Programme Hospitalier Recherche Clinique, Institut Pasteur, Inserm, French Public Health Agency.

Purpose: Patient-derived xenograft models are considered to represent the heterogeneity of human cancers and advanced preclinical models. Our consortium joins efforts to extensively develop and characterize a new collection of patient-derived colorectal cancer (CRC) models.Experimental Design: From the 85 unsupervised surgical colorectal samples collection, 54 tumors were successfully xenografted in immunodeficient mice and rats, representing 35 primary tumors, 5 peritoneal carcinoses and 14 metastases. Histologic and molecular characterization of patient tumors, first and late passages on mice includes the sequence of key genes involved in CRC (i.e., APC, KRAS, TP53), aCGH, and transcriptomic analysis.Results: This comprehensive characterization shows that our collection recapitulates the clinical situation about the histopathology and molecular diversity of CRC. Moreover, patient tumors and corresponding models are clustering together allowing comparison studies between clinical and preclinical data. Hence, we conducted pharmacologic monotherapy studies with standard of care for CRC (5-fluorouracil, oxaliplatin, irinotecan, and cetuximab). Through this extensive in vivo analysis, we have shown the loss of human stroma cells after engraftment, observed a metastatic phenotype in some models, and finally compared the molecular profile with the drug sensitivity of each tumor model. Through an experimental cetuximab phase II trial, we confirmed the key role of KRAS mutation in cetuximab resistance.Conclusions: This new collection could bring benefit to evaluate novel targeted therapeutic strategies and to better understand the basis for sensitivity or resistance of tumors from individual patients.

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Objectives: To study the effects of physical stimulation based on walking exercises, equilibrium and endurance on cognitive function and walking efficiency in patients with dementia. Methods: Randomized controlled trial including 31 subjects suffering from dementia (age: 81.8 ± 5.3 years). The intervention group (n = 16) benefited from a 15-week physical activity programme involving three 1-hour sessions per week. The control group (n = 15) did not practice any physical activities. Before and after rehabilitation, all subjects were evaluated with the Rapid Evaluation of Cognitive Functions test (ERFC French version) and walking analysis. Results: After the 15 weeks of rehabilitation, the subjects from the intervention group improved their overall ERFC score (p < 0.01), while those in the control group decreased their overall ERFC score. Interactions were also observed between walking parameters and groups (p < 0.01); the intervention group improved walking capacities through heightened walking speed, stride length and a reduction in double limb support time. Lastly, the subjects from the control group presented a reduction in both walking speed and stride length. Conclusion: This study shows that a physical activity programme can slow cognitive decline and improve quality of walking in elderly persons suffering from dementia.

Peri-operative SARS-CoV-2 infection increases postoperative mortality. The aim of this study was to determine the optimal duration of planned delay before surgery in patients who have had SARS-CoV-2 infection. This international, multicentre, prospective cohort study included patients undergoing elective or emergency surgery during October 2020. Surgical patients with pre-operative SARS-CoV-2 infection were compared with those without previous SARS-CoV-2 infection. The primary outcome measure was 30-day postoperative mortality. Logistic regression models were used to calculate adjusted 30-day mortality rates stratified by time from diagnosis of SARS-CoV-2 infection to surgery. Among 140,231 patients (116 countries), 3127 patients (2.2%) had a pre-operative SARS-CoV-2 diagnosis. Adjusted 30-day mortality in patients without SARS-CoV-2 infection was 1.5% (95%CI 1.4-1.5). In patients with a pre-operative SARS-CoV-2 diagnosis, mortality was increased in patients having surgery within 0-2 weeks, 3-4 weeks and 5-6 weeks of the diagnosis (odds ratio (95%CI) 4.1 (3.3-4.8), 3.9 (2.6-5.1) and 3.6 (2.0-5.2), respectively). Surgery performed ≥ 7 weeks after SARS-CoV-2 diagnosis was associated with a similar mortality risk to baseline (odds ratio (95%CI) 1.5 (0.9-2.1)). After a ≥ 7 week delay in undertaking surgery following SARS-CoV-2 infection, patients with ongoing symptoms had a higher mortality than patients whose symptoms had resolved or who had been asymptomatic (6.0% (95%CI 3.2-8.7) vs. 2.4% (95%CI 1.4-3.4) vs. 1.3% (95%CI 0.6-2.0), respectively). Where possible, surgery should be delayed for at least 7 weeks following SARS-CoV-2 infection. Patients with ongoing symptoms ≥ 7 weeks from diagnosis may benefit from further delay.

Recurrent clinical episode of Crohn's disease, preoperative steroids use, poor nutritional status, and the presence of abscess at the time of surgery significantly increased the risk of septic abdominal complications after first ileocecal resection for Crohn's disease. Knowledge of these risk factors could permit to propose a temporary stoma in very high-risk patients (i.e., with 3 or more risk factors).

LBA3503 Background: Promising results have been obtained during the last decade using cytoreductive surgery (CRS) plus HIPEC for selected patients with colorectal PC who are amenable to complete macroscopic resection. This is the first trial to evaluate the specific role of HIPEC, after CRS, for the treatment of PC of colorectal origin. Methods: Prodige 7 is a randomized phase III, multicenter trial. Patients with histologically proven and isolated PC, peritoneal cancer index (PCI) ≤25 were eligible. Randomization (1:1) was stratified by center, complete macroscopic resection (R0/1 vs R2), and neoadjuvant systemic chemotherapy. Patients were treated with CRS plus HIPEC with oxaliplatin or CRS alone, in association with systemic chemotherapy. The primary endpoint was the overall survival (OS). Secondary endpoints were relapse-free survival (RFS) and toxicity. 264 patients were required to show a gain in median OS from 30 to 48 months (HR = 0.625) with a two-sided α = 0,046 and 80% power. Results: 265 patients from 17 centers were included between February 2008 and January 2014: 132 in Arm without HIPEC and 133 in Arm with HIPEC. The median age was 60 years (range: 30-74). Baseline characteristics were well balanced. The overall post-operative mortality rate was 1.5% and was not different between the two arms. The morbidity rates did not differ statistically at 30 days. At 60 days, the grade 3-5 morbidity rate was significantly higher with HIPEC (24.1% vs. 13.6%, p= 0.030). After a median follow up of 63.8 months (95% CI: 58.9-69.8), the median OS was 41.2 months (95% CI 35.1-49.7) in the non-HIPEC Arm and 41.7 months (95% CI: 36.2-52.8) in the HIPEC Arm, HR = 1.00 (95% CI: 0.73-1.37) p = 0.995. The median RFS was 11.1 months (95% CI: 9-12.7) in non-HIPEC Arm and 13.1 months (95% CI: 12.1-15.7) in HIPEC Arm, HR = 0.90 (95% CI: 0.69-1.90) (p = 0.486), whilst the 1-year RFS rates were 46.1% in non-HIPEC Arm and 59 % in the HIPEC Arm. Conclusions: The therapeutic curative management of PC from colorectal cancer by CRS shows satisfactory survival results. While the addition of HIPEC with oxaliplatin does not influence the OS. Clinical trial information: NCT00769405.