Defining and targeting tumor-associated macrophages in malignant mesothelioma.

Defining the ontogeny of tumor-associated macrophages (TAM) is important to develop therapeutic targets for mesothelioma. We identified two distinct macrophage populations in mouse peritoneal and pleural cavities, the monocyte-derived, small peritoneal/pleural macrophages (SPM), and the tissue-resident large peritoneal/pleural macrophages (LPM). SPM rapidly increased in tumor microenvironment after tumor challenge and contributed to the vast majority of M2-like TAM. The selective depletion of M2-like TAM by conditional deletion of the Dicer1 gene in myeloid cells (D-/-) promoted tumor rejection. Sorted SPM M2-like TAM initiated tumorigenesis in vivo and in vitro, confirming their capacity to support tumor development. The transcriptomic and single-cell RNA sequencing analysis demonstrated that both SPM and LPM contributed to the tumor microenvironment by promoting the IL-2-STAT5 signaling pathway, inflammation, and epithelial-mesenchymal transition. However, while SPM preferentially activated the KRAS and TNF-α/NFkB signaling pathways, LPM activated the IFN-γ response. The importance of LPM in the immune response was confirmed by depleting LPM with intrapleural clodronate liposomes, which abrogated the antitumoral memory immunity. SPM gene signature could be identified in pleural effusion and tumor from patients with untreated mesothelioma. Five genes, TREM2, STAB1, LAIR1, GPNMB, and MARCO, could potentially be specific therapeutic targets. Accordingly, Trem2 gene deletion led to reduced SPM M2-like TAM with compensatory increase in LPM and slower tumor growth. Overall, these experiments demonstrate that SPM M2-like TAM play a key role in mesothelioma development, while LPM more specifically contribute to the immune response. Therefore, selective targeting of monocyte-derived TAM may enhance antitumor immunity through compensatory expansion of tissue-resident TAM.

Integrating Patient-Reported Outcomes Into Prognostication in Gastroesophageal Cancer: Results of a Population-Based Retrospective Cohort Analysis.

BACKGROUND: Patient-reported outcomes measures (PROM) are self-reflections of an individual's physical functioning and emotional well-being. The Edmonton Symptom Assessment Scale (ESAS) is a simple and validated PRO tool of 10 common symptoms and a patient-reported functional status (PRFS) measure. The prognostic value of this tool is unknown in patients with gastroesophageal cancer (GEC). In this study, we examined the association between the ESAS score and overall survival (OS) in patients with GEC, the prognostication difference between ESAS and Eastern Cooperative Oncology Group (ECOG), and assessed the correlation between PRFS and the physician-reported ECOG performance status (PS). METHODS: The study was a retrospective cohort study of 211 patients with GEC with localized (stages I-III) and metastatic disease who completed at least one baseline ESAS prior to treatment. Patients were grouped into 3 cohorts based on ESAS score. OS was assessed using the Kaplan-Meier method, and the concordance index (c-index) was calculated for ESAS and physician-reported ECOG. The agreement between PRFS and physician-ECOG was also assessed. RESULTS: In total, 211 patients were included. The median age was 60.8 years; 90% of patients were ECOG PS 0-1; 38% of patients were stages I-III, while 62% were de novo metastatic patients. Median OS in low, moderate, high symptom burden (SB) patients' cohorts was 19.17 m, 16.39 mm, and 12.68 m, respectively (P < .04). The ability to predict death was similar between physician-ECOG and ESAS (c-index 0.56 and 0.5753, respectively) and PRFS and physician-ECOG (c-index of 0.5615 and 0.5545, respectively). The PS agreement between patients and physicians was 50% with a weighted Kappa of 0.27 (95% CI: 0.17-0.38). CONCLUSION: Patient's SB seems to carry a prognostic significance. ESAS and physician-reported ECOG exhibit comparable prognostic values. Physicians and patients can frequently have divergent opinions on PS. ESAS takes a patient-centered approach and should be encouraged in practice among patients with GEC as an additional tool for prognostication.

Comparison of Four Clinical Prognostic Scores in Patients with Advanced Gastric and Esophageal Cancer.

