CT-based sarcopenia and outcomes in patients undergoing VATS anatomical resection for NSCLC

Objective

Sarcopenia is defined by a progressive loss of skeletal muscle mass and strength, combined with muscle fatty infiltration. Lung cancer patients frequently suffer from sarcopenia which may be associated with poorer post-operative outcomes. The aim of this study is to evaluate whether preoperative CT-based sarcopenia was associated with postoperative outcomes and survival after VATS resections in patients with early-stage non-small cell lung cancer (NSCLC).

Methods

We retrospectively reviewed all consecutive patients that underwent anatomical resection for NSCLC between 2012 and 2019. The skeletal muscle index (SMI) and muscle quality (SMRA and IMAT) were measured at the L3 vertebral level on preoperative CT or PET/CT scans. We used the following SMI cut-off values for sarcopenia: 52.4 cm2 /m2 for men and 38.5 cm2 /m2 for women.

Results

In total, 401 patients (sex ratio F/M: 173/228, mean age: 67 +/- 9.3 years) underwent VATS lobectomies (n=304) and segmentectomies (n=97) for NSCLC. Overall morbidity and mortality were 42.4% and 0.2%, respectively. The median length of stay was 7 days (IQR: 4–10). Sarcopenia was identified in 92 patients (23%). Patients with sarcopenia were predominantly males (75% vs 25%, p<0.001) and had lower BMI (21.4 vs 26.5, p<0.001). Patients with sarcopenia presented significantly increased morbidity (53.2% vs 39.2%, p=0.017) and had longer lengths of stay (6 vs 8 days, p=0.032). However, only lower BMI and ASA score >2 remained associated with increased morbidity on multivariate analysis. The median overall survival was comparable between patients with sarcopenia and those without sarcopenia (41 vs. 46 months, p=0.240).

Conclusion

Based on CT assessment alone, preoperative sarcopenia appeared to have little impact on postoperative clinical outcomes or overall survival in patients undergoing VATS pulmonary resection. Further studies should also consider muscle strength and physical performance, in addition to CT imaging, for preoperative risk assessment.

Cell death in lung transplantation. The roles of apoptosis, necroptois, and pyroptosis

Objective

For patients with end stage lung disease, lung transplantation (Ltx) is the unique treatment option. Nevertheless, a large number of lung allografts fail, because of acute or chronic rejection. Innate immune responses following Ltx play a critical role in the development of primary graft dysfunction, and ultimately promote the development of chronic lung allograft dysfunction, leading to increased mortality after lung transplantation. Here, we focus on the mechanisms responsible for disruption of the cells membranes integrity, resulting in the release of Damage Associated Molecular Patterns (DAMPs) and activation of cell death pathways triggering cell injury in lungs with different preservation status.

Methods

Rat lungs were exposed to cold ischemia (CI group, n=9) or warm ischemia (WI group, n=9). In CI group, after Perfadex flushing, and hypothermic preservation (4 h) left lung was transplanted. In WI group, after 1 h of in situ WI, flashing and 3 h cold preservation the left lung was transplanted. Lung mechanics were determined during reperfusion. Recipients were sacrificed at 30, 60 and 120 min after Ltx. Bronchoalveolar lavage (BAL) was performed on the grafts to measure markers of cellular injury, and cytokines. Cell death markers were determined in graft tissue. Biological samples were kept at -80°C for additional analysis.

Results

Compared to CI, WI group displayed significantly decreased graft function associated with increased activation of pyroptotic cell death (NLRP3, caspase1, IL-1β) pathway, whereas apoptotic (caspas3 and caspase7) and necroptotic (RIP1, RIP3, MLKL) cell death pathways activation were similar in both groups. WI group showed more important cellular damage with DAMPs release (LDH, sRAGE, HMGB) and inflammation (CXCL1, IL1-β, IL-33).

Conclusion

Our results suggest that pyroptosis could play a critical role in the development of early graft dysfunction in lungs subjected to warm ischemia. Inhibition of pyroptotic pathway could be a strategy to improve damaged donor lungs.

Uniportal VATS S9 segmentectomy: The ligamentum-based approach

Isolated resection of the lateral-basal segment (S9) is uncommon, and it is considered one of the most complex anatomic segmentectomies. First, the segmental arterial and venous supply is located deeply in the lung parenchyma, making the dissection difficult. Second, the cuboidal shape of the lateral basilar segment hampers the identification of the intersegmental plane. Although identifying the segmental arterial branches is easier from a fissure-based technique, the ligamentum-based approach emerges as a valid and safe alternative in cases of a fused fissure.

