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Treatment of recurrent malignant pleural mesothelioma (MPM) remains challenging. Our study examined the efficacy, tolerability, and safety of nivolumab with ipilimumab treatment for recurrent MPM after primary curative-intent surgery.Treatment comprised 360 mg nivolumab every 3 weeks and 1 mg/kg of ipilimumab every 6 weeks, both administered intravenously. Both were discontinued for progressive disease or serious adverse events (AEs). Additional post-treatment data were evaluated, including objective response rate (ORR), disease control rate (DCR), post-treatment survival, progression-free survival (PFS), and AEs. Tumor response was assessed using the modified Response Evaluation Criteria in Solid Tumors (RECIST 1.1). Survival analysis was estimated using a Kaplan-Meier plot. Feasibility analysis was performed using the National Cancer Institute Common Terminology Criteria for AEs version 5.0.Forty-one patients received nivolumab with ipilimumab for recurrent MPM after primary curative-intent surgery (median follow-up, 10.4 months; median treatment, 5.1 months). Overall, 18 patients exhibited partial response, 13 exhibited stable disease, and 10 had documented progressive disease. ORR and DCR were 43.9 and 75.6%, respectively. The 12-month post-treatment survival rate and PFS rate were 74.2 and 40.0%, respectively (median survival, not calculated; median PFS, 7.3 months). Further, 47 AEs were reported in 29 patients (70.7%), including grade 3-4 AEs in 14 patients (34.1%). Grade 4 hepatobiliary disorders were observed in 2 patients and grade 4 neutropenia was observed in 1.Nivolumab with ipilimumab treatment in patients with recurrent MPM after primary surgical treatment may be clinically efficacious, although serious AEs may be frequently observed.

We previously established a novel method of lung repair called the ventilation and anchoring (V/A) method. We evaluated the usefulness of the V/A method for controlling air leakage during pleurectomy/decortication (P/D).For this study, we enrolled patients with malignant pleural mesothelioma (MPM) who planned to receive P/D. Our lung repair method involves (1) suturing lung parenchyma for an apparent injured lesion and (2) coating the lung parenchyma with fibrin glue (FG) using the V/A method. The tidal volume (TV) was measured under pressure-controlled ventilation in the ipsilateral-affected lung 10 times at the following four points: after thoracotomy, at completion of visceral pleurectomy, after suturing lung parenchyma, and 5 min after coating with FG. The primary endpoint was the mean TV (mTV) change, and the secondary endpoints were the duration of air leakage and incidence of pleurodesis.Between April 2014 and April 2016, 25 patients of the 29 consecutive patients enrolled were eligible. The mTV significantly decreased after completion of visceral pleurectomy but significantly increased after repair of the lung parenchyma, especially after coating with FG. The median duration of postoperative air leakage was 4 days (range: 2-19 days). Postoperative air leakage 7 days was observed in 11 (44%) patients. Of these 11 patients, 6 received pleurodesis; however, no further revision was needed.Significant increases in TV were observed after coating with FG via the V/A method during P/D. Coating with FG using the V/A method can contribute to a reduction in air leakage during P/D.

Sepsis-induced endothelial acute respiratory distress syndrome is related to microvascular endothelial dysfunction caused by endothelial glycocalyx disruption. Recently, recombinant antithrombin (rAT) was reported to protect the endothelial glycocalyx from septic vasculitis; however, the underlying mechanism remains unknown. Here, we investigated the effect of rAT administration on vascular endothelial injury under endotoxemia. Lipopolysaccharide (LPS; 20 mg/kg) was injected intraperitoneally into 10-week-old male C57BL/6 mice, and saline or rAT was administered intraperitoneally at 3 and 24 hours after LPS administration. Subsequently, serum and/or pulmonary tissues were examined for inflammation and cell proliferation and differentiation by histologic, ultrastructural, and microarray analyses. The survival rate was significantly higher in rAT-treated mice than in control mice 48 hours after LPS injection (75% versus 20%; P

