244 research outputs found

    Clonal Patterns Between Pouch Neoplasia and Prior Colorectal Neoplasia in Inflammatory Bowel Disease Patients:An Exploratory Cohort Study

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    Prior colorectal neoplasia is the strongest predictor of pouch neoplasia in inflammatory bowel disease, but the underlying mechanism is unknown. We observed clonality between colorectal and pouch neoplasia in 30% of patients, indicating that most pouch neoplasia develops clonally independent from prior colorectal lesions.</p

    Differences in treatment of stage I colorectal cancers:A population-based study of colorectal cancers detected within and outside of a screening program

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    Background:Screen-detected colorectal cancers (CRCs) are often treated less invasively than stage-matched nonscreen-detected CRCs, but the reasons for this are not fully understood. This study evaluated the treatment of stage I CRCs detected within and outside of the screening program in the Netherlands. Methods:Data from the Netherlands Cancer Registry for all stage I CRCs diagnosed between January 1, 2008 and December 31, 2020 were analyzed, comparing patient, tumor, and treatment characteristics of screen-detected and nonscreen-detected stage I CRCs. Multivariable logistic regression was used to assess the association between treatment (local excision only vs. surgical oncologic resection) and patient and tumor characteristics, stratified for T stage and tumor location. Results:Screen-detected stage I CRCs were relatively more often T1 than T2 compared with non-screen-detected stage I CRCs (66.9 % vs. 53.3 %; P 0.001). When only T1 tumors were considered, both screen-detected colon and rectal cancers were more often treated with local excision only than non-screen-detected T1 cancers (odds ratio [OR] 2.19, 95%CI 1.93 2.49; and OR 1.29, 95 %CI 1.05 1.59, respectively), adjusted for sex, tumor location, lymphovascular invasion (LVI) status, and tumor differentiation. Conclusions:Less invasive treatment of screen-detected stage I CRC is partly explained by the higher rate of T1 cancers compared with non-screen-detected stage I CRCs. T1 stage I screen-detected CRCs were also more likely to undergo less invasive treatment than non-screen-detected CRCs, adjusted for risk factors such as LVI and tumor differentiation. Future research should investigate whether the choice of local excision was related to unidentified cancerrelated factors or the expertise of the endoscopists.</p

    Application profiling and resource management for MapReduce

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    Scale of data generated and processed is exponential growth in the Big Data ear. It poses a challenge that is far beyond the goal of a single computing system. Processing such vast amount of data on a single machine is impracticable in term of time or cost. Hence, distributed systems, which can harness very large clusters of commodity computers and processing data within restrictive time deadlines, are imperative. In this thesis, we target two aspects of distributed systems: application profiling and resource management. We study a MapReduce system in detail, which is a programming paradigm for large scale distributed computing, and presents solutions to tackle three key problems. Firstly, this thesis analyzes the characteristics of jobs running on the MapReduce system to reveal the problem—the Application scope of MapReduce has been extended beyond the original design goal that was large-scale data processing. This problem enables us to present a Workload Characteristic Oriented Scheduler (WCO), which strives for co-locating tasks of possibly different MapReduce jobs with complementing resource usage characteristics. Secondly, this thesis studies the current job priority mechanism focusing on resource management. In the MapReduce system, job priority only exists at scheduling level. High priority jobs are placed at the front of the scheduling queue and dispatched first. Resource, however, is fairly shared among jobs running at the same worker node without any consideration for their priorities. In order to resolve this, this thesis presents a non-intrusive slot layering solution, which dynamically allocates resource between running jobs based on their priority and efficiently reduces the execution time of high priority jobs while improves overall throughput. Last, based on the fact of underutilization of resource at each individual worker node, this thesis propose a new way, Local Resource Shaper (LRS), to smooth resource consumption of each individual job by automatically tuning the execution of concurrent jobs to maximize resource utilization while minimizing resource contention

    Pathologists' first opinions on barriers and facilitators of computational pathology adoption in oncological pathology: an international study.

