Longitudinal analysis of PD-L1 expression in patients with relapsed NSCLC.

BACKGROUND: The use and approval of immune checkpoint inhibitors for the treatment of non-small cell lung cancer (NSCLC) depends on PD-L1 expression in the tumor tissue. Nevertheless, PD-L1 often fails to predict response to treatment. One possible explanation could be a change in PD-L1 expression during the course of the disease and the neglect of reassessment. The purpose of this study was a longitudinal analysis of PD-L1 expression in patients with relapsed NSCLC. METHODS: We retrospectively analyzed PD-L1 expression in patients with early-stage NSCLC and subsequent relapse in preoperative samples, matched surgical specimens and biopsy samples of disease recurrence. Ventana PD-L1 (SP263) immunohistochemistry assay was used for all samples. PD-L1 expression was scored based on clinically relevant groups (0%, 1%-49%, and ≥50%). The primary endpoint was the change in PD-L1 score group between preoperative samples, matched surgical specimens and relapsed tumor tissue. RESULTS: 395 consecutive patients with stages I-III NSCLC and 136 (34%) patients with a subsequent relapse were identified. For 87 patients at least two specimens for comparison of PD-L1 expression between early stage and relapsed disease were available. In 72 cases, a longitudinal analysis between preoperative biopsy, the surgically resected specimen and biopsy of disease recurrence was feasible. When comparing preoperative and matched surgical specimens, a treatment-relevant conversion of PD-L1 expression group was found in 25 patients (34.7%). Neoadjuvant treatment showed no significant effect on PD-L1 alteration (p=0.39). In 32 (36.8%) out of 87 cases, a change in PD-L1 group was observed when biopsies of disease relapse were compared with early-stage disease. Adjuvant treatment was not significantly associated with a change in PD-L1 expression (p=0.53). 39 patients (54.2%) showed at least 1 change into a different PD-L1 score group during the course of disease. 14 patients (19.4%) changed the PD-L1 score group twice, 5 (6.9%) of them being found in all different score groups. CONCLUSION: PD-L1 expression shows dynamic changes during the course of disease. There is an urgent need for consensus guidelines to define a PD-L1 testing strategy including time points of reassessment, the number of biopsies to be obtained and judgment of surgical specimens.

Measuring the global mechanical properties of the human thorax: Costo-vertebral articulation.

Biomechanical simulation of the human thorax, e.g. for 3D-printed rib implant optimisation, requires an accurate knowledge of the associated articulation and tissue stiffness. The present study is focusing on determining the stiffness of the costo-vertebral articulations. Specimens of rib segments including the adjacent thoracic vertebrae and ligaments were obtained from two human post-mortem bodies at four different rib levels. The rib samples were loaded with a tensile force in the local longitudinal, sagittal and transverse direction and the resulting displacement was continuously measured. The moment-angle response of the rib articulations was also determined by applying a load at the rib end in the cranial - caudal direction and measuring the resulting displacement. The torsional load response of the costo-vertebral articulations at an applied moment between -0.1 Nm and 0.1 Nm corresponded to a median range of motion of 13.2° (6.4° to 20.9°). An almost uniform stiffness was measured in all tensile loading directions. The median displacement at the defined force of 28 N was 1.41 mm in the longitudinal, 1.55 mm in the sagittal, and 1.08 mm in the transverse direction. The measured moment-angle response of the costo-vertebral articulation is in line with the data from literature. On the contrary, larger displacements in longitudinal, sagittal and transverse directions were measured compared to the values found in literature.

The Prognostic Long-Term Impact of Chronic Obstructive Pulmonary Disease and Postoperative Mucostasis in Patients with Curatively Resected Non-Small Cell Lung Cancer.

Chronic obstructive pulmonary disease (COPD) serves as risk factor for the development of lung cancer and seems to have a prognostic impact after surgery for non-small cell lung cancer (NSCLC). The aim was to investigate the impact of COPD and postoperative mucostasis on the long-term survival after resected NSCLC. We retrospectively reviewed the data from 342 patients with curatively resected NSCLC. The prognostic long-term impact of COPD and postoperative mucostasis on overall survival (OS), recurrence free survival (RFS) and cancer specific survival (CSS) was calculated using univariable and multivariable Cox regression analyses. We found that 52.3% suffered from COPD and 25.4% had postoperative mucostasis. COPD was significantly more common among smokers (59.9%) compared with non-smokers (21.3%), (p < 0.001). There was a significant relationship between COPD and postoperative mucostasis (p = 0.006) and between smoking and mucostasis (p = 0.023). Patients with postoperative mucostasis had a significantly worse OS (p < 0.001), RFS (p = 0.009) and CSS (p = 0.008). The present analysis demonstrated that postoperative mucostasis, but not COPD, was associated with both worse short- and long-term outcomes for OS, RFS and CSS in curatively resected NSCLC.

