Predictive [18F]-FDG PET/CT-Based Radiogenomics Modelling of Driver Gene Mutations in Non-small Cell Lung Cancer.

RATIONALE AND OBJECTIVES: To investigate whether [18F]-FDG PET/CT-derived radiomics may correlate with driver gene mutations in non-small cell lung cancer (NSCLC) patients. MATERIALS AND METHODS: In this IRB-approved retrospective study, 203 patients with surgically treated NSCLC who underwent subsequent genomic analysis of the primary tumour at our institution between December 2004 and January 2014 were identified. Of those, 128 patients (mean age 62.4 ± 10.8 years; range: 35-84) received preoperative [18F]-FDG PET/CT as part of their initial staging and thus were included in the study. PET and CT image segmentation and feature extraction were performed semi-automatically with an open-source software platform (LIFEx, Version 6.30, lifexsoft.org). Molecular profiles using different next-generation sequencing (NGS) panels were collected from a web-based resource (cBioPortal.ca for Cancer genomics). Two statistical models were then built to evaluate the predictive ability of [18F]-FDG PET/CT-derived radiomics features for driver gene mutations in NSCLC. RESULTS: More than half (68/128, 53%) of all tumour samples harboured three or more gene mutations. Overall, 55% of tumour samples demonstrated a mutation in TP53, 26% of samples had alterations in KRAS and 17% in EGFR. Extensive statistical analysis resulted in moderate to good predictive ability. The highest Youden Index for TP53 was achieved using combined PET/CT features (0.70), for KRAS using PET features only (0.57) and for EGFR using CT features only (0.60). CONCLUSION: Our study demonstrated a moderate to good correlation between radiomics features and driver gene mutations in NSCLC, indicating increased predictive ability of genomic profiles using combined [18F]-FDG PET/CT-derived radiomics features.

Outcomes in older adults with metastatic esophageal and gastric carcinoma treated with palliative chemotherapy.

BACKGROUND: The incidence of esophageal and gastric carcinoma (GEC) in elderly patients is increasing, yet patients ≥75 years have historically been underrepresented in clinical trials. We sought to investigate palliative chemotherapy administration patterns and survival outcomes in older adults. MATERIALS AND METHODS: A retrospective analysis identified patients aged 65-74 (young-old) and ≥75 years (older-old) diagnosed with advanced GEC. Patient and tumor characteristics were recorded, with descriptive analysis, time-to-event data analysis using Kaplan-Meier curves and multivariate Cox proportional hazards regression analysis performed. RESULTS: One hundred and ninety-eight "young-old" and 109 'older-old' patients were identified. Patient characteristics were similar between groups except for Charlson Co-morbidity Index (CCI), with lower co-morbidities in the "young-old" compared to "older-old" cohort (P < .001; CCI = 0 in 103 (52%) "young-old" vs 31 (28%) "older-old"). The primary diagnosis in both groups was adenocarcinoma. 119 (60%) "young-old" and 25 (23%) "older-old" patients received chemotherapy (P < .001). Performance status was the primary explanation for chemotherapy non-receipt in both cohorts; age was the explanation in 21 (25%) "older-old" patients and none in the "young-old" patients. PFS for first-line systemic therapy in "young-old" patients was 6.4 (95% CI 5.9-7.6) versus 7.5 months (95% CI 5.1-11.3) in "older-old" patients (P = .69) whilst respective OS was 12.3 (95% CI 10.1-15.5) and 10.4 months (95% CI 9.0-14.6) (P = .0816). Toxicity prompted chemotherapy cessation in 17 (15%) "young-old" and 3 (13%) "older-old" patients (P = .97). Multivariate analysis identified CCI and ECOG performance status as predictive for PFS and OS, respectively. No causative relationship was identified with other variables. CONCLUSION: Our study of real-world older-adults show that significant number of "older-old" patients with GEC do not receive chemotherapy. Among "older-old" adults who do receive systemic therapy, outcomes are comparable; this underscores the importance of geriatric assessment-guided care and suggests that age alone should not be a barrier to receipt of chemotherapy in patients with advanced GEC.

Gastro-Esophageal Cancer: Can Radiomic Parameters from Baseline 18F-FDG-PET/CT Predict the Development of Distant Metastatic Disease?

