Active-set approaches are commonly used in algorithms for constrained numerical optimization. We propose that active-set techniques can beneficially be employed for evolutionary black-box ...optimization with explicit constraints and present an active-set evolution strategy. We experimentally evaluate its performance relative to those of several algorithms for constrained optimization and find that the active-set evolution strategy compares favourably for the problem set under consideration.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Approximately 7% of pancreatic cancers occur in patients with a germline mutation in
BRCA1
or
BRCA2
, an alteration that compromises DNA repair. In a randomized trial in patients with metastatic ...pancreatic cancer that had responded to platinum-based chemotherapy, progression-free survival was nearly twice as long with olaparib than with placebo (7.4 months vs. 3.8 months).
Main Recommendations
The following recommendations should only be applied after a thorough diagnostic evaluation including a contrast-enhanced computed tomography (CT) scan.
1
ESGE recommends colonic ...stenting to be reserved for patients with clinical symptoms and radiological signs of malignant large-bowel obstruction, without signs of perforation. ESGE does not recommend prophylactic stent placement.
Strong recommendation, low quality evidence.
2
ESGE recommends stenting as a bridge to surgery to be discussed, within a shared decision-making process, as a treatment option in patients with potentially curable left-sided obstructing colon cancer as an alternative to emergency resection.
Strong recommendation, high quality evidence.
3
ESGE recommends colonic stenting as the preferred treatment for palliation of malignant colonic obstruction.
Strong recommendation, high quality evidence.
4
ESGE suggests consideration of colonic stenting for malignant obstruction of the proximal colon either as a bridge to surgery or in a palliative setting.
Weak recommendation, low quality evidence.
5
ESGE suggests a time interval of approximately 2 weeks until resection when colonic stenting is performed as a bridge to elective surgery in patients with curable left-sided colon cancer.
Weak recommendation, low quality evidence.
6
ESGE recommends that colonic stenting should be performed or directly supervised by an operator who can demonstrate competence in both colonoscopy and fluoroscopic techniques and who performs colonic stenting on a regular basis.
Strong recommendation, low quality evidence.
7
ESGE suggests that a decompressing stoma as a bridge to elective surgery is a valid option if the patient is not a candidate for colonic stenting or when stenting expertise is not available.
Weak recommendation, low quality evidence.
Quantitative imaging in life sciences has evolved into a powerful approach combining advanced microscopy acquisition and automated analysis of image data. The focus of the present study is on the ...imaging-based evaluation of the posterior cricoarytenoid muscle (PCA) influenced by long-term functional electrical stimulation (FES), which may assist the inspiration of patients with bilateral vocal fold paresis. To this end, muscle cross-sections of the PCA of sheep were examined by quantitative image analysis. Previous investigations of the muscle fibers and the collagen amount have not revealed signs of atrophy and fibrosis due to FES by a laryngeal pacemaker. It was therefore hypothesized that regardless of the stimulation parameters the fat in the muscle cross-sections would not be significantly altered. We here extending our previous investigations using quantitative imaging of intramuscular fat in cross-sections. In order to perform this analysis both reliably and faster than a qualitative evaluation and time-consuming manual annotation, the selection of the automated method was of crucial importance. To this end, our recently established deep neural network IMFSegNet, which provides more accurate results compared to standard machine learning approaches, was applied to more than 300 H&E stained muscle cross-sections from 22 sheep. It was found that there were no significant differences in the amount of intramuscular fat between the PCA with and without long-term FES, nor were any significant differences found between the low and high duty cycle stimulated groups. This study on a human-like animal model not only confirms the hypothesis that FES with the selected parameters has no negative impact on the PCA, but also demonstrates that objective and automated deep learning-based quantitative imaging is a powerful tool for such a challenging analysis.
5‐Fluorouracil (5‐FU) is dosed by body surface area, a practice unable to reduce the interindividual variability in exposure. Endorsed by the International Association of Therapeutic Drug Monitoring ...and Clinical Toxicology (IATDMCT), we evaluated clinical evidence and strongly recommend TDM for the management of 5‐FU therapy in patients with colorectal or head‐and‐neck cancer receiving common 5‐FU regimens. Our systematic methodology provides a framework to evaluate published evidence in support of TDM recommendations in oncology.
