Low-Dose Continuous 5-Fluorouracil Combined with Leucovorin, nab-Paclitaxel, Oxaliplatin, and Bevacizumab for Patients with Advanced Pancreatic Cancer: A Retrospective Analysis.

BackgroundContinuous-infusion 5-fluorouracil (5FU) and calcium leucovorin plus nab-paclitaxel and oxaliplatin have been shown to be active in patients with pancreatic cancer. As a protracted low-dose infusion, 5FU is antiangiogenic, and has synergy with bevacizumab. As shown in the treatment of breast cancer, bevacizumab and nab-paclitaxel are also synergetic.ObjectiveIn this paper we retrospectively analyze the survival of 65 patients with advanced pancreatic cancer who were treated with low-dose continuous (metronomic) chemotherapy given in conjunction with conventional anti-VEGF therapy.Patients and methodsSince July of 2008, we have treated 65 patients with 5FU (180 mg/m2/day × 14 days) via an ambulatory pump. Calcium leucovorin (20 mg/m2 IV), nab-paclitaxel (60 mg/m2) IV as a 30-min infusion, and oxaliplatin (50 mg/m2) IV as a 60-min infusion were given on days 1, 8, and 15. Bevacizumab (5 mg/kg) IV over 30 min was administered on days 1 and 15. Cycles were repeated every 28-35 days. There were 42 women and 23 men, and the median age was 59 years. Forty-six patients had stage IV disease.ResultsThe median survival was 19 months, with 82% of patients surviving 12 months or longer. The overall response rate was 49%. There were 28 patients who had received prior treatment, 15 of whom responded to therapy. Fifty-two patients had elevated CA 19-9 prior to treatment. Of these, 21 patients had 90% or greater reduction in CA 19-9 levels. This cohort had an objective response rate of 71% and a median survival of 27 months. Thirty patients stopped treatment due to disease progression, and an additional 22 stopped because of toxicity. One patient died while on therapy.ConclusionsThis non-gemcitabine-based regimen resulted in higher response rates and better survival than what is commonly observed with therapy given at conventional dosing schedules. Low-dose continuous (metronomic therapy) cytotoxic chemotherapy combined with antiangiogenic therapy is safe and effective

Impact of cytokeratin-20 and carcinoembryonic antigen mRNA detection by RT-PCR in regional lymph nodes of patients with colorectal cancer

The reported rates for tumour cell involvement in the locoregional lymph nodes of colorectal cancer vary greatly, depending on the method used and case selection. In order to further evaluate the clinical value of molecular biologic detection of tumour cells we investigated 102 histologically tumour-free (pN0) regional lymph nodes from 51 consecutive, completely resected (UICC R0) colorectal carcinoma specimens for the presence of tumour cell mRNA by RT-PCR specific for carcinoembryonic antigen (CEA) and cytokeratin 20 (CK-20). Two lymph nodes located nearest to the primary tumour were investigated in each case. CK-20 mRNA was found in 31 of 51 patients (60.8%) and CEA mRNA in 30 of 51 patients (58.8%), respectively. Identical transcription patterns of CK-20 and CEA mRNA (both positive or both negative) were found in 38 of 51 patients (74.5%). There was a significantly higher proportion of cases with CEA positivity in the lymph nodes of tubulopapillary than of mucinous adenocarcinomas (P< 0.03). Detection of CK-20 and CEA mRNA correlated in nine of 12 cases (75.0%) with the risk of tumour recurrence (not significant) and showed a tendency towards shorter disease-free survival by univariate analysis (not significant). Our data indicate that CK-20 and CEA mRNA detection by RT-PCR may prove useful for the prediction of tumour recurrence of patients with pN0 colorectal carcinoma, although neither reach statistical significance in this series of patients. © 2000 Cancer Research Campaig