BACKGROUND: Prognostic scores that can identify patients at risk for early death are needed to aid treatment decision-making and patient selection for clinical trials. We compared the accuracy of four scores to predict early death (within 90 days) and overall survival (OS) in patients with metastatic gastric and esophageal (GE) cancer. METHODS: Advanced GE cancer patients receiving first-line systemic therapy were included. Prognostic risks were calculated using: Royal Marsden Hospital (RMH), MD Anderson Cancer Centre (MDACC), Gustave Roussy Immune (GRIm-Score), and MD Anderson Immune Checkpoint Inhibitor (MDA-ICI) scores. Overall survival (OS) was estimated using the Kaplan-Meier method. Cox proportional hazards models were used to analyze associations between prognostic scores and OS. The predictive discrimination was estimated using Harrell's c-index. Predictive ability for early death was measured using time-dependent AUCs. RESULTS: In total, 451 patients with metastatic GE cancer were included. High risk patients had shorter OS for all scores (RMH high- vs. low-risk median OS 7.9 vs. 12.2 months, P < .001; MDACC 6.8 vs. 11.9 months P < .001; GRIm-Score 5.3 vs. 13 months, P < .001; MDA-ICI 8.2 vs. 12.2 months, P < .001). On multivariable analysis, each prognostic score was significantly associated with OS. The GRIm-Score had the highest predictive discrimination and predictive ability for early death. CONCLUSIONS: The GRIm-Score had the highest accuracy in predicting early death and OS. Clinicians may use this score to identify patients at higher risk of early death to guide treatment decisions including clinical trial enrolment. This score could also be used as a stratification factor in future clinical trial designs.

18F-FDG PET/MRI in Detection of Pulmonary Malignancies: A Systematic Review and Meta-Analysis.

Background There have been conflicting results regarding fluorine 18-labeled fluorodeoxyglucose (18F-FDG) PET/MRI diagnostic performance in lung malignant neoplasms. Purpose To evaluate the diagnostic performance of 18F-FDG PET/MRI for the detection of pulmonary malignant neoplasms. Materials and Methods A systematic search was conducted within the Scopus, Web of Science, and PubMed databases until December 31, 2021. Published original articles that met the following criteria were considered eligible for meta-analysis: (a) detecting malignant lesions in the lung, (b) comparing 18F-FDG PET/MRI with a valid reference standard, and (c) providing data for the meta-analytic calculations. A hierarchical method was used to pool the performances. The bivariate model was used to find the summary points and 95% CIs. The hierarchical summary receiver operating characteristic model was used to draw the summary receiver operating characteristic curve and calculate the area under the curve. The Higgins I2 statistic and Cochran Q test were used for heterogeneity assessment. Results A total of 43 studies involving 1278 patients met the inclusion criteria and were included in the meta-analysis. 18F-FDG PET/MRI had a pooled sensitivity and specificity of 96% (95% CI: 84, 99) and 100% (95% CI: 98, 100), respectively. 18F-FDG PET/CT had a pooled sensitivity and specificity of 99% (95% CI: 61, 100) and 99% (95% CI: 94, 100), respectively, which were comparable with those of 18F-FDG PET/MRI. At meta-regression, studies in which contrast media (P = .03) and diffusion-weighted imaging (P = .04) were used as a part of a pulmonary 18F-FDG PET/MRI protocol showed significantly higher sensitivities. Conclusion Fluorine 18-labeled fluorodeoxyglucose (18F-FDG) PET/MRI was found to be accurate and comparable with 18F-FDG PET/CT in the detection of malignant pulmonary lesions, with significantly improved sensitivity when advanced acquisition protocols were used. © RSNA, 2023 Supplemental material is available for this article.

Omission of intraoperative pyloric procedures in minimally invasive esophagectomy: assessing the impact on patients.

