor networks without energy harvesting,
our prototype ECDSA implementation, despite still not fully
optimized, outperforms prior work by almost 50%, and achieves
an efficiency superior to NTRU signatures, natural candidates for
low-power devices. Finally, (4) we quantitatively discuss ways to
exploit harvested energy peaks to further improve efficiency
SecFUN: Security framework for underwater acoustic sensor networks
In this paper we introduce SecFUN, a security framework for underwater acoustic sensor networks (UASNs). Despite the increasing interest on UASNs, solutions to secure protocols from the network layer up to the application layer are still overlooked. The aim of this work is therefore manyfold. We first discuss common threats and countermeasures for UASNs. Then, we select the most effective cryptographic primitives to build our security framework (SecFUN). We show that SecFUN is flexible and configurable with different features and security levels to satisfy UASN deployment security requirements. SecFUN provides data confidentiality, integrity, authentication and non-repudiation by exploiting as building blocks AES in the Galois Counter Mode (GCM) and short digital signature algorithms. As a proof of concept of the proposed approach, we extend the implementation of the Channel-Aware Routing Protocol (CARP) to support the proposed cryptographic primitives. Finally, we run a performance evaluation of our proposed secure version of CARP in terms of the overall energy consumption and latency, employing GCM and the state of the art in short digital signature schemes such as ZSS, BLS and Quartz. Results show that a flexible and full-fledged security solution tailored to meet the requirements of UASNs can be provided at reasonable costs. © 2015 IEEE
Low-cost standard signatures for energy-harvesting wireless sensor networks
This work is motivated by a general question: Can micro-scale energy harvesting techniques be exploited to support low-cost standard security solutions on resource-constrained devices? We focus on guaranteeing integrity and authentication in Internet of Things (IoT) and Wireless Sensor Network (WSN) applications. In this paper we propose techniques to make ECDSA signatures low cost and implementable on resource-constrained devices. By combining precomputation techniques and energy harvesting capabilities of modern sensor nodes, we achieve significant improvement over prior works. In addition, we show the cost of ECDSA signatures can be reduced of up to a factor 10 by using harvesting-aware optimizations
Association between Low-Grade Chemotherapy-Induced Peripheral Neuropathy (CINP) and Survival in Patients with Metastatic Adenocarcinoma of the Pancreas
The combination of nab-paclitaxel and gemcitabine demonstrated greater efficacy than gemcitabine alone but resulted in higher rates of chemotherapy-induced peripheral neuropathy (CINP) in patients with metastatic pancreatic cancer (mPC). We aimed to evaluate the correlation between the development of treatment-related peripheral neuropathy and the efficacy of nab-P/Gem combination in these patients. mPC patients treated with nab-paclitaxel 125 mg/m2 and gemcitabine 1000 mg/m2 as a first-line therapy were included. Treatment-related adverse events, mainly peripheral neuropathy, were categorized using the National Cancer Institute Common Toxicity Criteria scale, version 4.02. Efficacy outcomes, including overall survival (OS), progression-free survival (PSF), and disease control rate (DCR), were estimated by the Kaplan–Meier model. A total of 153 patients were analyzed; of these, 47 patients (30.7%) developed grade 1–2 neuropathy. PFS was 7 months (95% CI (6–7 months)) for patients with grade 1–2 neuropathy and 6 months (95% CI (5–6 months)) for patients without peripheral neuropathy (p = 0.42). Median OS was 13 months (95% CI (10–18 months)) and 10 months (95% CI (8–13 months)) in patients with and without peripheral neuropathy, respectively (p = 0.04). DCR was achieved by 83% of patients with grade 1–2 neuropathy and by 58% of patients without neuropathy (p = 0.03). In the multivariate analysis, grade 1–2 neuropathy was independently associated with OS (HR 0.65; 95% CI, 0.45–0.98; p = 0.03). nab-P/Gem represents an optimal first-line treatment for mPC patients. Among possible treatment-related adverse events, peripheral neuropathy is the most frequent, with different grades and incidence. Our study suggests that patients experiencing CINP may have a more favorable outcome, with a higher disease control rate and prolonged median survival compared to those without neuropathy