We aimed to determine if clinical parameters and radiomics combined with sarcopenia status derived from baseline 18F-FDG-PET/CT could predict developing metastatic disease and overall survival (OS) in gastroesophageal cancer (GEC). Patients referred for primary staging who underwent 18F-FDG-PET/CT from 2008 to 2019 were evaluated retrospectively. Overall, 243 GEC patients (mean age = 64) were enrolled. Clinical, histopathology, and sarcopenia data were obtained, and primary tumor radiomics features were extracted. For classification (early-stage vs. advanced disease), the association of the studied parameters was evaluated. Various clinical and radiomics models were developed and assessed. Accuracy and area under the curve (AUC) were calculated. For OS prediction, univariable and multivariable Cox analyses were performed. The best model included PET/CT radiomics features, clinical data, and sarcopenia score (accuracy = 80%; AUC = 88%). For OS prediction, various clinical, CT, and PET features entered the multivariable analysis. Three clinical factors (advanced disease, age ≥ 70 and ECOG ≥ 2), along with one CT-derived and one PET-derived radiomics feature, retained their significance. Overall, 18F-FDG PET/CT radiomics seems to have a potential added value in identifying GEC patients with advanced disease and may enhance the performance of baseline clinical parameters. These features may also have a prognostic value for OS, improving the decision-making for GEC patients.

CRISPR-Cas Genome Editing in Ex Vivo Human Lungs to Rewire the Translational Path of Genome-Targeting Therapeutics.

The ongoing advancements in CRISPR-Cas technologies can significantly accelerate the preclinical development of both in vivo and ex vivo organ genome-editing therapeutics. One of the promising applications is to genetically modify donor organs prior to implantation. The implantation of optimized donor organs with long-lasting immunomodulatory capacity holds promise for reducing the need for lifelong potent whole-body immunosuppression in recipients. However, assessing genome-targeting interventions in a clinically relevant manner prior to clinical trials remains a major challenge owing to the limited modalities available. This study introduces a novel platform for testing genome editing in human lungs ex vivo, effectively simulating preimplantation genetic engineering of donor organs. We identified gene regulatory elements whose disruption via Cas nucleases led to the upregulation of the immunomodulatory gene interleukin 10 (IL-10). We combined this approach with adenoviral vector-mediated IL-10 delivery to create favorable kinetics for early (immediate postimplantation) graft immunomodulation. Using ex vivo organ machine perfusion and precision-cut tissue slice technology, we demonstrated the feasibility of evaluating CRISPR genome editing in human lungs. To overcome the assessment limitations in ex vivo perfused human organs, we conducted an in vivo rodent study and demonstrated both early gene induction and sustained editing of the lung. Collectively, our findings lay the groundwork for a first-in-human-organ study to overcome the current translational barriers of genome-targeting therapeutics.

The [18F]F-FDG PET/CT Radiomics Classifier of Histologic Subtypes and Anatomical Disease Origins across Various Malignancies: A Proof-of-Principle Study.

We aimed to investigate whether [18F]F-FDG-PET/CT-derived radiomics can classify histologic subtypes and determine the anatomical origin of various malignancies. In this IRB-approved retrospective study, 391 patients (age = 66.7 ± 11.2) with pulmonary (n = 142), gastroesophageal (n = 128) and head and neck (n = 121) malignancies were included. Image segmentation and feature extraction were performed semi-automatically. Two models (all possible subset regression [APS] and recursive partitioning) were employed to predict histology (squamous cell carcinoma [SCC; n = 219] vs. adenocarcinoma [AC; n = 172]), the anatomical origin, and histology plus anatomical origin. The recursive partitioning algorithm outperformed APS to determine histology (sensitivity 0.90 vs. 0.73; specificity 0.77 vs. 0.65). The recursive partitioning algorithm also revealed good predictive ability regarding anatomical origin. Particularly, pulmonary malignancies were identified with high accuracy (sensitivity 0.93; specificity 0.98). Finally, a model for the synchronous prediction of histology and anatomical disease origin resulted in high accuracy in determining gastroesophageal AC (sensitivity 0.88; specificity 0.92), pulmonary AC (sensitivity 0.89; specificity 0.88) and head and neck SCC (sensitivity 0.91; specificity 0.92). Adding PET-features was associated with marginal incremental value for both the prediction of histology and origin in the APS model. Overall, our study demonstrated a good predictive ability to determine patients' histology and anatomical origin using [18F]F-FDG-PET/CT-derived radiomics features, mainly from CT.

