Patient-Derived Lung Cancer "Sandwich Cultures" with a Preserved Tumor Microenvironment

In the past, different spheroid-, organotypic-, and three-dimensional (3D) bioprinting lung cancer models were established for in vitro drug testing and personalized medicine. These tissue models cannot depict the tumor microenvironment (TME) and, therefore, research addressing tumor cell-TME interactions is limited. To overcome this hurdle, we applied patient-derived lung tumor samples to establish new in vitro models. To analyze the tissue model properties, we established two-dimensional (2D) and 3D coculture tissue models exposed to static and dynamic culture conditions that afforded tissue culture for up to 28 days. Our tissue models were characterized by hematoxylin eosin staining, M30 enzyme-linked immunosorbent assay, and immunofluorescence staining against specific lung cancer markers (TTF-1 and p40/p63), cancer-associated fibroblast (CAF) markers (α-SMA and MCT4), and fibronectin (FN). The 3D models were generated with higher success rate than the corresponding 2D model. The cell density of the static 3D model increased from 21 to 28 days, whereas the apoptosis decreased. The dynamic 3D model possessed an even higher cell density than the static 3D model. We identified lung cancer cells, CAFs, and FN. Therefore, a novel in vitro 3D lung cancer model was established, which simulated the TME for 28 days and possessed a structural complexity.

Osteo-cartilaginous pain syndromes at the chest wall: results of costal cartilage excision

Background

Various pathologies of the lower ribs may lead to potentially severe pain in a heterogenous group of patients. Costal cartilage excision (CCE) has been shown to result in durable pain relief in some patients. Even though literature is scarce, we reviewed our experience with surgically treated osteo-cartilaginous pain syndromes (OCPSs) of the chest wall.

Methods

We performed a retrospective case series from two institutions including patients operated for OCPS from 2014 to 2022.

Results

Our case series consists of 11 patients (72.7% female) with OCPS that were treated by CCE. The median age was 43.5±17.1 years. Body mass index (BMI) was 23.6±3.4 kg/m² (range, 18.5-29.6). The interval between first symptoms and diagnosis was 2.6 years (range, 3-127). In 5 patients, symptoms started after preceding chest wall trauma. All but one case were unilateral with no significant predominance regarding the side (6 left/4 right/1 bilateral). Postoperative length of hospital stay was 2.3±0.6 days. There was no patient morbidity or mortality. At follow-up, OCPS related pain had ceased in 7 of 9 patients (78%). Two patients stated to have significantly less pain and two patients didn't have a follow-up.

Conclusions

Our analysis indicates that CCE in OCPS is safe and has good long-term results.

[Risky confirmation of a diagnosis: case series of three female patients with mediastinal mass syndrome]

Mediastinal mass syndrome (MMS) is a life-threatening complication of anesthesia for which prevention and treatment are a complication-prone interdisciplinary task. Clinical symptoms vary from asymptomatic patients up to life-threatening cardiorespiratory impairments, depending on the extent and size of a mediastinal tumor as well as the involvement of corresponding anatomical structures. Especially in the context of sedation or general anesthesia, there is a considerable risk of acute cardiopulmonary or respiratory decompensation related to tumor-induced compression of central blood vessels or even the large airways, which may result in severe complications, including death. In this case series three female patients are presented, who were each referred to this hospital with a mediastinal tumor for interventional or surgical confirmation of the diagnosis. Based on the case histories, characteristic complications are demonstrated and strategies to avoid possible adverse events of MMS are discussed. The specific anesthesiological requirements for MMS, the safety aspects of the choice of surgical and anesthesia procedures, circulatory and airway management for the required single-lung ventilation, and various aspects of the selection of the anesthetic agents are discussed in this case series.

Prospective Evaluation of Quantitative F-18-FDG-PET/CT for Pre-Operative Thoracic Lymph Node Staging in Patients with Lung Cancer as a Target for Computer-Aided Diagnosis

Purpose: Pre-operative assessment of thoracic lymphonodal (LN) involvement in patients with lung cancer (LC) is crucial when choosing the treatment modality. Visual assessment of F-18-FDG-PET/CT (PET/CT) is well established, however, there is still a need for prospective quantitative data to differentiate benign from malignant lesions which would simplify staging and guide the further implementation of computer-aided diagnosis (CAD). Methods: In this prospective study, 37 patients with confirmed lung cancer (m/f = 24/13; age: 70 [52–83] years) were analyzed. All patients underwent PET/CT and quantitative data (standardized uptake values) were obtained. Histological results were available for 101 thoracic lymph nodes. Quantitative data were matched to determine cut-off values for delineation between benign vs. malignant lymph nodes. Furthermore, a scoring system derived from these cut-off values was established. Statistical analyses were performed through ROC analysis. Results: Quantitative analysis revealed the optimal cut-off values (p < 0.01) for the differentiation between benign and malignant thoracic lymph nodes in patients suffering from lung cancer. The respective areas under the curve (AUC) ranged from 0.86 to 0.94. The highest AUC for a ratio of lymph node to healthy lung tissue was 0.94. The resulting accuracy ranged from 78.2% to 89.1%. A dedicated scoring system led to an AUC of 0.93 with a negative predictive value of 95.4%. Conclusion: Quantitative analysis of F-18-FDG-PET/CT data provides reliable results for delineation between benign and malignant thoracic lymph nodes. Thus, quantitative parameters can improve diagnostic accuracy and reliability and can also facilitate the handling of the steadily increasing number of clinical examinations.

