PAI-1 mediates acquired resistance to MET-targeted therapy in non-small cell lung cancer

Mechanisms underlying primary and acquired resistance to MET tyrosine kinase inhibitors (TKIs) in managing non-small cell lung cancer remain unclear. In this study, we investigated the possible mechanisms acquired for crizotinib in MET-amplified lung carcinoma cell lines. Two MET-amplified lung cancer cell lines, EBC-1 and H1993, were established for acquired resistance to MET-TKI crizotinib and were functionally elucidated. Genomic and transcriptomic data were used to assess the factors contributing to the resistance mechanism, and the alterations hypothesized to confer resistance were validated. Multiple mechanisms underlie acquired resistance to crizotinib in MET-amplified lung cancer cell lines. In EBC-1-derived resistant cells, the overexpression of SERPINE1, the gene encoding plasminogen activator inhibitor-1 (PAI-1), mediated the drug resistance mechanism. Crizotinib resistance was addressed by combination therapy with a PAI-1 inhibitor and PAI-1 knockdown. Another mechanism of resistance in different subline cells of EBC-1 was evaluated as epithelial-to-mesenchymal transition with the upregulation of antiapoptotic proteins. In H1993-derived resistant cells, MEK inhibitors could be a potential therapeutic strategy for overcoming resistance with downstream mitogen-activated protein kinase pathway activation. In this study, we revealed the different mechanisms of acquired resistance to the MET inhibitor crizotinib with potential therapeutic application in patients with MET-amplified lung carcinoma.

Utility of neutrophil-to-lymphocyte ratio as an indicator of tumor immune status in non-small cell lung cancer

BACKGROUND

Neutrophil-to-lymphocyte ratio (NLR) has been reported as a prognostic biomarker in non-small cell lung cancer (NSCLC); however, the underlying biological rationale remains unclear. The present study aimed to explore the potential utility of NLR as a surrogate biomarker for immune response to cancer and to elucidate the underlying mechanism.

METHODS

This retrospective study included the medical records of 120 patients with NSCLC who underwent surgery at the study institution in 2012. NLR in peripheral blood was determined from blood test within 30 days before surgery. Tumor immune status was evaluated using immunohistochemical staining to identify CD3+, CD8+ and FOXP3+ tumor-infiltrating lymphocytes (TILs), and the relationship of NLR, with clinicopathologic characteristics including 5-year overall survival (OS), and the tumor immune status was investigated. The median values of NLR and TIL count were used as cutoff points.

RESULTS

The 5-year OS was significantly better in patients with low NLR (<2.2) than in those with high NLR (≥2.2) (70.1% vs. 56.8%, P = 0.042) and in patients with high CD3+ TIL count (≥242) than in those with low CD3+ TIL count (<242) (70% vs. 56.8%, P = 0.019). Additionally, the CD3+ TIL count was negatively correlated with preoperative NLR (P = 0.005).

CONCLUSION

NLR might potentially reflect the immune status of tumor microenvironment, explaining its impact on prognosis of patients with NSCLC.

Postoperative Complications in Living Donors for Lung Transplantation

Background

Living donor lobar lung transplantation is a life-saving procedure for critically ill patients. This requires 2 healthy donors exposed to risks and without medical benefit. Therefore, the donor's safety and minimal postoperative complications are crucial. This study aimed to investigate the short-term outcomes and identify the risk factors affecting these outcomes.

Methods

The data of 175 living donors enrolled between 1998 and 2022 were analyzed. Donors were divided into era 1 (1998-2009) and era 2 (2010-2022).

Results

The overall incidence of postoperative complications was 39%, of which 7% were major complications. Donors who underwent surgery on the right side had a higher incidence of delayed pulmonary fistulae (P = 0.01) and elevated liver enzyme levels (P = 0.028). Living donor surgery on the right side (P = 0.01), era 2 (P = 0.01), and the need for plasty (P = 0.04) were predictors of postoperative complications.

Conclusions

Updated data on complications and their correlation with postoperative quality of life from this study could aid in the selection of potential donors and facilitate informed consent.

Effective division of the intersegmental plane using a robotic stapler in robotic pulmonary segmentectomy

PURPOSES

Robot-assisted thoracoscopic (RATS) segmentectomy is becoming increasingly common because of the expanded indications for segmentectomy and the widespread adoption of robotic surgery. The precise division of the intersegmental plane is necessary to ensure oncologic margins from the tumor and to preserve the lung function. In this study, we present a strategy for accurately dividing the intersegmental plane using a robotic stapler and review the surgical outcomes.

METHODS

RATS portal segmentectomy was performed using the Da Vinci Xi system and the intersegmental plane was dissected using a robotic stapler. We evaluated the perioperative outcomes in 92 patients who underwent RATS portal segmentectomy between May 2020 and January 2023. These results were compared with those of 82 patients who underwent complete video-assisted thoracoscopic surgery (CVATS) during the same period.

RESULTS

The operative and console times were 162 and 97 min, respectively. No intraoperative complications occurred, and postoperative complications were observed in four cases (4.3%). The operative time, blood loss, postoperative complications, and maximum incision size were significantly lower in the RATS group than in the CVATS group. However, RATS requires a significantly higher number of staplers than CVATS.

CONCLUSIONS

The division of the intersegmental plane using a robotic stapler in RATS portal segmentectomy was, therefore, found to be safe and effective.

Restrictive allograft dysfunction rather than bronchiolitis obliterans syndrome had a major impact on the overall survival after living-donor lobar lung transplantation

PURPOSE

Chronic lung allograft dysfunction (CLAD) is a known long-term fatal disorder after lung transplantation. In this study, we evaluated the CLAD classification of the International Society for Heart and Lung Transplantation (ISHLT) for living-donor lobar lung transplantation (LDLLT).

METHODS

We conducted a single-center retrospective review of data from 73 patients who underwent bilateral LDLLT between 1998 and 2019. Factors related to opacity on computed tomography (CT) and restriction on pulmonary function tests (PFTs) were also analyzed.

RESULTS

Overall, 26 (36%) patients were diagnosed with CLAD, including restrictive allograft syndrome (RAS), n = 10 (38.5%); bronchiolitis obliterans syndrome (BOS), n = 8 (30.8%); mixed, n = 1 (3.8%); undefined, n = 2 (7.7%); and unclassified, n = 5 (19.2%). The 5-year survival rate after the CLAD onset was 60.7%. The survival of patients with BOS was significantly better than that of patients with RAS (p = 0.012). In particular, patients with restriction on PFT had a significantly worse survival than those without restriction (p = 0.001).