High complication rate with titanium plates for chest wall reconstruction following tumour resection.

OBJECTIVES: The reconstruction of the chest wall defect after tumour resection presents a challenge. Titanium rib plates were presented as a reconstruction option due to its biocompatibility, flexibility and pliability. The aim of this study was to evaluate the outcome of single-centre cohort treated with chest wall reconstruction after tumour resections, with a focus on the titanium rib plates reconstruction. METHODS: We retrospectively reviewed the data of 26 patients who underwent wide resection for malignancies of the chest wall, where reconstruction was performed using polypropylene mesh, porcine dermal collagen mesh with or without titanium rib plates, operated on between 2012 and 2019. Events being associated with the surgery requiring revision were rated as complications. RESULTS: Most of the patients had primary tumours (n = 19; 73%). A mean of 3.7 ribs (range: 1-7) was resected. Reconstruction was performed with titanium rib plates (13 patients, 50%), of these 11 were performed with additional mesh grafts. The remaining 13 patients (50%) underwent reconstruction with mesh grafts only. Fourteen patients (54%) developed a complication requiring surgical revision, after a median of 5.5 months. The most common complication was wound healing deficit (n = 4), plate fracture (n = 2), mesh rupture (n = 2), infection (n = 2) and local recurrence (n = 2). The only factor being associated with the development of complications was the usage of a plate (P = 0.015), irrespective of defect size (P = 0.29). CONCLUSIONS: The high complication rate is found when using titanium plates for chest wall reconstruction after tumour resection. A high caution is recommended in choosing the chest wall reconstruction method.

Measurement of global mechanical properties of human thorax: Costal cartilage.

Surgical resection of chest wall tumours may lead to a loss of ribcage stability and requires reconstruction to allow for physical thorax functioning. When titanium implants are used especially for larger, lateral defects, they tend to break. Implant failures are mainly due to specific mechanical requirements for chest-wall reconstruction which must mimic the physiological properties and which are not yet met by available implants. In order to develop new implants, the mechanical characteristics of ribs, joints and cartilages are investigated. Rib loading is highly dependent on the global thorax kinematics, making implant development substantially challenging. Costal cartilage contributes vastly to the entire thorax load-deformation behaviour, and also to rib loading patterns. Computational models of the thoracic cage require mechanical properties on the global stiffness, to simulate rib kinematics and evaluate stresses in the ribs and costal cartilage. In this study the mechanical stiffness of human costal cartilage is assessed with bending, torsion and tensile tests. The elastic moduli for the bending in four major directions ranged from 2.2 to 60.8 MPa, shear moduli ranged from 5.7 to 24.7 MPa for torsion, and tensile elastic moduli ranging from 5.6 to 29.6 MPa. This article provides mechanical properties for costal cartilage. The results of these measurements are used for the development of a whole thorax finite element model to investigate ribcage biomechanics and subsequently to design improved rib implants.

Autophagy, Oxidative Stress and Cancer Development.

Autophagy is an important cellular repair mechanism, aiming at sequestering misfolded and dysfunctional proteins and damaged cell organelles. Dysfunctions in the autophagy process have been linked to several diseases, like infectious and neurodegenerative diseases, type II diabetes mellitus and cancer. Living organisms are constantly subjected to some degree of oxidative stress, mainly induced by reactive oxygen and nitrogen species. It has been shown that autophagy is readily induced by reactive oxygen species (ROS) upon nutrient deprivation. In recent years, research has increasingly focused on outlining novel therapeutic targets related to the autophagy process. With this review of the literature, we want to give an overview about the link between autophagy, oxidative stress and carcinogenesis.

Identification of Novel Low-Density Neutrophil Markers Through Unbiased High-Dimensional Flow Cytometry Screening in Non-Small Cell Lung Cancer Patients.