[Occult and Retained Haemothorax - Recommendations of the Interdisciplinary Thoracic Trauma Task Group of the German Trauma Society (DGU - Section NIS) and the German Society for Thoracic Surgery (DGT)]

The management of occult and retained haemothorax is challenging for all involved in the care of polytrauma patients in terms of diagnosis and treatment. The focus of decision making is preventing sequelae such as pleural empyema and avoiding a trapped lung. An interdisciplinary task force of the German Society for Thoracic Surgery (DGT) and the German Trauma Society (DGU) on thoracic trauma offers recommendations for post-trauma care of patients with occult and/or retained haemothorax, as based on a comprehensive literature review.

[Treatment of Persistent Parenchymal Lung Injuries in Thoracic Trauma: Lung Laceration, Pleural Fistula and Pneumothorax]

Thoracic trauma is a frequent injury pattern with high patient morbidity and mortality. Preclinical and clinical emergency treatment is consented in a national S3-guideline. Following emergency therapy one third of patients may develop lung lacerations, pleural fistulation and persisting pneumothorax. An interdisciplinary working group of the German Society for Thoracic Surgery and the German Society for Traumatology reviewed the published medical literature on treatment of those injuries and assessed the existing evidence according to consensus recommendations. An inconsistent classification of those subsequent lung injuries was found. Evidence for diagnostic and therapeutic recommendations is small.

Human 3D Airway Tissue Models for Real-Time Microscopy: Visualizing Respiratory Virus Spreading

Our knowledge about respiratory virus spreading is mostly based on monolayer cultures that hardly reflect the complex organization of the airway epithelium. Thus, there is a strong demand for biologically relevant models. One possibility to study virus spreading at the cellular level is real-time imaging. In an attempt to visualize virus spreading under somewhat more physiological conditions, Calu-3 cells and human primary fibroblasts were co-cultured submerged or as air-liquid interface (ALI). An influenza A virus (IAV) replicating well in cell culture, and carrying a red fluorescent protein (RFP) reporter gene was used for real-time imaging. Our three-dimensional (3D) models exhibited important characteristics of native airway epithelium including a basement membrane, tight junctions and, in ALI models, strong mucus production. In submerged models, first fluorescence signals appeared between 9 and 12 h post infection (hpi) with a low multiplicity of infection of 0.01. Virus spreading further proceeded in the immediate vicinity of infected cells. In ALI models, RFP was found at 22 hpi and later. Consequently, the progression of infection was delayed, in contrast to the submerged model. With these features, we believe that our 3D airway models can deliver new insights in the spreading of IAV and other respiratory viruses.

Early Career Support for Biomedical Exchange Students with an International Mentor-to-Mentor Concept - The Biomedical Education Program (BMEP)

In medicine, many international exchange opportunities exist, yet often only towards the end of the course of study. Opportunities for students to gain high-level international research experience early during the studies are rare. A good student-mentor relationship during a research stay abroad is a key factor for scientific success. The aims of this paper are to report on an international exchange and education program that has funded more than 700 students and has been carefully developed and advanced over more than 40 years, its mentor-to-mentor concept and potential success factors for building and maintain such programs. A summary of the history, the concept and the experiences of students is provided, along with a discussion of evaluation results and success factors. The Biomedical Education Program (BMEP) team has - within the last seven years of leadership by the authors - selected and funded 83 German students from different biomedical studies who went abroad for research projects. Preliminary evaluation results show a high degree of satisfaction with the program and its mentor-to-mentor concept, which we deem to be the key to success. Further factors include continued funding, determination, self-organization and assertiveness, an excellent alumni network and a meticulous selection process for both, students and hosts. Further, more detailed evaluation of survey results has to follow. Our results may support the build-up of similar exchange programs.

Entwicklung der akademischen Thoraxchirurgie in Deutschland

Die Thoraxchirurgie ist in Deutschland vornehmlich an außeruniversitären thoraxchirurgischen Kliniken abgebildet und nur an verhältnismäßig wenigen Universitätskliniken klinisch als eigenständige Abteilung oder Klinik und wissenschaftlich als W2- oder W3-Professur etabliert. Infolgedessen ist die Gewinnung von fachärztlichem Nachwuchs und insbesondere die Generierung von akademisch tätigen Thoraxchirurgen als Kontaktpersonen für Forschende aus den unterschiedlichen Bereichen der Lebens- und Ingenieurwissenschaften sowie für die Weiterentwicklung des Fachgebiets Thoraxchirurgie deutlich schwieriger als in anderen chirurgischen Fächern. In den medizinischen Fakultäten stehen die Lehre, Forschung und Patientenversorgung gleichberechtigt nebeneinander. Für die Übernahme dieser Aufgaben durch Thoraxchirurgen werden Konzepte zum Ausbau und der Förderung der akademischen Thoraxchirurgie in der deutschen Hochschulmedizin benötigt. Ein strukturiertes Curriculum Akademische Thoraxchirurgie kann zusätzlich zu Mentorenprogrammen, Fördermöglichkeiten und zusätzlichen Freiräumen für die Forschung bzw. Lehre die akademische Karriere in der Thoraxchirurgie unterstützen.

