Characterizing ice particles using two-dimensional reflections of a lidar beam.

We report a phenomenon manifesting itself as brief flashes of light on the snow's surface near a lidar beam. The flashes are imaged and interpreted as specular reflection patterns from individual ice particles. Such patterns have a two-dimensional structure and are similar to those previously observed in forward scattering. Patterns are easiest to capture from particles with well-defined horizontal facets, such as near-horizontally aligned plates. The patterns and their position can be used to determine properties such as ice particle shape, size, roughness, alignment, and altitude. Data obtained at Summit in Greenland show the presence of regular hexagonal and scalene plates, columns, and rounded plates of various sizes, among others.

Analysis of lymphatic and blood vessel invasion biomarkers in T1 esophagogastric adenocarcinomas for improved patient prognostication.

Lymphovascular invasion (LVI) in T1 esophagogastric adenocarcinoma may predict risk of recurrence despite definitive treatment with surgery or endoscopic resection. Podoplanin and CD34 are emerging biomarkers of lymphatic and blood vessel invasion, respectively, and could be adopted to refine LVI assessment. A consecutive series of 65 patients with T1 adenocarcinomas diagnosed at Nottingham University Hospitals were investigated. T1 tumors from 43/65 patients who received primary surgery only were suitable for LVI evaluation by hematoxylin and eosin (H&E) staining as well as by CD34 and Podoplanin immunohistochemistry. LVI was correlated to clinicopathological features and recurrence free survival. H&E staining detected LVI in 11.6% (5/43) of T1 tumors. CD34 and Podoplanin immunohistochemistry significantly improved LVI detection to 25.6% (11/43). Compared with LVI by H&E, immunohistochemical evaluation of blood vessel invasion (CD34) or lymphatic vessel invasion (Podoplanin) was significantly associated with higher grade (P = 0.005), submucosal invasion (T1b) (P = 0.018), lymph node positivity (N1) (P = 0.029) and poor recurrence free survival (P = 0.0003). Our study provides evidence that CD34 and Podoplanin immunohistochemistry could improve LVI detection and allow better prognostication of patients and optimum selection of definitive treatment. Larger multicenter studies are required for further validation that could have significant clinical implications.

Endoscopic TriModal imaging and biomarkers for neoplasia conjoined: a feasibility study in Barrett's esophagus.

In Barrett's esophagus (BE), the normal squamous lining of the esophagus is replaced by specialized columnar epithelium. Endoscopic surveillance with autofluorescence imaging (AFI) and molecular biomarkers have been studied separately to detect early neoplasia (EN) in BE. The combination of advanced-imaging modalities and biomarkers has not been investigated; AFI may help detecting biomarkers as a risk-stratification tool. We retrospectively evaluated a cohort of patients undergoing endoscopy for EN in BE with AFI and correlated five biomarkers (HPP1, RUNX3, p16, cyclin A, and p53) in tissue samples with AFI and dysplasia status. Fifty-eight samples from a previous prospective study were selected: 15 true-positive (TP: AFI-positive, EN), 21 false-positive (FP: AFI-positive, no EN), 12 true-negative (TN1; AFI-negative, no EN in sample), 10 true-negative (TN2: AFI-negative, no EN in esophagus). Methylation-specific RT-PCR was performed for HPP1, RUNX3, p16, and immunohistochemistry for cyclin A, p53. P < 0.05 was considered statistically significant. Bonferroni correction was used for multiple comparisons. P16, cyclin A, p53 correlated with dysplasia (P < 0.01, P = 0.003, P < 0.001, respectively). Increased p16 methylation was observed between TP versus TN2 (P = 0.003) and TN1 versus TN2 (P = 0.04) subgroups, suggesting a field defect. Only p53 correlated with AFI-status (P = 0.003). After exclusion of EN samples, significance was lost. Although correlation with dysplasia status was confirmed for p16, cyclin A and p53, underlining the importance of these biomarkers as an early event in neoplastic progression, none of the investigated biomarkers correlated with AFI status. A larger prospective study is needed to assess the combination of AFI and a larger panel of biomarkers to improve risk stratification in BE.

