Achieving Near-Optimal Traffic Engineering Solutions for Current OSPF/IS-IS Networks

Traffic engineering is aimed at distributing traffic so as to optimize a given performance criterion. The ability to carry out such an optimal distribution depends on the routing protocol and the forwarding mechanisms in use in the network. In IP networks running the OSPF or IS-IS protocols, routing is along shortest paths, and forwarding mechanisms are constrained to distributing traffic uniformly over equal cost shortest paths. These constraints often make achieving an optimal distribution of traffic impossible. In this paper, we propose and evaluate an approach that is capable of realizing near optimal traffic distribution without any change to existing routing protocols and forwarding mechanisms. In addition, we explore the trade-off that exists between performance and the overhead associated with the additional configuration steps that our solution requires. The paper\u27s contributions are in formulating and evaluating an approach to traffic engineering for existing IP networks that achieves performance levels comparable to that offered when deploying other forwarding technologies such as MPLS

Nationwide trends in chemotherapy use and survival of elderly patients with metastatic pancreatic cancer

Despite an aging population and underrepresentation of elderly patients in clinical trials, studies on elderly patients with metastatic pancreatic cancer are scarce. This study investigated the use of chemotherapy and survival in elderly patients with metastatic pancreatic cancer. From the Netherlands Cancer Registry, all 9407 patients diagnosed with primary metastatic pancreatic adenocarcinoma in 2005–2013 were selected to investigate chemotherapy use and overall survival (OS), using Kaplan–Meier and Cox proportional hazard regression analyses. Over time, chemotherapy use increased in all age groups (<70 years: from 26 to 43%, 70–74 years: 14 to 25%, 75–79 years: 5 to 13%, all P < 0.001, and ≥80 years: 2 to 3% P = 0.56). Median age of 2,180 patients who received chemotherapy was 63 years (range 21–86 years, 1.6% was ≥80 years). In chemotherapy-treated patients, with rising age (<70, 70–74, 75–79, ≥80 years), microscopic tumor verification occurred less frequently (91-88-87-77%, respectively, P = 0.009) and OS diminished (median 25-26-19-16 weeks, P = 0.003). After adjustment for confounding factors, worse survival of treated patients ≥75 years persisted. Despite limited chemotherapy use in elderly age, suggestive of strong selection, elderly patients (≥75 years) who received chemotherapy for metastatic pancreatic cancer exhibited a worse survival compared to younger patients receiving chemotherapy

Establishing and Coordinating a Nationwide Multidisciplinary Study Group: Lessons Learned by the Dutch Pancreatic Cancer Group

Surgical oncolog

A phase ib clinical trial of metformin and chloroquine in patients with IDH1-mutated solid tumors

Simple SummaryMutations in the isocitrate dehydrogenase 1 (IDH1) gene occur in high-grade chondrosarcoma, high-grade glioma and intrahepatic cholangiocarcinoma. Due to the lack of effective treatment options, these aggressive types of cancer have a dismal outcome. The metabolism of IDH1-mutated cancer cells is reprogrammed in order to produce the oncometabolite D-2-hydroxyglutarate (D-2HG). In this clinical trial, we used the oral antidiabetic drug metformin and the oral antimalarial drug chloroquine to disrupt the vulnerable metabolism of IDH1-mutated solid tumors. We found that the combination regimen of metformin and chloroquine is well tolerated, but the combination did not induce a clinical response in this patient population. Secondly, we confirmed the clinical usefulness of D/L-2HG ratios in serum as a biomarker and the ddPCR-facilitated detection of an IDH1 mutation in circulating DNA from peripheral blood.Background: Mutations in isocitrate dehydrogenase 1 (IDH1) occur in 60% of chondrosarcoma, 80% of WHO grade II-IV glioma and 20% of intrahepatic cholangiocarcinoma. These solid IDH1-mutated tumors produce the oncometabolite D-2-hydroxyglutarate (D-2HG) and are more vulnerable to disruption of their metabolism. Methods: Patients with IDH1-mutated chondrosarcoma, glioma and intrahepatic cholangiocarcinoma received oral combinational treatment with the antidiabetic drug metformin and the antimalarial drug chloroquine. The primary objective was to determine the occurrence of dose-limiting toxicities (DLTs) and the maximum tolerated dose (MTD). Radiological and biochemical tumor responses to metformin and chloroquine were investigated using CT/MRI scans and magnetic resonance spectroscopy (MRS) measurements of D-2HG levels in serum. Results: Seventeen patients received study treatment for a median duration of 43 days (range: 7-74 days). Of twelve evaluable patients, 10 patients discontinued study medication because of progressive disease and two patients due to toxicity. None of the patients experienced a DLT. The MTD was determined to be 1500 mg of metformin two times a day and 200 mg of chloroquine once a day. A serum D/L-2HG ratio of >= 4.5 predicted the presence of an IDH1 mutation with a sensitivity of 90% and a specificity of 100%. By utilization of digital droplet PCR on plasma samples, we were able to detect tumor-specific IDH1 hotspot mutations in circulating tumor DNA (ctDNA) in investigated patients. Conclusion: Treatment of advanced IDH1-mutated solid tumors with metformin and chloroquine was well tolerated but did not induce a clinical response in this phase Ib clinical trial.Molecular tumour pathology - and tumour geneticsMTG