CONCLUSIONS

CLAD after bilateral LDLLT does not have a major impact on the recipient survival, especially in patients with BOS. Restriction on PFT may predict a particularly poor prognosis in patients with CLAD after bilateral LDLLT.

Impact of the neutrophil-to-lymphocyte ratio on patients with locally advanced non-small cell lung cancer who suffer radiation pneumonitis during the course of induction chemoradiotherapy followed by surgery

PURPOSE

Radiation pneumonitis (RP) is an obstacle for patients after surgery following induction chemoradiotherapy for locally advanced non-small cell lung cancer (LA-NSCLC). We performed a comparative analysis of the association between clinicopathological factors, including the neutrophil-to-lymphocyte ratio (NLR) and prognosis, in LA-NSCLC patients with or without RP during induction chemoradiotherapy followed by surgery.

METHODS

The subjects of this analysis were 168 patients undergoing trimodality therapy for LA-NSCLC between January, 1999 and May, 2019. Patients were divided into two groups: the RP group (n = 41) and the non-RP group (n = 127). We compared the clinicopathological factors including the NLR between the groups and analyzed the association between the NLR and prognosis.

RESULTS

The RP group had more patients with tumors located in the lower lobe, more bilobar resections, shorter operative times, no implementation of postoperative adjuvant chemotherapy, and a higher postoperative NLR than the non-RP group. There were no significant differences in serious postoperative complications and the prognosis. Patients with a low postoperative NLR had a significantly better prognosis in the non-RP group, and a trend toward a better prognosis even in the RP group.

CONCLUSION

Postoperative NLR may be a useful prognostic factor, even for patients who suffer RP after trimodality therapy for LA-NSCLC.

Plasma concentrations of histidine-rich glycoprotein in primary graft dysfunction after lung transplantation

OBJECTIVES

Histidine-rich glycoprotein has been reported as an anti-inflammatory glycoprotein that inhibits acute lung injury in mice with sepsis and as a prognostic biomarker in patients with sepsis. We investigated the relationship between plasma concentrations of histidine-rich glycoprotein and the risk of occurrence of primary graft dysfunction.

METHODS

According to the primary graft dysfunction grade at post-transplant 72 h, patients who underwent lung transplantation were divided into three groups: non-primary graft dysfunction group (grade 0-1), moderate primary graft dysfunction group (grade 2), and severe primary graft dysfunction group (grade 3). The plasma concentrations of histidine-rich glycoprotein measured daily during the first post-transplant 7 days were compared among the three groups. Appropriate cutoff values of the concentrations were set for survival analyses after lung transplantation.

RESULTS

A total of 68 patients were included. The plasma histidine-rich glycoprotein concentration at post-transplant 72 h was significantly lower in the severe primary graft dysfunction group (n = 7) than in the other two groups [non-primary graft dysfunction group (n = 43), P = 0.042; moderate primary graft dysfunction group (n = 18), P = 0.040]. Patients with plasma histidine-rich glycoprotein concentration ≥34.4 µg/ml at post-transplant 72 h had significantly better chronic lung allograft dysfunction-free survival (P = 0.012) and overall survival (P = 0.037) than those with the concentration <34.4 µg/ml.

CONCLUSIONS

Plasma histidine-rich glycoprotein concentrations at post-transplant 72 h might be associated with the risk of development of primary graft dysfunction.

In vivo lung perfusion for prompt recovery from primary graft dysfunction after lung transplantation

BACKGROUND

No proven treatment after the development of primary graft dysfunction (PGD) is currently available. Here, we established a novel strategy of in vivo lung perfusion (IVLP) for the treatment of PGD. IVLP involves the application of an in vivo isolated perfusion circuit to an implanted lung. This study aimed to explore the effectiveness of IVLP vs conventional post-lung transplant (LTx) extracorporeal membrane oxygenation (ECMO) treatment using an experimental swine LTx PGD model.

METHODS

After 1.5-hour warm ischemia of the donor lungs, a left LTx was performed. Following the confirmation of PGD development, pigs were divided into 3 groups (n = 5 each): control (no intervention), ECMO, and IVLP. After 2 hours of treatment, a 4-hour functional assessment was conducted, and samples were obtained.

RESULTS

Significantly better oxygenation was achieved in the IVLP group (p ≤ 0.001). Recovery was confirmed immediately and maintained during the following 4-hour observation. The IVLP group also demonstrated better lung compliance than the control group (p = 0.045). A histologic evaluation showed that the lung injury score and terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed significantly fewer injuries and a better result in the wet-to-dry weight ratio in the IVLP group.

CONCLUSIONS

A 2-hour IVLP is technically feasible and allows for prompt recovery from PGD after LTx. The posttransplant short-duration IVLP strategy can complement or overcome the limitations of the current practice for donor assessment and PGD management.

Clinical Features of Patients With Second Primary Lung Cancer After Head and Neck Cancer

BACKGROUND

In survivors of head and neck cancer (HNC), second primary lung cancer (SPLC) often develop as a result of a common risk factor, that is, smoking. A multicenter experience was reviewed to evaluate how the history of a diagnosis of HNC affects the outcomes of patients undergoing pulmonary resection for SPLC.

METHODS

A multicenter retrospective analysis of patients hospitalized between January 2012 and December 2018 was performed. From a cohort of 4521 patients undergoing therapeutic pulmonary resection for primary non-small cell lung cancer, 100 patients with a previous history of HNC (HNC group) were identified. These patients were compared with a control group consisting of 200 patients without an HNC history from the same cohort pair-matched with operating facility, age, sex, and pathologic stage of lung cancer.

RESULTS

At the time of surgery for SPLC, the HNC group showed malnutrition with a lower prognostic nutritional index compared with the control group (P < .001). The HNC group was determined to have postoperative complications more frequently (P = .02). The 5-year overall survival rates in the HNC and control groups were 59.0% and 83.2%, respectively (P < .001). Statistically, HNC history, lower prognostic nutritional index, squamous cell lung cancer, and TNM stage were identified to be independently associated with poor survival.

CONCLUSIONS

Patients with SPLC after primary HNC often present with malnutrition and are predisposed to postoperative complications and poor survival after pulmonary resection.