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    Computational pathology (CPath) algorithms detect, segment or classify cancer in whole slide images, approaching or even exceeding the accuracy of pathologists. Challenges have to be overcome before these algorithms can be used in practice. We therefore aim to explore international perspectives on the future role of CPath in oncological pathology by focusing on opinions and first experiences regarding barriers and facilitators. We conducted an international explorative eSurvey and semi-structured interviews with pathologists utilizing an implementation framework to classify potential influencing factors. The eSurvey results showed remarkable variation in opinions regarding attitude, understandability and validation of CPath. Interview results showed that barriers focused on the quality of available evidence, while most facilitators concerned strengths of CPath. A lack of consensus was present for multiple factors, such as the determination of sufficient validation using CPath, the preferred function of CPath within the digital workflow and the timing of CPath introduction in pathology education. The diversity in opinions illustrates variety in influencing factors in CPath adoption. A next step would be to quantitatively determine important factors for adoption and initiate validation studies. Both should include clear case descriptions and be conducted among a more homogenous panel of pathologists based on sub specialization

    The Importance of the Pathologist’s Role in Assessment of the Quality of the Mesorectum

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    Total mesorectal excision (TME) is considered standard of care for rectal cancer treatment. Failure to remove the mesorectal fat envelope entirely may explain part of observed local and distant recurrences. Several studies suggest quality of the mesorectum after TME surgery as determined by pathological evaluation may influence prognosis. We aimed to determine the prognostic value of the plane of surgery as well as factors influencing the likelihood of a high-quality specimen by reviewing the literature. A pooled meta-analysis of relevant outcome data was performed where appropriate. A muscularis propria resection plane was found to increase the risk of local recurrence (RR 2.72 [95 % CI 1.36 to 5.44]) and overall recurrence (RR 2.00 [95 % CI 1.17 to 3.42]) compared to an (intra)mesorectal plane. Plane of surgery is an important factor in rectal cancer treatment and the documentation by pathologists is essential for the improvement of TME quality and patient outcome

    Socio-demographic and cultural factors related to non-participation in the Dutch colorectal cancer screening programme

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    BackgroundHigh participation rates are essential for a screening programme to be beneficial. To reach non-participants in a targeted manner, insight in characteristics of non-participants is needed. We investigated demographic differences between participants and non-participants in the Dutch faecal immunochemical test-based colorectal cancer (CRC) screening programme.MethodsIn this population-based cohort study, we included all invitees for CRC screening in 2018 and 2019. Participation status, birth year, and sex were extracted from the Dutch national screening information system and linked to demographic characteristics from Statistics Netherlands, including migration background, level of education, socioeconomic category, household composition, and household income. A multivariable logistic regression was used to assess the association between demographic factors and participation.ResultsA total of 4,383,861 individuals were invited for CRC screening in 2018 and 2019, of which 3,170,349 (72.3%) participated. Individuals were less likely to participate when they were single and/or living with others (single with other residents versus couple: odds ratio [OR] 0.34, 95% confidence interval [CI]: 0.31–0.38), had a migration background (e.g. Moroccan migrant versus Dutch background: OR 0.43, 95% CI: 0.42–0.44), or had a low income (lowest versus highest quintile: OR 0.45, 95% CI: 0.44–0.45). Although to a lesser extent, non-participation was also significantly associated with being male, being younger, receiving social welfare benefits and having a low level of education.ConclusionWe found that individuals who were single and/or living with others, immigrants from Morocco or individuals with low income were the least likely to participate in the Dutch CRC screening programme. Targeted interventions are needed to minimise inequities in CRC screening.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

    Endoscopic and surgical treatment outcomes of colitis-associated advanced colorectal neoplasia:a multicenter cohort study