Neutrophils have been described as a phenotypically heterogeneous cell type that possess both pro- and anti-tumor properties. Recently, a subset of neutrophils isolated from the peripheral blood mononuclear cell (PBMC) fraction has been described in cancer patients. These low-density neutrophils (LDNs) show a heterogeneous maturation state and have been associated with pro-tumor properties in comparison to mature, high-density neutrophils (HDNs). However, additional studies are necessary to characterize this cell population. Here we show new surface markers that allow us to discriminate between LDNs and HDNs in non-small cell lung cancer (NSCLC) patients and assess their potential as diagnostic/prognostic tool. LDNs were highly enriched in NSCLC patients (median=20.4%, range 0.3-76.1%; n=26) but not in healthy individuals (median=0.3%, range 0.1-3.9%; n=14). Using a high-dimensional human cell surface marker screen, we identified 12 surface markers that were downregulated in LDNs when compared to HDNs, while 41 surface markers were upregulated in the LDN subset. Using flow cytometry, we confirmed overexpression of CD36, CD41, CD61 and CD226 in the LDN fraction. In summary, our data support the notion that LDNs are a unique neutrophil population and provide novel targets to clarify their role in tumor progression and their potential as diagnostic and therapeutic tool.

A nomogram illustrating the probability of anastomotic leakage following cervical esophagogastrostomy.

BACKGROUND: Early diagnosis of anastomotic dehiscence following cervical esophagogastrostomy may become difficult. Estimation of an individual probability could help to establish preventive and diagnostic measures. The predictive impact of epidemiological, surgery-related data and laboratory parameters on the development of anastomotic dehiscence was investigated in the immediate perioperative period. METHODS: Retrospective study in 412 patients with cervical esophagogastrostomy following esophagectomy. Epidemiological data, risk factors, underlying disease, pre-treatment- and surgery-related data, C-reactive protein and albumin levels pre-and post-operatively were evaluated. We applied univariable and multivariable logistic regression analysis and developed a nomogram for individual risk assessment. RESULTS: There were 345 male, 67 female patients, mean aged 61.5 years; 284 had orthotopic, 128 retrosternal gastric pull-up; 331 patients had carcinoma, 81 non-malignant disease. Mean duration of operation was 184 min; 235 patients had manual, 113 mechanical and 64 semi-mechanical suturing; 76 patients (18.5%) developed anastomotic dehiscence clinically evident at mean 11.4 days after surgery. In univariable testing young age, retrosternal conduit transposition, manual suturing, high body mass index, high ASA and high postoperative levels of C-reactive protein were predictors for anastomotic leakage. These six parameters which had yielded a p < 0.1 in the univariable analysis, were entered into a multivariable analysis and a nomogram allowing the determination of the patient's individual risk was created. CONCLUSION: By using the nomogram as a supportive measure in the perioperative management, the patient's individual probability of developing an anastomotic leak could be quantified which may help to take preventive measures improving the outcome.

Multi-channel lung sound classification with convolutional recurrent neural networks.

In this paper, we present an approach for multi-channel lung sound classification, exploiting spectral, temporal and spatial information. In particular, we propose a frame-wise classification framework to process full breathing cycles of multi-channel lung sound recordings with a convolutional recurrent neural network. With our recently developed 16-channel lung sound recording device, we collect lung sound recordings from lung-healthy subjects and patients with idiopathic pulmonary fibrosis (IPF), within a clinical trial. From the lung sound recordings, we extract spectrogram features and compare different deep neural network architectures for binary classification, i.e. healthy vs. pathological. Our proposed classification framework with the convolutional recurrent neural network outperforms the other networks by achieving an F-score of F1≈92%. Together with our multi-channel lung sound recording device, we present a holistic approach to multi-channel lung sound analysis.

Hazard Curves for Tumor Recurrence and Tumor-Related Death Following Esophagectomy for Esophageal Cancer.