A Barrier to Defend - Models of Pulmonary Barrier to Study Acute Inflammatory Diseases

Pulmonary diseases represent four out of ten most common causes for worldwide mortality. Thus, pulmonary infections with subsequent inflammatory responses represent a major public health concern. The pulmonary barrier is a vulnerable entry site for several stress factors, including pathogens such as viruses, and bacteria, but also environmental factors e.g. toxins, air pollutants, as well as allergens. These pathogens or pathogen-associated molecular pattern and inflammatory agents e.g. damage-associated molecular pattern cause significant disturbances in the pulmonary barrier. The physiological and biological functions, as well as the architecture and homeostatic maintenance of the pulmonary barrier are highly complex. The airway epithelium, denoting the first pulmonary barrier, encompasses cells releasing a plethora of chemokines and cytokines, and is further covered with a mucus layer containing antimicrobial peptides, which are responsible for the pathogen clearance. Submucosal antigen-presenting cells and neutrophilic granulocytes are also involved in the defense mechanisms and counterregulation of pulmonary infections, and thus may directly affect the pulmonary barrier function. The detailed understanding of the pulmonary barrier including its architecture and functions is crucial for the diagnosis, prognosis, and therapeutic treatment strategies of pulmonary diseases. Thus, considering multiple side effects and limited efficacy of current therapeutic treatment strategies in patients with inflammatory diseases make experimental in vitro and in vivo models necessary to improving clinical therapy options. This review describes existing models for studyying the pulmonary barrier function under acute inflammatory conditions, which are meant to improve the translational approaches for outcome predictions, patient monitoring, and treatment decision-making.

[Robotic-assisted Thoracic Surgery]

In the last decade robotic-assisted thoracoscopic surgery (RATS) emerged as a new minimally invasive surgical modality to operate pulmonary, mediastinal and esophageal diseases. Superior to video-assisted thoracoscopic surgery (VATS), RATS affords accurate surgical manipulation in spatially confined anatomical regions. Numerous surgical case studies demonstrated technical reliability and oncological equivalence of RATS compared to open surgery and VATS. Consequently, the number of RATS operations for oncological and non-oncological resections is rising rapidly. The lacking evidence of therapy improvement in the context of significantly increased treatment costs slows the development. Currently, various new companies introduce new robotic surgical platforms into the market and it is expected that market competition will change the costs of these modern therapies. This article summarizes the technical features of RATS and its anesthesiologic implications for patient management.

Surgical stabilization of serial rib fractures is advantageous in patients with relevant traumatic brain injury

Purpose

To evaluate the clinical benefit of surgical stabilization of rib fractures (SSRF) in polytrauma patients with serial rib fractures.

Methods

Retrospective single-center cohort analysis in trauma patients. Serial rib fracture was defined as three consecutive ribs confirmed by chest computer tomography (CT). Study cohort includes 243 patients that were treated conservatively and 34 patients that underwent SSRF. Demographic patient data, trauma mechanism, injury pattern, Injury Severity Score (ISS), Glasgow Coma Scale (GCS) and hospital course were analyzed. Two matched pair analyses stratified for ISS (32 pairs) and GCS (25 pairs) were performed.

Results

The majority of patients was male (74%) and aged 55 ± 20 years. Serial rib fractures were associated with more than 6 broken ribs in average (6.3 ± 3.7). Other thoracic bone injury included sternum (18%), scapula (16%) and clavicula (13%). Visceral injury consisted of pneumothorax (51%), lung contusion (33%) and diaphragmatic rupture (2%). Average ISS was 22 ± 7.3. Overall hospital stay was 15.9 and ICU stay 7.4 days. In hospital, mortality was 13%. SSRF did not improve hospital course or postoperative complications in the complete study cohort. However, patients with a significantly reduced GCS (7.6 ± 5.3 vs 11.22 ± 4.8; p = 0.006) benefitted from SSRF. Matched pair analysis stratified for GCS showed shorter ICU stays (9 vs 15 days; p = 0.005) including shorter respirator time (143 vs 305 h; p = 0.003).

Conclusion

Patients with serial rib fractures and simultaneous moderate or severe traumatic brain injury benefit from surgical stabilization of rib fractures.

Susceptibility of Human Airway Tissue Models Derived From Different Anatomical Sites to Bordetella pertussis and Its Virulence Factor Adenylate Cyclase Toxin

To study the interaction of human pathogens with their host target structures, human tissue models based on primary cells are considered suitable. Complex tissue models of the human airways have been used as infection models for various viral and bacterial pathogens. The Gram-negative bacterium Bordetella pertussis is of relevant clinical interest since whooping cough has developed into a resurgent infectious disease. In the present study, we created three-dimensional tissue models of the human ciliated nasal and tracheo-bronchial mucosa. We compared the innate immune response of these models towards the B. pertussis virulence factor adenylate cyclase toxin (CyaA) and its enzymatically inactive but fully pore-forming toxoid CyaA-AC^-. Applying molecular biological, histological, and microbiological assays, we found that 1 µg/ml CyaA elevated the intracellular cAMP level but did not disturb the epithelial barrier integrity of nasal and tracheo-bronchial airway mucosa tissue models. Interestingly, CyaA significantly increased interleukin 6, interleukin 8, and human beta defensin 2 secretion in nasal tissue models, whereas tracheo-bronchial tissue models were not significantly affected compared to the controls. Subsequently, we investigated the interaction of B. pertussis with both differentiated primary nasal and tracheo-bronchial tissue models and demonstrated bacterial adherence and invasion without observing host cell type-specific significant differences. Even though the nasal and the tracheo-bronchial mucosa appear similar from a histological perspective, they are differentially susceptible to B. pertussis CyaA in vitro. Our finding that nasal tissue models showed an increased innate immune response towards the B. pertussis virulence factor CyaA compared to tracheo-bronchial tissue models may reflect the key role of the nasal airway mucosa as the first line of defense against airborne pathogens.