Pyloroplasty or pyloromyotomy is often undertaken during esophagectomy to aid gastric emptying postoperatively. Minimally invasive esophagectomy (MIE) frequently omits a pyloric procedure. The impact on perioperative outcomes and the need for subsequent interventions is unclear. This study assesses the requirements for endoscopic balloon dilation of the pylorus (EPD) following MIE. Patients undergoing MIE from 2016 to 2020 were reviewed. Patients undergoing open resection, or an intraoperative pyloric procedure were excluded. Demographic, clinical and pathological data were reviewed. Univariable and multivariable analysis were performed as appropriate. In total, 171 patients underwent MIE. There were no differences in age (median 65 vs. 65 years, P = 0.6), pathological stage (P = 0.10) or ASA status (P = 0.52) between those requiring and not requiring endoscopic pyloric dilation (EPD). Forty-three patients (25%) required EPD, with a total of 71 procedures. Twenty-seven patients (16%) had EPD on their index admission. Seventy-five patients (43%) had a postoperative complication. Higher ASA status was associated with increased requirement for EPD (odds ratio 10.8, P = 0.03). On multivariable analysis, there was no association between the need for a pyloric procedure and overall survival (P = 0.14). Eight patients (5%) required insertion of a feeding jejunostomy in the postoperative period, with no difference between those with or without EPD (P = 0.11). Two patients required subsequent surgical pyloromyotomy for delayed gastric emptying. Although pyloroplasty or pyloromyotomy can safely be excluded during MIE, a quarter of patients will require postoperative EPD procedures. The impact of excluding pyloric procedures on gastric emptying requires further study.

Differential prognostic significance of sarcopenia in metastatic esophageal squamous and adenocarcinoma.

BACKGROUND: Sarcopenia indicates poor prognosis in various malignancies. We evaluated the association of sarcopenia with overall (OS) and progression-free survival (PFS) in metastatic esophageal cancer (MEC) patients, a population often presenting with poor nutritional status. METHODS: In newly diagnosed MEC patients managed at the Princess Margaret (PM) Cancer Centre (diagnosed 2006-2015), total muscle area, visceral adiposity (VA), and subcutaneous adiposity (SA) were quantified on abdominal computed tomography at L3. Sarcopenia was determined using published cutoffs, based on sex and height. RESULTS: Of 202 MEC patients, most were male (166/82%), < 65 years (116/57%), and had adenocarcinoma histology (141/70%); 110/54% had recurrent MEC after initial curative-intent treatment; 92/46% presented with de novo MEC. At stage IV diagnosis, 20/10% were underweight, 97/48% were normal-weight and 84/42% were overweight/obese; 103/51% were sarcopenic. Sarcopenia was associated with worse median OS (4.6 vs. 7.9 months; log-rank p = 0.03) and 1-year survival, even after adjusting for other body composition variables (e.g., BMI, VA, and SA): adjusted-HR 1.51 [95% CI 1.1-2.2, p = 0.02]. In post hoc analysis, sarcopenia was highly prognostic in adenocarcinomas (p = 0.003), but not squamous cell carcinomas (SCC). In patients receiving palliative systemic treatment (104/51%), sarcopenia was associated with shorter PFS (p = 0.004) in adenocarcinoma patients (75/72%). CONCLUSIONS: In metastatic esophageal adenocarcinomas, sarcopenia is associated with worse PFS and OS. In metastatic esophageal SCC, there was a non-significant trend for worse PFS but no association with OS. In order to offset the poor prognosis associated with sarcopenia particularly in metastatic esophageal adenocarcinoma patients, future research should focus on possible countermeasures.

Outcomes of lung transplantation from organ donation after medical assistance in dying: First North American experience.

Over 2.5% of deaths in Canada occur as a result from medical assisting in dying (MAID), and a subset of these deaths result in organ donation. However, detailed outcomes of lung transplant recipients using these donors is lacking. This is a retrospective single center cohort study comparing lung transplantation outcomes after donation using MAID donors compared to neurologically determined death and controlled donation after circulatory death (NDD/cDCD) donors from February 2018 to July 2021. Thirty-three patients received lungs from MAID donors, and 560 patients received lungs from NDD/cDCD donors. The donor diagnoses leading to MAID provision were degenerative neurological diseases (n = 33) and end stage organ failure (n = 5). MAID donors were significantly older than NDD/cDCD donors (56 [IQR 49-64] years vs. 48 [32-59]; p = .0009). Median ventilation period and 30 day mortality were not significantly different between MAID and NDD/cDCD lungs recipients (ventilation: 1 day [1-3] vs 2 days [1-3]; p = .37, deaths 0% [0/33] vs. 2% [11/560], p = .99 respectively). Intermediate-term outcomes were also similar. In summary, for lung transplantation using donors after MAID, recipient outcomes were excellent. Therefore, where this practice is permitted, donation after MAID should be strongly considered for lung transplantation as a way to respect donor wishes while substantially improving outcomes for recipients with end-stage lung disease.

