Post-Operative Functional Outcomes in Early Age Onset Rectal Cancer

Background: Impairment of bowel, urogenital and fertility-related function in patients treated for rectal cancer is common. While the rate of rectal cancer in the young (<50 years) is rising, there is little data on functional outcomes in this group. Methods: The REACCT international collaborative database was reviewed and data on eligible patients analysed. Inclusion criteria comprised patients with a histologically confirmed rectal cancer, <50 years of age at time of diagnosis and with documented follow-up including functional outcomes. Results: A total of 1428 (n=1428) patients met the eligibility criteria and were included in the final analysis. Metastatic disease was present at diagnosis in 13%. Of these, 40% received neoadjuvant therapy and 50% adjuvant chemotherapy. The incidence of post-operative major morbidity was 10%. A defunctioning stoma was placed for 621 patients (43%); 534 of these proceeded to elective restoration of bowel continuity. The median follow-up time was 42 months. Of this cohort, a total of 415 (29%) reported persistent impairment of functional outcomes, the most frequent of which was bowel dysfunction (16%), followed by bladder dysfunction (7%), sexual dysfunction (4.5%) and infertility (1%). Conclusion: A substantial proportion of patients with early-onset rectal cancer who undergo surgery report persistent impairment of functional status. Patients should be involved in the discussion regarding their treatment options and potential impact on quality of life. Functional outcomes should be routinely recorded as part of follow up alongside oncological parameters

Characterisation of the flow around car wheels for a future optimisation of tyres

Cette thèse, collaboration entre Michelin et l’ONERA, propose de mettre en œuvre des simulations instationnaires URANS grâce au code Navier-Stokes elsA de l’ONERA en vue d’analyser l’écoulement complexe 3D instationnaire se développant au voisinage des roues d'un véhicule et d’identifier les mécanismes à l’origine de la production de traînée.En effet, les roues (jantes et pneumatiques) constituent un nouvel axe de recherche prometteur en aérodynamique automobile car on estime de 20% à 40% la contribution des roues et passages de roues à la traînée totale. Cependant, leur optimisation nécessite en premier lieu une compréhension complète des phénomènes aérodynamiques mis en jeu. Les analyses spatio-temporelles menées sur roue isolée et sur véhicule pour trois types de pneumatiques (lisse, rugueux, avec sillons) apportent de nouveaux éléments de compréhension sur la physique de l’écoulement. Ce travail répond notamment aux limites principales des études précédentes grâce à la description de l'écoulement sur des géométries de référence incluant des pneumatiques déformés lisses et grâce à l’étude de l’instationnarité. Les analyses spatiales permettent de décrire l’organisation des structures tourbillonnaires sur roue isolée puis autour des roues avant et arrière d’un véhicule simplifié. Les analyses temporelles facilitent quant à elles la compréhension de la dynamique de l’écoulement par la mise en évidence de la génération des tourbillons et des mécanismes d’interaction avec la carrosserie. Des validations expérimentales sont effectuées à la fois sur roue isolée et sur véhicule en soufflerie. Enfin, l’utilisation de plusieurs types de pneumatiques démontre leur capacité à modifier les caractéristiques spatio-temporelles de l’ensemble de l’écoulement et à jouer ainsi sur la puissance dissipée par le véhicule via la traînée et le moment de rotation des roues.As a collaborative task between Michelin and ONERA, this thesis aims to investigate the complex unsteady 3D flow around car wheels and to identify the mechanisms of drag production linked to this part of the car thanks to URANS unsteady numerical simulations using ONERA’s Navier-Stokes code elsA. The wheels (i.e. rims and tyres) are indeed a promising research topic in the field of car aerodynamics. The part of the total drag due to the wheels and wheelhouses is indeed estimated between 20% and 40%. The first step towards wheel optimisation is to achieve full understanding of the aerodynamic phenomena produced around them. The analysis of the flow for three types of tyres (smooth, rough, grooved), both around isolated wheels and around a simplified vehicle, brings further understanding of the flow physics. This work completes previous studies in this field thanks to the description of basic flows around smooth wheels and the study of unsteady effects. It describes the arrangement of vortical structures around an isolated wheel and around the front and rear wheels of a simplified vehicle. Moreover, the analysis of the flow unsteadiness facilitates understanding of the flow dynamics by highlighting the generation of the main vortices and the interaction phenomena with the car body. The validation of numerical models is performed with specific experiments by Michelin on both an isolated wheel and a vehicle configuration. Finally, the use of different tyres shows their ability to modify both space and time characteristics of the whole flow, thus modifying the power dissipated by the car drag and the rotation moment of the wheels