How to prepare for academic leadership: scientific training curriculum

Thoracic surgery has evolved into an independent discipline out of general surgery practice over the past decades. The development of the field of thoracic surgery was generated from surgeons being motivated to move this field forward by constant analysis and critical appraisal and review of current practice, as well as identification of new research approaches as the pool and generator of innovation. For this purpose, scientific skills are needed that are currently not covered during the surgical training. In the present overview, we will try to summarize important factors for an academic career, although none of these recommendations are validated and also not realistic to be uniquely applied to every geographical setting. Several key factors will be described being necessary for pursuing basic science, translational, and clinical research as a surgeon scientist introducing “from bench to bedside” research ideas into clinic and “from bedside to bench” bringing important clinical problems back to the lab.

Activity of Tracheal Cytotoxin of Bordetella pertussis in a Human Tracheobronchial 3D Tissue Model

Bordetella pertussis is a highly contagious pathogen which causes whooping cough in humans. A major pathophysiology of infection is the extrusion of ciliated cells and subsequent disruption of the respiratory mucosa. Tracheal cytotoxin (TCT) is the only virulence factor produced by B. pertussis that has been able to recapitulate this pathology in animal models. This pathophysiology is well characterized in a hamster tracheal model, but human data are lacking due to scarcity of donor material. We assessed the impact of TCT and lipopolysaccharide (LPS) on the functional integrity of the human airway mucosa by using in vitro airway mucosa models developed by co-culturing human tracheobronchial epithelial cells and human tracheobronchial fibroblasts on porcine small intestinal submucosa scaffold under airlift conditions. TCT and LPS either alone and in combination induced blebbing and necrosis of the ciliated epithelia. TCT and LPS induced loss of ciliated epithelial cells and hyper-mucus production which interfered with mucociliary clearance. In addition, the toxins had a disruptive effect on the tight junction organization, significantly reduced transepithelial electrical resistance and increased FITC-Dextran permeability after toxin incubation. In summary, the results indicate that TCT collaborates with LPS to induce the disruption of the human airway mucosa as reported for the hamster tracheal model.

Susceptibility of primary human airway epithelial cells to Bordetella pertussis adenylate cyclase toxin in two- and three-dimensional culture conditions

The human pathogen Bordetella pertussis targets the respiratory epithelium and causes whooping cough. Its virulence factor adenylate cyclase toxin (CyaA) plays an important role in the course of infection. Previous studies on the impact of CyaA on human epithelial cells have been carried out using cell lines derived from the airways or the intestinal tract. Here, we investigated the interaction of CyaA and its enzymatically inactive but fully pore-forming toxoid CyaA-AC^– with primary human airway epithelial cells (hAEC) derived from different anatomical sites (nose and tracheo-bronchial region) in two-dimensional culture conditions. To assess possible differences between the response of primary hAEC and respiratory cell lines directly, we included HBEC3-KT in our studies. In comparative analyses, we studied the impact of both the toxin and the toxoid on cell viability, intracellular cAMP concentration and IL-6 secretion. We found that the selected hAEC, which lack CD11b, were differentially susceptible to both CyaA and CyaA-AC^–. HBEC3-KT appeared not to be suitable for subsequent analyses. Since the nasal epithelium first gets in contact with airborne pathogens, we further studied the effect of CyaA and its toxoid on the innate immunity of three-dimensional tissue models of the human nasal mucosa. The present study reveals first insights in toxin–cell interaction using primary hAEC.

[Operability and Pathological Response of Non-Small Cell Lung Cancer (NSCLC) after Neoadjuvant Therapy with Immune Checkpoint Inhibition]

BACKGROUND

 The blockade of immune escape mechanisms (e. g. PD1 /PD-L1) using immune checkpoint inhibition (ICI) can significantly prolong survival and induce remission in patients with advanced non-small cell lung cancer (NSCLC). Less is known about neoadjuvant ICI in patients with resectable (UICC stage III) or oligometastatic (UICC stage IVa) NSCLC.

METHODS

 Tissue biopsies from patients with advanced or oligometastatic NSCLC were screened for PD-L1 expression. In case of PD-L1-expression > 50 %, ECOG status of 0 or 1 and expected operability, patients received ICI. After about four weeks, patients underwent thoracic surgical resection. In all patients, a complete staging, including PET-CT, cMRI, and endobronchial ultrasound, was performed. The tolerability, the radiological and the histopathological tumor response as well as the surgical and oncological outcomes were analyzed.

FINDINGS

 Four patients (2 male, 2 female, age 56 - 78 years, n = 3 adenocarcinoma, n = 1 squamous cell carcinoma) with local advanced tumors received ICI before surgical resection. In three cases the mediastinal lymph nodes were positive. One patient had a single cerebral metastasis which was treated with radiotherapy. All four patients underwent therapy with two to six cycles of ICI (3 × pembrolizumab, 1 × atezolizumab) without any complication, and ICI did not delay the time of surgical resection. According to iRECIST, three patients showed partial response (PR), one patient had stable disease (SD). All tumors were completely resected. The thoracic surgical procedures proved to be technically unproblematic despite inflammatory changes. There were neither treatment-related deaths nor perioperative complications. In the resectates, complete pathological response (CPR, regression grade III ) and regression grade IIb were detected twice. The average time of follow-up was 12 (1 - 24) months. Patients with PPR developed distant metastasis after six months or a local recurrence after four months. The CPR patient is relapse free to date.