Utility of bile acids in large airway bronchial wash versus bronchoalveolar lavage as biomarkers of microaspiration in lung transplant recipients: a retrospective cohort study.

BACKGROUND: Bronchoalveolar lavage (BAL) is a key tool in respiratory medicine for sampling the distal airways. BAL bile acids are putative biomarkers of pulmonary microaspiration, which is associated with poor outcomes after lung transplantation. Compared to BAL, large airway bronchial wash (LABW) samples the tracheobronchial space where bile acids may be measurable at more clinically relevant levels. We assessed whether LABW bile acids, compared to BAL bile acids, are more strongly associated with poor clinical outcomes in lung transplant recipients. METHODS: Concurrently obtained BAL and LABW at 3 months post-transplant from a retrospective cohort of 61 lung transplant recipients were analyzed for taurocholic acid (TCA), glycocholic acid (GCA), and cholic acid by mass spectrometry and 10 inflammatory proteins by multiplex immunoassay. Associations between bile acids with inflammatory proteins and acute lung allograft dysfunction were assessed using Spearman correlation and logistic regression, respectively. Time to chronic lung allograft dysfunction and death were evaluated using multivariable Cox proportional hazards and Kaplan-Meier methods. RESULTS: Most bile acids and inflammatory proteins were higher in LABW than in BAL. LABW bile acids correlated with inflammatory proteins within and between sample type. LABW TCA and GCA were associated with acute lung allograft dysfunction (OR = 1.368; 95%CI = 1.036-1.806; P = 0.027, OR = 1.064; 95%CI = 1.009-1.122; P = 0.022, respectively). No bile acids were associated with chronic lung allograft dysfunction. Adjusted for risk factors, LABW TCA and GCA predicted death (HR = 1.513; 95%CI = 1.014-2.256; P = 0.042, HR = 1.597; 95%CI = 1.078-2.366; P = 0.020, respectively). Patients with LABW TCA in the highest tertile had worse survival compared to all others. CONCLUSIONS: LABW bile acids are more strongly associated than BAL bile acids with inflammation, acute lung allograft dysfunction, and death in lung transplant recipients. Collection of LABW may be useful in the evaluation of microaspiration in lung transplantation and other respiratory diseases.

Influence of sarcopenia, clinical data, and 2-[18F] FDG PET/CT in outcome prediction of patients with early-stage adenocarcinoma esophageal cancer.

PURPOSE: To determine the prognostic value of sarcopenia measurements done on staging 2-[18F] FDG PET/CT together with metabolic activity of the tumor in patients with adenocarcinoma esophagogastric cancer with surgical treatment. METHODS: Patients with early-stage, surgically treated esophageal adenocarcinoma and available pre-treatment 2-[18F] FDG PET/CT were included. The standard uptake value (SUV) and SUV normalized by lean body mass (SUL) were recorded. Skeletal muscle index (SMI) was measured at the L3 level on the CT component of the PET/CT. Sarcopenia was defined as SMI < 34.4cm2/m2 in women and < 45.4cm2/m2 in men. RESULTS: Of the included 145 patients. 30% were sarcopenic at baseline. On the univariable Cox proportional hazards analysis, ECOG, surgical T and N staging, lymphovascular invasion (LVI) positive lymph nodes, and sarcopenia were significant prognostic factors concerning RFS and OS. On multivariable Cox regression analysis, surgical N staging (p = 0.025) and sarcopenia (p = 0.022) remained significant poor prognostic factors for OS and RFS. Combining the clinical parameters with the imaging-derived nutritional evaluation of the patient but not metabolic parameters of the tumor showed improved predictive ability for OS and RFS. CONCLUSION: Combining the patients' imaging-derived sarcopenic status with standard clinical data, but not metabolic parameters, offered an overall improved prognostic value concerning OS and RFS.