The Modeling of Roughness Effect on the Performance of a Controlled Diffusion Airfoil

peer reviewedThe manufacturing and operational roughness of aerodynamic profiles impacts both the laminar and the turbulent boundary layers state, directly affecting the aerodynamic and thermal performance of typical turbomachinery components. By better understanding the underlying physical mechanisms, the present work aims at building a more refined and comprehensive model to take the effects of surface finish into account. The model is implemented into the MIT Multiple Blade Interacting Streamtube Euler Solver (MISES) and is validated against experimental results for different roughness levels, Reynolds number, and Mach number regimes. In the proposed model, the roughness effects on the turbulent boundary layer (BL) state are included through the modification of the turbulent skin friction law, while the roughness level is implemented through a new definition of ks that accounts for the influence of the roughness skewness. Particular emphasis is placed on the modeling of the transitionally rough regime. Finally, roughness effects on transition are modeled by implementing the Mayle rough-induced onset transition criterion. Results are validated in terms of the total pressure loss coefficient and the outlet flow angle, leading to a marked improvement in terms of agreement with the experimental data

Comparison of Various CFD Codes for LES Simulations of Turbomachinery: From Inviscid Vortex Convection to Multi-Stage Compressor

peer reviewedSome possible future High Fidelity CFD codes for LES simulation of turbomachinery are compared on several test cases increasing in complexity, starting from a very simple inviscid Vortex Convection to a multistage axial experimental compressor. Simulations were performed between 2013 and 2016 by major Safran partners (Cenaero, Cerfacs, CORIA and Onera) and various numerical methods compared: Finite Volume, Discontinuous Galerkin, Spectral Differences. Comparison to analytical results, to experimental data or to RANS simulations are performed to check and measure accuracy. CPU efficiency versus accuracy are also presented. It clearly appears that the level of maturity could be different between codes and numerical approaches. In the end, advantages and disadvantages of every codes obtained during this project are presented

Characteristics of Early-Onset vs Late-Onset Colorectal Cancer: A Review.

ImportanceThe incidence of early-onset colorectal cancer (younger than 50 years) is rising globally, the reasons for which are unclear. It appears to represent a unique disease process with different clinical, pathological, and molecular characteristics compared with late-onset colorectal cancer. Data on oncological outcomes are limited, and sensitivity to conventional neoadjuvant and adjuvant therapy regimens appear to be unknown. The purpose of this review is to summarize the available literature on early-onset colorectal cancer.ObservationsWithin the next decade, it is estimated that 1 in 10 colon cancers and 1 in 4 rectal cancers will be diagnosed in adults younger than 50 years. Potential risk factors include a Westernized diet, obesity, antibiotic usage, and alterations in the gut microbiome. Although genetic predisposition plays a role, most cases are sporadic. The full spectrum of germline and somatic sequence variations implicated remains unknown. Younger patients typically present with descending colonic or rectal cancer, advanced disease stage, and unfavorable histopathological features. Despite being more likely to receive neoadjuvant and adjuvant therapy, patients with early-onset disease demonstrate comparable oncological outcomes with their older counterparts.Conclusions and relevanceThe clinicopathological features, underlying molecular profiles, and drivers of early-onset colorectal cancer differ from those of late-onset disease. Standardized, age-specific preventive, screening, diagnostic, and therapeutic strategies are required to optimize outcomes

Characteristics of Early-Onset vs Late-Onset Colorectal Cancer: A Review.