Adjuvant chemotherapy for colon cancer (UICC stage II and III) has been under investigation over the last 30 years, regarding treatment duration and regimens. In this review, choice of regimen, its ...duration, possible limitations and future perspectives are discussed. Monotherapy with 5-fluorouracil was followed by addition of oxaliplatin, resulting in improved 3-yr disease free survival (DFS) and overall survival (OS) rates, but also increased peripheral sensory neurotoxicity (PSN). The International Duration Evaluation of Adjuvant therapy (IDEA) collaboration demonstrated less toxicity, especially PSN, when shortening treatment duration to 3 months. However, formally, the anticipated non-inferiority of 3 months with fluoropyrimidine (FP)/oxaliplatin over 6 months (at 3-yr DFS) was not met for all patients groups, although subgroup analyses showed non-inferiority with capecitabine/oxaliplatin (CAPOX) rather than with FOLFOX, and also in relation to the prognostic information (e.g., clinical low-risk group, pT1-3 N0). In addition, first data of newer parameters like Immunoscore
and ctDNA show promising results as stratification parameters. Further investigations to better define clinical risk groups and prognostic factors are mandatory. Besides this, individual decision-making of treatment intensity (FP or FP/oxaliplatin) and duration should always consider patient characteristics and preferences, also given the absolute relatively small differences and their clinical relevance.
Summary Background Bevacizumab plus fluoropyrimidine-based chemotherapy is standard treatment for first-line and bevacizumab-naive second-line metastatic colorectal cancer. We assessed continued use ...of bevacizumab plus standard second-line chemotherapy in patients with metastatic colorectal cancer progressing after standard first-line bevacizumab-based treatment. Methods In an open-label, phase 3 study in 220 centres in Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, the Netherlands, Norway, Portugal, Saudi Arabia, Spain, Sweden, and Switzerland, patients (aged ≥18 years) with unresectable, histologically confirmed metastatic colorectal cancer progressing up to 3 months after discontinuing first-line bevacizumab plus chemotherapy were randomly assigned in a 1:1 ratio to second-line chemotherapy with or without bevacizumab 2·5 mg/kg per week equivalent (either 5 mg/kg every 2 weeks or 7·5 mg/kg every 3 weeks, intravenously). The choice between oxaliplatin-based or irinotecan-based second-line chemotherapy depended on the first-line regimen (switch of chemotherapy). A combination of a permuted block design and the Pocock and Simon minimisation algorithm was used for the randomisation. The primary endpoint was overall survival, analysed by intention to treat. This trial is registered with ClinicalTrials.gov , number NCT00700102. Findings Between Feb 1, 2006, and June 9, 2010, 409 (50%) patients were assigned to bevacizumab plus chemotherapy and 411 (50%) to chemotherapy alone. Median follow-up was 11·1 months (IQR 6·4–15·6) in the bevacizumab plus chemotherapy group and 9·6 months (5·4–13·9) in the chemotherapy alone group. Median overall survival was 11·2 months (95% CI 10·4–12·2) for bevacizumab plus chemotherapy and 9·8 months (8·9–10·7) for chemotherapy alone (hazard ratio 0·81, 95% CI 0·69–0·94; unstratified log-rank test p=0·0062). Grade 3–5 bleeding or haemorrhage (eight 2% vs one <1%), gastrointestinal perforation (seven 2% vs three <1%), and venous thromboembolisms (19 5% vs 12 3%) were more common in the bevacizumab plus chemotherapy group than in the chemotherapy alone group. The most frequently reported grade 3–5 adverse events were neutropenia (65 16% in the bevacizumab and chemotherapy group vs 52 13% in the chemotherapy alone group), diarrhoea (40 10% vs 34 8%, respectively), and asthenia (23 6% vs 17 4%, respectively). Treatment-related deaths were reported for four patients in the bevacizumab plus chemotherapy group and three in the chemotherapy alone group. Interpretation Maintenance of VEGF inhibition with bevacizumab plus standard second-line chemotherapy beyond disease progression has clinical benefits in patients with metastatic colorectal cancer. This approach is also being investigated in other tumour types, including metastatic breast and non-small cell lung cancers. Funding F Hoffmann-La Roche.
Abstract Squamous cell carcinoma of the anus (SCCA) is a rare cancer but its incidence is increasing throughout the world, and is particularly high in the human immunodeficiency virus positive (HIV+) ...population. A multidisciplinary approach is mandatory (involving radiation therapists, medical oncologists, surgeons, radiologists and pathologists). SCCA usually spreads in a loco-regional manner within and outside the anal canal. Lymph node involvement at diagnosis is observed in 30–40% of cases while systemic spread is uncommon with distant extrapelvic metastases recorded in 5–8% at onset, and rates of metastatic progression after primary treatment between 10% and 20%. SCCA is strongly associated with human papilloma virus (HPV, types 16–18) infection. The primary aim of treatment is to achieve cure with loco-regional control and preservation of anal function, with the best possible quality of life. Treatment dramatically differs from adenocarcinomas of the lower rectum. Combinations of 5FU-based chemoradiation and other cytotoxic agents (mitomycin C) have been established as the standard of care, leading to complete tumour regression in 80–90% of patients with locoregional failures in the region of 15%. There is an accepted role for surgical salvage. Assessment and treatment should be carried out in specialised centres treating a high number of patients as early as possible in the clinical diagnosis. To date, the limited evidence from only 6 randomised trials 1,2,3,4,5,6,7 , the rarity of the cancer, and the different behaviour/natural history depending on the predominant site of origin, (the anal margin, anal canal or above the dentate line) provide scanty direction for any individual oncologist. Here we aim to provide guidelines which can assist medical, radiation and surgical oncologists in the practical management of this unusual cancer.