Prognostic Impact of Tumor-Infiltrating Lymphocytes, Tertiary Lymphoid Structures, and Neutrophil-to-Lymphocyte Ratio in Pulmonary Metastases from Uterine Leiomyosarcoma

BACKGROUND

The presence of tumor-infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLSs) in tumor tissue has been related to the prognosis in various malignancies. Meanwhile, neutrophil-to-lymphocyte ratio (NLR) as a systemic inflammation marker also has been associated with the prognosis in them. However, few reports have investigated the relationship between pulmonary metastases from sarcoma and these biomarkers.

METHODS

We retrospectively recruited 102 patients undergoing metastasectomy for pulmonary metastases from uterine leiomyosarcoma at Okayama University Hospital from January 2006 to December 2019. TILs and TLSs were evaluated by immunohistochemical staining of surgically resected specimens of pulmonary metastases using anti-CD3/CD8/CD103/Foxp3/CD20 antibodies. NLR was calculated from the blood examination immediately before the most recent pulmonary metastasectomy. We elucidated the relationship between the prognosis and these factors. Because we considered that the status of tumor tissue and systemic inflammation were equally valuable, we also assessed the impact of the combination of TILs or TLSs and NLR on the prognosis.

RESULTS

As for TILs, CD3-positive cells and CD8-positive cells were correlated with the prognosis. The prognosis was significantly better in patients with CD3-high group, CD8-high group, TLSs-high group, and NLR-low group, respectively. The prognosis of CD8-high/NLR-low group and TLSs-high/NLR-low group was significantly better than that of CD8-low/NLR-high group and TLSs-low/NLR-high group, respectively.

CONCLUSIONS

CD3-positive TILs, CD8-positive TILs, TLSs, and NLR are correlated with the prognosis, respectively. The combination of CD8-positive TILs or TLSs and NLR may be the indicators to predict the prognosis of patients with pulmonary metastases from uterine leiomyosarcoma.

Periostin secreted by cancer-associated fibroblasts promotes cancer progression and drug resistance in non-small cell lung cancer

Cancer-associated fibroblasts (CAFs) are important components in the tumor microenvironment, and we sought to identify effective therapeutic targets in CAFs for non-small cell lung cancer (NSCLC). In this study, we established fibroblast cell lines from the cancerous and non-cancerous parts of surgical lung specimens from patients with NSCLC and evaluated the differences in behaviors towards NSCLC cells. RNA sequencing analysis was performed to investigate the differentially expressed genes between normal fibroblasts (NFs) and CAFs, and we identified that the expression of periostin (POSTN), which is known to be overexpressed in various solid tumors and promote cancer progression, was significantly higher in CAFs than in NFs. POSTN increased cell proliferation via NSCLC cells' ERK pathway activation and induced epithelial-mesenchymal transition (EMT), which improved migration in vitro. In addition, POSTN knockdown in CAFs suppressed these effects, and in vivo experiments demonstrated that the POSTN knockdown improved the sensitivity of EGFR-mutant NSCLC cells for osimertinib treatment. Collectively, our results showed that CAF-derived POSTN is involved in tumor growth, migration, EMT induction, and drug resistance in NSCLC. Targeting CAF-secreted POSTN could be a potential therapeutic strategy for NSCLC. KEY MESSAGES: • POSTN is significantly upregulated in CAFs compared to normal fibroblasts in NCSLC. • POSTN increases cell proliferation via activation of the NSCLC cells' ERK pathway. • POSTN induces EMT in NSCLC cells and improves the migration ability. • POSTN knockdown improves the sensitivity for osimertinib in EGFR-mutant NSCLC cells.

Elderly lung transplant recipients show acceptable long-term outcomes for lung transplantation: A propensity score-matched analysis

PURPOSE

Although the performance lung transplantation (LTx) in the elderly (≥ 60 years) has increased globally, the situation in Japan remains quite different, because the age limit at registration for cadaveric transplantation is 60 years. We investigated the long-term outcomes of LTx in the elderly in Japan.

METHODS

This was a single-center retrospective study. We divided the patients into two groups according to age: the younger group (< 60 years; Y group; n = 194) and the elderly group (≥ 60 years; E group; n = 10). We performed three-to-one propensity score matching to compare the long-term survival between the E and Y groups.

RESULTS

In the E group, the survival rate was significantly worse (p = 0.003), and single-LTx was more frequent (p = 0.036). There was a significant difference in the indications for LTx between the two groups (p < 0.001). The 5-year survival rate after single-LTx in the E group was significantly lower than that in the Y group (p = 0.006). After propensity score matching, the 5-year survival rates of the two groups were comparable (p = 0.55). However, the 5-year survival rate after single-LTx in the E group was significantly lower than that in the Y group (p = 0.007).

CONCLUSION

Elderly patients showed acceptable long-term survival after LTx.

Percentage of low attenuation area on computed tomography detects chronic lung allograft dysfunction, especially bronchiolitis obliterans syndrome, after bilateral lung transplantation

INTRODUCTION

The percentage of low attenuation area (%LAA) on computed tomography (CT) is useful for evaluating lung emphysema, and higher %LAA was observed in patients with chronic lung allograft dysfunction (CLAD). This study investigated the relationship between the %LAA and the development of CLAD after bilateral lung transplantation (LT).

METHODS

We conducted a single-center retrospective study of 75 recipients who underwent bilateral LT; the recipients were divided into a CLAD group (n = 30) and a non-CLAD group (n = 45). The %LAA was calculated using CT and compared between the two groups from 4 years before to 4 years after the diagnosis of CLAD. The relationships between the %LAA and the percent baseline values of the pulmonary function test parameters were also calculated.

RESULTS

The %LAA was significantly higher in the CLAD group than in the non-CLAD group from 2 years before to 2 years after the diagnosis of CLAD (P < .05). In particular, patients with bronchiolitis obliterans syndrome (BOS) exhibited significant differences even from 4 years before to 4 years after diagnosis (P < .05). Significant negative correlations between the %LAA and the percent baseline values of the forced expiratory volume in 1 s (r = -.36, P = .0031), the forced vital capacity (r = -.27, P = .027), and the total lung capacity (r = -.40, P < .001) were seen at the time of CLAD diagnosis.

CONCLUSION

The %LAA on CT was associated with the development of CLAD and appears to have the potential to predict CLAD, especially BOS, after bilateral LT.

