144 research outputs found

    Detailed examination of lymph nodes improves prognostication in colorectal cancer

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    Up to 30% of stage II patients with curatively resected colorectal cancer (CRC) will develop disease recurrence. We evaluated whether examination of lymph nodes by multilevel sectioning and immunohistochemical staining can improve prognostication. Lymph nodes (n = 780) from 36 CRC patients who had developed disease recurrence (cases) and 72 patients who showed no recurrence of disease for at least 5 years (controls) were analyzed. Sections of 4 levels at 200-mu m interval were immunohistochemically stained for cytokeratin expression. The first level was analyzed by conventional and automated microscopy, and the 3 following levels were analyzed by automated microscopy for the presence of tumor cells. Overall, cases showed more micrometastases (3 patients) than controls (1 patient). Analysis of a second level led to the additional detection of 1 patient with micrometastases (case) and 1 patient with macrometastasis (case). Examining more levels only led to additional isolated tumor cells, which were equally divided between cases and controls. Likewise, automated microscopy resulted only in detection of additional isolated tumor cells when compared with conventional microscopy. In multivariate analysis, micrometastases [odds ratio (OR) 26.3, 95% confidence interval (CI) 1.9-364.8, p = 0.015], T4 stage (OR 4.8, 95% CI 1.4-16.7, p = 0.013) and number of lymph nodes (OR 0.9, 95% CI 0.8-1.0, p = 0.028) were independent predictors for disease recurrence. Lymph node analysis of 2 levels and immunohistochemical staining add to the detection of macrometastases and micrometastases in CRC. Micrometastases were found to be an independent predictor of disease recurrence. Isolated tumor cells were of no prognostic significance.</p

    Auditory Sensory Processing and Phonological Development in High IQ and Exceptional Readers, Typically Developing Readers, and Children With Dyslexia: A Longitudinal Study

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    Phonological difficulties characterize children with developmental dyslexia across languages, but whether impaired auditory processing underlies these phonological difficulties is debated. Here the causal question is addressed by exploring whether individual differences in sensory processing predict the development of phonological awareness in 86 English‐speaking lower‐ and middle‐class children aged 8 years in 2005 who had dyslexia, or were age‐matched typically developing children, some with exceptional reading/high IQ. The predictive relations between auditory processing and phonological development are robust for this sample even when phonological awareness at Time 1 (the autoregressor) is controlled. High reading/IQ does not much impact these relations. The data suggest that basic sensory abilities are significant longitudinal predictors of growth in phonological awareness in children

    Oxaliplatin induces drug resistance more rapidly than cisplatin in H69 small cell lung cancer cells

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    Cisplatin produces good responses in solid tumours including small cell lung cancer (SCLC) but this is limited by the development of resistance. Oxaliplatin is reported to show activity against some cisplatin-resistant cancers but there is little known about oxaliplatin in SCLC and there are no reports of oxaliplatin resistant SCLC cell lines. Studies of drug resistance mainly focus on the cellular resistance mechanisms rather than how the cells develop resistance. This study examines the development of cisplatin and oxaliplatin resistance in H69 human SCLC cells in response to repeated treatment with clinically relevant doses of cisplatin or oxaliplatin for either 4 days or 2h. Treatments with 200ng/ml cisplatin or 400ng/ml oxaliplatin for 4 days produced sublines (H69CIS200 and H69OX400 respectively) that showed low level (approximately 2-fold) resistance after 8 treatments. Treatments with 1000ng/ml cisplatin or 2000ng/ml oxaliplatin for 2h also produced sublines, however these were not stably resistant suggesting shorter treatment pulses of drug may be more effective. Cells survived the first five treatments without any increase in resistance, by arresting their growth for a period and then regrowing. The period of growth arrest was reduced after the sixth treatment and the H69CIS200 and H69OX400 sublines showed a reduced growth arrest in response to cisplatin and oxaliplatin treatment suggesting that "regrowth resistance" initially protected against drug treatment and this was further upregulated and became part of the resistance phenotype of these sublines. Oxaliplatin dose escalation produced more surviving sublines than cisplatin dose escalation but neither set of sublines were associated with increased resistance as determined by 5-day cytotoxicity assays, also suggesting the involvement of regrowth resistance. The resistant sublines showed no change in platinum accumulation or glutathione levels even though the H69OX400 subline was more sensitive to buthionine sulfoximine treatment. The H69CIS200 cells were cross-resistant to oxaliplatin demonstrating that oxaliplatin does not have activity against low level cisplatin resistance. Relative to the H69 cells, the H69CIS200 and H69OX400 sublines were more sensitive to paclitaxel and taxotere suggests the taxanes may be useful in the treatment of platinum resistant SCLC. These novel cellular models of cisplatin and oxaliplatin resistant SCLC will be useful in developing strategies to treat platinum-resistant SCLC