BACKGROUND: The knowledge of both patterns and risk of relapse following resection for esophageal cancer is crucial for establishing appropriate surveillance schedules. The aim of this study was to evaluate the pattern of hazards for tumor recurrence and tumor-related death in the postoperative long-term follow-up after esophagectomy. METHODS: Retrospective single-center analysis of 362 patients, with resected esophageal cancer. Multivariate Cox proportional hazard model was used. RESULTS: A total of 192 (53%) had postoperative tumor recurrence. The relapse patterns of adenocarcinoma and squamous-cell carcinoma showed that each had a single peak, 12 months after surgery. After induction there was one peak at 5 months, the non-induced patients peaked 11 months, postoperatively. At 18 months, the recurrence hazard declined sharply in all cases. The hazard curves for tumor-related death were bimodal for adenocarcinoma, with two peaks at 6 and 22 months and one single peak for squamous-cell carcinoma at 18 months after surgery, showing pronounced decline later on. CONCLUSION: In curatively resected esophageal cancer, both tumor recurrence hazard and hazard for tumor-related death showed distinct, partly bimodal patterns. It could be justified to intensify the surveillance during the first two postoperative years by initiating a close-meshed follow-up to detect and treat tumor recurrence, as early as possible.

Hazards of Recurrence, Second Primary, or Other Tumor at Ten Years After Surgery for Non-Small-Cell Lung Cancer.

INTRODUCTION: Better treatment options entail the risk of multiple tumors in a patient's lifetime. We studied the incidence, risk factors, and prognostic impact of second primaries and other malignancies in patients with operated non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: We retrospectively analyzed 342 consecutive patients with curatively resected NSCLC between 2003 and 2007. RESULTS: Among the 342 patients analyzed, 172 (50.3%) developed locoregional and/or distant recurrence; 25 (7.3%) had a second primary lung cancer, 97 (28.3%) had 1 or more malignancies other than NSCLC either in their history (n = 61; 17.8%) or following resection (n = 64; 18.7%). One hundred fifteen patients (33.6%) had a malignancy other than primary NSCLC. Eight patients developed both a second primary lung cancer and another malignancy. Older age and lower N-stage were significantly correlated with the occurrence of an additional tumor, as shown by a logistic regression nomogram. Whereas the risk of recurrence decreases over time, the risk of developing a second tumor, particularly a second primary lung cancer, remains high during up to 10 years of follow-up. One hundred seventy patients (49.7%) died of the primary (n = 158; 46.2%) or second primary (n = 12; 3.5%) NSCLC, 23 (6.7%) died of another malignancy, and 66 (19.3%) died due to unrelated causes (overall 10-year survival, 33.3%). CONCLUSIONS: Second primary lung cancer or other malignancy occurs in 33% of patients with NSCLC; 26% of patients are affected within 10 years after resection of lung cancer. With curative treatment of secondary tumors, there is no negative influence on long-term prognosis of NSCLC; therefore, follow-up beyond 5 years is strongly advisable.

Preoperative Peak Oxygen Consumption: A Predictor of Survival in Resected Lung Cancer.

The peak oxygen consumption (VO2 peak) serves as a prognostic factor in cardio-respiratory diseases and plays an important role in cancer patients. The long-term prognostic relevance of VO2 peak in lung cancer patients has not been investigated extensively. The aim of this study was to evaluate the impact of the preoperative VO2 peak on the postoperative long-term survival in patients with operated lung cancer. Retrospective analysis of 342 patients with curatively resected non-small-cell lung cancer using a multivariate Cox proportional hazard model. Results: Preoperative VO2 peak ranged from 10.2 to 51.8 mL/kg/min (mean: 18.3 ± 4.6), VO2 peak % of predicted ranged from 32 to 172% (mean: 65.2 ± 18.0%). Overall 10-year survival was 23%. A Log-rank test comparing predicted VO2 peak ≥ 60% with predicted VO2 peak < 60% showed overall survival of 30% and 17%, respectively (p < 0.001) and non-tumour-related survival of 71% and 51% (p = 0.001) at 10 years. In multivariable Cox analysis, overall 10-year survival correlated with a high predicted VO2 peak% (p = 0.001) and low N-stage corresponding to N0 and N1 (p < 0.001). Non-tumour-related death correlated with low VO2 peak% of predicted (p = 0.001), and age (p < 0.001). Low preoperative VO2 peak was associated with both decreased postoperative overall survival and decreased non-tumour-related survival during the 10-year follow-up.

Interposition of Retrosternal Pedicled Jejunum After Hypopharyngolaryngo-Esophagogastrectomy.