Advances in adjuvant therapy of biliary tract cancer: an overview of current clinical evidence based on phase II and III trials

Patients with biliary tract cancer (BTC) have a high recurrence rate after complete surgical resection. To reduce the risk of recurrence and to improve survival, several chemotherapeutic agents that have shown to be active in locally advanced and metastatic BTC have been investigated in the adjuvant setting in prospective clinical trials. Based on the results of the BILCAP phase III trial, capecitabine was adapted as the standard of care by the ASCO clinical practice guideline. Ongoing randomized controlled trials mainly compare capecitabine with gemcitabine-based chemotherapy or chemoradiotherapy. This review provides an update of adjuvant therapy in BTC based on published data of phase II and III trials and ongoing randomized controlled trials (RCTs)

Meta-analysis comparing upfront surgery with neoadjuvant treatment in patients with resectable or borderline resectable pancreatic cancer

Background: Studies comparing upfront surgery with neoadjuvant treatment in pancreatic cancer may report only patients who underwent resection and so survival will be skewed. The aim of this study was to report survival by intention to treat in a comparison of upfront surgery versus neoadjuvant treatment in resectable or borderline resectable pancreatic cancer. Methods: MEDLINE, Embase and the Cochrane Library were searched for studies reporting median overall survival by intention to treat in patients with resectable or borderline resectable pancreatic cancer treated with or without neoadjuvant treatment. Secondary outcomes included overall and R0 resection rate, pathological lymph node rate, reasons for unresectability and toxicity of neoadjuvant treatment. Results: In total, 38 studies were included with 3484 patients, of whom 1738 (49·9 per cent) had neoadjuvant treatment. The weighted median overall survival by intention to treat was 18·8months for neoadjuvant treatment and 14·8months for upfront surgery; the difference was larger among patients whose tumours were resected (26·1 versus 15·0months respectively). The overall resection rate was lower with neoadjuvant treatment than with upfront surgery (66·0 versus 81·3 per cent; P<0·001), but the R0 rate was higher (86·8 (95 per cent c.i. 84·6 to 88·7) versus 66·9 (64·2 to 69·6) per cent; P<0·001). Reported by intention to treat, the R0 rates were 58·0 and 54·9 per cent respectively (P=0·088). The pathological lymph node rate was 43·8 per cent after neoadjuvant therapy and 64·8 per cent in the upfront surgery group (P<0·001). Toxicity of at least grade III was reported in up to 64 per cent of the patients. Conclusion: Neoadjuvant treatment appears to improve overall survival by intention to treat, despite lower overall resection rates for resectable or borderline resectable pancreatic cancer. PROSPERO registration number: CRD42016049374

Treatment and Survival of Elderly Patients with Stage I–II Pancreatic Cancer: A Report of the EURECCA Pancreas Consortium

Background: Elderly patients with pancreatic cancer are underrepresented in clinical trials, resulting in a lack of evidence. Objective: The aim of this study was to compare treatment and overall survival (OS) of patients aged ≥ 70 years with stage I–II pancreatic cancer in the EURECCA Pancreas Consortium. Methods: This was an observational cohort study of the Belgian (BE), Dutch (NL), and Norwegian (NOR) cancer registries. The primary outcome was OS, while secondary outcomes were resection, 90-day mortality after resection, and (neo)adjuvant and palliative chemotherapy. Results: In total, 3624 patients were included. Resection (BE: 50.2%; NL: 36.2%; NOR: 41.3%; p < 0.001), use of (neo)adjuvant chemotherapy (BE: 55.9%; NL: 41.9%; NOR: 13.8%; p < 0.001), palliative chemotherapy (BE: 39.5%; NL: 6.0%; NOR: 15.7%; p < 0.001), and 90-day mortality differed (BE: 11.7%; NL: 8.0%; NOR: 5.2%; p < 0.001). Furthermore, median OS in patients with (BE: 17.4; NL: 15.9; NOR: 25.4 months; p < 0.001) and without resection (BE: 7.0; NL: 3.9; NOR: 6.5 months; p < 0.001) also differed. Conclusions: Differences were observed in treatment and OS in patients aged ≥ 70 years with stage I–II pancreatic cancer, between the population-based cancer registries. Future studies should focus on selection criteria for (non)surgical treatment in older patients so that clinicians can tailor treatment