An inter-observer agreement study of autofluorescence endoscopy in Barrett's esophagus among expert and non-expert endoscopists.

BACKGROUND: Autofluorescence imaging (AFI), which is a "red flag" technique during Barrett's surveillance, is associated with significant false positive results. The aim of this study was to assess the inter-observer agreement (IOA) in identifying AFI-positive lesions and to assess the overall accuracy of AFI. METHODS: Anonymized AFI and high resolution white light (HRE) images were prospectively collected. The AFI images were presented in random order, followed by corresponding AFI + HRE images. Three AFI experts and 3 AFI non-experts scored images after a training presentation. The IOA was calculated using kappa and accuracy was calculated with histology as gold standard. RESULTS: Seventy-four sets of images were prospectively collected from 63 patients (48 males, mean age 69 years). The IOA for number of AF positive lesions was fair when AFI images were presented. This improved to moderate with corresponding AFI and HRE images [experts 0.57 (0.44-0.70), non-experts 0.47 (0.35-0.62)]. The IOA for the site of AF lesion was moderate for experts and fair for non-experts using AF images, which improved to substantial for experts [κ = 0.62 (0.50-0.72)] but remained at fair for non-experts [κ = 0.28 (0.18-0.37)] with AFI + HRE. Among experts, the accuracy of identifying dysplasia was 0.76 (0.7-0.81) using AFI images and 0.85 (0.79-0.89) using AFI + HRE images. The accuracy was 0.69 (0.62-0.74) with AFI images alone and 0.75 (0.70-0.80) using AFI + HRE among non-experts. CONCLUSION: The IOA for AF positive lesions is fair to moderate using AFI images which improved with addition of HRE. The overall accuracy of identifying dysplasia was modest, and was better when AFI and HRE images were combined.

An engineered lipocalin specific for CTLA-4 reveals a combining site with structural and conformational features similar to antibodies.

Biomolecular reagents that enable the specific molecular recognition of proteins play a crucial role in basic research as well as medicine. Up to now, antibodies (immunoglobulins) have been widely used for this purpose. Their predominant feature is the vast repertoire of antigen-binding sites that arise from a set of 6 hypervariable loops. However, antibodies suffer from practical disadvantages because of their complicated architecture, large size, and multiple functions. The lipocalins, on the other hand, have evolved as a protein family that primarily serves for the binding of small molecules. Here, we show that an engineered lipocalin, derived from human Lcn2, can specifically bind the T cell coreceptor CTLA-4 as a prescribed protein target with subnanomolar affinity. Crystallographic analysis reveals that its reshaped cup-like binding site, which is formed by 4 variable loops, provides perfect structural complementarity with this "antigen." Furthermore, comparison with the crystal structure of the uncomplexed engineered lipocalin indicates a pronounced induced-fit mechanism, a phenomenon so far considered typical for antibodies. By recognizing the same epitope on CTLA-4 that interacts with the counterreceptors B7.1/B7.2 on antigen-presenting cells the engineered Lcn2 exhibits strong, cross-species antagonistic activity, as evidenced by biological effects comparable with a CTLA-4-specific antibody. With its proven stimulatory activity on T cells in vivo, the CTLA-4 blocking lipocalin offers potential for immunotherapy of cancer and infectious disease. Beyond that, lipocalins with engineered antigen-binding sites, so-called Anticalins, provide a class of small ( approximately 180 residues), structurally simple, and robust binding proteins with applications in the life sciences in general.

Tumour regression and ERCC1 nuclear protein expression predict clinical outcome in patients with gastro-oesophageal cancer treated with neoadjuvant chemotherapy.