EGFR Mutation is a Prognostic Factor in Lung Cancer Patients with Pleural Dissemination Detected During or After Surgery

BACKGROUND

Primary lung tumors are sometimes resected when either pleural dissemination (PD) or malignant pleural effusion (MPE) exists. This study clarified the prognostic factors for non-small cell lung cancer (NSCLC) with either PD and MPE, or both, detected during or after surgery.

PATIENTS AND METHODS

We examined patients with NSCLC from a multicenter database who had either PD, MPE, or both, detected during or after surgery between 2005 and 2015. Hazard ratios and 95% confidence intervals were estimated using the Cox proportional hazards model adjusted for potential confounding factors.

RESULTS

Among 9463 registered patients, PD, MPE, or both, were found in 114 patients with NSCLC during or after surgery. Primary tumor resection and exploratory thoracotomy were performed in 65 and 49 patients, respectively. In univariate analysis, adenocarcinoma, clinically undetected lymph node metastasis (c-N0 or unknown), EGFR mutation, and combination of chemotherapy or tyrosine kinase inhibitors after surgery were better prognostic factors for overall survival (OS), whereas in the multivariate analysis, adenocarcinoma, clinically undetected lymph node metastasis, and EGFR mutation were favorable independent prognostic factors in OS. Additionally, limited to patients with EGFR mutation, patients with primary lung tumor resection showed a significantly better 5-year OS than those with exploratory thoracotomy (86.4 vs. 44.8%; p < 0.001).

CONCLUSION

Our findings show that surgical resection of primary tumors could improve the prognosis of patients with PD, MPE, or both, detected during or after surgery when the tumors harbor an EGFR mutation.

S100A8/A9 as a prognostic biomarker in lung transplantation

OBJECTIVES

S100A8/A9 is a damage-associated molecule that augments systemic inflammation. However, its role in the acute phase after lung transplantation (LTx) remains elusive. This study aimed to determine S100A8/A9 levels after lung transplantation (LTx) and evaluate their impact on overall survival (OS) and chronic lung allograft dysfunction (CLAD)-free survival.

METHODS

Sixty patients were enrolled in this study, and their plasma S100A8/A9 levels were measured on days 0, 1, 2, and 3 after LTx. The association of S100A8/A9 levels with OS and CLAD-free survival was assessed using univariate and multivariate Cox regression analyses.

RESULTS

S100A8/A9 levels were elevated in a time-dependent manner until 3 days after LTx. Ischemic time was significantly longer in the high S100A8/9 group than in the low S100A8/A9 group (p = .017). Patients with high S100A8/A9 levels (> 2844 ng/mL) had worse prognosis (p = .031) and shorter CLAD-free survival (p = .045) in the Kaplan-Meier survival analysis than those with low levels. Furthermore, multivariate Cox regression analysis showed that high S100A8/A9 levels were a determinant of poor OS (hazard ratio [HR]: 3.7; 95% confidence interval [CI]: 1.2-12; p = .028) and poor CLAD-free survival (HR: 4.1; 95% CI: 1.1-15; p = .03). In patients with a low primary graft dysfunction grade (0-2), a high level of S100A8/A9 was also a poor prognostic factor.

CONCLUSIONS

Our study provided novel insights into the role of S100A8/A9 as a prognostic biomarker and a potential therapeutic target for LTx.

Identification of genetic loci associated with renal dysfunction after lung transplantation using an ethnic-specific single-nucleotide polymorphism array

Renal dysfunction is a long-term complication associated with an increased mortality after lung transplantation (LT). We investigated the association of single-nucleotide polymorphisms (SNPs) with the development of renal dysfunction after LT using a Japanese-specific SNP array. First, eligible samples of 34 LT recipients were genotyped using the SNP array and divided into two groups, according to the presence of homozygous and heterozygous combinations of mutant alleles of the 162 renal-related SNPs. To identify candidate SNPs, the renal function tests were compared between the two groups for each SNP. Next, we investigated the association between the candidate SNPs and the time course of changes of the estimated glomerular filtration rate (eGFR) in the 99 recipients until 10 years after the LT. ΔeGFR was defined as the difference between the postoperative and preoperative eGFR values. Eight SNPs were identified as the candidate SNPs in the 34 recipients. Validation analysis of these 8 candidate SNPs in all the 99 recipients showed that three SNPs, namely, rs10277115, rs4690095, and rs792064, were associated with significant changes of the ΔeGFR. Pre-transplant identification of high-risk patients for the development of renal dysfunction after LT based on the presence of these SNPs might contribute to providing personalized medicine.

Pulmonary alveolar proteinosis after lung transplantation: Two case reports and literature review

Pulmonary alveolar proteinosis (PAP) affecting transplanted lungs is not well recognized. Herein, we report two cases of PAP after lung transplantation (LTx). The first case was a 4-year-old boy with hereditary pulmonary fibrosis who underwent bilateral LTx and presented with respiratory distress on postoperative day (POD) 23. He was initially treated for acute rejection, died due to infection on POD 248, and was diagnosed with PAP at autopsy. The second case involved a 52-year-old man with idiopathic pulmonary fibrosis who underwent bilateral LTx. On POD 99, chest computed tomography revealed ground-glass opacities. Bronchoalveolar lavage and transbronchial biopsy led to a diagnosis of PAP. Follow-up with immunosuppression tapering resulted in clinical and radiological improvement. PAP after lung transplantation mimics common acute rejection; however, is potentially transient or resolved with tapering immunosuppression, as observed in the second case. Transplant physicians should be aware of this rare complication to avoid misconducting immunosuppressive management.

Surgical outcome of ipsilateral anatomical resection for lung cancer after pulmonary lobectomy

OBJECTIVES

Ipsilateral reoperation after pulmonary lobectomy is often challenging because of adhesions from the previous operation. We retrospectively examined the surgical outcome and prognosis of ipsilateral anatomical resection for lung cancer after pulmonary lobectomy using a multicentre database.

METHODS

We evaluated the perioperative outcomes and overall survival of 51 patients who underwent pulmonary lobectomy followed by ipsilateral anatomical resection for lung cancer between January 2012 and December 2018. In addition, patients with stage I non-small-cell lung cancer (NSCLC) were compared with 3411 patients with stage I lung cancer who underwent pulmonary resection without a prior ipsilateral lobectomy.