Background Evaluation of tumor markers may facilitate follow-up of malignant pleural mesothelioma (MPM). We aimed was to evaluate the value of tumor markers for monitoring and predicting recurrence in patients with MPM. Methods In total, 152 patients who underwent curative-intent surgery after induction chemotherapy for MPM between July 2004 and December 2017 were retrospectively reviewed. Preoperative and postoperative (≤3 months after surgery) levels of soluble mesothelin-related peptide (SMRP), cytokeratin 19 fragment (Cyfra21-1), and tissue polypeptide antigen (TPA) and rates of recurrence and non-recurrence were evaluated. Factors associated with recurrence-free survival (RFS) were assessed using the Kaplan-Meier method and Cox proportional hazards model. Results Of the 152 patients, the positive rates of preoperative SMRP, Cyfra21-1, and TPA, levels were 26.7%, 8.6%, 9.6%, respectively; the respective postoperative levels were 4.0%, 6.3%, and 6.5%; the respective levels in patients with recurrence were 39.3%, 31.4%, 28.6%; the respective levels in patients with no recurrence were 3.7%, 0.0%, 3.8%. Nearly half (45.2%) of the patients with recurrence exhibited an increase in one or more tumor marker levels. Multivariate analysis revealed that the preoperative positive rates of one or more of the three tumor markers (hazard ratio: 1.8, 95% confidence interval: 1.1-2.8; P=0.02) were independent significant predictors of recurrence. Conclusions The positive rates of SMRP, Cyfra21-1, and TPA in recurrence-free patients were extremely low, with high specificity. Preoperative levels of SMRP, Cyfra21-1, and TPA, which identified patients with a high risk for recurrence, could improve management of patients with MPM.

Background and purpose Disruption of the endothelial glycocalyx is causally related to microvascular endothelial dysfunction, a characteristic of sepsis-induced acute respiratory distress syndrome (ARDS). Recombinant human thrombomodulin (rhTM) attenuates vascular endothelial injuries, but the underlying mechanism remains elusive. Here, we investigated the structural basis and molecular mechanisms of rhTM effects on vascular endothelial injury in a model of sepsis. Experimental approach LPS (20 mg·kg-1 ) was intraperitoneally injected into 10-week-old male C57BL6 mice, and saline or rhTM was intraperitoneally injected 3 and 24 h after LPS injection. Using serum and/or lung tissue, histological, ultrastructural, and microarray analyses were performed. Key results Survival rate of rhTM-treated mice was significantly higher than that of control mice 48 h after LPS injection. Serum concentrations of IL-6 and high-mobility group box 1 were lower in the rhTM-treated group than in the control. Injury to the endothelial glycocalyx in pulmonary capillaries was attenuated by rhTM treatment. Gene set enrichment analysis revealed up-regulation of gene sets corresponding to cell proliferation/differentiation and anti-inflammation, such as the TGF-β pathway, and negative regulation of IL-6, upon rhTM treatment. Gene expression of heparan sulfate 6-O-sulfotransferase 1 and endothelial cell-specific molecule 1 (components of the endothelial glycocalyx) was significantly preserved by rhTM treatment, and their protein expression levels were maintained in endothelial cells. Conclusion and implications Our findings show that rhTM treatment affected inflammation, cell proliferation/differentiation, and glycocalyx synthesis in serum and lung tissue, subsequently attenuating ARDS caused by endothelial injury.

To investigate the incidence and risk factors of chest wall metastasis (CWM) at biopsy sites in patients with malignant pleural mesothelioma (MPM). This retrospective cohort study was conducted in 262 consecutive MPM patients who underwent multimodal treatment in which including neoadjuvant chemotherapy (NAC) and curative-intent surgery, from August 2009 to March 2021. CWM was evaluated radiologically (r-CWM) and pathologically (p-CWM). We also investigated the risk factors of p-CWM and the consistency between r-CWM and p-CWM. Of 262 patients, 25 patients were excluded from analysis due to missing data or impossibility of evaluation. Of the eligible 237 patients, pleural biopsy was performed via video-assisted thoracoscopic surgery in 197 (83.1%) and medical thoracoscopy in 40 (16.9%). Pleurodesis was performed after pleural biopsy in 74 patients (31.2%). All patients received NAC followed by curative-intent surgery. Radiological examination showed r-CWM in 43 patients (18.1%), while pathological examination showed p-CWM in 135 patients (57.0%). The incidence of p-CWM was significantly higher in the patients who received pleurodesis after pleural biopsy (77.0% vs. 47.9%