AIMS: Neoadjuvant chemotherapy followed by surgery is the standard of care for patients with gastro-oesophageal adenocarcinoma. Previously, we validated the utility of the tumour regression grade (TRG) as a histopathological marker of tumour downstaging in patients receiving platinum-based neoadjuvant chemotherapy. In this study we profiled key DNA repair and damage signalling factors and correlated them with clinicopathological outcomes, including TRG response. METHODS AND RESULTS: Formalin-fixed human gastro-oesophageal cancers were constructed into tissue microarrays (TMAs). The first set consisted of 142 gastric/gastro-oesophageal cancer cases not exposed to neoadjuvant chemotherapy and the second set consisted of 103 gastric/gastro-oesophageal cancer cases exposed to preoperative platinum-based chemotherapy. Expressions of ERCC1, XPF, FANCD2, APE1 and p53 were investigated using immunohistochemistry. In patients who received neoadjuvant chemotherapy, favourable TRG response (TRG 1, 2 or 3) was associated with improvement in disease-specific survival (P=0.038). ERCC1 nuclear expression correlated with lack of histopathological response (TRG 4 or 5) to neoadjuvant chemotherapy (P=0.006) and was associated with poor disease-specific (P=0.020) and overall survival (P=0.040). CONCLUSIONS: We provide evidence that tumour regression and ERCC1 nuclear protein expression evaluated by immunohistochemistry are promising predictive markers in gastro-oesophageal cancer patients receiving neoadjuvant platinum-based chemotherapy.

High-resolution endoscopy and endoscopic ultrasound for evaluation of early neoplasia in Barrett's esophagus.

BACKGROUND: Endoscopic ultrasound (EUS) is useful for detecting depth of invasion and nodal involvement in patients with early Barrett's neoplasia (EBN), precluding endoscopic management. This study aimed to determine whether the lesion morphology of the EBN shown on high-resolution endoscopy predicts EUS and histologic tumor stage. METHODS: Retrospective series from two tertiary referral centers were studied. Patients with EBN referred for EUS evaluation before treatment were identified, and data were collected from endoscopies, a database, and case notes. All patients had high-resolution endoscopy followed by radial EUS. RESULTS: This study included 50 patients (22 men) with a median age of 69 years (interquartile range, 60-79 years). Visible lesions in the Barrett's segment were described as Paris types 0-1 (n = 9), 0-IIb (n = 12), 0-IIa (n = 12), 0-IIa + IIc (n = 6), and 0-IIc (n = 5). Of the 50 patients, 46 (92%) had either EMR (n = 17), esophagectomy (n = 23), or both (n = 6). All 12 patients (100%) with Paris 0-IIb lesions had T0/T1 m staging on EUS confirmed with resection histology. The sensitivity for EUS T-staging for Paris classification was 71.4% for type 0-I, 100% for type 0-IIb, 83% for type 0-IIa, 66.7% for type 0-IIa + IIc, and 66.7% for type IIc. Overall, 8 (17%) of the 46 patients were understaged and 2 (4%) were overstaged. For detecting submucosal invasion, EUS had a sensitivity of 66%, a specificity of 93%, a negative predictive value of 85%, and a diagnostic accuracy of 84.4%. CONCLUSION: Submucosal invasion is detected by EUS for 26% of patients with EBN. The value of EUS staging before resection for type 0-IIb early Barrett's cancer (flat lesions) is limited because 100% of these lesions are limited to the mucosa. For the management algorithm in this selected cohort, the use of EUS should be reconsidered.

Biomarkers of response to therapy in oesophago-gastric cancer.

Cancer of the oesophagus, gastro-oesophageal junction (GOJ) and stomach remains a major health problem worldwide. The evidence base for the optimal management of patients with operable oesophago-gastric cancer is evolving. Accepted approaches include preoperative chemotherapy followed by surgery (oesophageal cancer), chemo-radiotherapy alone (oesophageal cancer) and perioperative chemotherapy (gastric and gastro-oesophageal adenocarcinomas). The underlying principles behind neoadjuvant therapy are to improve resectability of the tumour by tumour shrinkage/downstaging and to treat occult metastatic disease as early as possible. The response rate to cytotoxic therapy is about 40% in oesophago-gastric cancer. Available evidence suggests that a favourable histopathological response to cytotoxic therapy may be a useful positive predictive marker in oesophago-gastric cancer. However, the ability to predict tumour response in routine clinical practice is difficult and is an area of intense investigation. There is evolving evidence for the role of predictive biomarkers in cancer in general and oesophago-gastric cancer in particular. We provide an overview on the current status of radiological and biological predictive biomarkers. We have focussed on clinical translational investigations and, where appropriate, provided pre-clinical insights. Whether predictive markers will be routinely incorporated in clinical practice remains to be seen as biomarker research is expensive and the data generated from these investigations are complex. It is clear that a concerted international effort between academia and industry is critical if personalised medicine as a practical reality for our cancer patients is to be realised.