CONCLUSION

 In selected patients, neoadjuvant therapy with ICI is well tolerated and can induce a complete remission of the tumor. Treatment with ICI has no negative impact on the surgical procedure. Prognosis seems to be promising in CPR and limited in PPR.

Redistribution of pulmonary ventilation after lung surgery detected with electrical impedance tomography

BACKGROUND

Regional ventilation of the lung can be visualized by pulmonary electrical impedance tomography (EIT). The aim of this study was to examine the post-operative redistribution of regional ventilation after lung surgery dependent on the side of surgery and its association with forced vital capacity.

METHODS

In this prospective, observational cohort study 13 patients undergoing right and 13 patients undergoing left-sided open or video-thoracoscopic procedures have been investigated. Pre-operative measurements with EIT and spirometry were compared with data obtained 3 days post-operation. The center of ventilation (COV) within a 32 × 32 pixel matrix was calculated from EIT data. The transverse axis coordinate of COV, COVx (left/right), was modified to COVx' (ipsilateral/contralateral). Thus, COVx' shows a negative change if ventilation shifts contralateral independent of the side of surgery. This enabled testing with two-way ANOVA for repeated measurements (side, time).

RESULTS

The perioperative shift of COVx' was dependent on the side of surgery (P = .007). Ventilation shifted away from the side of surgery after the right-sided surgery (COVx'-1.97 pixel matrix points, P < .001), but not after the left-sided surgery (COVx'-0.61, P = .425). The forced vital capacity (%predicted) decreased from 94 (83-109)% (median [quartiles]; [left-sided]) and 89 (80-97)% (right-sided surgery) to 61 (59-66)% and 62 (40-72)% (P < .05), respectively. The perioperative changes in forced vital capacity (%predicted) were weakly associated with the shift of COVx'.

CONCLUSION

Only after right-sided lung surgery, EIT showed reduced ventilation on the side of surgery while vital capacity was markedly reduced in both groups.

Investigation on Ciliary Functionality of Different Airway Epithelial Cell Lines in Three-Dimensional Cell Culture

Three-dimensional respiratory tissue models have been generated using, for example, human primary airway epithelial cells (hAEC) or respective cell lines. To investigate ciliopathies, such as primary ciliary dyskinesia, the presence of functional kinocilia in vitro is an essential prerequisite. Since access to hAEC of healthy donors is limited, we aimed to identify a respiratory epithelial cell line that is capable to display functional kinocilia on at least 60% of the apical surface. Thus, we cultured four different human respiratory cell lines with human primary airway fibroblasts under airlift conditions, characterized the morphology, and analyzed ciliary function. Only one of the tested cell lines showed beating kinocilia; however, <10% of the whole surface was covered and ciliary beating was undirected. Positive control tissue models using hAEC and fibroblasts displayed expected directed ciliary beating pattern around 11 Hz. Our data show that the available cell lines are not suitable for basic and applied research questions whenever functional kinocilia are required and that, rather, hAEC- or human induced pluripotent stem cell-derived tissue models need to be generated.

Temperature Controlled and Monitored Ex Vivo Lung Perfusion System for Research and Training Purposes

Ex vivo lung perfusion (EVLP) is a preservation method for donor lungs, which keep lungs viable in a physiological environment outside of a body for a short period of time. EVLP is established clinically for lung transplantation. Experimental applications for EVLP are e.g. lung cancer research or medical device development and testing. For preservation, a lung is ventilated artificially in an organ chamber and perfused antegrade through the pulmonary artery. Here we introduce a thermoregulation system for an experimental EVLP system to be used for translational research approaches as well as for training medical staff. To implement physiological culture conditions that are a prerequisite for lung preservation and tissue homeostasis, a thermoregulation is needed to rewarm the explanted lung tissue (storage temperature 4°C). Technically, the EVLP system must be thermally insulated, so loss of caloric is avoided. For monitoring, temperature sensors are integrated within the lung, in the organ chamber and in the afferent perfusate tube, whereby the measured values determine the thermoregulation. Initial tests using thermal packs (cooled to 4-6°C) placed on a heating mat, as a part of the perfusion circuit, showed that the perfusate temperature falls to 34°C, but restores after approximately 60 minutes (36.5°C), whereby the thermal pack is warmed. With this setup longer perfusion times should be obtained rather than without thermoregulation due to normothermic perfusion of the lung.

Management of Spontaneous Pneumothorax and Postinterventional Pneumothorax: German S3-Guideline

In Germany, 10,000 cases of spontaneous pneumothorax are treated inpatient every year. The German Society for Thoracic Surgery (DGT), in co-operation with the German Society for Pulmonology (DGP), the German Radiological Society (DRG) and the German Society of Internal Medicine (DGIM) has developed an S3 guideline on spontaneous pneumothorax and postinterventional pneumothorax moderated by the German Association of Scientific Medical Societies (AWMF).