OBJECTIVES Impact of pleurectomy/decortication (P/D) on quality of life (QOL) is not widely reported. We investigated QOL and lung function after P/D. METHODS A single-centre, retrospective cohort study was performed among patients who underwent P/D for malignant mesothelioma between June 2014 and June 2018 at Hyogo College of Medicine. Data at 4 points before and 3, 6 and 12 months on QOL and lung function were evaluated with the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) and pulmonary function tests. RESULTS Forty-five out of 65 patients completed SF-36. Physical function and role physical decreased from 78 to 65 and 69 to 41 and did not recover. Body pain decreased from 74 to 52. It increased to 62 at 12 months but was lower than before. General health perceptions, vitality and social function decreased from 56 to 49, 50 to 47 and 63 to 50, respectively, but returned to baseline. Role emotional decreased from 75 to 54, then once increased to 63, but decreased again to 58. Mental health tended to improve from 58 to 70. Thirty-eight patients out of 45 completed pulmonary function tests. Forced vital capacity and forced expiratory volume in 1 s decreased from 98% to 61% and 93% to 67% and did not increase. Right-sided surgery or complications was the risk factors of poor lung function but no significant risk factors in QOL. CONCLUSIONS This study suggests that P/D had an impact on QOL. Despite the lack of recovery in lung function QOL in mental aspects tended to improve, suggesting that pulmonary function tests alone are limited in assessing QOL.

We compared less invasive surgery with conventional surgery for malignant pleural mesothelioma (MPM). We retrospectively reviewed consecutive patients with MPM who received surgery at Hyogo College of Medicine between July 2004 and April 2016. Patients underwent multimodal treatment comprising chemotherapy (neoadjuvant and/or adjuvant) and surgery with or without 54 Gy hemithoracic radiotherapy. Patients were grouped into 3 groups according to the surgery intended: Conventional extrapleural pneumonectomy was intended in Group 1 (until August 2009); less invasive extrapleural pneumonectomy was intended in Group 2 (after September 2009); pleurectomy/decortication was intended in Group 3 (after September 2012). We included 152 patients (median age 64 [37-71] years; 131 men, 21 women), mostly with epithelioid subtypes (91.4%). Of them, 149 (98.0%) underwent neoadjuvant chemotherapy and 117 (77.0%) underwent surgery (60 had extrapleural pneumonectomy and 57 had pleurectomy/decortication). Macroscopic complete resection was achieved in 94.9% (111/117), and the mortality rates at 30 and 90 days were 1.7% (2/117) and 3.4% (4/117), respectively. The overall median survival time and progression-free survival for all 152 patients were 34.9 and 17.4 months. The overall median survival time for Groups 1, 2, and 3 were 18.5, 41.9, and 43.4 months, respectively. The progression-free survival for Groups 1, 2, and 3 were 12.0, 24.5, and 21.8 months, respectively. Compared with conventional surgical techniques, less invasive surgery for MPM yielded lower surgical risks and comparable or improved survival.

Background Limited options exist for treating post-recurrence patients with malignant pleural mesothelioma (MPM). This study aimed to evaluate the efficacy and feasibility of nivolumab in patients with post-operative recurrence of MPM in a real-world setting. Methods This study included 35 patients with post-operative recurrence of MPM. Treatment consisted of 240-mg intravenous nivolumab administration every 2 weeks until progressive disease (PD) or serious adverse events (AEs). Additional post-treatment data were evaluated, including objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), post-treatment survival and AEs. Tumor response was assessed using the modified Response Evaluation Criteria in Solid Tumors. Survival analysis was performed using the Kaplan–Meier method. The feasibility analysis including AEs was performed with the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0. Results Of the 35 patients who received nivolumab, median follow-up was 6 months. The median treatment duration was 3 months (range: 1–14 months), and median of 8 cycles (range: 2–32 cycles) was administered. Best overall responses were follows: 1 patient had complete response, 6 had partial response, 18 had stable disease and 8 had PD. The ORR was 20.0%, and the DCR was 77.1%. The median overall survival and PFS were 13.1 and 4.4 months, respectively. There were grade-3 AEs in four patients (11.4%). No grade-4 or -5 AEs were observed. Conclusion Nivolumab treatment in patients with post-operative recurrence of MPM seems safe and clinical efficacy.