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    BACKGROUND: Inflammatory bowel disease (IBD) patients are at increased risk of advanced neoplasia (high-grade dysplasia or colorectal cancer). The authors aimed to (1) assess synchronous and metachronous neoplasia following (sub)total or proctocolectomy, partial colectomy or endoscopic resection for advanced neoplasia in IBD, and (2) identify factors associated with treatment choice. MATERIAL AND METHODS: In this retrospective multicenter cohort study, the authors used the Dutch nationwide pathology databank (PALGA) to identify patients diagnosed with IBD and colonic advanced neoplasia (AN) between 1991 and 2020 in seven hospitals in the Netherlands. Logistic and Fine &amp; Gray's subdistribution hazard models were used to assess adjusted subdistribution hazard ratios for metachronous neoplasia and associations with treatment choice. RESULTS: The authors included 189 patients (high-grade dysplasia n =81; colorectal cancer n =108). Patients were treated with proctocolectomy ( n =33), (sub)total colectomy ( n =45), partial colectomy ( n =56) and endoscopic resection ( n =38). Partial colectomy was more frequently performed in patients with limited disease and older age, with similar patient characteristics between Crohn's disease and ulcerative colitis. Synchronous neoplasia was found in 43 patients (25.0%; (sub)total or proctocolectomy n =22, partial colectomy n =8, endoscopic resection n =13). The authors found a metachronous neoplasia rate of 6.1, 11.5 and 13.7 per 100 patient-years after (sub)total colectomy, partial colectomy and endoscopic resection, respectively. Endoscopic resection, but not partial colectomy, was associated with an increased metachronous neoplasia risk (adjusted subdistribution hazard ratios 4.16, 95% CI 1.64-10.54, P &lt;0.01) compared with (sub)total colectomy. CONCLUSION: After confounder adjustment, partial colectomy yielded a similar metachronous neoplasia risk compared to (sub)total colectomy. High metachronous neoplasia rates after endoscopic resection underline the importance of strict subsequent endoscopic surveillance.</p

    Endoscopic and surgical treatment outcomes of colitis-associated advanced colorectal neoplasia:a multicenter cohort study

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    BACKGROUND: Inflammatory bowel disease (IBD) patients are at increased risk of advanced neoplasia (high-grade dysplasia or colorectal cancer). The authors aimed to (1) assess synchronous and metachronous neoplasia following (sub)total or proctocolectomy, partial colectomy or endoscopic resection for advanced neoplasia in IBD, and (2) identify factors associated with treatment choice.MATERIAL AND METHODS: In this retrospective multicenter cohort study, the authors used the Dutch nationwide pathology databank (PALGA) to identify patients diagnosed with IBD and colonic advanced neoplasia (AN) between 1991 and 2020 in seven hospitals in the Netherlands. Logistic and Fine &amp; Gray's subdistribution hazard models were used to assess adjusted subdistribution hazard ratios for metachronous neoplasia and associations with treatment choice.RESULTS: The authors included 189 patients (high-grade dysplasia n =81; colorectal cancer n =108). Patients were treated with proctocolectomy ( n =33), (sub)total colectomy ( n =45), partial colectomy ( n =56) and endoscopic resection ( n =38). Partial colectomy was more frequently performed in patients with limited disease and older age, with similar patient characteristics between Crohn's disease and ulcerative colitis. Synchronous neoplasia was found in 43 patients (25.0%; (sub)total or proctocolectomy n =22, partial colectomy n =8, endoscopic resection n =13). The authors found a metachronous neoplasia rate of 6.1, 11.5 and 13.7 per 100 patient-years after (sub)total colectomy, partial colectomy and endoscopic resection, respectively. Endoscopic resection, but not partial colectomy, was associated with an increased metachronous neoplasia risk (adjusted subdistribution hazard ratios 4.16, 95% CI 1.64-10.54, P &lt;0.01) compared with (sub)total colectomy.CONCLUSION: After confounder adjustment, partial colectomy yielded a similar metachronous neoplasia risk compared to (sub)total colectomy. High metachronous neoplasia rates after endoscopic resection underline the importance of strict subsequent endoscopic surveillance.</p
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