METHOD

Based on the source guideline of the British Thoracic Society (BTS2010) for spontaneous pneumothorax, a literature search on spontaneous pneumothorax was carried out from 2008 onwards, for post-interventional pneumothorax from 1960 onwards. Evidence levels according to the Oxford Center for Evidence-Based Medicine (2011) were assigned to the relevant studies found. Recommendations according to GRADE (A: "we recommend"/"we do not recommend", B: "we suggest"/"we do not suggest") were determined in three consensus conferences by the nominal group process.

RESULTS

The algorithms for primary and secondary pneumothorax differ in the indication for CT scan as well as in the indication for chest drainage application and video-assisted thoracic surgery (VATS). Indication for surgery is recommended individually taking into account the risk of recurrence, life circumstances, patient preferences and procedure risks. For some forms of secondary pneumothorax, a reserved indication for surgery is recommended. Therapy of postinterventional spontaneous pneumothorax is similar to that of primary spontaneous pneumothorax.

DISCUSSION

The recommendations of the S3 Guideline provide assistance in managing spontaneous pneumothorax and post-interventional pneumothorax. Whether this will affect existing deviant diagnostic and therapeutic measures will be demonstrated by future epidemiological studies.

Management of Spontaneous Pneumothorax and Post-Interventional Pneumothorax: German S3 Guideline

In Germany, 10,000 cases of spontaneous pneumothorax are treated inpatient every year. The German Society for Thoracic Surgery, in co-operation with the German Society for Pulmonology, the German Radiological Society, and the German Society of Internal Medicine has developed an S3 guideline on spontaneous pneumothorax and post-interventional pneumothorax moderated by the German Association of Scientific Medical Societies.

METHOD

Based on the source guideline of the British Thoracic Society (2010) for spontaneous pneumothorax, a literature search on spontaneous pneumothorax was carried out from 2008 onwards, for post-interventional pneumothorax from 1960 onwards. Evidence levels according to the Oxford Center for Evidence-Based Medicine (2011) were assigned to the relevant studies found. Recommendations according to grade (A: "we recommend"/"we do not recommend," B: "we suggest"/"we do not suggest") were determined in 3 consensus conferences by the nominal group process.

RESULTS

The algorithms for primary and secondary pneumothorax differ in the indication for CT scan as well as in the indication for chest drainage application and video-assisted thoracic surgery. Indication for surgery is recommended individually taking into account the risk of recurrence, life circumstances, patient preferences, and procedure risks. For some forms of secondary pneumothorax, a reserved indication for surgery is recommended. Therapy of post-interventional spontaneous pneumothorax is similar to that of primary spontaneous pneumothorax.

DISCUSSION

The recommendations of the S3 Guideline provide assistance in managing spontaneous pneumothorax and post-interventional pneumothorax. Whether this will affect existing deviant diagnostic and therapeutic measures will be demonstrated by future epidemiological studies.

Recurrence of Spontaneous Pneumothorax Is Not Associated with Allegedly Risk-Prone Lifestyle Conduct

PURPOSE

Spontaneous pneumothorax (PNTX) is a common disease frequently operated at specialized thoracic surgery units. Videothoracoscopic surgery (VATS) has become the standard for treatment and recurrence prevention. While there is broad consensus regarding indications and techniques of PNTX surgery, postoperative risks and consecutive patient behavioral advice have not been sufficiently elucidated.

METHODS

Single-center cohort analysis of 641 patients operated for primary PNTX by VATS over 10 years. Putatively recurrence-prone lifestyle activities (smoking status, flying habits, and scuba diving) and actual occurrence of recurrences were correlated.

RESULTS

Follow-up rate was 46% (279/607 patients). Mean time interval between primary operation and follow-up was 61 (range: 5-177) months. In 10 patients (3.6%), a PNTX recurrence was observed. Regarding postoperative risk behavior reported at follow-up, 28% of patients were active smokers (15 ± 7 cigarettes/day), 59% traveled by plane repeatedly, and only two patients did scuba diving (0.7%). Low body-mass-index was associated with an increase in PNTX recurrence, whereas smoking, flying, and scuba diving could not be identified as risk factors.

CONCLUSION

In our study, none of the supposed "classic" lifestyle-associated risk factors for PNTX recurrence after VATS proved to be a significant threat. Postoperative patient behavior might not be constrained by overcautious medical advice.

MicroRNA-21 versus microRNA-34: Lung cancer promoting and inhibitory microRNAs analysed in silico and in vitro and their clinical impact

MicroRNAs are well-known strong RNA regulators modulating whole functional units in complex signaling networks. Regarding clinical application, they have potential as biomarkers for prognosis, diagnosis, and therapy. In this review, we focus on two microRNAs centrally involved in lung cancer progression. MicroRNA-21 promotes and microRNA-34 inhibits cancer progression. We elucidate here involved pathways and imbed these antagonistic microRNAs in a network of interactions, stressing their cancer microRNA biology, followed by experimental and bioinformatics analysis of such microRNAs and their targets. This background is then illuminated from a clinical perspective on microRNA-21 and microRNA-34 as general examples for the complex microRNA biology in lung cancer and its diagnostic value. Moreover, we discuss the immense potential that microRNAs such as microRNA-21 and microRNA-34 imply by their broad regulatory effects. These should be explored for novel therapeutic strategies in the clinic.

Targeting CXCR4 with [68Ga]Pentixafor: a suitable theranostic approach in pleural mesothelioma?

C-X-C motif chemokine receptor 4 (CXCR4) is a key factor for tumor growth and metastasis in several types of human cancer. This study investigated the feasibility of CXCR4-directed imaging with positron emission tomography/computed tomography (PET/CT) using [⁶⁸Ga]Pentixafor in malignant pleural mesothelioma.