Endothelial glycocalyx coats healthy vascular endothelium and plays an important role in vascular homeostasis. Although cerebral capillaries are categorized as continuous, as are those in the heart and lung, they likely have specific features related to their function in the blood brain barrier. To test that idea, brains, hearts and lungs from C57BL6 mice were processed with lanthanum-containing alkaline fixative, which preserves the structure of glycocalyx, and examined using scanning and transmission electron microscopy. We found that endothelial glycocalyx is present over the entire luminal surface of cerebral capillaries. The percent area physically covered by glycocalyx within the lumen of cerebral capillaries was 40.1 ± 4.5%, which is significantly more than in cardiac and pulmonary capillaries (15.1 ± 3.7% and 3.7 ± 0.3%, respectively). Upon lipopolysaccharide-induced vascular injury, the endothelial glycocalyx was reduced within cerebral capillaries, but substantial amounts remained. By contrast, cardiac and pulmonary capillaries became nearly devoid of glycocalyx. These findings suggest the denser structure of glycocalyx in the brain is associated with endothelial protection and may be an important component of the blood brain barrier.

The change in TNM classification of malignant pleural mesothelioma (MPM) between the seventh and eighth edition classifications has resulted in the downstaging of many advanced-stage patients into pathological stage IB. Many mesotheliomas without lymph node metastasis have been classified as stage IB in the eighth edition classification. Stage IB mesotheliomas comprised a heterogeneous group with different prognosis. It is necessary to clarify the prognostic factors in this group. Between September 2009 and August 2016, a total of 89 patients with MPM underwent curative intent surgery [pleurectomy decortication n = 57 (64.1%), extrapleural pneumonectomy n = 32 (35.9%)] at our institution. Of these, 40 were reclassified as stage IB according to the eighth edition TNM classification. Independent unfavorable prognostic factors were identified by univariate analyses using the log-rank test and Cox proportional hazards regression models. Three independent significant factors were identified that indicated an unfavorable prognosis: a nonepithelioid subtype, lymphovascular invasion, and preoperative forced expiratory volume in 1 s (FEV1)

Myocardial injury in sepsis may be caused by a burst of several inflammatory mediators, leading to vascular endothelial injuries. However, the contribution of neutrophil elastase (NE) to myocardial injury in sepsis is still unknown. We aimed to evaluate whether endotoxemia-induced myocardial injury is associated with NE. Lipopolysaccharide (LPS) was injected intraperitoneally at a dose of 20 mg/kg into granulocyte-colony-stimulating-factor knockout mice (G-CSF-KO), which have few neutrophils, and littermate control mice. The survival rate of G-CSF-KO mice 48 hours after LPS injection was significantly greater than that of control mice. The serum level of troponin I in G-CSF-KO mice was significantly lower than that in control mice. In addition, the concentration of inflammatory cytokine interleukin-6 (IL-6) was significantly decreased 6 and 12 hours after LPS administration compared with that in control mice. Ultrastructural analysis revealed that vascular endothelial structures and the endothelial glycocalyx in G-CSF-KO mice were clearly preserved. Next, mice were injected with 0.2 mg/kg sivelestat (an NE inhibitor) after LPS administration. The survival rate was significantly higher and the serum level of troponin I was lower in sivelestat-injected mice than in control mice, respectively. Furthermore, IL-6 levels were significantly decreased 6 and 12 hours after LPS administration compared with those in control mice. Vascular endothelial structures and the endothelial glycocalyx in sivelestat-treated mice were clearly preserved at the ultrastructural level. In conclusion, NE is significantly associated with myocardial injury in endotoxemia. Inhibition of NE may be a useful tool for the management of endotoxemia.

Pleural biopsy through video-assisted thoracic surgery (VATS pleural biopsy) is the most reliable diagnostic procedure for malignant pleural mesothelioma (MPM). However, definitive diagnosis of MPM is occasionally difficult to establish. This study aims to investigate clinicopathological features of MPM patients who failed diagnosis by the first VATS pleural biopsy. Four hundred consecutive patients with suspected MPM who received VATS pleural biopsy between March 2004 and July 2017 were enrolled in this retrospective study. Patients, whose histological diagnoses were not definitive in the first VATS pleural biopsy, were followed up as atypical mesothelial proliferation (AMP) or non-specific pleuritis (NSP). Re-examination was performed in cases strongly suspected of having MPM. Of the 400 patients, 267 (66.8%) were pathologically diagnosed with MPM, 25 with metastatic carcinoma and 6 with benign pleural disease by the first VATS pleural biopsy. Of the remaining 102 patients diagnosed with AMP or NSP, 10 patients (9.8%) were subsequently diagnosed with MPM. Analysis of the clinical course revealed that only insufficient tissue for diagnosis was obtained via VATS pleural biopsy in all cases and that it was caused by very early stage without visible tumour in 4 patients, intrathoracic inflammation in 4 and desmoplastic MPM in 2. In our review, 9.8% of patients diagnosed with AMP or NSP in first VATS pleural biopsy were subsequently diagnosed with MPM due to insufficient tissue for diagnosis. Definitive diagnosis via VATS pleural biopsy is sometimes challenging in following situation; very early stage, intrathoracic inflammation and desmoplastic MPM.

