348 research outputs found
Biologic Therapy in Head and Neck Cancer: A Road with Hurdles
The epidermal growth factor receptor (EGFR) is overexpressed in the vast majority of cases of squamous cell carcinoma of the head and neck (SCCHN). A high EGFR expression is associated with an unfavorable prognosis. Cetuximab is a chimeric human/murine IgG1 antibody which binds with high affinity to the EGFR. It is the only targeted agent which got approval for the treatment of SCCHN from the regulatory agencies of Europe and the United States, both in locoregionally advanced disease, in association with radiation, and in recurrent/metastatic disease. The outcome of trials involving other EGFR-directed monoclonal antibodies, that is, zalutumumab and panitumumab, was consistent with the results with cetuximab. However these trials failed to meet their primary endpoint. The results with EGFR-directed tyrosine kinase inhibitors have been disappointing. Other potential targets for treatment in SCCHN include the entire ErbB family, the vascular endothelial growth factor (VEGF) and its receptor (VEGFR), the insulin-like growth factor 1 receptor (IGF-1R), the insulin receptor (IR), histone deacetylases (HDAC), the mammalian target of rapamycin (mTOR), the platelet-derived growth factor receptor (PDGFR), heat-shock protein 90 (HSP90), nuclear factor-kappa B (NF-κB), aurora A or B, and phosphatidylinositol 3-kinase (PIK3CA)
A non-randomized comparison of gemcitabine-based chemoradiation with or without induction chemotherapy for locally advanced squamous cell carcinoma of the head and neck
<p>Abstract</p> <p>Background</p> <p>Concomitant chemotherapy and radiotherapy (chemoradiation; CRT) is the standard treatment for locoregionally advanced squamous cell carcinoma of the head and neck (LA-SCCHN). CRT improves local control and overall survival (OS) when compared to radiotherapy (RT) alone. Induction chemotherapy (IC) reduces the risk of distant metastases (DM) and improves OS by 5% with the use of cisplatin/infusional 5 fluorouracil (PF) in meta-analysis. Adding a taxane to PF in the IC regimen confers a better outcome. Sequential treatment (ST) of IC followed by CRT is therefore under active investigation in multiple phase III trials.</p> <p>Methods</p> <p>We compared the outcome of two cohorts of patients (pts) with LA-SCCHN treated at our institution with CRT (n = 27) or ST (n = 31), respectively. CRT consisted of GEM 100 mg/m<sup>2 </sup>weekly + conventional RT (70 Gy); ST consisted of the same CRT preceded by platinum-based IC.</p> <p>Results</p> <p>Response to IC: complete 8 (26%), partial 20 (65%), stable 1, progressive 1, not evaluable 1. Median follow up of the surviving pts: for CRT 73 months, for ST 51 months. Median time to distant metastasis (TDM) was for CRT 23.6 months, for ST not reached. Median OS was for CRT 20.2 months, for ST 40.2 months. Cox regression analysis, taking into account age, T and N stage and tumor site, showed a hazard ratio with ST of 1.190 for time to locoregional failure (p = 0.712), 0.162 for TDM (p = 0.002), and 0.441 for overall survival (OS) (p = 0.026).</p> <p>Conclusion</p> <p>TDM and OS were found significantly longer in the ST cohort without a reduced locoregional control. Notwithstanding the limitations of a non-randomized single-center comparison, the results are in line with very preliminary data of randomized comparisons suggesting an improved outcome with ST.</p
The Short-term Car Flow Planning Model in Rail Freight Company – Case Study
AbstractWith the promotion of the environmentally friendly transportation modes (the European Commission supports the freight transport operations in the rail sector), an increase in the diversification of the demand is observed. While most rail freight companies tend to apply fixed schedules, this approach is not effective turns out to be ineffective due to the need to meet the customer's specific requirements.The purpose of this paper is to present a case study of empty wagon flow planning over a medium term horizon and to discuss the opportunities of improvement of this plans by discrete optimization. In order to increase the utilization and availability of wagons, the planning procedure with a rolling horizon has to be implemented. Unfortunately, since the plan has to be updated ca. every 4hours, this planning approach needs effective optimization tools. Our hybrid two-stage approach is designed to be implemented in such business environment. This formulation allows us to solve real life instances even for a 7-day time horizon
cTNM vs. pTNM: the effect of not applying ultrasonography in the identification of cervical nodal disease
Accurate clinical staging of oral squamous cell cancer can be quite difficult to achieve especially if nodal involvement is identified. Radiologically-assisted clinical staging is more accurate and informs the clinician of loco-regional and distant metastasis
Study protocol for a randomized controlled trial: Prophylactic swallowing exercises in head-and-neck cancer patients treated with (chemo)radiotherapy (PRESTO trial)
Interventions for the treatment of oral cavity and oropharyngeal cancer:chemotherapy