Preoperative and Postoperative Approaches to Gastroesophageal Cancer: What is All the Fuss About.

Gastroesophageal cancers carry poor prognoses, and are a leading cause of cancer-related morbidity and mortality worldwide. Even in those with resectable disease, more than half of patients treated with surgery alone experience disease recurrence. Multimodality approaches using preoperative and postoperative chemotherapy and/or radiotherapy have been established, resulting in incremental improvements in outcomes. Globally, there is no standardized approach, and treatment varies with geographic location. The question remains of how to select the optimal perioperative treatment that will maximize benefit for patients while avoiding toxicities from unnecessary therapies. This article reviews currently available evidence supporting preoperative and postoperative therapy in gastroesophageal cancers, with an emphasis on recent practice-changing trials and ongoing areas of investigation, including the role of immune checkpoint inhibition and biomarker-guided treatment.

Predicting donor lung acceptance for transplant during ex vivo lung perfusion: The EX vivo lung PerfusIon pREdiction (EXPIRE).

Ex vivo lung perfusion (EVLP) has being increasingly used for the pretransplant assessment of extended-criteria donor lungs. Mathematical models to predict lung acceptance during EVLP have not been reported so far. Thus, we hypothesized that predictors of lung acceptance could be identified and used to develop a mathematical model describing the clinical decision-making process used in our institution. Donor lungs characteristics and EVLP physiologic parameters included in our EVLP registry were examined (derivation cohort). Multivariable logistic regression analysis was performed to identify predictors independently associated with lung acceptance. A mathematical model (EX vivo lung PerfusIon pREdiction [EXPIRE] model) for each hour of EVLP was developed and validated using a new cohort (validation cohort). Two hundred eighty donor lungs were assessed with EVLP. Of these, 186 (66%) were accepted for transplantation. ΔPO2 and static compliance/total lung capacity were identified as independent predictors of lung acceptance and their respective cut-off values were determined. The EXPIRE model showed a low discriminative power at the first hour of EVLP assessment (AUC: 0.69 [95% CI: 0.62-0.77]), which progressively improved up to the fourth hour (AUC: 0.87 [95% CI: 0.83-0.92]). In a validation cohort, the EXPIRE model demonstrated good discriminative power, peaking at the fourth hour (AUC: 0.85 [95% CI: 0.76-0.94]). The EXPIRE model may help to standardize lung assessment in centers using the Toronto EVLP technique and improve overall transplant rates.

Lung donation after medical assistance in dying at home.

Organ donation after medical assistance in dying (MAID) has only been possible for patients having the MAID procedure performed at a hospital facility due to prohibitive warm ischemic times. Herein, we describe a protocol for lung donation following MAID at home and demonstrate excellent postoperative outcomes. Lung donation following MAID at home is possible and should be considered by transplant programs.

Transcriptomic investigation reveals donor-specific gene signatures in human lung transplants.

INTRODUCTION: Transplantation of lungs from donation after circulatory death (DCD) in addition to donation after brain death (DBD) became routine worldwide to address the global organ shortage. The development of ex vivo lung perfusion (EVLP) for donor lung assessment and repair contributed to the increased use of DCD lungs. We hypothesise that a better understanding of the differences between lungs from DBD and DCD donors, and between EVLP and directly transplanted (non-EVLP) lungs, will lead to the discovery of the injury-specific targets for donor lung repair and reconditioning. METHODS: Tissue biopsies from human DBD (n=177) and DCD (n=65) donor lungs, assessed with or without EVLP, were collected at the end of cold ischaemic time. All samples were processed with microarray assays. Gene expression, network and pathway analyses were performed using R, Ingenuity Pathway Analysis and STRING. Results were validated with protein assays, multiple logistic regression and 10-fold cross-validation. RESULTS: Our analyses showed that lungs from DBD donors have upregulation of inflammatory cytokines and pathways. In contrast, DCD lungs display a transcriptome signature of pathways associated with cell death, apoptosis and necrosis. Network centrality revealed specific drug targets to rehabilitate DBD lungs. Moreover, in DBD lungs, tumour necrosis factor receptor-1/2 signalling pathways and macrophage migration inhibitory factor-associated pathways were activated in the EVLP group. A panel of genes that differentiate the EVLP from the non-EVLP group in DBD lungs was identified. CONCLUSION: The examination of gene expression profiling indicates that DBD and DCD lungs have distinguishable biological transcriptome signatures.