Background/aim We performed multimodality therapy comprising preoperative chemotherapy, extrapleural pneumonectomy (EPP), and radiation therapy for patients with malignant pleural mesothelioma (MPM). Although multimodality therapy resulted in good prognosis, further improvement is required. Therefore, herein, we analysed the prognostic factors using surgical specimens and searched for suitable molecular targets to improve the prognosis after multidisciplinary treatment. Patients and methods Forty-six patients with MPM underwent multimodality therapy. Paraffin-embedded surgical samples were used for immunohistochemistry to evaluate the expression of phosphorylated (p-) AKT, extracellular signal-regulated kinase (ERK), mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK), eukaryotic translation initiation factor 4E-binding protein 1 (4E-BP1), and S6 ribosomal protein (S6RP). Results On univariate and multivariate analyses, significant differences were observed according to the histological type, pathological stage, and p-mTOR expression rate. Conclusion The prognosis of MPM is affected by p-mTOR expression, suggesting that molecular-targeted treatment might be used during multimodal therapy for MPM.

Background Most patients with malignant pleural mesothelioma experience recurrence after treatment. However no clinical studies have evaluated postrecurrence survival after pleurectomy/decortication for malignant pleural mesothelioma. This study aimed to clarify postrecurrence survival, treatment, prognostic factors, and recurrence pattern after pleurectomy/decortication. Methods We conducted a retrospective cohort study of 90 patients who underwent neoadjuvant chemotherapy followed by pleurectomy/decortication at our hospital between September 2012 and December 2017. Survival and recurrence were calculated using the Kaplan-Meier method with the log-rank test. Clinical factors related to postrecurrence survival were assessed using multivariate analysis with the Cox proportional hazards model. Results Of 90 patients, 57 (63.3%) developed recurrence. The 1- and 3-year recurrence-free survival rates were 69.7% and 34.0%, respectively (median recurrence-free survival time, 19.0 months). With regard to initial recurrence, 39 patients (68.4%) developed local recurrence, 6 (10.5%) developed distant recurrence, and 12 (21.1%) developed both local and distant recurrences. The 1-year postrecurrence survival rate was 59.5% (median post-recurrence survival time, 14.4 months). Forty-three patients (75.4%) underwent a postrecurrence treatment. Multivariate analysis revealed that postrecurrence treatment (hazard ratio, 0.2; 95% confidence interval, 0.07-0.55; P = .002), performance status 0 to 1 (hazard ratio, 0.24; 95% confidence interval, 0.08-0.76; P = .01), and disease-free interval more than 12 months (hazard ratio, 0.4; 95% confidence interval, 0.16-0.99; P = .04) were the independent, favorable, and significant prognostic factors of postrecurrence survival. Conclusions Postrecurrence survival after pleurectomy/decortication is acceptable, and postrecurrence treatment, performance status, and disease-free interval are important prognostic factors of postrecurrence survival.

An RNA chaperone of Escherichia coli, called host factor required for phage Qb RNA replication (Hfq), forms a complex with small noncoding RNAs to facilitate their binding to target mRNA for the alteration of translation efficiency and stability. Although the role of Hfq in the virulence and drug resistance of bacteria has been suggested, how this RNA chaperone controls the infectious state remains unknown. In the present study, we addressed this issue using Drosophila melanogaster as a host for bacterial infection. In an assay for abdominal infection using adult flies, an E. coli strain with mutation in hfq was eliminated earlier, whereas flies survived longer compared with infection with a parental strain. The same was true with flies deficient in humoral responses, but the mutant phenotypes were not observed when a fly line with impaired hemocyte phagocytosis was infected. The results from an assay for phagocytosis in vitro revealed that Hfq inhibits the killing of E. coli by Drosophila phagocytes after engulfment. Furthermore, Hfq seemed to exert this action partly through enhancing the expression of s38, a stress-responsive s factor that was previously shown to be involved in the inhibition of phagocytic killing of E. coli, by a posttranscriptional mechanism. Our study indicates that the RNA chaperone Hfq contributes to the persistent infection of E. coli by maintaining the expression of bacterial genes, including one coding for s38, that help bacteria evade host immunity. ©2016 by The American Association of Immunologists, Inc., Embargo Period 12 months