<b>Background:</b> Oral cavity and oropharyngeal cancers are frequently described as part of a group of oral cancers or head and neck cancer. Treatment of oral cavity cancer is generally surgery followed by radiotherapy, whereas oropharyngeal cancers, which are more likely to be advanced at the time of diagnosis, are managed with radiotherapy or chemoradiation. Surgery for oral cancers can be disfiguring and both surgery and radiotherapy have significant functional side effects, notably impaired ability to eat, drink and talk. The development of new chemotherapy agents, new combinations of agents and changes in the relative timing of surgery, radiotherapy, and chemotherapy treatments may potentially bring about increases in both survival and quality of life for this group of patients.<p></p>
<b>Objectives:</b> To determine whether chemotherapy, in addition to radiotherapy and/or surgery for oral cavity and oropharyngeal cancer results in improved survival, disease free survival, progression free survival, locoregional control and reduced recurrence of disease. To determine which regimen and time of administration (induction, concomitant or adjuvant) is associated with better outcomes.<p></p>
<b>Search strategy:</b> Electronic searches of the Cochrane Oral Health Group's Trials Register, CENTRAL, MEDLINE, EMBASE, AMED were undertaken on 28th July 2010. Reference lists of recent reviews and included studies were also searched to identify further trials.<p></p>
<b>Selection criteria:</b> Randomised controlled trials where more than 50% of participants had primary tumours in the oral cavity or oropharynx, and which compared the addition of chemotherapy to other treatments such as radiotherapy and/or surgery, or compared two or more chemotherapy regimens or modes of administration, were included.<p></p>
<b>Data collection and analysis:</b> Trials which met the inclusion criteria were assessed for risk of bias using six domains: sequence generation, allocation concealment, blinding, completeness of outcome data, selective reporting and other possible sources of bias. Data were extracted using a specially designed form and entered into the characteristics of included studies table and the analysis sections of the review. The proportion of participants in each trial with oral cavity and oropharyngeal cancers are recorded in Additional Table 1.<p></p>
<b>Main results:</b> There was no statistically significant improvement in overall survival associated with induction chemotherapy compared to locoregional treatment alone in 25 trials (hazard ratio (HR) of mortality 0.92, 95% confidence interval (CI) 0.84 to 1.00). Post-surgery adjuvant chemotherapy was associated with improved overall survival compared to surgery +/- radiotherapy alone in 10 trials (HR of mortality 0.88, 95% CI 0.79 to 0.99), and there was an additional benefit of adjuvant concomitant chemoradiotherapy compared to radiotherapy in 4 of these trials (HR of mortality 0.84, 95% CI 0.72 to 0.98). Concomitant chemoradiotherapy resulted in improved survival compared to radiotherapy alone in patients whose tumours were considered unresectable in 25 trials (HR of mortality 0.79, 95% CI 0.74 to 0.84). However, the additional toxicity attributable to chemotherapy in the combined regimens remains unquantified.<p></p>
<b>Authors' conclusions:</b> Chemotherapy, in addition to radiotherapy and surgery, is associated with improved overall survival in patients with oral cavity and oropharyngeal cancers. Induction chemotherapy is associated with a 9% increase in survival and adjuvant concomitant chemoradiotherapy is associated with a 16% increase in overall survival following surgery. In patients with unresectable tumours, concomitant chemoradiotherapy showed a 22% benefit in overall survival compared with radiotherapy alone.<p></p>
Study protocol for a randomized controlled trial : prophylactic swallowing exercises in head-and-neck cancer patients treated with (chemo)radiotherapy (PRESTO trial)
Background: Dysphagia is a common and serious complication after (chemo)radiotherapy (CRT) for head-and-neck cancer (HNC) patients. Prophylactic swallowing exercises (PSE) can have a significantly positive effect on post-treatment swallowing function. However, low adherence rates are a key issue in undermining this positive effect. This current randomized trial will investigate the effect of adherence-improving measures on patients' swallowing function, adherence and quality of life (QOL).
Methods: This ongoing trial will explore the difference in adherence and swallowing-related outcome variables during and after PSE in HNC patients performing the same therapy schedule, receiving different delivery methods. One hundred and fifty patients treated in various hospitals will be divided into three groups. Group 1 performs PSE at home, group 2 practices at home with continuous counseling through an app and group 3 receives face-to-face therapy by a speech and language pathologist. The exercises consist of tongue-strengthening exercises and chin-tuck against resistance with effortful swallow. The Iowa Oral Performance Instrument and the Swallowing Exercise Aid are used for practicing. Patients are evaluated before, during and after treatment by means of strength measurements, swallowing and QOL questionnaires.
Discussion: Since low adherence rates undermine the positive impact of PSE on post-treatment swallowing function, there is need to develop an efficient PSE protocol maximizing adherence rates
Application of Simple Smart Logic for Waterflooding Reservoir Management
A simple smart logic for controlling inflow control valves (ICV) in waterflooding reservoir management is implemented and analyzed, with the final objective of improving the long term financial return of a petroleum reservoir.