Shuttle imaging radar experiment.

The shuttle imaging radar (SIR-A) acquired images of a variety of the earth's geologic areas covering about 10 million square kilometers. Structural and geomorphic features such as faults, folds, outcrops, and dunes are clearly visible in both tropical and arid regions. The combination of SIR-A and Seasat images provides additional information about the surface physical properties: topography and roughness. Ocean features were also observed, including large internal waves in the Andaman Sea.

Endoscopic-ultrasound-guided mural trucut biopsy in the investigation of unexplained thickening of esophagogastric wall.

BACKGROUND AND AIMS: Esophageal and/or gastric wall thickening raises the possibility of malignancy. Endoscopic-ultrasound-(EUS-)guided targeted biopsy of the thickened wall is possible. We aimed to evaluate the efficacy and safety of EUS-guided mural trucut biopsies (TCB) in detecting underlying malignancy in patients with thickened esophagogastric wall and negative mucosal biopsies. METHODS: Patients with alarm symptoms referred for EUS-guided sampling after negative endoscopy and mucosal biopsy were included in the study. All patients had radial EUS reporting abnormal thickening of the esophageal/gastric wall. A linear-array echoendoscope and a 19-gauge trucut needle were used for sampling. Clinical and investigatory data were collected prospectively between 2004 and 2008. RESULTS: Thirty-one patients (20 men) aged 60 - 74 years (median 67 years) were included. All patients had thickened esophageal wall (n = 10), gastric wall (n = 21), or both on radial EUS. Prior to EUS, patients had undergone 1 - 5 endoscopies (median 1.2) and 2 - 8 mucosal biopsies (median 4). The median esophageal and gastric wall thicknesses were 12 and 18 mm respectively. During sampling 1 - 5 needle punctures (median 3) were made. On EUS-TCB, an adequate specimen for histology was obtained in 28/31 patients (90 %). The size of the tissue cores was 4 - 10 mm (median 6mm). Malignancy was confirmed in 16/31 patients (54 %) on histology, and in 11/31 patients (35.4 %) an underlying malignancy was excluded. There was no significant correlation between wall thickness and biopsy size (rho = 0.11, 95 %CI- 0.25 to - 0.45, two-sided P = 0.53). EUS-TCB had sensitivity, specificity, and positive and negative predictive values of 85 %, 100 %, 100 %, and 74 % respectively. There were no immediate or late complications. CONCLUSIONS: EUS-guided mural TCB is a safe and effective technique in the investigation of esophagogastric wall thickening in patients with alarm symptoms and has high sensitivity and specificity for the diagnosis of a cancer.

An emergency department intervention to protect an overlooked group of children at risk of significant harm.

BACKGROUND: Parental psychiatric disorder, especially depression, personality disorder and deliberate self-harm, is known to put children at greater risk of mental illness, neglect or physical, emotional and sexual abuse. Without a reliable procedure to identify children of parents presenting with these mental health problems, children at high risk of significant harm can be easily overlooked. Although deliberate self-harm constitutes a significant proportion of emergency presentations, there are no guidelines which address the emergency physician's role in identifying and assessing risk to children of these patients. METHODS: A robust system was jointly developed with the local social services child protection team to identify and risk-stratify children of parents with mental illness. This allows us to intervene when we identify children at immediate risk of harm and to ensure that social services are aware of potential risk to all children in this group. The referral process was audited repeatedly to refine the agreed protocol. RESULTS: The proportion of patients asked by the emergency department personnel about dependent children increased and the quality of information received by the social services child protection team improved. CONCLUSIONS: All emergency departments should acknowledge the inadequacy of information available to them regarding patients' children and consider a policy of referral to social services for all children of parents with mental health presentations. This process can only be developed through close liaison within the multidisciplinary child protection team.