Six patients with pleural mesothelioma underwent [⁶⁸Ga]Pentixafor-PET/CT. 2′-[¹⁸F]fluoro-2′-deoxy-D-glucose ([¹⁸F]FDG)-PET/CT (4/6 patients) and immunohistochemistry obtained from biopsy or surgery (all) served as standards of reference. Additionally, 9 surgical mesothelioma samples were available for histological work-up.

Whereas [¹⁸F]FDG-PET depicted active lesions in all patients, [⁶⁸Ga]Pentixafor-PET/CT recorded physiologic tracer distribution and none of the 6 patients presented [⁶⁸Ga]Pentixafor-positive lesions. This finding paralleled results of immunohistochemistry which also could not identify relevant CXCR4 surface expression in the samples analyzed.

In contrast to past reports, our data suggest widely absence of CXCR4 expression in pleural mesothelioma. Hence, robust cell surface expression should be confirmed prior to targeting this chemokine receptor for diagnosis and/or therapy.

The impact of pulmonary metastasectomy in patients with previously resected colorectal cancer liver metastases

Background

40–50% of patients with colorectal cancer (CRC) will develop liver metastases (CRLM) during the course of the disease. One third of these patients will additionally develop pulmonary metastases.

Methods

137 consecutive patients with CRLM, were analyzed regarding survival data, clinical, histological data and treatment. Results were stratified according to the occurrence of pulmonary metastases and metastases resection.

Results

39% of all patients with liver resection due to CRLM developed additional lung metastases. 44% of these patients underwent subsequent pulmonary resection. Patients undergoing pulmonary metastasectomy showed a significantly better five-year survival compared to patients not qualified for curative resection (5-year survival 71.2% vs. 28.0%; p = 0.001). Interestingly, the 5-year survival of these patients was even superior to all patients with CRLM, who did not develop pulmonary metastases (77.5% vs. 63.5%; p = 0.015). Patients, whose pulmonary metastases were not resected, were more likely to redevelop liver metastases (50.0% vs 78.6%; p = 0.034). However, the rate of distant metastases did not differ between both groups (54.5 vs.53.6; p = 0.945).

Conclusion

The occurrence of colorectal lung metastases after curative liver resection does not impact patient survival if pulmonary metastasectomy is feasible. Those patients clearly benefit from repeated resections of the liver and the lung metastases.

Non-Coding RNAs in Lung Cancer: Contribution of Bioinformatics Analysis to the Development of Non-Invasive Diagnostic Tools

Lung cancer is currently the leading cause of cancer related mortality due to late diagnosis and limited treatment intervention. Non-coding RNAs are not translated into proteins and have emerged as fundamental regulators of gene expression. Recent studies reported that microRNAs and long non-coding RNAs are involved in lung cancer development and progression. Moreover, they appear as new promising non-invasive biomarkers for early lung cancer diagnosis. Here, we highlight their potential as biomarker in lung cancer and present how bioinformatics can contribute to the development of non-invasive diagnostic tools. For this, we discuss several bioinformatics algorithms and software tools for a comprehensive understanding and functional characterization of microRNAs and long non-coding RNAs.

Comparison of volatile organic compounds from lung cancer patients and healthy controls-challenges and limitations of an observational study

This paper outlines the design and performance of an observational study on the profiles of volatile organic compounds (VOCs) in the breath of 37 lung cancer patients and 23 healthy controls of similar age. The need to quantify each VOC considered as a potential disease marker on the basis of individual calibration is elaborated, and the quality control measures required to maintain reproducibility in breath sampling and subsequent instrumental trace VOC analysis using solid phase microextraction-gas chromatography-mass spectrometry over a study period of 14 months are described. Twenty-four VOCs were quantified on the basis of their previously suggested potential as cancer markers. The concentration of aromatic compounds in the breath was increased, as expected, in smokers, while lung cancer patients displayed significantly increased levels of oxygenated VOCs such as aldehydes, 2-butanone and 1-butanol. Although sets of selected oxygenated VOCs displayed sensitivities and specificities between 80% and 90% using linear discriminant analysis (LDA) with leave-one-out cross validation, the effective selectivity of the breath VOC approach with regard to cancer detection is clearly limited. Results are discussed against the background of the literature on volatile cancer marker investigations and the prospects of linking increased VOC levels in patients' breath with approaches that employ sniffer dogs. Experience from this study and the literature suggests that the currently available methodology is not able to use breath VOCs to reliably discriminate between cancer patients and healthy controls. Observational studies often tend to note significant differences in levels of certain oxygenated VOCs, but without the resolution required for practical application. Any step towards the exploitation of differences in VOC profiles for illness detection would have to solve current restrictions set by the low and variable VOC concentrations. Further challenges are the technical complexity of studies involving breath sampling and possibly the limited capability of current analytical procedures to detect unstable marker candidates.