Intrapleural hyperthermic chemotherapy induces pro-immunogenic e-selectin expression in the vasculature of malignant pleural mesothelioma

Objective

Malignant pleural mesothelioma (MPM) is a deadly disease with dismal prognosis. Prior studies combining surgery with intrapleural hyperthermic chemotherapy (IPHC) have shown improved survivals in selected patients with MPM. However, the mechanisms by which IPHC acts on MPM and its microenvironment remains unknown. Here we focus on tumor endothelial adhesion molecule expression patterns.

Methods

First, we determined the impact of IPHC on MPM tumor and vascular compartments in vitro using a novel bioincubater for hyperthermic cell culture. The cytotoxicity of normo (37 °C) / hyperthermic (42 °C for 60 minutes) cisplatin/carboplatin therapies were evaluated on four MPM (MSTO211H, H-Meso, AE17 and AB12) and one endothelial (EC-RF24) cell lines at a minimum of 24 hours using a presto-blue assay. Second, we treated endothelial cells with IPHC (60 min, 42 °C at optimized cytotoxic concentrations) and determined its impact on pro-immunogenic adhesion molecule (E-selectin, VE-cadherin, VCAM and Connexin-43) expression at 24 hours by Western blot.

Results

Tumor and endothelial cell viability decreased with increasing doses of both chemotherapeutics but was not affected by hyperthermia (IC50 with or without hyperthermia of each cell line at 24 hours reported in Figure 1A). Interestingly, endothelial cell line IC50 was much higher than that of MPM tumor cells for both chemotherapeutics (Figure 1A). Pro-immunogenic adhesion molecule E-Selectin was increased at 24 hours by IPHC with both chemotherapeutics while VE-Cadherin, VCAM and Connexin-43 were not affected (Figure 1B).

Conclusion

Hyperthermia adds no cytotoxicity to intrapleural chemotherapy. However, IPHC favors pro-immunogenic endothelial E-selectin expression. The latter could help induce patient immunity against their MPM and improve survival. Confirmation of these findings in vivo is mandatory.

VE/VCO2 slope predicts short- and long-term outcome after anatomical pulmonary resection by VATS

Objective

The ventilation-to-carbon dioxide output (VE/VCO2) slope could predict morbidity and mortality after lung resection. The aim of the study was to identify whether VE/VCO2 slope obtained from cardiopulmonary exercise test (CPET) was an independent predictor of cardiopulmonary complications after anatomical pulmonary resection by video-assisted thoracic surgery (VATS).

Methods

We reviewed the files of all consecutive patients that underwent pulmonary anatomical resections by VATS between January 2010 and October 2020. The data were extracted from the registry of the Centre for Thoracic Surgery of Western Switzerland. Pneumonectomies were excluded from the study. We used a multivariable Cox regression to investigate the risk of cardiopulmonary complications associated with the VE/VCO2 slope and other possible confounders, including the Charlson Comorbidity Index (CCI), the CPET data and pulmonary functions.

Results

In total, 1392 patients (mean age: 66±11 years; ratio female: 47%) underwent anatomical resection by VATS. CPET was performed in 204 patients (15%). However, the VE/VCO2 slope data were available in 145 patients, which were included for the analysis. Patients underwent segmentectomies (N = 42) and lobectomies (N = 101) mainly for lung cancer (96%). The average percentage of the predicted VO2max was of 70±17%. Maximal effort during the CPET (respiratory coefficient ratio >1.1) was not reached in 30% of patients, without impact on the VE/VCO2 slope (39±6 vs 37±7, P = 0.21). Cardiopulmonary complications appeared in 32% of patients with no mortality at 90 days. In the multivariate analysis, VE/VCO2 slope >35 was correlated with cardiopulmonary complications (OR 3.5, 95% CI [1.3-9.3], P = 0.012). CCI, pulmonary functions, peak VO2 and the extension of the anatomical resection was not associated with cardiopulmonary complications.

Conclusion

VE/VCO2 slope above 35 predicts postoperative cardiopulmonary complications in anatomical resections by VATS. The VE/VCO2 slope is independent of the intensity of effort during the CPET. The impact of prehabilitation on the slope should be determined.

Antiangiogenic immunotherapy suppresses desmoplastic and chemoresistant intestinal tumors in mice

Mutations in APC promote colorectal cancer (CRC) progression through uncontrolled WNT signaling. Patients with desmoplastic CRC have a significantly worse prognosis and do not benefit from chemotherapy, but the mechanisms underlying the differential responses of APC-mutant CRCs to chemotherapy are not well understood. We report that expression of the transcription factor prospero homeobox 1 (PROX1) was reduced in desmoplastic APC-mutant human CRCs. In genetic Apc-mutant mouse models, loss of Prox1 promoted the growth of desmoplastic, angiogenic, and immunologically silent tumors through derepression of Mmp14. Although chemotherapy inhibited Prox1-proficient tumors, it promoted further stromal activation, angiogenesis, and invasion in Prox1-deficient tumors. Blockade of vascular endothelial growth factor A (VEGFA) and angiopoietin-2 (ANGPT2) combined with CD40 agonistic antibodies promoted antiangiogenic and immunostimulatory reprogramming of Prox1-deficient tumors, destroyed tumor fibrosis, and unleashed T cell-mediated killing of cancer cells. These results pinpoint the mechanistic basis of chemotherapy-induced hyperprogression and illustrate a therapeutic strategy for chemoresistant and desmoplastic CRCs.