Iron-induced mucosal pathology of the upper gastrointestinal tract: a common finding in patients on oral iron therapy.

AIMS: Upper gastrointestinal injury from iron tablets at therapeutic dose is not widely recognized. The aim was to document cases of iron-related upper gastrointestinal (GI) pathology and to determine frequency of occurrence. METHODS AND RESULTS: We prospectively studied patients with iron deficiency anaemia undergoing upper GI endoscopy from November 2005 to July 2006. Cases of upper GI iron deposition from these and other cases extracted retrospectively between 1999 and 2006 were examined histopathologically and patient notes were reviewed. In the prospective study, 15/160 patients investigated for iron deficiency anaemia [16.1% (15/93) of those taking oral iron tablets] had iron deposition noted on routine haematoxylin and eosin staining. In this plus the retrospective series, 59 patients were identified with 64 episodes of iron deposition. Eighty-six percent (6/7) with oesophageal iron deposition had associated erosion. Sixty-three percent (29/46) with gastric iron deposition had erosion and 80% (37/46) had reactive gastritis. Duodenal deposition was usually (91%, 10/11) within macrophages in villous tips with no erosion. Ninety-eight percent (58/59) of iron deposition cases had documented oral iron intake. CONCLUSIONS: Iron deposition in the upper GI tract is common in patients taking iron tablets. It is frequently associated with mucosal disruption in the oesophagus and stomach.

Narrow-band imaging with magnification in Barrett's esophagus: validation of a simplified grading system of mucosal morphology patterns against histology.

BACKGROUND AND STUDY AIMS: Validation of a simplified classification of mucosal morphology in prediction of histology in Barrett's esophagus using narrow-band imaging with magnification (NBI-Z) and assessing its reproducibility by endoscopists experienced in the use of NBI (NBI-experts) and by endoscopists who were new to NBI (non-NBI-experts). PATIENTS AND METHODS: In a prospective cohort study of 109 patients with Barrett's esophagus at a single tertiary referral center, mucosal patterns visualized in Barrett's esophagus on NBI-Z were classified into four easily distinguishable types: A, round pits with regular microvasculature; B, villous/ridge pits with regular microvasculature; C, absent pits with regular microvasculature; D, distorted pits with irregular microvasculature. The NBI-Z grading was compared with the final histopathological diagnosis, and positive (PPV) and negative predictive values (NPV) were calculated. The reproducibility of the grading was then assessed by NBI-expert and non-NBI-expert endoscopists, and interobserver and intraobserver agreement were calculated using kappa statistics. RESULTS: Per-biopsy analysis: In 903 out of 1021 distinct areas (87.9%) the NBI-Z grading corresponded to the histological diagnosis. Per-patient analysis: The PPV and NPV for type A pattern (columnar mucosa without intestinal metaplasia) were 100% and 97% respectively; for types B and C (intestinal metaplasia) they were 88% and 91% respectively, and for type D (high-grade dysplasia) 81% and 99% respectively. Inter- and intraobserver agreement: The mean kappa values in assessing the various patterns were 0.71 and 0.87 in the non-expert group; 0.78 and 0.91 in the expert group. CONCLUSIONS: This study has validated a simplified classification of the various morphologic patterns visualized in Barrett's esophagus and confirmed its reproducibility when used by NBI-expert and non-NBI-expert endoscopists.

Transgenic Leishmania and the immune response to infection.