Prognostic Impact of CXCR7 and CXCL12 Expression in Patients with Esophageal Adenocarcinoma.

BACKGROUND: Chemokines are major regulators of cell trafficking and adhesion. The chemokine CXCL12 and its receptors, CXCR4 and CXCR7, have been reported as biomarkers in various cancers, including esophageal cancer; however, there are few studies in esophageal adenocarcinoma (EAC). In this study, we investigated the relationship between expression of CXCL12, CXCR4, and CXCR7, and prognosis in patients with EAC. METHODS: This study examined 55 patients with EAC who were treated in Toronto General Hospital from 2001 to 2010. Tissue microarray immunohistochemistry was used to evaluate the expression of CXCL12, CXCR4, and CXCR7. Evaluation of immunohistochemistry was performed by a pathologist without knowledge of patients' information and results were compared with the patients' clinicopathological features and survival. RESULTS: High CXCR7 expression was significantly associated with lymphatic invasion (present vs absent, P = 0.005) and higher number of lymph node metastases (pN0-1 vs pN2-3, P = 0.0014). Patients with high CXCR7 expression (n = 23) were associated with worse overall (OS) and disease-free survival (DFS) (P = 0.0221, P = 0.0090, respectively), and patients with high CXCL12 (n = 24) tended to have worse OS and DFS (P = 0.1091, P = 0.1477, respectively). High expression of both CXCR7 and CXCL12 was an independent prognostic factor for OS and DFS on multivariate analysis (HR = 0.3, 95% CI: 0.1-0.9, P = 0.0246, HR = 0.3, 95% CI: 0.1-0.8, P = 0.0134, respectively). CONCLUSIONS: High CXCR7 expression was associated with poor prognosis in patients with EAC, and high expression of CXCR7 with its ligand CXCL12 had a stronger association with prognosis. Further study of this potential biomarker using whole tissue samples and a larger sample size is warranted.

[Lung transplant with ex vivo lung perfusion, Chilean and Latin American first experience]. / Trasplante pulmonar ex vivo . Primera experiencia en Chile y Latinoamérica.

BACKGROUND: The number of patients waiting for a lung transplant worldwide greatly exceeds the number of available donors. Ex vivo lung perfusion is a useful tool that allows marginal donor lungs to be evaluated and reconditioned for a successful lung transplantation. AIM: To describe the first Chilean and Latin American experience in ex vivo lung perfusion for marginal donor lungs before transplantation. MATERIAL AND METHODS: Descriptive analysis of all ex vivo lung perfusion conducted for marginal donor lungs at a private clinic, from April 2019 to October 2020. High risk donor lungs and rejected lungs from other transplantation centers were included. The "Toronto Protocol" was used for ex vivo lung perfusion. Donor lung characteristics and recipient outcomes were studied. RESULTS: During the study period, five ex vivo lung perfusions were performed. All lungs were reconditioned and transplanted. No complications were associated. There were no primary graft dysfunctions and only one chronic allograft dysfunction. There was no mortality during the first year. The median arterial oxygen partial pressure/fractional inspired oxygen ratio increased from 266 mm Hg in the donor lung to 419 after 3 hours of ex vivo lung perfusion (p = 0.043). CONCLUSIONS: ex vivo lung perfusion is a safe and useful tool that allows marginal donor lungs to be reconditioned and successfully transplanted.

Initial lung transplantation experience with uncontrolled donation after cardiac death in North America.

Uncontrolled donation after cardiac death (uDCD) has the potential to ameliorate the shortage of suitable lungs for transplant. To date, no lung transplant data from these donors are available from North America. We describe the successful use of these donors using a simple method of in situ lung inflation so that the organ can be protected from warm ischemic injury. Forty-four potential donors were approached, and family consent was obtained in 30 cases (68%). Of these, the lung transplant team evaluated 16 uDCDs on site, and 14 were considered for transplant pending ex vivo lung perfusion assessment. Five lungs were ultimately used for transplant (16.7% use rate from consented donors). The mean warm ischemic time was 2.8 hours. No primary graft dysfunction grade 3 was observed at 24, 48, or 72 hours after transplant. Median intensive care unit stay was 5 days (range: 2-78 days), and median hospital stay was 17 days (range: 8-100 days). The 30-day mortality was 0%. Four of 5 patients are alive at a median of 651 days (range: 121-1254 days) with preserved lung function. This study demonstrates the proof of concept and the potential for uDCD lung donation using a simple donor intervention.