Reconstruction of the upper gastrointestinal tract presents a surgical challenge after esophagogastrectomy, especially when it includes hypopharyngolaryngectomy. Reconstruction is generally undertaken with interposed colon as a substitute conduit, but it carries several risks. Alternative reconstruction of the foregut with pedicled retrosternal jejunum anastomosed at the level of the base of the tongue is described.

Prognostic value of cyclin A2 and B1 expression in lung carcinoids.

Carcinoid classification in the lung is still based on morphological criteria. Although there are many studies investigating the role of Ki-67 proliferation index in the classification of lung neuroendocrine tumours, it is still not used in routine diagnostics. Interestingly, cyclins, which have a crucial role in controlling the cell cycle, have not been thoroughly studied in lung neuroendocrine tumours. The aim of our study was to investigate the correlation of cyclin A2 and B1 expression with prognosis, Ki-67 proliferation index, and carcinoid morphology. A cohort of 134 resected typical and atypical carcinoids was stained with antibodies against Ki-67, cyclin A2 and B1. The positive nuclear reaction was assessed in hot spot areas and expressed as the percentage of tumour cells. Univariate analyses found the highest relative hazard between low and high cyclin A2 expression both with respect to overall survival [hazard ratio (HR)=16; 95% confidence interval (CI) 4.8-51; p=0.0000054], and relapse (HR=8; 95% CI 3.1-21; p=0.00002). In multivariate analysis for overall survival cyclin A2 (HR=10; 95% CI 2.5->100; p=0.0082) and B1 (HR=6.5; 95% CI 1.5-35; p=0.02) remained significant when adjusted for other risk factors, whereas Ki-67 was no longer significant (HR=0.64; 95% CI 0.003-5.5; p=0.65). This suggests that Ki-67 is closer to conventional risk factors for survival than cyclin A2 and B1. Furthermore, the analysis revealed 4 mitoses per 2 mm2 as a more powerful prognostic cut-off than currently accepted 2 mitoses. We have clearly demonstrated that application of cyclin A2 and cyclin B1 might bring additional value regarding the overall and progression-free survival of patients with carcinoids of the lung.

Crackle and Breathing Phase Detection in Lung Sounds with Deep Bidirectional Gated Recurrent Neural Networks.

In this paper, we present a method for event detection in single-channel lung sound recordings. This includes the detection of crackles and breathing phase events (inspiration/expiration). Therefore, we propose an event detection approach with spectral features and bidirectional gated recurrent neural networks (BiGRNNs). In our experiments, we use multichannel lung sound recordings from lung-healthy subjects and patients diagnosed with idiopathic pulmonary fibrosis, collected within a clinical trial. We achieve an event-based F-score of F1 ≈ 86% for breathing phase events and F1 ≈ 72% for crackles. The proposed method shows robustness regarding the contamination of the lung sound recordings with noise, bowel and heart sounds.

Immune cell landscape in therapy-naïve squamous cell and adenocarcinomas of the lung.

Squamous cell and adenocarcinomas of the lung develop different mechanisms during carcinogenesis to evade attacks of the immune system. Besides the well-known check-point control programmed death 1 and its ligand, many more mechanisms, acting either tumoricidal or in favor of tumor progression, exist. Analysis of the immune cell profiles in resected tissues and bronchoalveolar lavage samples and correlation between them and with overall survival data was performed. In all tumor samples in this study, cells of the immune system expressed a tumor-cooperating phenotype. High numbers of regulatory T cells, or alternatively expression of Vista on lymphocytes was present. Tumoricidal dendritic cells were absent in tumor tissue, and barely present in bronchoalveolar lavage, whereas tumor-friendly monocytoid and plasmocytoid dendritic cells were seen in both. Alveolar macrophages were predominantly differentiated into tumor-cooperating M2 types, whereas tumoricidal M1 macrophages were absent or rare. The expression of PDL1 on tumor cells did not correlate with any other immune cells. Expression of PD1 on lymphocytes was frequently encountered. None of analyzed immune cells showed correlation with overall survival. Immune cells in bronchoalveolar lavage and tissue did not correlate. For the first time, a tissue-based analysis of different immune cells in squamous cell and adenocarcinomas of the lung is provided, trying to explain their potential role in tumor development and progression. Discordant numbers of cells with bronchoalveolar lavage are most probably due to the fact that bronchoalveolar lavage reflects the situation in the whole lung, where chronic obstructive lung disease and other conditions are present.