Genetic manipulation of single-celled organisms such as the Leishmania parasite enables in depth analysis of the consequences of genotypic change on biological function. In probing the immune responses to infection, use of transgenic Leishmania has the potential to unravel both the contribution of the parasite to the infection process and the cellular interactions and mechanisms that characterize the innate and adaptive immune responses of the host. Here, we briefly review recent technical advances in parasite genetics and explore how these methods are being used to investigate parasite virulence factors, elucidate immune regulatory mechanisms and contribute to the development of novel therapeutics for the leishmaniases. Recent developments in imaging technology, such as bioluminescence and intravital imaging, combined with parasite transfection with fluorescent or enzyme-encoding marker genes, provides a rich opportunity for novel assessment of intimate, real-time host-parasite interactions at a previously unexplored level. Further advances in transgenic technology, such as the introduction of robust inducible gene cassettes for expression in intracellular parasite stages or the development of RNA interference methods for down-regulation of parasite gene expression in the host, will further advance our ability to probe host-parasite interactions and unravel disease-promoting mechanisms in the leishmaniases.

The role of dendritic cells in the induction and regulation of immunity to microbial infection.

Dendritic cells (DCs) play a critical role in the initiation and regulation of immune responses. Recent advances have begun to uncover the nature and diversity of DC-pathogen interactions and the modulation of DC function by microbial stimuli. Antigen pulsed DCs have also been shown in several infection models to induce high levels of protective immunity and to display immunotherapeutic potential. The study of the function of DCs in the response to infection is thus an exciting and rapidly expanding field with important implications for both fundamental and clinical immunology.

Novel endoscopic observation in Barrett's oesophagus using high resolution magnification endoscopy and narrow band imaging.

BACKGROUND: High resolution magnification endoscopy with narrow band imaging (NBI) may improve the detection of specialised intestinal metaplasia (SIM) and dysplasia in Barrett's oesophagus. AIMS: To describe the magnified endoscopic features with the use of NBI in Barrett's oesophagus. METHODS: Three hundred and forty-four areas from 50 patients with Barrett's oesophagus were studied using high resolution magnification endoscopy (HRME) with NBI and targeted biopsies were obtained. The sensitivity, specificity, predictive values of the various patterns for the prediction of SIM and dysplasia were calculated. RESULTS: The magnified endoscopic features of Barrett's oesophagus with the use of NBI consist of microstructural/microvascular patterns. The yield of SIM according to the patterns was: (i) Regular microstructural pattern with tubular/linear/villous pattern 90.6% and with circular pattern 0%; and (ii) Absent microstructural pattern 98.9%. The sensitivity, specificity, positive and negative predictive values of the combination of regular microstructural pattern (tubular/villous/linear) and absent microstructural pattern to detect SIM were 100%, 78.8%, 93.5% and 100%, respectively. The sensitivity, specificity, positive and negative predictive values of the irregular microvascular/microstructural pattern for the prediction of high grade dysplasia were 90%, 100%, 99.2% and 100%, respectively. CONCLUSION: High resolution magnification endoscopy with NBI allows clear visualisation of microstructural and microvascular patterns within Barrett's oesophagus, and allows targeted biopsy with a high yield of SIM and high grade dysplasia.

High-resolution magnification endoscopy can reliably identify normal gastric mucosa, Helicobacter pylori-associated gastritis, and gastric atrophy.