Such a control is based in a reactive simple logic that responds to the watercut measured in the ICV. Basically, when the watercut increases, the ICV is set to close proportionally. For comparison purposes, four strategies are presented: base case scenario with conventional control, the best completion configuration found by trial-and-error, the reactive control, and a deterministic optimal control based on Nonlinear Gradient Method with adjoint-gradient formulation is shown for comparison purposes. Finally, all four strategies are tested again in different reservoir realizations in order to mimic the geological uncertainties.
Two different synthetic reservoir models were studied. First, a simple cube with a five-spot well configuration, in which the permeability field has a horizontal pattern defined by lognormal distributions. The second model is a benchmark proposed by the Dutch university, TU delft, with 101 channelized permeability fields representing river patterns.
For the first model, no significant relative gain is found neither in the variable control nor in the optimal control. Manly because of the high homogeneity of the reservoir models. Therefore, no intelligent completion is recommended. On the other hand, for the second and more complex case, the results indicate an expressive relative gain in the use of simple reactive logic. Besides, this type of control achieves results nearly as good as the optimal control.
The test in different realizations, however, shows that reservoir characterization is still a key part of any attempt to improve production. Although the variable reactive control is semi-independent, with action being taken based on measurements, some parameters need a priori model to be tuned
Outcome in recurrent head neck cancer treated with salvage-IMRT
BACKGROUND: Recurrent head neck cancer (rHNC) is a known unfavourable prognostic condition. The purpose of this work was to analyse our rHNC subgroup treated with salvage-intensity modulated radiation therapy (IMRT) for curable recurrence after initial surgery alone. Patients Between 4/2003-9/2008, 44 patients with squamous cell rHNC were referred for IMRT, mean/median 33/21 (3-144) months after initial surgery. None had prior head neck radiation. 41% underwent definitive, 59% postoperative IMRT (66-72.6Gy). 70% had simultaneous chemotherapy. METHODS: Retrospective analysis of the outcome following salvage IMRT in rHNC patients was performed. RESULTS: After mean/median 25/21 months (3-67), 22/44 (50%) patients were alive with no disease; 4 (9%) were alive with disease. 18 patients (41%) died of disease. Kaplan Meier 2-year disease specific survival (DSS), disease free survival (DFS), local and nodal control rates of the cohort were 59/49/56 and 68%, respectively. Known risk factors (advanced initial pTN, marginal initial resection, multiple recurrences) showed no significant outcome differences. Risk factors and the presence of macroscopic recurrence gross tumor volume (rGTV) in oral cavity patients vs others resulted in statistically significantly lower DSS (30 vs 70% at 2 years, p=0.03). With respect to the assessed unfavourable outcome following salvage treatment, numbers needed to treat to avoid one recurrence with initial postoperative IMRT have, in addition, been calculated. CONCLUSION: A low salvage rate of only ~50% at 2 years was found. Calculated numbers of patients needed to treat with postoperative radiation after initial surgery, in order to avoid recurrence and tumor-specific death, suggest a rather generous use of adjuvant irradiation, usually with simultaneous chemotherapy
Effects of Cetuximab and Erlotinib on the behaviour of cancer stem cells in head and neck squamous cell carcinoma.
The therapeutic responses of many solid tumours to chemo- and radio-therapies are far from fully effective but therapies targeting malignancy-related cellular changes show promise for further control. In head and neck squamous cell carcinoma, the epidermal growth factor receptor (EGFR) is commonly overexpressed and investigation of agents that block this receptor indicate a limited response when used alone but an ability to enhance the actions of other drugs. The hierarchical stem cell patterns present in tumours generate cellular heterogeneity and this is further complicated by cancer stem cells (CSC) shifting between epithelial (Epi-CSC) and mesenchymal (EMT-CSC) states. To clarify how such heterogeneity influences responses to EGFR blocking, we examined the effects of Cetuximab and Erlotinib on the cell sub-populations in HNSCC cell lines. These agents reduced cell proliferation for all subpopulations but induced little cell death. They did however induce large shifts of cells between the EMT-CSC, Epi-CSC and differentiating cell compartments. Loss of EMT-CSCs reduced cell motility and is expected to reduce invasion and metastasis. EGFR blocking also induced shifts of Epi-CSCs into the differentiating cell compartment which typically has greater sensitivity to chemo/radiation, an effect expected to enhance the overall response of tumour cell populations to adjunctive therapies.This work was supported by the National Centre for
the Replacement, Refinement and Reduction of Animals
in Research (NC3Rs, Grant number: NC/L00061X/1),
by The São Paulo Research Foundation (FAPESP Grant
numbers 2014/12658-3 and 2011/21395-8), and by the
Barts and The London Charitable Foundation
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