Lung Transplant Immunomodulation with Genetically Engineered Mesenchymal Stromal Cells-Therapeutic Window for Interleukin-10.

Lung transplantation results are compromised by ischemia-reperfusion injury and alloimmune responses. Ex vivo lung perfusion (EVLP) is used to assess marginal donor lungs before transplantation but is also an excellent platform to apply novel therapeutics. We investigated donor lung immunomodulation using genetically engineered mesenchymal stromal cells with augmented production of human anti-inflammatory hIL-10 (MSCsIL-10). Pig lungs were placed on EVLP for 6 h and randomized to control (n = 7), intravascular delivery of 20 × 106 (n = 5, low dose) or 40 × 106 human MSCs IL-10 (n = 6, high dose). Subsequently, single-lung transplantation was performed, and recipient pigs were monitored for 3 days. hIL-10 secretion was measured during EVLP and after transplantation, and immunological effects were assessed by cytokine profile, T and myeloid cell characterization and mixed lymphocyte reaction. MSCIL-10 therapy rapidly increased hIL-10 during EVLP and resulted in transient hIL-10 elevation after lung transplantation. MSCIL-10 delivery did not affect lung function but was associated with dose-related immunomodulatory effects, with the low dose resulting in a beneficial decrease in apoptosis and lower macrophage activation, but the high MSCIL-10 dose resulting in inflammation and cytotoxic CD8+ T cell activation. MSCIL-10 therapy during EVLP results in a rapid and transient perioperative hIL-10 increase and has a therapeutic window for its immunomodulatory effects.

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.

Impact of telehealth postoperative care on early outcomes following esophagectomy.

OBJECTIVES: To address the short-term clinical outcomes of patients postesophagectomy who underwent telehealth care following surgery. The primary objective was to compare the frequency of emergency department admission between telehealth and in-person cohorts. Secondary objectives included comparing the frequency of endoscopies and clinic visits, as well as reasons for emergency department admission. METHODS: We conducted a retrospective cohort study to assess the clinical outcomes of patients who underwent esophagectomy between March 2018 and May 2022. Patients attending telehealth (phone or video call) surgical follow-up visits, largely due to the COVID-19 pandemic, were compared with a pre-COVID cohort of patients attending standard in-person care. Demographic data, clinical and disease characteristics, and hospital visit data within 6 months of operation were collected. This included surgical clinic visits, endoscopies, and emergency department admissions. RESULTS: There were 168 patients who underwent esophagectomy and had follow-up care between March 2018 and May 2022; 76 telehealth and 92 in-person. Patients attending telehealth appointments had significantly fewer emergency department admissions (0.45 vs 0.79, P = .037) and more endoscopy visits (1.37 vs 0.91, P = .020) compared with patients attending in-person visits. The number of follow-up surgical clinic visits did not differ between the groups. The most frequent reasons for emergency visits for the telehealth cohort included dysphagia, feeding-tube problems, and failure to thrive. For the in-person cohort, feeding-tube complications, inflammation/infection, and failure to thrive were the most common reasons. CONCLUSIONS: A program of virtual follow-up, with integrated in person visits and endoscopy as required, is feasible and safe for following patients postesophagectomy.

A radiographic score for human donor lungs on ex vivo lung perfusion predicts transplant outcomes.

BACKGROUND: Ex vivo lung perfusion (EVLP) is an advanced platform for isolated lung assessment and treatment. Radiographs acquired during EVLP provide a unique opportunity to assess lung injury. The purpose of our study was to define and evaluate EVLP radiographic findings and their association with lung transplant outcomes. METHODS: We retrospectively evaluated 113 EVLP cases from 2020-21. Radiographs were scored by a thoracic radiologist blinded to outcome. Six lung regions were scored for 5 radiographic features (consolidation, infiltrates, atelectasis, nodules, and interstitial lines) on a scale of 0 to 3 to derive a score. Spearman's correlation was used to correlate radiographic scores to biomarkers of lung injury. Machine learning models were developed using radiographic features and EVLP functional data. Predictive performance was assessed using the area under the curve. RESULTS: Consolidation and infiltrates were the most frequent findings at 1 hour EVLP (radiographic lung score 2.6 (3.3) and 4.6 (4.3)). Consolidation (r = -0.536 and -0.608, p < 0.0001) and infiltrates (r = -0.492 and -0.616, p < 0.0001) were inversely correlated with oxygenation (∆pO2) at 1 hour and 3 hours of EVLP. First-hour consolidation and infiltrate lung scores predicted transplant suitability with an area under the curve of 87% and 88%, respectively. Prediction of transplant outcomes using a machine learning model yielded an area under the curve of 80% in the validation set. CONCLUSIONS: EVLP radiographs provide valuable insight into donor lungs being assessed for transplantation. Consolidation and infiltrates were the most common abnormalities observed in EVLP lungs, and radiographic lung scores predicted the suitability of donor lungs for transplant.