    Candidate biomarkers for specific intraoperative near-infrared imaging of soft tissue sarcomas: a systematic review

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    Simple SummaryNear-infrared imaging of tumors during surgery facilitates the oncologic surgeon to distinguish malignant from healthy tissue. The technique is based on fluorescent tracers binding to tumor biomarkers on malignant cells. Currently, there are no clinically available fluorescent tracers that specifically target soft tissue sarcomas. This review searched the literature to find candidate biomarkers for soft tissue sarcomas, based on clinically used therapeutic antibodies. The search revealed 7 biomarkers: TEM1, VEGFR-1, EGFR, VEGFR-2, IGF-1R, PDGFR alpha, and CD40. These biomarkers are abundantly present on soft tissue sarcoma tumor cells and are already being targeted with humanized monoclonal antibodies. The conjugation of these antibodies with a fluorescent dye will yield in specific tracers for image-guided surgery of soft tissue sarcomas to improve the success rates of tumor resections.Surgery is the mainstay of treatment for localized soft tissue sarcomas (STS). The curative treatment highly depends on complete tumor resection, as positive margins are associated with local recurrence (LR) and prognosis. However, determining the tumor margin during surgery is challenging. Real-time tumor-specific imaging can facilitate complete resection by visualizing tumor tissue during surgery. Unfortunately, STS specific tracers are presently not clinically available. In this review, STS-associated cell surface-expressed biomarkers, which are currently already clinically targeted with monoclonal antibodies for therapeutic purposes, are evaluated for their use in near-infrared fluorescence (NIRF) imaging of STS. Clinically targeted biomarkers in STS were extracted from clinical trial registers and a PubMed search was performed. Data on biomarker characteristics, sample size, percentage of biomarker-positive STS samples, pattern of biomarker expression, biomarker internalization features, and previous applications of the biomarker in imaging were extracted. The biomarkers were ranked utilizing a previously described scoring system. Eleven cell surface-expressed biomarkers were identified from which 7 were selected as potential biomarkers for NIRF imaging: TEM1, VEGFR-1, EGFR, VEGFR-2, IGF-1R, PDGFR alpha, and CD40. Promising biomarkers in common and aggressive STS subtypes are TEM1 for myxofibrosarcoma, TEM1, and PDGFR alpha for undifferentiated soft tissue sarcoma and EGFR for synovial sarcoma.Surgical oncolog

    Selection of optimal molecular targets for tumor-specific imaging in pancreatic ductal adenocarcinoma

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    Discrimination of pancreatic ductal adenocarcinoma (PDAC) from chronic pancreatitis (CP) or peritumoral inflammation is challenging, both at preoperative imaging and during surgery, but it is crucial for proper therapy selection. Tumor-specific molecular imaging aims to enhance this discrimination and to help select and stratify patients for resection. We evaluated various biomarkers for the specific identification of PDAC and associated lymph node metastases. Using immunohistochemistry (IHC), expression levels and patterns were investigated of integrin avβ6, carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), Cathepsin E (Cath E), epidermal growth factor receptor (EGFR), hepatocyte growth factor receptor (c-MET), thymocyte differentiation antigen 1 (Thy1), and urokinase-type plasminogen activator receptor (uPAR). In a first cohort, multiple types of pancreatic tissue were evaluated (n=62); normal pancreatic tissue (n=8), CP (n=7), PDAC (n=9), tumor associated lymph nodes (n=32), and PDAC after neoadjuvant radiochemotherapy (n=6). In a second cohort, tissues were investigated (n=55) with IHC and immunofluorescence (IF) for concordance of biomarker expression in all tissue types, obtained from an individual patient. Integrin avβ6 and CEACAM5 showed significantly higher expression levels in PDAC versus normal pancreatic tissue (P=0.001 and P < 0.001, respectively) and CP (P=0.003 and P < 0.001, respectively). Avβ6 and CEACAM5 expression identified tumor-positive lymph nodes correctly in 84% and 68%, respectively, and in 100% of tumor-negative nodes for both biomarkers. In conclusion, avβ6 and CEACAM5 are excellent biomarkers to differentiate PDAC from surrounding tissue and to identify lymph node metastases. Individually or combined, these biomarkers are promising targets for tumor-specific molecular imaging of PDAC

