Anti-tumor CD8+ T cells are a key determinant for overall survival in patients following surgical resection for solid malignancies. Using a mouse model of cancer vaccination (adenovirus expressing melanoma tumor-associated antigen (TAA)—dopachrome tautomerase (AdDCT) and resection resulting in major surgical stress (abdominal nephrectomy), we demonstrate that surgical stress results in a reduction in the number of CD8+ T cell that produce cytokines (IFNγ, TNFα, Granzyme B) in response to TAA. This effect is secondary to both reduced proliferation and impaired T cell function following antigen binding. In a prophylactic model, surgical stress completely abrogates tumor protection conferred by vaccination in the immediate postoperative period. In a clinically relevant surgical resection model, vaccinated mice undergoing a positive margin resection with surgical stress had decreased survival compared to mice with positive margin resection alone. Preoperative immunotherapy with IFNα significantly extends survival in surgically stressed mice. Importantly, myeloid derived suppressor cell (MDSC) population numbers and functional impairment of TAA-specific CD8+ T cell were altered in surgically stressed mice. Our observations suggest that cancer progression may result from surgery-induced suppression of tumor-specific CD8+ T cells. Preoperative immunotherapies aimed at targeting the prometastatic effects of cancer surgery will reduce recurrence and improve survival in cancer surgery patients.

Multicenter preclinical studies have been suggested as a method to improve reproducibility, generalizability and potential clinical translation of preclinical work. In these studies, multiple independent laboratories collaboratively conduct a research experiment using a shared protocol. The use of a multicenter design in preclinical experimentation is a recent approach and only a handful of preclinical multicenter studies have been published. Here, we systematically identify, assess and synthesize published preclinical multicenter studies investigating interventions using in vivo models. Synthesized data included study methods/design, basic characteristics, outcomes, and barriers and facilitators. Study risk of bias, completeness of reporting and the degree of collaboration were evaluated using established methods. The database searches identified 3095 citations and 12 studies met inclusion criteria. The multicenter study design was applied across a diverse range of diseases including stroke, heart attack, traumatic brain injury, and diabetes. The median number of centers was 4 (range 2-6) and the median sample size was 135 (range 23-384). Most studies had lower risk of bias and higher completeness of reporting than typically seen in single-centered studies. Only four of the twelve studies produced results consistent with previous single-center studies, highlighting a central concern of preclinical research: irreproducibility and poor generalizability of findings from single laboratories. Our review suggests that multicenter preclinical studies may provide a method to robustly assess therapies prior to considering clinical translation. Registered with PROSPERO CRD42018093986.

Despite decades of preclinical research, no experimentally derived therapies for sepsis have been successfully adopted into routine clinical practice. Factors that contribute to this crisis of translation include poor representation by preclinical models of the complex human condition of sepsis, bias in preclinical studies, as well as limitations of single-laboratory methodology. To overcome some of these shortcomings, multicentre preclinical studies—defined as a research experiment conducted in two or more research laboratories with a common protocol and analysis—are expected to maximize transparency, improve reproducibility, and enhance generalizability. The ultimate objective is to increase the efficiency and efficacy of bench-to-bedside translation for preclinical sepsis research and improve outcomes for patients with life-threatening infection. To this end, we organized the first meeting of the National Preclinical Sepsis Platform (NPSP). This multicentre preclinical  research collaboration of Canadian sepsis researchers and stakeholders was established to study the pathophysiology of sepsis and accelerate movement of promising therapeutics into early phase clinical trials. Integrated knowledge translation and shared decision-making were emphasized to ensure the goals of the platform align with clinical researchers and patient partners. 29 participants from 10 independent labs attended and discussed four main topics: (1) objectives of the platform; (2) animal models of sepsis; (3) multicentre methodology and (4) outcomes for evaluation. A PIRO model (predisposition, insult, response, organ dysfunction) for experimental design was proposed to strengthen linkages with interdisciplinary researchers and key stakeholders. This platform represents an important resource for maximizing translational impact of preclinical sepsis research.

Background: Multicentric approaches are widely used in clinical trials to assess generalizability of findings, however they are novel in laboratory-based experimentation. It is unclear how multilaboratory studies may differ in conduct and results from single lab studies. Here we synthesized characteristics of these studies and quantitatively compared their outcomes to those generated by single laboratory studies.Methods: MEDLINE and Embase were systematically searched. Screening and data extractions were completed in duplicate by independent reviewers. Multilaboratory studies investigating interventions using in vivo animal models were included. Study characteristics were extracted. Systematic searches were then performed to identify single center studies matched by intervention and disease. Difference in standardized mean differences (DSMD) was then calculated across studies to assess differences in effect estimates based on study design (>0 indicates larger effects in single center studies).Results: Sixteen multilaboratory studies met inclusion criteria and were matched to 100 single center studies. The multicenter study design was applied across a diverse range of diseases, including traumatic brain injury, myocardial infarction, and diabetes. The median number of centers was 4 (range 2-6) and the median sample size was 111 (range 23-384) with rodents most frequently used. Multicenter studies adhered to practices that reduce risk of bias significantly more often than single center studies. Multicenter studies also demonstrated significantly smaller effect sizes than single center studies (DSMD 0.72 [95% confidence interval 0.43-1]).Conclusion: Multilaboratory studies demonstrate trends that have been well recognized in clinical research (i.e. smaller treatment effects with multicentric evaluation and greater rigour in study design). This approach may provide a method to robustly assess interventions and generalizability of findings between laboratories.Funding: uOttawa Junior Clinical Research Chair; The Ottawa Hospital Anesthesia Alternate Funds Association; Canadian Anesthesia Research Foundation; Government of Ontario Queen Elizabeth II Graduate Scholarship in Science and Technology.Clinical trial registration: PROSPERO CRD4201809398.