Potential therapeutic targets for lung repair during human ex vivo lung perfusion.

INTRODUCTION: The ex vivo lung perfusion (EVLP) technique has been developed to assess the function of marginal donor lungs and has significantly increased donor lung utilisation. EVLP has also been explored as a platform for donor lung repair through injury-specific treatments such as antibiotics or fibrinolytics. We hypothesised that actively expressed pathways shared between transplantation and EVLP may reveal common mechanisms of injury and potential therapeutic targets for lung repair prior to transplantation. MATERIALS AND METHODS: Retrospective transcriptomics analyses were performed with peripheral tissue biopsies from "donation after brain death" lungs, with 46 pre-/post-transplant pairs and 49 pre-/post-EVLP pairs. Pathway analysis was used to identify and compare the responses of donor lungs to transplantation and to EVLP. RESULTS: 22 pathways were enriched predominantly in transplantation, including upregulation of lymphocyte activation and cell death and downregulation of metabolism. Eight pathways were enriched predominantly in EVLP, including downregulation of leukocyte functions and upregulation of vascular processes. 27 pathways were commonly enriched, including activation of innate inflammation, cell death, heat stress and downregulation of metabolism and protein synthesis. Of the inflammatory clusters, Toll-like receptor/innate immune signal transduction adaptor signalling had the greatest number of nodes and was central to inflammation. These mechanisms have been previously speculated as major mechanisms of acute lung injury in animal models. CONCLUSION: EVLP and transplantation share common molecular features of injury including innate inflammation and cell death. Blocking these pathways during EVLP may allow for lung repair prior to transplantation.

How Many Nodes Need to be Removed to Make Esophagectomy an Adequate Cancer Operation, and Does the Number Change When a Patient has Chemoradiotherapy Before Surgery?

INTRODUCTION AND DESIGN: Node dissection during esophagectomy is an important aspect of esophageal cancer staging. Controversy remains as to how many nodes need to be resected in order to properly stage a patient and whether the removal of more nodes carries a stage-independent survival benefit. A review of the literature performed by a group of experts in the subject may help define a minimum accepted number of lymph nodes to be resected in both primary surgery and post-induction therapy scenarios. RESULTS AND CONCLUSIONS: The existing evidence generally supports the goal of obtaining a minimum of 15 lymph nodes for pathological examination in both primary surgery and post-induction therapy scenarios.

Towards donor lung recovery-gene expression changes during ex vivo lung perfusion of human lungs.

We and others have demonstrated that acellular normothermic ex vivo lung perfusion of high-risk donor lungs can result in posttransplant outcomes equivalent to that of contemporaneous lung transplantation using standard donor lungs. However, the mechanism of this effect remains unclear. Given the restoration of cellular metabolic activity during normothermic perfusion, one possibility is that of lung healing via natural innate recovery mechanisms. We explored this by examining the gene expression changes occurring in human lungs during ex vivo lung perfusion. Human lungs clinically rejected for transplantation were perfused for 12 hours of EVLP with biopsies taken at the start, at 1 hour, at 3 hours, and then every 3 hours thereafter to 12 hours. Temporal changes were identified in 2585 genes using the Short Time-series Expression Miner and used for pathway analysis. Despite increases in endothelial markers of inflammation, circulating leukocyte cell-specific gene expression fell over 12 hours of ex vivo lung perfusion (EVLP), suggesting an interrupted inflammation response secondary to washout of circulating leukocytes. Analysis of these gene changes suggests lung recovery follows specific stages: cellular death, cellular preservation, cellular reorganization, and cellular invasion. EVLP may improve posttransplant lung function by washout of leukocytes and facilitating innate mechanisms of repair.