Background: Programmed death 1 (PD-1) blockade with Nivolumab are effective in patients with malignant pleural mesothelioma (MPM), however; successful predictive biomarker has not been available. Unlike invasive test with tumor biopsy, peripheral blood is safe and easily obtainable source of biomarkers. We have previously reported that T cell receptor (TCR) diversity of CD8+PD-1+ T cells were effective to predict response to anti-PD-1 antibody treatment in non-small cell lung cancer (NSCLC) patients (AACR2019: Abstract nr 2230). In this study, Next generation sequence(NGS)-based TCR α and β repertoires were examined with peripheral CD8+PD-1+ T cells isolated from 11 patients with MPM and treatment responses were evaluated 2 months after anti-PD-1 antibody treatment. Methods: Peripheral blood mononuclear cells were collected from 11 MPM patients enrolled in this study before administration of anti-PD-1 antibody (Nivolumab). NGS-based TCR α and β repertoire analysis were performed with CD8+PD-1+ T cells isolated with FACS sorting by Repertoire Genesis Inc. TCR diversity was statistically evaluated by Shannon, Simpson and Diversity Evenness 50 (DE50) indices. CT scan was performed during week 8 of treatment and used to determine response to nivolumab. This study was approved by the Ethical Committee of Hyogo College of Medicine. Results: Three of 11 (27.3%) MPM patients responded to anti-PD-1 treatment. There were good correlation of all diversity indices between TCRα and TCRβ. TCRβ diversity was significantly higher among responders than non-responders based on DE50 (0.0019 ± 0.00032 vs 0.0011 ± 0.00042, P < 0.05). Also, responders exhibited a clear trend to have higher TCR diversity of CD8+PD-1+ T cells in terms of Shannon, normalized Shannon and Simpson indices. Conclusion: Like NSCLC patients, PD-1 blockade was more effective in MPM patients who had higher levels of TCR diversity in peripheral CD8+PD-1+ T cells. This result suggested the TCR diversity of peripheral CD8+PD-1+ T cells has potential to predict response to immune checkpoint inhibitors in various tumor patient. Further clinical study would be needed to verify effectiveness of this biomarker. Citation Format: Seiji Matsumoto, Takaji Matsutani, Yoshiko Fujita, Ryo Takahashi, Takashi Yokoi, Hiroshi Kodama, Yoshie Inao, Kazutaka Kitaura, Tohoru Nakamichi, Akifumi Nakamura, Ayumi Kuroda, Aki Kobayashi, Masaki Hashimoto, Nobuyuki Kondo, Ryuji Suzuki, Koichiro Yamakado, Takashi Kijima, Seiki Hasegawa. Effective prediction of treatment responders with anti-PD-1 antibody in malignant pleural mesothelioma by diversity of peripheral CD8+PD-1+ T cell subpopulation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4478.

Objectives Definitive diagnosis of the T-component is sometimes challenging in malignant pleural mesothelioma (MPM). Pleural thickness has been reported to be a prognostic factor for MPM and is a potential T-component. Methods We conducted a historical cohort study of patients who underwent neoadjuvant chemotherapy (NAC) and curative-intent surgery as a multimodal treatment for MPM from January 2007 to June 2016. The maximum measurement of pleural thickness among 3 levels and the sum at each level determined using axial computed tomography imaging before and after NAC were termed as "max" and "sum," respectively. We assessed the association between pleural thickness and the primary and secondary end points of overall survival and recurrence-free survival. Survival was analyzed using the Kaplan–Meier curve, log rank test, and multivariate Cox regression model. Results We enrolled 105 patients. We excluded 1 because of missing data; thus, the sample size was 104. The median follow-up period was 29.1 months with recurrence in 78 patients (70.3%) and death in 67 (60.4%). Max and sum ranged from pre (before NAC) values of 0 to 35 (median, 6.05) and 0 to 97 (median, 12.9) to post (after NAC) values of 0 to 30.8 (median, 4.25) and 0 to 67.0 (median, 9.25), respectively. Post values max and sum were associated with overall survival and recurrence-free survival. Post sum values were associated with recurrence (adjusted hazard ratio, 2.59; 95% confidence interval, 1.42-3.83) and death (adjusted hazard ratio, 2.13; 95% confidence interval, 1.16-4.52), respectively. Conclusions Pleural thickness after NAC was an independent prognostic factor in patients who underwent multimodal treatment.