BACKGROUND AND STUDY AIMS: The aims of the study were to describe the magnified endoscopic findings in the gastric body, correlate these with histology, and evaluate their reproducibility in the assessment of the magnified endoscopic patterns seen. PATIENTS AND METHODS: A total of 95 consecutive dyspeptic patients underwent upper gastrointestinal endoscopy with a magnifying endoscope. The endoscopists classified the magnified endoscopic patterns and correlated them with the histological findings. In the second part of the study, 200 images were shown to five endoscopists in order to examine inter- and intraobserver variability in image assessment. RESULTS: The magnified endoscopic findings in the gastric body were categorized into four types: type 1, honeycomb-type subepithelial capillary network (SECN) with regular arrangement of collecting venules and regular, round pits; type 2, honeycomb-type SECN with regular, round pits, but loss of collecting venules; type 3, loss of normal SECN and collecting venules, with enlarged white pits surrounded by erythema; and type 4, loss of normal SECN and round pits, with irregular arrangement of collecting venules. The sensitivity, specificity, and positive and negative predictive values of the type 1 pattern for predicting normal gastric mucosa were 92.7% (95% confidence interval [CI] 93.2-97.3%), 100% (95% CI 83.9-100%), 100% (95% CI 92.9-100%), and 83.8% (95% CI 65.5-93.9%). The sensitivity, specificity, and positive and negative predictive values of types 2 and 3 patterns for predicting a Helicobacter pylori-infected stomach were 100% (95% CI 83.9-100%), 92.7% (95% CI 93.2-97.3%), 83.8% (95% CI 65.5-93.9%), and 100% (95% CI 92.9-100%). The sensitivity, specificity, and positive and negative predictive values of a type 4 pattern for predicting gastric atrophy were 90% (95% CI 66.8-98.2%), 96% (95% CI 87.9-98.9%), 85.7% (95% CI 62.6-96.2%), and 97.3% (95% CI 89.6-99.5%. The kappa values for inter- and intraobserver agreement in predicting normal gastric mucosa, H. pylori gastritis, and gastric atrophy were 0.864 and 0.913 respectively. CONCLUSION: High-resolution magnification endoscopy can reliably identify the normal gastric mucosa, H. pylori-associated gastritis, and gastric atrophy in a Western population.

Building confidence in quantitative systems pharmacology models: An engineer's guide to exploring the rationale in model design and development.

This tutorial promotes good practice for exploring the rationale of systems pharmacology models. A safety systems engineering inspired notation approach provides much needed rigor and transparency in development and application of models for therapeutic discovery and design of intervention strategies. Structured arguments over a model's development, underpinning biological knowledge, and analyses of model behaviors are constructed to determine the confidence that a model is fit for the purpose for which it will be applied.

Postoperative survival following perioperative MAGIC versus neoadjuvant OE02-type chemotherapy in oesophageal adenocarcinoma.

The optimal management of resectable oesophageal adenocarcinoma is controversial, with many centres using neoadjuvant chemotherapy following the Medical Research Council (MRC) oesophageal working group (OE02) trial and the MRC Adjuvant Gastric Infusional Chemotherapy (MAGIC) trial. The more intensive MAGIC regimen is used primarily in gastric cancer but some also use it for oesophageal cancer. A database of cancer resections (2001-2013) provided information on survival of patients following either OE02 or MAGIC-type treatment. The data were compared using Kaplan-Meier analysis. Straight-to-surgery patients were also reviewed and divided into an 'early' cohort (2001-2006, OE02 era) and a 'late' cohort (2006-2013, MAGIC era) to estimate changes in survival over time. Subgroup analysis was performed for responders (tumour regression grade [TRG] 1-3) versus non-responders (TRG 4 and 5) and for anatomical site (gastro-oesophageal junction [GOJ] vs oesophagus). An OE02 regimen was used for 97 patients and 275 received a MAGIC regimen. Those in the MAGIC group were of a similar age to those undergoing OE02 chemotherapy but the proportion of oesophageal cancers was higher among MAGIC patients than among those receiving OE02 treatment. MAGIC patients had a significantly lower stage following chemotherapy than OE02 patients and a higher median overall survival although TRG was similar. On subgroup analysis, this survival benefit was maintained for GOJ and oesophageal cancer patients as well as non-responders. Analysis of responders showed no difference between regimens. 'Late' group straight-to-surgery patients were significantly older than those in the 'early' group. Survival, however, was not significantly different for these two cohorts. Although the original MAGIC trial comprised few oesophageal cancer cases, our patients had better survival with MAGIC than with OE02 chemotherapy in all anatomical subgroups, even though there was no significant change in operative survival over the time period in which these patients were treated. The use of the MAGIC regimen should therefore be encouraged in cases of operable oesophagogastric adenocarcinoma.