RESULTS

Ipsilateral anatomical resections included 10 completion pneumonectomies, 19 pulmonary lobectomies and 22 pulmonary segmentectomies. Operative time was 312.2 ± 134.5 min, and intraoperative bleeding was 522.2 ± 797.5 ml. Intraoperative and postoperative complications occurred in 9 and 15 patients, respectively. However, the 5-year overall survival rate after anatomical resection followed by ipsilateral lobectomy was 83.5%. Furthermore, in patients with c-stage I NSCLC, anatomical resection followed by ipsilateral lobectomy was not associated with worse survival than anatomical resection without prior ipsilateral lobectomy.

CONCLUSIONS

Anatomical resection following ipsilateral lobectomy is associated with a high frequency of intraoperative and postoperative complications. However, the 5-year overall survival in patients with c-stage I NSCLC who underwent ipsilateral anatomical resection after pulmonary lobectomy is comparable to that in patients who underwent anatomical resection without prior pulmonary lobectomy.

Diagnostic value of circulating microRNA-21 in chronic lung allograft dysfunction after bilateral cadaveric and living-donor lobar lung transplantation

Background

MicroRNAs (miRNAs) involved in the pathogenesis of pulmonary fibrosis have been shown to be associated with the development of chronic lung allograft dysfunction (CLAD) after lung transplantation (LT). We investigated the role of circulating miRNAs in the diagnosis of CLAD after bilateral LT, including cadaveric LT (CLT) and living-donor lobar LT (LDLLT).

Methods

The subjects of this retrospective study were 37 recipients of bilateral CLT (n = 23) and LDLLT (n = 14), and they were divided into a non-CLAD group (n = 24) and a CLAD group (n = 13). The plasma miRNA levels of the two groups were compared, and correlations between their miRNAs levels and percent baseline forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC), and total lung capacity (TLC) values were calculated from one year before to one year after the diagnosis of CLAD.

Results

The plasma levels of both miR-21 and miR-155 at the time of the diagnosis of CLAD were significantly higher in the CLAD group than in the non-CLAD group (miR-21, P = 0.0013; miR-155, P = 0.042). The miR-21 levels were significantly correlated with the percent baseline FEV1, FVC, and TLC value of one year before and at the time of diagnosis of CLAD (P < 0.05). A receiver operating characteristic curve analysis of the performance of miR-21 levels in the diagnosis of CLAD yielded an area under the curve of 0.89.

Conclusion

Circulating miR-21 appears to be of potential value in diagnosing CLAD after bilateral LT.

Donor's long-term quality of life following living-donor lobar lung transplantation

INTRODUCTION

Living-donor lobar lung transplantation is an alternative procedure to deceased donation lung transplantation. It involves graft donation from healthy donors; however, only a few reports have discussed its long-term prognosis in living lung donors and their associated health-related quality of life. This study aimed to examine living lung donors' health-related quality of life.

METHODS

In our cross-sectional survey of living lung donors, we assessed health-related quality of life-based on three key aspects (physical, mental, and social health) using the 36-Item Short Form Health Survey. We also evaluated chronic postoperative pain and postoperative breathlessness using the numeric rating scale and the modified Medical Research Council Dyspnea scale, respectively.

RESULTS

We obtained consent from 117 of 174 living lung donors. The average scores of the living lung donors on the 36-Item Short Form Health Survey were higher than the national average. However, some donors had poorer physical, mental, and social health, with lower summary scores than the national averages. Low mental component summary predictors included donor age (<40 years; odds ratio = 10.2; p < .001) and recipient age (<18 years; odds ratio = 2.73; p < .032). Low role-social component summary predictors included high lung allocation score (≥50; odds ratio = 3.94, p < .002) and recipient death (odds ratio = 3.64; p = .005). There were no predictors for a physical component summary. Additionally, many donors did not complain of pain or dyspnea.

CONCLUSIONS

Living lung donors maintained an acceptable long-term health-related quality of life after surgery. Potential donors should be informed of relevant risk factors, and high-risk donors should receive appropriate support.

The impact of prognostic nutrition index on the waitlist mortality of lung transplantation

OBJECTIVE

The prognostic nutrition index (PNI), calculated using serum albumin and total lymphocyte count, is a recent topical index related to inflammation. Preoperative PNI is regarded as a new preoperative prognostic score in lung transplantation (LTx). This study aimed to investigate the impact of PNI at the time of registration as a prognostic parameter of mortality on the waiting list for LTx.

METHODS

A retrospective review was conducted on the data of 132 adult patients registered for LTx in our department between January 2013 and June 2020. Patients who finally received LTx were analyzed as censored data. The overall survival was evaluated using the Kaplan-Meier method for pre-registered clinical factors including the PNI at the time of registration. Overall survival was calculated from the date of listing to the Japan Organ Transplant Network to the date of death.

RESULTS

The low-PNI group had a significantly worse prognosis. Multivariate analysis demonstrated that age (p = 0.023), idiopathic interstitial pneumonia (p < 0.001), lung allocation score (LAS) (p < 0.001), and PNI (p < 0.001) were independent prognostic factors for waitlist mortality.

CONCLUSIONS

PNI at the time of registration can be an independent prognostic parameter in registered candidates for LTx.

Drug repositioning of tranilast to sensitize a cancer therapy by targeting cancer‐associated fibroblast

Cancer‐associated fibroblasts (CAFs) are a major component of the tumor microenvironment that mediate resistance of cancer cells to anticancer drugs. Tranilast is an antiallergic drug that suppresses the release of cytokines from various inflammatory cells. In this study, we investigated the inhibitory effect of tranilast on the interactions between non–small cell lung cancer (NSCLC) cells and the CAFs in the tumor microenvironment. Three EGFR‐mutant NSCLC cell lines, two KRAS‐mutant cell lines, and three CAFs derived from NSCLC patients were used. To mimic the tumor microenvironment, the NSCLC cells were cocultured with the CAFs in vitro, and the molecular profiles and sensitivity to molecular targeted therapy were assessed. Crosstalk between NSCLC cells and CAFs induced multiple biological effects on the NSCLC cells both in vivo and in vitro, including activation of the STAT3 signaling pathway, promotion of xenograft tumor growth, induction of epithelial‐mesenchymal transition (EMT), and acquisition of resistance to molecular‐targeted therapy, including EGFR‐mutant NSCLC cells to osimertinib and of KRAS‐mutant NSCLC cells to selumetinib. Treatment with tranilast led to inhibition of IL‐6 secretion from the CAFs, which, in turn, resulted in inhibition of CAF‐induced phospho‐STAT3 upregulation. Tranilast also inhibited CAF‐induced EMT in the NSCLC cells. Finally, combined administration of tranilast with molecular‐targeted therapy reversed the CAF‐mediated resistance of the NSCLC cells to the molecular‐targeted drugs, both in vitro and in vivo. Our results showed that combined administration of tranilast with molecular‐targeted therapy is a possible new treatment strategy to overcome drug resistance caused by cancer‐CAF interaction.