Thoracoscopic thymectomy using a left-side approach

The surgical treatment of myasthenia gravis involves the complete resection of the thymus and the mediastinal fat between the two phrenic nerves. This procedure has been shown to have a positive impact on the rate of remission. In this video tutorial we illustrate the technical aspects of radical thymectomy using a left thoracoscopic approach.

Pyrrolidine dithiocarbamate administered during ex-vivo lung perfusion promotes rehabilitation of injured donor rat lungs obtained after prolonged warm ischemia

Damaged lung grafts obtained after circulatory death (DCD lungs) and warm ischemia may be at high risk of reperfusion injury after transplantation. Such lungs could be pharmacologically reconditioned using ex-vivo lung perfusion (EVLP). Since acute inflammation related to the activation of nuclear factor kappaB (NF-κB) is instrumental in lung reperfusion injury, we hypothesized that DCD lungs might be treated during EVLP by pyrrolidine dithiocarbamate (PDTC), an inhibitor of NF-κB. Rat lungs exposed to 1h warm ischemia and 2 h cold ischemia were subjected to EVLP during 4h, in absence (CTRL group, N = 6) or in presence of PDTC (2.5g/L, PDTC group, N = 6). Static pulmonary compliance (SPC), peak airway pressure (PAWP), pulmonary vascular resistance (PVR), and oxygenation capacity were determined during EVLP. After EVLP, we measured the weight gain of the heart-lung block (edema), and the concentration of LDH (cell damage), proteins (permeability edema) and of the cytokines IL-6, TNF-α and CINC-1 in bronchoalveolar lavage (BAL), and we evaluated NF-κB activation by the degree of phosphorylation and degradation of its inhibitor IκBα in lung tissue. In CTRL, we found significant NF-κB activation, lung edema, and a massive release of LDH, proteins and cytokines. SPC significantly decreased, PAWP and PVR increased, while oxygenation tended to decrease. Treatment with PDTC during EVLP inhibited NF-κB activation, did not influence LDH release, but markedly reduced lung edema and protein concentration in BAL, suppressed TNFα and IL-6 release, and abrogated the changes in SPC, PAWP and PVR, with unchanged oxygenation. In conclusion, suppression of innate immune activation during EVLP using the NF-κB inhibitor PDTC promotes significant improvement of damaged rat DCD lungs. Future studies will determine if such rehabilitated lungs are suitable for in vivo transplantation.

Impact of lung function changes after induction radiochemotherapy on resected T4 non-small cell lung cancer outcome

BACKGROUND

Induction radiochemotherapy, followed by resection, for T4 non-small cell lung cancer, has shown promising long-term survival but may be associated with increased postoperative morbidity and death, depending on patient selection. Here, we determined the effect of induction radiochemotherapy on pulmonary function and whether postinduction pulmonary function changes predict hospital morbidity and death and long-term survival.

METHODS

A consecutive prospective cohort of 72 patients with T4 N0-2 M0 non-small cell lung cancer managed by radiochemotherapy, followed by resection, is reported. All patients underwent thoracoabdominal computed tomography or fusion positron emission tomography-computed tomography, brain imaging, mediastinoscopy, echocardiography, ventilation-perfusion scintigraphy, and pulmonary function testing before and after induction therapy. Resection was performed if the postoperative forced expiratory volume in 1 second and diffusion capacity of the lung for carbon monoxide exceeded 30% predicted and if the postoperative maximum oxygen consumption exceeded 10 mL/kg/min.

RESULTS

The postoperative 90-day mortality rate was 8% (lobectomy, 2%; pneumonectomy, 21%; p=0.01). All deaths after pneumonectomy occurred after right-sided procedures. The 3-year and 5-year survival was 50% (95% confidence interval, 36% to 62%) and 45% (95% confidence interval, 31% to 57%) and was significantly associated with completeness of resection (p=0.004) and resection type (pneumonectomy vs lobectomy, p=0.01). There was no correlation between postinduction pulmonary function changes and postoperative morbidity or death or long-term survival in patients managed by lobectomy or pneumonectomy.

CONCLUSIONS

In properly selected patients with T4 N0-2 M0 non-small cell lung cancer, resection after induction radiochemotherapy can be performed with a reasonable postoperative mortality rate and long-term survival, provided the resection is complete and a right-sided pneumonectomy is avoided. Postinduction pulmonary function changes did not correlate with postoperative morbidity or death or with long-term outcome.