Background: Circulating tumour cells (CTCs) are a potential surrogate for distant metastasis and are considered a useful clinical prognostic marker for metastatic colorectal cancer (mCRC). This prospective study evaluated the preoperative CTC count as a prognostic factor for pulmonary metastasectomy in mCRC patients. Methods: Seventy-nine mCRC patients who underwent curative-intent pulmonary metastasectomy were included. Preoperatively, 7.5 mL of peripheral blood from each patient was quantitatively evaluated for CTCs with the CellSearch ® system. The clinical significance of CTC count was evaluated according to Kaplan-Meier analyses and log-rank test. Multivariate analyses of the perioperative variables were performed. Results: The distribution of CTC counts were as follows; 0 in 66 patients (83.5%), 1 in eight patients (10.1%), 2 in three patients (3.8%), and 3 and 6 in one patient (1.3%). The patients with multiple CTCs (CTC count ≥2) had significant shorter disease-free survival (DFS) (P=0.005, median DFS; 19.8 vs . 8.6 months) and overall survival (OS) (P=0.035, median DFS; not reached vs . 37.8 months), respectively. Multivariate analysis showed the patients with multiple CTCs had elevated risk of recurrence [hazard ratio (HR), 3.28; 95% confidence interval (CI), 1.24–8.67; P=0.017]. Conclusions: The detected rate of CTCs was quite low in mCRC patients who underwent pulmonary metastasectomy. The patient with multiple CTCs had shorter DFS in this study. The larger prospective clinical study is needed to establish the meaning of CTC in mCRC candidate for pulmonary metastasectomy.

Background: Anti-PD-1 antibodies (nivolumab) are effective in the treatment of many cancers, including malignant melanoma, non-small cell lung cancer (NSCLC), renal cell cancer, and head and neck squamous cell carcinoma. Immune checkpoint inhibitors (ICIs) are only effective in around 20% of patients, which saw a demand for the development of biomarkers that predict a therapeutic response before administering treatment. As the biomarkers intratumoral PD-L1 expression and tumor mutation burden (TMB) both require tumor tissue biopsy, there is now a demand for safer and less invasive biomarkers. Peripheral and tumor CD8+PD-1+ T cells share neoantigen-specific T-cell receptors (TCRs), and are presumed to act as effector T cells with an antitumor effect at the tumor site. We analyzed the diversity in terms of TCR α and β repertoires on peripheral CD8+PD-1+ T cells and examined the relationship between this diversity and therapeutic effect of nivolumab. Methods: This study used patients administered nivolumab after exhibiting no response to chemotherapy for recurrence following surgery. Peripheral blood mononuclear cells were collected from patients before administration of nivolumab. CD8+PD-1+ T cells were subjected to FACS sorting, NGS-based TCR repertoire analysis was performed by Repertoire Genesis Inc., and TCR diversity was evaluated statistically. CT scan was performed during week 12 of treatment and used to determine response to nivolumab. This study was approved by the Ethical Committee of Hyogo College of Medicine. Results: Six of 12 patients responded to treatment. Upon comparing these responders (CR, PR) with non-responders (SD, PD), there were no differences in the proportion of PD-1+ in CD8+ T cells and the proportion of CD8+PD-1+ T cells in gated lymphocytes. TCR α diversity was significantly higher among responders than non-responders based on Shannon index, Simpson index and DE50 (P < 0.05, P < 0.05, P < 0.01, respectively). TCR β diversity was also significantly higher among responders than non-responders based on Shannon index, Simpson index and DE50 (all P < 0.01). Progression-free survival (PFS) was 371 days for responders and 148 days for non-responders. Overall survival (OS) was 633 days for responders and 308 days for non-responders, showing a significant difference between the groups. Conclusion: TCR repertoire analysis was performed on CD8+PD-1+ T cells in easily-obtainable peripheral blood before nivolumab treatment in patients with NSCLC, and nivolumab was observed to be effective in patients with high TCR diversity. This result indicates the TCR diversity of peripheral CD8+PD-1+ T cells is effective as a predictive biomarker for response to ICI therapy. In the future, we intend to analyze TMB and neoepitopes using surgical specimens of these patients and determine the efficacy of this biomarker for cancers other than NSCLC. Citation Format: Seiji Matsumoto, Takaji Matsutani, Yoshiko Fujita, Kazutaka Kitaura, Tohoru Nakamichi, Akifumi Nakamura, Ayumi Kuroda, Masaki Hashimoto, Nobuyuki Kondo, Ryuji Suzuki, Seiki Hasegawa. Diversity of peripheral CD8+PD-1+ T cells is a novel predictive biomarker for response to anti-PD-1 antibody treatment in lung cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2230.