ImportanceThe incidence of early-onset colorectal cancer (younger than 50 years) is rising globally, the reasons for which are unclear. It appears to represent a unique disease process with different clinical, pathological, and molecular characteristics compared with late-onset colorectal cancer. Data on oncological outcomes are limited, and sensitivity to conventional neoadjuvant and adjuvant therapy regimens appear to be unknown. The purpose of this review is to summarize the available literature on early-onset colorectal cancer.ObservationsWithin the next decade, it is estimated that 1 in 10 colon cancers and 1 in 4 rectal cancers will be diagnosed in adults younger than 50 years. Potential risk factors include a Westernized diet, obesity, antibiotic usage, and alterations in the gut microbiome. Although genetic predisposition plays a role, most cases are sporadic. The full spectrum of germline and somatic sequence variations implicated remains unknown. Younger patients typically present with descending colonic or rectal cancer, advanced disease stage, and unfavorable histopathological features. Despite being more likely to receive neoadjuvant and adjuvant therapy, patients with early-onset disease demonstrate comparable oncological outcomes with their older counterparts.Conclusions and relevanceThe clinicopathological features, underlying molecular profiles, and drivers of early-onset colorectal cancer differ from those of late-onset disease. Standardized, age-specific preventive, screening, diagnostic, and therapeutic strategies are required to optimize outcomes

Post-Operative Functional Outcomes in Early Age Onset Rectal Cancer

BackgroundImpairment of bowel, urogenital and fertility-related function in patients treated for rectal cancer is common. While the rate of rectal cancer in the young (<50 years) is rising, there is little data on functional outcomes in this group.MethodsThe REACCT international collaborative database was reviewed and data on eligible patients analysed. Inclusion criteria comprised patients with a histologically confirmed rectal cancer, <50 years of age at time of diagnosis and with documented follow-up including functional outcomes.ResultsA total of 1428 (n=1428) patients met the eligibility criteria and were included in the final analysis. Metastatic disease was present at diagnosis in 13%. Of these, 40% received neoadjuvant therapy and 50% adjuvant chemotherapy. The incidence of post-operative major morbidity was 10%. A defunctioning stoma was placed for 621 patients (43%); 534 of these proceeded to elective restoration of bowel continuity. The median follow-up time was 42 months. Of this cohort, a total of 415 (29%) reported persistent impairment of functional outcomes, the most frequent of which was bowel dysfunction (16%), followed by bladder dysfunction (7%), sexual dysfunction (4.5%) and infertility (1%).ConclusionA substantial proportion of patients with early-onset rectal cancer who undergo surgery report persistent impairment of functional status. Patients should be involved in the discussion regarding their treatment options and potential impact on quality of life. Functional outcomes should be routinely recorded as part of follow up alongside oncological parameters

La défense sociale et la nouvelle pénologie comme outils d'analyse de la conception du libéré conditionnel dans la législation belge (1888-2006)

Importance The incidence of early-onset colorectal cancer (younger than 50 years) is rising globally, the reasons for which are unclear. It appears to represent a unique disease process with different clinical, pathological, and molecular characteristics compared with late-onset colorectal cancer. Data on oncological outcomes are limited, and sensitivity to conventional neoadjuvant and adjuvant therapy regimens appear to be unknown. The purpose of this review is to summarize the available literature on early-onset colorectal cancer. Observations Within the next decade, it is estimated that 1 in 10 colon cancers and 1 in 4 rectal cancers will be diagnosed in adults younger than 50 years. Potential risk factors include a Westernized diet, obesity, antibiotic usage, and alterations in the gut microbiome. Although genetic predisposition plays a role, most cases are sporadic. The full spectrum of germline and somatic sequence variations implicated remains unknown. Younger patients typically present with descending colonic or rectal cancer, advanced disease stage, and unfavorable histopathological features. Despite being more likely to receive neoadjuvant and adjuvant therapy, patients with early-onset disease demonstrate comparable oncological outcomes with their older counterparts. Conclusions and Relevance The clinicopathological features, underlying molecular profiles, and drivers of early-onset colorectal cancer differ from those of late-onset disease. Standardized, age-specific preventive, screening, diagnostic, and therapeutic strategies are required to optimize outcomes