Hysteretic Optimization For Spin Glasses

The recently proposed Hysteretic Optimization (HO) procedure is applied to the 1D Ising spin chain with long range interactions. To study its effectiveness, the quality of ground state energies found as a function of the distance dependence exponent, $\sigma$, is assessed. It is found that the transition from an infinite-range to a long-range interaction at $\sigma=0.5$ is accompanied by a sharp decrease in the performance . The transition is signaled by a change in the scaling behavior of the average avalanche size observed during the hysteresis process. This indicates that HO requires the system to be infinite-range, with a high degree of interconnectivity between variables leading to large avalanches, in order to function properly. An analysis of the way auto-correlations evolve during the optimization procedure confirm that the search of phase space is less efficient, with the system becoming effectively stuck in suboptimal configurations much earlier. These observations explain the poor performance that HO obtained for the Edwards-Anderson spin glass on finite-dimensional lattices, and suggest that its usefulness might be limited in many combinatorial optimization problems.Comment: 6 pages, 9 figures. To appear in JSTAT. Author website: http://www.bgoncalves.co

Hiatus deletion, phonological rule or phonetic coarticulation?

Wetensch. publicatieFaculteit der Lettere

A pearl on SAT solving in Prolog

A succinct SAT solver is presented that exploits the control provided by delay declarations to implement watched literals and unit propagation. Despite its brevity the solver is surprisingly powerful and its elegant use of Prolog constructs is presented as a programming pearl

Focused Local Search for Random 3-Satisfiability

A local search algorithm solving an NP-complete optimisation problem can be viewed as a stochastic process moving in an 'energy landscape' towards eventually finding an optimal solution. For the random 3-satisfiability problem, the heuristic of focusing the local moves on the presently unsatisfiedclauses is known to be very effective: the time to solution has been observed to grow only linearly in the number of variables, for a given clauses-to-variables ratio $\alpha$ sufficiently far below the critical satisfiability threshold $\alpha_c \approx 4.27$. We present numerical results on the behaviour of three focused local search algorithms for this problem, considering in particular the characteristics of a focused variant of the simple Metropolis dynamics. We estimate the optimal value for the ``temperature'' parameter $\eta$ for this algorithm, such that its linear-time regime extends as close to $\alpha_c$ as possible. Similar parameter optimisation is performed also for the well-known WalkSAT algorithm and for the less studied, but very well performing Focused Record-to-Record Travel method. We observe that with an appropriate choice of parameters, the linear time regime for each of these algorithms seems to extend well into ratios $\alpha > 4.2$ -- much further than has so far been generally assumed. We discuss the statistics of solution times for the algorithms, relate their performance to the process of ``whitening'', and present some conjectures on the shape of their computational phase diagrams.Comment: 20 pages, lots of figure

A pilot study evaluating concordance between blood-based and patient-matched tumor molecular testing within pancreatic cancer patients participating in the Know Your Tumor (KYT) initiative

Recent improvements in next-generation sequencing (NGS) technology have enabled detection of biomarkers in cell-free DNA in blood and may ultimately replace invasive tissue biopsies. However, a better understanding of the performance of blood-based NGS assays is needed prior to routine clinical use. As part of an IRBapproved molecular profiling registry trial of pancreatic ductal adenocarcinoma (PDA) patients, we facilitated blood-based NGS testing of 34 patients from multiple community-based and high-volume academic oncology practices. 23 of these patients also underwent traditional tumor tissue-based NGS testing. cfDNA was not detected in 9/34 (26%) patients. Overall concordance between blood and tumor tissue NGS assays was low, with only 25% sensitivity of blood-based NGS for tumor tissue NGS. Mutations in KRAS, the major PDA oncogene, were only detected in 10/34 (29%) blood samples, compared to 20/23 (87%) tumor tissue biopsies. The presence of mutations in circulating DNA was associated with reduced overall survival (54% in mutation-positive versus 90% in mutation-negative). Our results suggest that in the setting of previously treated, advanced PDA, liquid biopsies are not yet an adequate substitute for tissue biopsies. Further refinement in defining the optimal patient population and timing of blood sampling may improve the value of a blood-based test. © Pishvaian et al