Human Organotypic Lung Tumor Models: Suitable For Preclinical 18F-FDG PET-Imaging

Development of predictable in vitro tumor models is a challenging task due to the enormous complexity of tumors in vivo. The closer the resemblance of these models to human tumor characteristics, the more suitable they are for drug-development and –testing. In the present study, we generated a complex 3D lung tumor test system based on acellular rat lungs. A decellularization protocol was established preserving the architecture, important ECM components and the basement membrane of the lung. Human lung tumor cells cultured on the scaffold formed cluster and exhibited an up-regulation of the carcinoma-associated marker mucin1 as well as a reduced proliferation rate compared to respective 2D culture. Additionally, employing functional imaging with 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography (FDG-PET) these tumor cell cluster could be detected and tracked over time. This approach allowed monitoring of a targeted tyrosine kinase inhibitor treatment in the in vitro lung tumor model non-destructively. Surprisingly, FDG-PET assessment of single tumor cell cluster on the same scaffold exhibited differences in their response to therapy, indicating heterogeneity in the lung tumor model. In conclusion, our complex lung tumor test system features important characteristics of tumors and its microenvironment and allows monitoring of tumor growth and -metabolism in combination with functional imaging. In longitudinal studies, new therapeutic approaches and their long-term effects can be evaluated to adapt treatment regimes in future.

A Combined 3D Tissue Engineered In Vitro/In Silico Lung Tumor Model for Predicting Drug Effectiveness in Specific Mutational Backgrounds

In the present study, we combined an in vitro 3D lung tumor model with an in silico model to optimize predictions of drug response based on a specific mutational background. The model is generated on a decellularized porcine scaffold that reproduces tissue-specific characteristics regarding extracellular matrix composition and architecture including the basement membrane. We standardized a protocol that allows artificial tumor tissue generation within 14 days including three days of drug treatment. Our article provides several detailed descriptions of 3D read-out screening techniques like the determination of the proliferation index Ki67 staining's, apoptosis from supernatants by M30-ELISA and assessment of epithelial to mesenchymal transition (EMT), which are helpful tools for evaluating the effectiveness of therapeutic compounds. We could show compared to 2D culture a reduction of proliferation in our 3D tumor model that is related to the clinical situation. Despite of this lower proliferation, the model predicted EGFR-targeted drug responses correctly according to the biomarker status as shown by comparison of the lung carcinoma cell lines HCC827 (EGFR -mutated, KRAS wild-type) and A549 (EGFR wild-type, KRAS-mutated) treated with the tyrosine-kinase inhibitor (TKI) gefitinib. To investigate drug responses of more advanced tumor cells, we induced EMT by long-term treatment with TGF-beta-1 as assessed by vimentin/pan-cytokeratin immunofluorescence staining. A flow-bioreactor was employed to adjust culture to physiological conditions, which improved tissue generation. Furthermore, we show the integration of drug responses upon gefitinib treatment or TGF-beta-1 stimulation - apoptosis, proliferation index and EMT - into a Boolean in silico model. Additionally, we explain how drug responses of tumor cells with a specific mutational background and counterstrategies against resistance can be predicted. We are confident that our 3D in vitro approach especially with its in silico expansion provides an additional value for preclinical drug testing in more realistic conditions than in 2D cell culture.

Host-integration of a tissue-engineered airway patch: two-year follow-up in a single patient

Different bioengineering techniques have been applied repeatedly for the reconstruction of extensive airway defects in the last few years. While short-term surgical success is evident, there is a lack of long-term results in patients. Here, we report the case of a young male who received a 5×2 cm bioartificial airway patch for tracheoesophageal reconstruction focusing on clinical defect healing and histomorphological tissue reorganization 2.5 years after surgery. We generated bioartificial airway tissue using a cell-free biological vascularized scaffold that was re-endothelialized and reseeded with the recipient's autologous primary cells and we implanted it into the recipient's left main bronchus. To investigate host-integration 2.5 years after the implantation, we obtained biopsies of the implant and adjacent tracheal tissue and processed these for histological and immunohistochemical analyses. The early postoperative course was uneventful and the transplanted airway tissue was integrated into the host. 2.5 years after transplantation, a bronchoscopy confirmed the scar-free reconstruction of the former airway defect. Histological work-up documented respiratory airway mucosa lining the bronchial reconstruction, making it indistinguishable from native airway mucosa. After transplantation, our bioartificial airway tissue provided perfect airway healing, with no histological evidence of tissue dedifferentiation.

[Pneumothorax]

The presence of air between the visceral pleura and the parietal pleura with consecutive retraction of the lung from the chest wall is called pneumothorax. Regarding the genesis of the pneumothorax, a distinction is drawn between spontaneous and traumatic pneumothorax. The spontaneous pneumothorax is, depending on whether a congenital or an acquired pulmonary disease can be found, grouped into a primary spontaneous pneumothorax (PSP) without underlying lung disease and a secondary spontaneous pneumothorax (SSP) with the presence of a known lung disease. The traumatic pneumothorax is classified, depending on the cause, into penetrating and non-penetrating (blunt) traumatic events. A special form of the traumatic pneumothorax is the iatrogenic pneumothorax occurring as a result of diagnostic and/or therapeutic interventions. Clinically, a pneumothorax can range from an asymptomatic to an acute life-threatening situation. The required initial measures depend primarily on the patient's clinical condition. They vary from immediate insertion of a chest tube to wait and see with monitoring. The insertion of a chest tube is still the accepted therapeutic standard, but other procedures like aspiration of air through a needle or small catheter, particularly for small spontaneous pneumothoraces, represent alternative therapy options as well. The short-term goal is to treat possibly existing dyspnea and pain; in the long run a recurrence of the pneumothorax should be prevented. Until now, no uniform treatment algorithms or standardised therapy principles exist to achieve the therapeutic intentions of lung expansion and freedom from pain and late relapse.