Survival and prognostic factors in patients undergoing pulmonary metastasectomy for lung metastases from retroperitoneal sarcoma

BACKGROUND

Soft-tissue sarcomas are rare malignancies that consist of many different histologic subtypes and arise in various locations in the body. In patients with lung metastases from retroperitoneal sarcomas, the long-term outcomes and prognostic factors are unknown. This study is a retrospective review of patients undergoing pulmonary metastasectomy for retroperitoneal sarcoma metastases at one institution, with the purpose of determining prognostic factors and clinical outcomes.

METHODS

This is a single-center, retrospective cohort study of patients undergoing pulmonary metastasectomy for lung metastases from various sarcomas at Okayama University Hospital from January 2006 to December 2018. The Kaplan-Meier method and log-rank test were used for the analyses, and cut-off values of continuous variables were determined by a receiver operating characteristic curve analysis.

RESULTS

Twenty-four patients underwent the first pulmonary metastasectomy for lung metastases from retroperitoneal sarcoma in our hospital. Leiomyosarcoma was the most common histologic subtype of retroperitoneal sarcoma (79.2%, n = 19). Median overall survival was 49.9 months, and the 3-year and 5-year survival rates after the first pulmonary metastasectomy were 62.5% and 26.4% respectively. In univariate analysis, age ≥56 years, disease-free interval < 15 months, and size of metastasis (≥ 27 mm) were associated with poor survival.

CONCLUSION

Pulmonary metastasectomy can be considered as an effective management strategy in retroperitoneal sarcoma patients with lung metastases in appropriately selected cases, just as it is for other sarcomas.

Paediatric lung transplantation: the impact of age on the survival

OBJECTIVES

We herein review the outcomes of paediatric lung transplantation (LTx) and analyse subgroups divided by age.

METHODS

We retrospectively reviewed 43 consecutive paediatric LTx recipients (< 18 years old: cadaveric LTx [n = 9], living-donor lobar LTx [n = 34]). We also analysed subgroups of patients 1-6 years old (n = 10) and 7-17 years old (n = 33).

RESULTS

The 1-, 5- and 10-year overall survival (OS) rates in paediatric recipients were 93%, 82% and 67%, respectively. The 1-, 5- and 10-year graft dysfunction (GD)-free survival rates in paediatric recipients were 85%, 59% and 31%, respectively. The 1- and 5-year OS in the 1- to 6-year-old vs. 7- to 17-year-old groups were 70% vs. 100% and 48% vs. 93%, respectively (p < 0.0001). The 1- and 5-year GD-free survival rates in the 1- to 6-year-old vs. 7- to 17-year-old groups were 60% vs. 93% and 24% vs. 69%, respectively (p = 0.024). The 1- to 6-year-old group showed higher rates of non-standard LTx (p = 0.0001), interstitial pneumonia (p = 0.004) and ventilator dependency (p = 0.007) than the 7- to 17-year-old group.

CONCLUSION

Paediatric recipients under 7 years old seemed to have a higher risk of mortality and GD than those 7 years old and older.

Safety of salvage lung resection after immunotherapy for unresectable non-small cell lung cancer

BACKGROUND

The safety of salvage lung resection after immune checkpoint inhibitor (ICI) therapy in patients with advanced non-small cell lung cancer (NSCLC) is not well understood.

METHODS

In this retrospective multicenter study, we reviewed perioperative morbidity and mortality rates in 11 patients (8 men, 3 women; median age 70 years) who underwent salvage lung resection for unresectable NSCLC after ICI therapy in the 4 years since 2017. Operative factors were also compared according to operating time (> 6 h, n = 7; < 6 h, n = 4).

RESULTS

The clinical stage at the time of diagnosis was IIIA in 2 patients, IIIB in 4, IVA in 2, and IVB in 3. Eight patients received pembrolizumab and 3 received durvalumab. Two patients received an ICI agent alone, 3 underwent chemoradiotherapy, and 6 received chemotherapy. Lobectomy was performed in 10 cases and bilobectomy in 1 case. All patients underwent complete resection. Median operating time was 429 (range 169-570) min with a median blood loss of 199 (range 10-5, 140) mL. The only intraoperative complication was damage to the pulmonary artery. The perioperative morbidity and mortality rates were 27% and 0%, respectively. The 90-day mortality rate was 9% (1 patient died of acute exacerbation of interstitial pneumonia). Patients in whom the operating time was > 6 h more frequently had lymph node metastasis at the time of initial diagnosis (100% vs 25%, p = 0.02).

CONCLUSIONS

Salvage lung resection was tolerated after ICI therapy in these patients. Lymph node metastasis at the time of initial diagnosis might make salvage surgery difficult.

Unique Angiogenesis From Cardiac Arterioles During Pericardial Adhesion Formation

Objectives

The molecular mechanisms underlying post-operative pericardial adhesions remain poorly understood. We aimed to unveil the temporal molecular and cellular mechanisms underlying tissue dynamics during adhesion formation, including inflammation, angiogenesis, and fibrosis.

Methods and Results

We visualized cell-based tissue dynamics during pericardial adhesion using histological evaluations. To determine the molecular mechanism, RNA-seq was performed. Chemical inhibitors were administered to confirm the molecular mechanism underlying adhesion formation. A high degree of adhesion formation was observed during the stages in which collagen production was promoted. Histological analyses showed that arterioles excessively sprouted from pericardial tissues after the accumulation of neutrophils on the heart surface in mice as well as humans. The combination of RNA-seq and histological analyses revealed that hyperproliferative endothelial and smooth muscle cells with dedifferentiation appeared in cytokine-exposed sprouting vessels and adhesion tissue but not in quiescent vessels in the heart. SMAD2/3 and ERK activation was observed in sprouting vessels. The simultaneous abrogation of PI3K/ERK or TGF-β/MMP9 signaling significantly decreased angiogenic sprouting, followed by inhibition of adhesion formation. Depleting MMP9-positive neutrophils shortened mice survival and decreased angiogenic sprouting and fibrosis in the adhesion. Our data suggest that TGF-β/matrix metalloproteinase-dependent tissue remodeling and PI3K/ERK signaling activation might contribute to unique angiogenesis with dedifferentiation of vascular smooth muscle cells from the contractile to the synthetic phenotype for fibrosis in the pericardial cavity.