Airway pepsinogen A4 identifies lung transplant recipients with microaspiration and predicts chronic lung allograft dysfunction.

BACKGROUND: Aspiration is a known risk factor for adverse outcomes post-lung transplantation. Airway bile acids are the gold-standard biomarker of aspiration; however, they are released into the duodenum and likely reflect concurrent gastrointestinal dysmotility. Previous studies investigating total airway pepsin have found conflicting results on its relationship with adverse outcomes post-lung transplantation. These studies measured total pepsin and pepsinogen in the airways. Certain pepsinogens are constitutively expressed in the lungs, while others, such as pepsinogen A4 (PGA4), are not. We sought to evaluate the utility of measuring airway PGA4 as a biomarker of aspiration and predictor of adverse outcomes in lung transplant recipients (LTRs) early post-transplant. METHODS: Expression of PGA4 was compared to other pepsinogens in lung tissue. Total pepsin and PGA4 were measured in large airway bronchial washings and compared to preexisting markers of aspiration. Two independent cohorts of LTRs were used to assess the relationship between airway PGA4 and chronic lung allograft dysfunction (CLAD). Changes to airway PGA4 after antireflux surgery were assessed in a third cohort of LTRs. RESULTS: PGA4 was expressed in healthy human stomach but not lung. Airway PGA4, but not total pepsin, was associated with aspiration. Airway PGA4 was associated with an increased risk of CLAD in two independent cohorts of LTRs. Antireflux surgery was associated with reduced airway PGA4. CONCLUSIONS: Airway PGA4 is a marker of aspiration that predicts CLAD in LTRs. Measuring PGA4 at surveillance bronchoscopies can help triage high-risk LTRs for anti-reflux surgery.

Extending the age criteria of lung transplant donors to 70+ years old does not significantly affect recipient survival.

OBJECTIVES: To determine the impact of older donor age (70+ years) on long-term survival and freedom from chronic lung allograft dysfunction in lung transplant (LTx) recipients. METHODS: A retrospective single-center study was performed on all LTx recipients from 2002 to 2017 and a modern subgroup from 2013 to 2017. Recipients were stratified into 4 groups based on donor lung age (<18, 18-55, 56-69, ≥70 years). Donor and recipient characteristics were compared using χ2 tests for differences in proportions and analysis of variance for differences in means. Univariable and multivariable Cox regression was used to describe differences in long-term survival and freedom from chronic lung allograft dysfunction. RESULTS: Between 2002 and 2017, 1600 LTx were performed, 98 of which were performed from donors aged 70 years or older. Recipients of 70+ years donor lungs were significantly older with a mean age of 55.5 ± 12.9 years old (P = .001) and had more Status 3 (urgent) recipients (37.4%, P = .002). After multivariable regression, there were no significant differences in survival or freedom from chronic lung allograft dysfunction between the 4 strata of recipients. CONCLUSIONS: Lung transplantation using donors 70 years old or older can be considered when all other parameters suggest excellent donor lung function without compromising short- or long-term outcomes.

Oesophageal stasis is a risk factor for chronic lung allograft dysfunction and allograft failure in lung transplant recipients.