    EpCAM as multi-tumour target for near-infrared fluorescence guided surgery

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    Background: Evaluation of resection margins during cancer surgery can be challenging, often resulting in incomplete tumour removal. Fluorescence-guided surgery (FGS) aims to aid the surgeon to visualize tumours and resection margins during surgery. FGS relies on a clinically applicable imaging system in combination with a specific tumour-targeting contrast agent. In this study EpCAM (epithelial cell adhesion molecule) is evaluated as target for FGS in combination with the novel Artemis imaging system. Methods: The NIR fluorophore IRDye800CW was conjugated to the well-established EpCAM specific monoclonal antibody 323/A3 and an isotype IgG1 as control. The anti-EpCAM/800CW conjugate was stable in serum and showed preserved binding capacity as evaluated on EpCAM positive and negative cell lines, using flow cytometry and cell-based plate assays. Four clinically relevant orthotopic tumour models, i.e. colorectal cancer, breast cancer, head and neck cancer, and peritonitis carcinomatosa, were used to evaluate the performance of the anti-EpCAM agent with the clinically validated Artemis imaging system. The Pearl Impulse small animal imaging system was used as reference. The specificity of the NIRF signal was confirmed using bioluminescence imaging and green-fluorescent protein. Results: All tumour types could clearly be delineated and resected 72 h after injection of the imaging agent. Using NIRF imaging millimetre sized tumour nodules were detected that were invisible for the naked eye. Fluorescence microscopy demonstrated the distribution and tumour specificity of the anti-EpCAM agent. Conclusions: This study shows the potential of an EpCAM specific NIR-fluorescent agent in combination with a clinically validated intraoperative imaging system to visualize various tumours during surgery

    Being Transparent About Brilliant Failures:An Attempt to Use Real-World Data in a Disease Model for Patients with Castration-Resistant Prostate Cancer

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    Background: Real-world disease models spanning multiple treatment lines can provide insight into the (cost) effectiveness of treatment sequences in clinical practice. Objective: Our objective was to explore whether a disease model based solely on real-world data (RWD) could be used to estimate the effectiveness of treatments for patients with castration-resistant prostate cancer (CRPC) that could then be suitably used in a cost-effectiveness analysis. Methods: We developed a patient-level simulation model using patient-level data from the Dutch CAPRI registry as input parameters. Time to event (TTE) and overall survival (OS) were estimated with multivariate regression models, and type of event (i.e., next treatment or death) was estimated with multivariate logistic regression models. To test internal validity, TTE and OS from the simulation model were compared with the observed outcomes in the registry. Results: Although patient characteristics and survival outcomes of the simulated data were comparable to those in the observed data (median OS 20.6 vs. 19.8 months, respectively), the disease model was less accurate in estimating differences between treatments (median OS simulated vs. observed population: 18.6 vs. 17.9 [abiraterone acetate plus prednisone], 24.0 vs. 25.0 [enzalutamide], 20.2 vs. 18.7 [docetaxel], and 20.0 vs. 23.8 months [radium-223]). Conclusions: Overall, the disease model accurately approximated the observed data in the total CRPC population. However, the disease model was unable to predict differences in survival between treatments due to unobserved differences. Therefore, the model is not suitable for cost-effectiveness analysis of CRPC treatment. Using a combination of RWD and data from randomised controlled trials to estimate treatment effectiveness may improve the model

    Preclinical evaluation of EpCAM-binding designed ankyrin repeat proteins (DARPins) as targeting moieties for bimodal near-infrared fluorescence and photoacoustic imaging of cancer

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    PurposeFluorescence-guided surgery (FGS) can play a key role in improving radical resection rates by assisting surgeons to gain adequate visualization of malignant tissue intraoperatively. Designed ankyrin repeat proteins (DARPins) possess optimal pharmacokinetic and other properties for in vivo imaging. This study aims to evaluate the preclinical potential of epithelial cell adhesion molecule (EpCAM)-binding DARPins as targeting moieties for near-infrared fluorescence (NIRF) and photoacoustic (PA) imaging of cancer.MethodsEpCAM-binding DARPins Ac2, Ec4.1, and non-binding control DARPin Off7 were conjugated to IRDye 800CW and their binding efficacy was evaluated on EpCAM-positive HT-29 and EpCAM-negative COLO-320 human colon cancer cell lines. Thereafter, NIRF and PA imaging of all three conjugates were performed in HT-29_luc2 tumor-bearing mice. At 24 h post-injection, tumors and organs were resected and tracer biodistributions were analyzed.ResultsAc2-800CW and Ec4.1-800CW specifically bound to HT-29 cells, but not to COLO-320 cells. Next, 6 nmol and 24 h were established as the optimal in vivo dose and imaging time point for both DARPin tracers. At 24 h post-injection, mean tumor-to-background ratios of 2.60 & PLUSMN; 0.3 and 3.1 & PLUSMN; 0.3 were observed for Ac2-800CW and Ec4.1-800CW, respectively, allowing clear tumor delineation using the clinical Artemis NIRF imager. Biodistribution analyses in non-neoplastic tissue solely showed high fluorescence signal in the liver and kidney, which reflects the clearance of the DARPin tracers.ConclusionOur encouraging results show that EpCAM-binding DARPins are a promising class of targeting moieties for pan-carcinoma targeting, providing clear tumor delineation at 24 h post-injection. The work described provides the preclinical foundation for DARPin-based bimodal NIRF/PA imaging of cancer.Vascular SurgerySurgical oncolog
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