Conclusions

Our findings provide new insights in developing prevention strategies for pericardial adhesions by targeting the recruitment of vascular cells from heart tissues.

Completely Video-assisted Thoracoscopic Lobectomy for Congenital Lobar Emphysema in a Young Adult

Congenital lobar emphysema (CLE) is defined as the hyperinflation of pulmonary lobes due to obstruction of the flow of air via a known or unknown etiology, which causes pressure symptoms in the adjacent organs. CLE is mainly diagnosed in the neonatal period, and very few adult cases have been reported. Here we report a 34-year-old male with muscular dystrophy who was diagnosed with CLE on examination. He underwent a right lower lobectomy via 3-portal completely video-assisted thoracoscopic surgery, and his symptoms improved. Thoracoscopic surgery helped preserve the respiratory muscles and led to the improvement of respiratory function in this patient.

Lung recruitment after cardiac arrest during procurement of atelectatic donor lungs is a protective measure in lung transplantation

Background

Brain-dead donors are susceptible to pulmonary atelectasis (AT). In procurement surgery, lung recruitment under circulatory conditions and cold-flushing for atelectatic donor lungs often provoke graft injury due to the acute blood inflow. We hypothesized that lung recruitment without blood circulation can mitigate graft injury. This study aimed to examine the benefits of lung recruitment subsequent to cardiac arrest using a porcine lung-transplant model.

Methods

Thirteen donor pigs were categorized into the non-atelectatic (No-AT) group (n=3) representing a healthy control group; AT-BCR group (n=5), in which AT was reverted by conventional blood-circulated recruitment (BCR); and AT-no-BCR group (n=5), in which AT was reverted by no-BCR following circulatory arrest. In the atelectatic donor models, the left main bronchus was ligated for 24 hours prior to lung procurement. Left lung transplantation (LTx) was subsequently performed in the thirteen recipient pigs. After 6 hours evaluation, the recipients were euthanized and the lung grafts were excised.

Results

The post-transplant PaO₂/FiO₂ ratio was significantly higher in the AT-no-BCR group than in the AT-BCR group (P=0.015). Wet/dry ratio, histological findings of graft injury and tissue interleukin-8 expression in the AT-no-BCR group were similar to those of the No-AT group.

Conclusions

Lung recruitment without circulation after circulatory arrest could be more protective for atelectatic donor lung than the conventional procedure.

Effect of preoperative long-term use of corticosteroids on the development of post-transplant lymphoproliferative disorders after lung transplantation: a single-center experience in Japan

PURPOSE

Post-transplant lymphoproliferative disorder (PTLD) is a major complication of lung transplantation (LTx). However, few studies on PTLD in Asian populations have been reported. We explored the characteristics of Japanese PTLD cases after LTx.

METHODS

We retrospectively reviewed 195 cases of LTx at our institute. We summarized the clinical experiences of 7 PTLD cases and analyzed the patient characteristics and survival outcomes of patients with (n = 7) and without (n = 188) PTLD.

RESULTS

All PTLD patients were taking corticosteroids preoperatively (p = 0.0030), and the duration of preoperative corticosteroid therapy was significantly longer in the PTLD group (p = 0.0064) than in the non-PTLD group. The overall survival after LTx was significantly worse in the PTLD group (p = 0.027) than in the non-PLTD group. Among the three patients who died within 1 year after the PTLD onset, two died of opportunistic infections without residual PTLD lesions. Chronic lung allograft dysfunction (CLAD) or bronchiolitis obliterans at an autopsy were diagnosed after PTLD treatment in four cases.

CONCLUSIONS

Long-term preoperative corticosteroid therapy may be a risk factor for PTLD after LTx. Opportunistic infections are lethal complications of PTLD, regardless of the effectiveness of PTLD treatment. CLAD occurs at a high rate after PTLD treatment, and close monitoring is required.

Protective effects of anti-HMGB1 monoclonal antibody on lung ischemia reperfusion injury in mice

During ischemia reperfusion (IR) injury, high mobility group box 1 (HMGB1), a chromatin binding protein, is released from necrotic cells and triggers inflammatory responses. We assessed the therapeutic effect of a neutralizing anti-HMGB1 monoclonal antibody (mAb) on lung IR injury. A murine hilar clamp model of IR was used, where mice were divided into sham and IR groups with intravenous administration of anti-HMGB 1 mAb or control mAb. We analyzed the effect of anti-HMGB1 mAb against IR injury by assessing lung oxygenation, lung injury score, neutrophil infiltration, expression of proinflammatory cytokines and chemokines, levels of mitogen-activated protein kinase (MAPK) signaling, and measurement of apoptotic cells. Anti-HMGB1 mAb significantly decreased the plasma level of HMGB1 elevated by IR. The severity of IR injury represented by oxygenation capacity, lung injury score, and neutrophil infiltration was significantly improved by anti-HMGB1 mAb treatment. The expression of proinflammatory factors, including IL-1β, IL-6, IL-12, TNF-α, CXCL-1, and CXCL-2, and phosphorylation of p38 MAPK were both significantly reduced by anti-HMGB1 mAb treatment. Furthermore, anti-HMGB1 mAb treatment suppressed apoptosis, as determined through TUNEL assays. Overall, anti-HMGB1 mAb ameliorated lung IR injury by reducing inflammatory responses and apoptosis. Our findings indicate that anti-HMGB1 mAb has potential for use as a therapeutic to improve IR injury symptoms during lung transplantation.

Lung transplantation for idiopathic multicentric Castleman disease: potential efficacy and tolerability of a humanized anti-interleukin-6 receptor monoclonal antibody

BACKGROUND

Idiopathic multicentric Castleman disease (iMCD) is a rare polyclonal lymphoproliferative disease caused by the overrepresentation of interleukin-6 (IL-6). Tocilizumab (TCZ) is a humanized monoclonal antibody that binds to the IL-6 receptor and is approved for the treatment of iMCD. The efficacy and tolerability of TCZ in patients with iMCD undergoing lung transplantation (LTx) remain unknown.