Background: Morbidity and mortality in lung transplant recipients are often triggered by recurrent aspiration events, potentiated by oesophageal and gastric disorders. Previous small studies have shown conflicting associations between oesophageal function and the development of chronic lung allograft dysfunction (CLAD). Herein, we sought to investigate the relationship between oesophageal motility disorders and long-term outcomes in a large retrospective cohort of lung transplant recipients. Methods: All lung transplant recipients at the Toronto Lung Transplant Program from 2012 to 2018 with available oesophageal manometry testing within the first 7 months post-transplant were included in this study. Patients were categorised according to the Chicago Classification of oesophageal disorders (v3.0). Associations between oesophageal motility disorders with the development of CLAD and allograft failure (defined as death or re-transplantation) were assessed. Results: Of 487 patients, 57 (12%) had oesophagogastric junction outflow obstruction (OGJOO) and 47 (10%) had a disorder of peristalsis (eight major, 39 minor). In a multivariable analysis, OGJOO was associated with an increased risk of CLAD (HR 1.71, 95% CI 1.15-2.55, p=0.008) and allograft failure (HR 1.69, 95% CI 1.13-2.53, p=0.01). Major disorders of peristalsis were associated with an increased risk of CLAD (HR 1.55, 95% CI 1.01-2.37, p=0.04) and allograft failure (HR 3.33, 95% CI 1.53-7.25, p=0.002). Minor disorders of peristalsis were not significantly associated with CLAD or allograft failure. Conclusion: Lung transplant recipients with oesophageal stasis characterised by OGJOO or major disorders of peristalsis were at an increased risk of adverse long-term outcomes. These findings will help with risk stratification of lung transplant recipients and personalisation of treatment for aspiration prevention.

Tumor differentiation impacts response to neoadjuvant therapy and survival in patients with esophageal adenocarcinoma.

OBJECTIVE: The current staging system for esophageal adenocarcinoma only considers tumor grade in early tumors. The aim of this study was to evaluate the impact of tumor differentiation on response to neoadjuvant chemoradiotherapy and survival in patients with locally advanced esophageal adenocarcinoma. METHODS: This was a multi-institution retrospective review of all patients with esophageal cancer who underwent neoadjuvant chemoradiotherapy followed by esophagectomy from January 2010 to December 2017. Response to neoadjuvant therapy and survival was compared between patients with well- or moderately differentiated (G1/2) tumors versus poorly differentiated (G3) tumors. RESULTS: There were 550 patients, 485 men (88.2%) and 65 women. The median age was 61 years, and the tumor was G1/2 in 288 (52.4%) and G3 in 262 patients. Overall clinical stage before neoadjuvant therapy was similar between groups. Pathologic complete response (pCR) was found in 87 patients (15.8%). The frequency of pCR was similar between groups, but residual disease in the esophagus and lymph nodes was significantly more likely with G3 tumors. Median follow-up was 63 months and absolute survival, overall survival, and disease-free survival were all significantly worse in patients with G3 tumors. Further, even with pCR, patients with G3 tumors had significantly worse survival. CONCLUSIONS: This study showed that response to neoadjuvant therapy was not affected by tumor differentiation. However, poor differentiation was associated with worse survival compared with patients with G1/2 tumors, even among those with pCR. These results suggest that poor differentiation should be considered as an added risk factor for clinical staging in patients with locally advanced esophageal adenocarcinoma.

Epidemiology of Postoperative Complications After Esophagectomy: Implications for Management.

BACKGROUND: Despite advances in operative techniques and postoperative care, esophagectomy remains a morbid operation. Leveraging complication epidemiology and the correlation of these complications may improve rescue and refine early recovery pathways. METHODS: This study retrospectively reviewed all esophagectomies performed at a tertiary academic center from 2014 to 2021 and quantified the timing of the most common complications. Daily incidence values for index complications were calculated, and a covariance matrix was created to examine the correlation of the complications with each other. Study investigators performed a Cox proportional hazards analysis to clarify the association between early diagnosis of postoperative atrial fibrillation and pneumonia with subsequent anastomotic leak. RESULTS: The study analyzed 621 esophagectomies, with 580 (93.4%) cervical anastomoses and 474 (76%) patients experiencing complications. A total of 159 (25.6%) patients had postoperative atrial fibrillation, and 155 (25.0%) had an anastomotic leak. The median (interquartile range [IQR]) postoperative day of these complications was day 2 (IQR, days 2-3) and day 8 (IQR, days 7-11), respectively. Our covariance matrix found significant associations in the variance of the most common postoperative complications, including pneumonia, atrial fibrillation, anastomotic leak, and readmissions. Early postoperative atrial fibrillation (hazard ratio, 8.1; 95% CI, 5.65-11.65) and postoperative pneumonia (hazard ratio, 3.8; 95% CI, 1.98-7.38) were associated with anastomotic leak. CONCLUSIONS: Maintaining a high index of suspicion for early postoperative complications is crucial for rescuing patients after esophagectomy. Early postoperative pneumonia and atrial fibrillation may be sentinel complications for an anastomotic leak, and their occurrence may be used to prompt further clinical investigation. Early recovery protocols should consider the development of early complications into postoperative feeding and imaging algorithms.

