| 1. |
- Heidsma, Charlotte M, et al.
(författare)
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International Validation of a Nomogram to Predict Recurrence after Resection of Grade 1 and 2 Nonfunctioning Pancreatic Neuroendocrine Tumors
- 2022
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Ingår i: Neuroendocrinology. - : S. Karger. - 0028-3835 .- 1423-0194. ; 112:6, s. 571-579
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Despite the low recurrence rate of resected nonfunctional pancreatic neuroendocrine tumors (NF-pNETs), nearly all patients undergo long-term surveillance. A prediction model for recurrence may help select patients for less intensive surveillance or identify patients for adjuvant therapy. The objective of this study was to assess the external validity of a recently published model predicting recurrence within 5 years after surgery for NF-pNET in an international cohort. This prediction model includes tumor grade, lymph node status and perineural invasion as predictors.METHODS: Retrospectively, data were collected from 7 international referral centers on patients who underwent resection for a grade 1-2 NF-pNET between 1992 and 2018. Model performance was evaluated by calibration statistics, Harrel's C-statistic, and area under the curve (AUC) of the receiver operating characteristic curve for 5-year recurrence-free survival (RFS). A sub-analysis was performed in pNETs >2 cm. The model was improved to stratify patients into 3 risk groups (low, medium, high) for recurrence.RESULTS: Overall, 342 patients were included in the validation cohort with a 5-year RFS of 83% (95% confidence interval [CI]: 78-88%). Fifty-eight patients (17%) developed a recurrence. Calibration showed an intercept of 0 and a slope of 0.74. The C-statistic was 0.77 (95% CI: 0.70-0.83), and the AUC for the prediction of 5-year RFS was 0.74. The prediction model had a better performance in tumors >2 cm (C-statistic 0.80).CONCLUSIONS: External validity of this prediction model for recurrence after curative surgery for grade 1-2 NF-pNET showed accurate overall performance using 3 easily accessible parameters. This model is available via www.pancreascalculator.com.
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| 2. |
- Kazemahvazi, Sohrab, 1981-, et al.
(författare)
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Dynamic failure of clamped circular plates subjected to an underwater shock
- 2007
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Ingår i: Journal of Mechanics of Materials and Structures. - : Mathematical Sciences Publishers. - 1559-3959. ; 2:10, s. 2007-2023
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Tidskriftsartikel (refereegranskat)abstract
- Clamped circular copper plates have been subjected to exponentially decaying underwater blast waves with peak pressures in the range 10MPa to 300MPa and decay constants varying between 0.05ms to 1.1 ms. The deformation and failure modes were observed by high-speed photography. For the thin plates considered in this study, the failure modes were primarily governed by the peak pressures and were reasonably independent of the blast wave decay constant. Three modes of deformation and failure were identified. At low pressures, the plates undergo bending and stretching without rupture (mode I). At intermediate pressures a range of tensile tearing modes were observed, from petalling failures to tearing at the supports with increasing blast pressures. These tearing modes are referred to as mode II failures. At the highest pressures investigated here, the plate tears at the supports in a manner that is reminiscent of a shear-off failure. This failure is labeled as mode III. Scanning electron micrographs of the failure surfaces showed that in all cases, the local failure mechanism was tensile necking. Finite element (FE) simulations employing a local shear failure criterion are used to model the rupture of the material. Appropriately calibrated FE models capture all failure modes with sufficient fidelity.
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| 3. |
- Kazemahvazi, Sohrab, et al.
(författare)
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Impact Properties of Corrugated Composite Sandwich Cores
- 2010
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The out-of-plane impact properties of corrugated carbon fibre composite cores have been investigated experimentally. Cores with slender core members show dynamic strengthening of approximately 12 times compared to quasi-static experiments whereas cores with stocky core members show a dynamic strengthening of approximately 2 times. Carbon fibre corrugated cores have superior compressive performance in the density range of 100 kgm-3 to 300 kgm-3.
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| 4. |
- Klimstra, David S., et al.
(författare)
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Pathology reporting of neuroendocrine tumors : application of the Delphic consensus process to the development of a minimum pathology data set
- 2010
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Ingår i: American Journal of Surgical Pathology. - 0147-5185 .- 1532-0979. ; 34:3, s. 300-313
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Tidskriftsartikel (refereegranskat)abstract
- Epithelial neuroendocrine tumors (NETs) have been the subject of much debate regarding their optimal classification. Although multiple systems of nomenclature, grading, and staging have been proposed, none has achieved universal acceptance. To help define the underlying common features of these classification systems and to identify the minimal pathology data that should be reported to ensure consistent clinical management and reproducibility of data from therapeutic trials, a multidisciplinary team of physicians interested in NETs was assembled. At a group meeting, the participants discussed a series of "yes" or "no" questions related to the pathology of NETs and the minimal data to be included in the reports. After discussion, anonymous votes were taken, using the Delphic principle that 80% agreement on a vote of either yes or no would define a consensus. Questions that failed to achieve a consensus were rephrased once or twice and discussed, and additional votes were taken. Of 108 questions, 91 were answerable either yes or no by more than 80% of the participants. There was agreement about the importance of proliferation rate for tumor grading, the landmarks to use for staging, the prognostic factors assessable by routine histology that should be reported, the potential for tumors to progress biologically with metastasis, and the current status of advanced immunohistochemical and molecular testing for treatment-related biomarkers. The lack of utility of a variety of immunohistochemical stains and pathologic findings was also agreed upon. A consensus could not be reached for the remaining 17 questions, which included both minor points related to extent of disease assessment and some major areas such as terminology, routine immunohistochemical staining for general neuroendocrine markers, use of Ki67 staining to assess proliferation, and the relationship of tumor grade to degree of differentiation. On the basis of the results of the Delphic voting, a minimum pathology data set was developed. Although there remains disagreement among experts about the specific classification system that should be used, there is agreement about the fundamental pathology data that should be reported. Examination of the areas of disagreement reveals significant opportunities for collaborative study to resolve unanswered questions.
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| 5. |
- Li, Constance H., et al.
(författare)
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Sex differences in oncogenic mutational processes
- 2020
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Sex differences have been observed in multiple facets of cancer epidemiology, treatment and biology, and in most cancers outside the sex organs. Efforts to link these clinical differences to specific molecular features have focused on somatic mutations within the coding regions of the genome. Here we report a pan-cancer analysis of sex differences in whole genomes of 1983 tumours of 28 subtypes as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium. We both confirm the results of exome studies, and also uncover previously undescribed sex differences. These include sex-biases in coding and non-coding cancer drivers, mutation prevalence and strikingly, in mutational signatures related to underlying mutational processes. These results underline the pervasiveness of molecular sex differences and strengthen the call for increased consideration of sex in molecular cancer research.
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| 6. |
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