CASE PRESENTATION

We present the case of a 48-year-old iMCD patient with end-stage lung disease (ESLD) who was successfully treated with cadaveric single-LTx. Intravenous TCZ was used to stabilize the iMCD patient every 2 weeks, except for withdrawal immediately after LTx. At 32 month post-transplant, the patient remained asymptomatic without evidence of rejection, development of de novo donor-specific antibody (DSA), and recurrent iMCD in the native lung.

CONCLUSIONS

Single-LTx can be a feasible treatment option for ESLD caused by iMCD. TCZ can be used safely and may be beneficial in recipients with iMCD, and TCZ in combination with usual immunosuppression can be helpful in stabilizing iMCD patients pre- and post-LTx.

Robot-assisted thoracoscopic lobectomy for severe incomplete interlober fissure

An incomplete interlobar fissure makes thoracoscopic lobectomy difficult and is predictive of morbidity after thoracoscopic lobectomy. This report demonstrates the robot-assisted thoracoscopic (RATS) lobectomy technique for patients with severe incomplete interlobar fissures. A fissureless approach was chosen for pulmonary resection. Near-infrared fluorescence imaging with intravenous indocyanine green (ICG) was used to detect the interlobar line after transection of the bronchus, pulmonary artery and vein. Interlobar fissure was identified and divided by robotic staplers. This combined technique using ICG and fissureless lobectomy made RATS lobectomy safe for patients with severe incomplete interlobar fissures.

A Giant Thymic Cyst Accompanied by Acute Mediastinitis

We encountered a rare case of thymic cyst accompanied by mediastinitis. A 39-year-old Japanese male presented with fever and chest pain. The chest CT revealed a mass composed of a lobular cystic lesion with inflammation, suggesting the onset of mediastinitis. A definitive histological diagnosis was not obtained, and we performed a thymectomy. Pathologically, the thymic cyst was accompanied by multiple cavities, mimicking thymic cysts, caused by the inflammatory abscess. The surrounding adipose tissue showed inflammatory cell infiltrations with chronic fibrosis. These findings indicate that clinicians should be aware that thymic cysts may cause severe mediastinitis.

Emphysematous changes and lower levels of plasma irisin are associated with bronchiolitis obliterans syndrome after bilateral living-donor lobar lung transplantation

PURPOSE

Decreased irisin levels may be associated with the development of emphysema. Similarly, emphysematous changes may develop in patients with chronic lung allograft dysfunction (CLAD) after living-donor lobar lung transplantation (LDLLT). We investigated the severity of emphysematous changes and the relationship between irisin levels and CLAD after bilateral LDLLT and cadaveric lung transplantation (CLT).

METHODS

The subjects of this retrospective study were 59 recipients of bilateral LDLLT (n = 31) or CLT (n = 28), divided into a non-CLAD group (n = 41), a LDLLT-CLAD group (n = 11), and a CLT-CLAD group (n = 7). We compared the severity of emphysematous changes, the skeletal muscle mass, and the plasma irisin levels among the groups.

RESULTS

The emphysematous changes were significantly more severe in the LDLLT-CLAD and CLT-CLAD groups (p = 0.046 and 0.036), especially in patients with bronchiolitis obliterans syndrome (BOS), than in the non-CLAD group. Although the skeletal muscle mass was similar in all the groups, the plasma irisin levels were significantly lower in the LDLLT-CLAD group (p = 0.022), especially in the patients with BOS after LDLLT, than in the non-CLAD group.

CONCLUSION

Emphysematous changes and lower levels of plasma irisin were associated with CLAD, especially in patients with BOS, after bilateral LDLLT.

Lung transplantation for bronchiectasis due to hyper-immunoglobulin E syndrome

Hyper-immunoglobulin E syndrome (HIES) is one of the primary immunodeficiencies characterized by recurrent staphylococcal skin and lung infections that result in lung destruction and critically diminished pulmonary function. Despite the lack of definitive treatment, there have been no reports of successful lung transplantation (LTx) for HIES patients. We report the case of a 42-year-old female HIES patient with progressive bronchiectasis whose pulmonary infection was controlled prior to transplantation and subsequent LTx was uneventful. LTx may be feasible in HIES if the patient is immunologically stable preoperatively, and peri-operative infections, especially Aspergillus infections, are well-controlled.

Quality of life after partial lung resection with uniportal versus 3-port video-assisted thoracoscopic surgery: a prospective randomized controlled study

PURPOSE

The effect of uniportal video-assisted thoracoscopic surgery (uni-VATS) versus that of conventional VATS on postoperative quality of life (QOL) is unclear. This prospective randomized controlled study compared uni-VATS and conventional 3-port VATS in terms of QOL and patient satisfaction.

METHODS

The subjects of this study were 84 patients with pulmonary nodules or bullous formation, randomized to undergo uniportal or conventional 3-port video-assisted thoracoscopic partial lung resection. The primary endpoint was postoperative pain, assessed using a numeric rating scale on postoperative day (POD) 1.

RESULTS

No differences were found in the numeric rating scale on POD 1 after uni-VATS and conventional 3-port VATS. There were also no differences in blood loss, operative time, complication rate, surgical margin, analgesic requirement, vital capacity (VC), forced expiratory volume in 1 s (FEV1), the 6-min walk test (6MWT), C-reactive protein (CRP) levels, white blood cell count (WBC), or duration of chest tube drainage and hospital stay. Differences were found in the numeric rating scale on days 2, 3, 5, and 10 and in the patient satisfaction score on PODs 5 and 10.

CONCLUSIONS

Uni-VATS is associated with less chest pain and better patient satisfaction in the short term but without differences in complication rates or surgical margins from the lesions.

CLINICAL TRIAL REGISTRY NUMBER

University Hospital Medical Information Network Clinical Trial Registry (UMIN000015340 http://www.umin.ac.jp/english/ ).

Robot-assisted intrathoracic procedure for dumbbell tumour in the prone position

A 24-year-old man presented with a dumbbell-shaped right posterior mediastinal mass. The patient was placed in the prone position following general anaesthesia and intubation. After laminectomy and dissection of the dorsal part of the tumour using a posterior approach were performed, the tumour was completely resected using a robotic approach in the thoracic cavity without repositioning. This is the first report of robotic resection for posterior mediastinal tumour in the prone position as well as a novel combined posterior approach and robotic resection for dumbbell tumours.