A machine-learning approach to human ex vivo lung perfusion predicts transplantation outcomes and promotes organ utilization.

Ex vivo lung perfusion (EVLP) is a data-intensive platform used for the assessment of isolated lungs outside the body for transplantation; however, the integration of artificial intelligence to rapidly interpret the large constellation of clinical data generated during ex vivo assessment remains an unmet need. We developed a machine-learning model, termed InsighTx, to predict post-transplant outcomes using n = 725 EVLP cases. InsighTx model AUROC (area under the receiver operating characteristic curve) was 79 ± 3%, 75 ± 4%, and 85 ± 3% in training and independent test datasets, respectively. Excellent performance was observed in predicting unsuitable lungs for transplantation (AUROC: 90 ± 4%) and transplants with good outcomes (AUROC: 80 ± 4%). In a retrospective and blinded implementation study by EVLP specialists at our institution, InsighTx increased the likelihood of transplanting suitable donor lungs [odds ratio=13; 95% CI:4-45] and decreased the likelihood of transplanting unsuitable donor lungs [odds ratio=0.4; 95%CI:0.16-0.98]. Herein, we provide strong rationale for the adoption of machine-learning algorithms to optimize EVLP assessments and show that InsighTx could potentially lead to a safe increase in transplantation rates.

Identification of regional variation in gene expression and inflammatory proteins in donor lung tissue and ex vivo lung perfusate.

OBJECTIVE: Diagnosing lung injury is a challenge in lung transplantation. It has been unclear if a single biopsy specimen is truly representative of the entire organ. Our objective was to investigate lung inflammatory biomarkers using human lung tissue biopsies and ex vivo lung perfusion perfusate. METHODS: Eight human donor lungs declined for transplantation were air inflated, flash frozen, and partitioned from apex to base. Biopsies were then sampled throughout the lung. Perfusate was sampled from 4 lung lobes in 8 additional donor lungs subjected to ex vivo lung perfusion. The levels of interleukin-6, interleukin-8, interleukin-10, and interleukin-1ß were measured using quantitative reverse transcription polymerase chain reaction from lung biopsies and enzyme-linked immunosorbent assay from ex vivo lung perfusion perfusate. RESULTS: The median intra-biopsy equal-variance P value was .50 for messenger RNA biomarkers in tissue biopsies. The median intra-biopsy coefficient of variance was 18%. In donors with no apparent focal injuries, the biopsies in each donor showed no difference in various lung slices, with a coefficient of variance of 20%. The exception was biopsies from the lingula and injured focal areas that demonstrated larger differences. Cytokines in ex vivo lung perfusion perfusate showed minimal variation among different lobes (coefficient of variance = 4.9%). CONCLUSIONS: Cytokine gene expression in lung biopsies was consistent, and the biopsy analysis reflects the whole lung, except when specimens were collected from the lingula or an area of focal injury. Ex vivo lung perfusion perfusate also provides a representative measurement of lung inflammation from the draining lobe. These results will reassure clinicians that a lung biopsy or an ex vivo lung perfusion perfusate sample can be used to inform donor lung selection.

Time to extubation for lung transplant recipients represents a pragmatic end-point to guide the development of prognostic tests.

The field of transplantation would benefit from the integration of advanced precision medicine techniques. Although predictive tests for lung transplantation require a well-defined clinical end-point, there exists no consensus regarding which outcomes are optimal end-points for these purposes. While many possible candidate end-points exist, we propose that time-to-extubation is an optimal end-point for prognostic tests because of its: clinical relevance; objectiveness; stability over time; and association with healthcare expenditure. Herein, we describe the rationale for this selection and present the limitations of alternative outcomes for this purpose. Using a 72-hour cut-off, time to extubation correlated well with Primary Graft Dysfunction Grade 3, intensive care unit and hospital length of stay, and a greater than 2-fold increase in healthcare cost ratios. Given that time-to-extubation is an objective measure that is readily measured by all lung transplant centers, this metric represents a preferred primary end-point for prognostic tests developed for lung transplantation.