Summary Background The definition of a best maintenance strategy following combination chemotherapy plus bevacizumab in metastatic colorectal cancer is unclear. We investigated whether no ...continuation of therapy or bevacizumab alone are non-inferior to fluoropyrimidine plus bevacizumab, following induction treatment with a fluoropyrimidine plus oxaliplatin plus bevacizumab. Methods In this open-label, non-inferiority, randomised phase 3 trial, we included patients aged 18 years or older with histologically confirmed, previously untreated metastatic colorectal cancer, Eastern Cooperative Oncology Group (ECOG) performance status of 0–2, adequate bone marrow, liver, and renal function, no pre-existing neuropathy greater than grade 1, and measurable disease, from 55 hospitals and 51 private practices in Germany. After 24 weeks of induction therapy with either fluorouracil plus leucovorin plus oxaliplatin or capecitabine plus oxaliplatin, both with bevacizumab, patients without disease progression were randomly assigned centrally by fax (1:1:1) to standard maintenance treatment with a fluoropyrimidine plus bevacizumab, bevacizumab alone, or no treatment. Both patients and investigators were aware of treatment assignment. Stratification criteria were response status, termination of oxaliplatin, previous adjuvant treatment with oxaliplatin, and ECOG performance status. At first progression, re-induction with all drugs of the induction treatment was a planned part of the protocol. Time to failure of strategy was the primary endpoint, defined as time from randomisation to second progression after maintenance (and if applicable re-induction), death, or initiation of further treatment including a new drug. Time to failure of strategy was equivalent to time to first progression for patients who did not receive re-induction (for any reason). The boundary for assessment of non-inferiority was upper limit of the one-sided 98·8% CI 1·43. Analyses were done by intention to treat. The study has completed recruitment, but follow-up of participants is ongoing. The trial is registered with ClinicalTrials.gov , number NCT00973609. Findings Between Sept 17, 2009, and Feb 21, 2013, 837 patients were enrolled and 472 randomised; 158 were randomly assigned to receive fluoropyrimidine plus bevacizumab, 156 to receive bevacizumab monotherapy, and 158 to receive no treatment. Median follow-up from randomisation is 17·0 months (IQR 9·5–25·4). Median time to failure of strategy was 6·9 months (95% CI 6·1–8·5) for the fluoropyrimidine plus bevacizumab group, 6·1 months (5·3–7·4) for the bevacizumab alone group, and 6·4 months (4·8–7·6) for the no treatment group. Bevacizumab alone was non-inferior to standard fluoropyrimidine plus bevacizumab (hazard ratio HR 1·08 95% CI 0·85–1·37; p=0·53; upper limit of the one-sided 98·8% CI 1·42), whereas no treatment was not (HR 1·26 0·99–1·60; p=0·056; upper limit of the one-sided 98·8% CI 1·65). The protocol-defined re-induction after first progression was rarely done (30 19% patients in the fluoropyrimidine plus bevacizumab group, 67 43% in the bevacizumab monotherapy group, and 73 46% in the no treatment group. The most common grade 3 adverse event was sensory neuropathy (21 13% of 158 patients in the fluoropyrimidine plus bevacizumab group, 22 14% of 156 patients in the bevacizumab alone group, and 12 8% of 158 patients in the no treatment group). Interpretation Although non-inferiority for bevacizumab alone was demonstrated for the primary endpoint, maintenance treatment with a fluoropyrimidine plus bevacizumab may be the preferable option for patients following an induction treatment with a fluoropyrimidine, oxaliplatin, and bevacizumab, as it allows the planned discontinuation of the initial combination without compromising time with controlled disease. Only a few patients were exposed to re-induction treatment, thus deeming the primary endpoint time to failure of strategy non-informative and clinically irrelevant. Progression-free survival and overall survival should be considered primary endpoints in future trials exploring maintenance strategies. Funding RochePharma AG and AIO Studien gGmbH.
While noise is a phenomenon present in many real world optimization problems, the understanding of its potential effects on the performance of evolutionary algorithms is still incomplete. This paper ...investigates the effects of fitness proportionate Gaussian noise for a (1 + 1)-ES with isotropic normal mutations on the quadratic sphere in the limit of infinite search-space dimensionality. It is demonstrated experimentally that the results provide a good approximation for finite space dimensionality. It is shown that overvaluation as a result of failure to re-evaluate parental fitness leads to both reduced success probabilities and improved performance. Implications for mutation strength adaptation rules are discussed and optimal re-sampling rates are computed.
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