Implementation of contemporary chemotherapy for patients with metastatic pancreatic ductal adenocarcinoma: a population-based analysis

Background: Positive results of randomized trials led to the introduction of FOLFIRINOX in 2012 and gemcitabine with nab-paclitaxel in 2015 for patients with metastatic pancreatic ductal adenocarcinoma. It is unknown to which extent these new chemotherapeutic regimens have been implemented in clinical practice and what the impact has been on overall survival. Material and methods: Patients diagnosed with metastatic pancreatic ductal adenocarcinoma between 2007–2016 were included from the population-based Netherlands Cancer Registry. Multilevel logistic regression and Cox regression analyses, adjusting for patient, tumor, and hospital characteristics, were used to analyze variation of chemotherapy use. Results: In total, 8726 patients were included. The use of chemotherapy increased from 31% in 2007–2011 to 37% in 2012–2016 (p <.001). Variation in the use of any chemotherapy between centers decreased (adjusted range 2007–2011: 12–67%, 2012–2016: 20–54%) whereas overall survival increased from 5.6 months to 6.4 months (p <.001) for patients treated with chemotherapy. Use of FOLFIRINOX and gemcitabine with nab-paclitaxel varied widely in 2015–2016, but both showed a more favorable overall survival compared to gemcitabine monotherapy (median 8.0 vs. 7.0 vs. 3.8 months, respectively). In the period 2015–2016, FOLFIRINOX was used in 60%, gemcitabine with nab-paclitaxel in 9.7% and gemcitabine monotherapy in 25% of patients receiving chemotherapy. Conclusion: Nationwide variation in the use of chemotherapy decreased after the implementation of FOLFIRINOX and gemcitabine with nab-paclitaxel. Still a considerable proportion of patients receives gemcitabine monotherapy. Overall survival did improve, but not clinically relevant. These results emphasize the need for a structured implementation of new chemotherapeutic regimens

Conditional Survival After Resection for Pancreatic Cancer: A Population-Based Study and Prediction Model

Background: Conditional survival is the survival probability after already surviving a predefined time period. This may be informative during follow-up, especially when adjusted for tumor characteristics. Such prediction models for patients with resected pancreatic cancer are lacking and therefore conditional survival was assessed and a nomogram predicting 5-year survival at a predefined period after resection of pancreatic cancer was developed. Methods: This population-based study included patients with resected pancreatic ductal adenocarcinoma from the Netherlands Cancer Registry (2005–2016). Conditional survival was calculated as the median, and the probability of surviving up to 8 years in patients who already survived 0–5 years after resection was calculated using the Kaplan–Meier method. A prediction model was constructed. Results: Overall, 3082 patients were included, with a median age of 67 years. Median overall survival was 18 months (95% confidence interval 17–18 months), with a 5-year survival of 15%. The 1-year conditional survival (i.e. probability of surviving the next year) increased from 55 to 74 to 86% at 1, 3, and 5 years after surgery, respectively, while the median overall survival increased from 15 to 40 to 64 months at 1, 3, and 5 years after surgery, respectively. The prediction model demonstrated that the probability of achieving 5-year survival at 1 year after surgery varied from 1 to 58% depending on patient and tumor characteristics. Conclusions: This population-based study showed that 1-year conditional survival was 55% 1 year after resection and 74% 3 years after resection in patients with pancreatic cancer. The prediction model is available via www.pancreascalculator.com to inform patients and caregivers

Nationwide trends in incidence, treatment and survival of pancreatic ductal adenocarcinoma

Background: In recent years, new treatment options have become available for pancreatic ductal adenocarcinoma (PDAC) including 5-fluorouracil, leucovorin, irinotecan and oxaliplatin. The impact hereof has not been assessed in nationwide cohort studies. This population-based study aimed to investigate nationwide trends in incidence, treatment and survival of PDAC. Materials and methods: Patients wi