e20067 Background: It is difficult to predict prognosis for malignant pleural mesothelioma (MPM). The association of thoracic asymmetry and survival in patients with MPM was reported by Cho et al. in at the 18th World Conference on Lung Cancer. Here we investigated the survival impact of thoracic cavity reduction during neoadjuvant chemotherapy (NAC). Methods: The subjects were patients with resectable epithelioid MPM who underwent NAC with platinum and pemetrexed followed by surgery at the Hyogo College of Medicine from Jan 2009 to Aug 2018. The length of the ant-post and med-lat extent of both hemithoraces at the level of carina was measured before and after NAC. Asymmetric ratio (ASR) was defined as the product of the ant-post and med-lat extent of affected side divided by those of healthy side. Results: One hundred thirty-three patients were enrolled: median age 66 (16-79) years, M/F 112/21, R/L 70/63, extrapleural pneumonectomy 40 and pleurectomy/decortication 93. Significantly poor prognosis was associated with ≥ 10mm reduction of the med-lat extent of affected side during NAC and ≥ 10% reduction of the product of the ant-post and med-lat extent of affected side during NAC (p = 0.0021). ASR ≤ 0.9 before or after NAC was not associated with significantly poor survival. Conclusions: This study revealed that thoracic cavity reduction during NAC was associated with significantly poor prognosis of MPM.

8548 Background: Since any surgery for malignant pleural mesothelioma (MPM) are cytoreductive, effective chemotherapy is a prerequisite for surgery. In this context, we give neo-adjuvant chemotherapy (NAC) to all surgical candidates. Methods: Hyogo College of Medicine MPM Surgery Program mandates all surgical candidates to receive NAC, and only patients with stable disease (SD) or better response proceeds to surgery. The program comprised NAC followed by extrapleural pneumonectomy (EPP) and hemithoracic radiation until 2012, and NAC followed by pleurectomy/decortication (P/D) and postoperative chemotherapy thereafter. Eligibility criteria are histologically confirmed non-sarcomatoid MPM, clinically resectable stage (T1-3N0-1M0), performance status 0–1, and no major comorbidity. Results: From December 2006 to December 2018, 225 patients were enrolled. Of 225, 24 patients (10.7%, Group A) did not proceed to surgery because of progressive disease (n=23) or serious adverse events (n=2). Of the remaining 201 patients with partial response (n=38, 16.9%) or stable disease (n=163, 72.4%), 19 refused surgery (Group B), 16 received exploratory thoracotomy (Group C), and 165 completed surgery (Group D, EPP58, P/D107). Surgical mortality rates at 30 and 90 days were 1.1% (n=2) and 2.8% (n=5), and surgical morbidity (≧grade 3) was 26.0% (n=47). Median survival time and survival rates of each group were shown in the table. Briefly, 2-yr survival competed among Group B,C and D, whereas 5-yr survival rapidly dropped in Group B and C. Conclusions: Approximately 90% of MPM patients with surgical intent successfully underwent either of EPP or P/D after effective chemotherapy with acceptable surgical mortality and morbidity. Comparison of patients who refused or accepted surgery suggested that surgery contributed to long-term survival. [Table: see text]

e24326Background: The prognosis of malignant pleural mesothelioma (MPM) is very poor; a new drug for MPM is need. The percentage of p16 loss in MPM patients is high. We hypothesized that CDK4/6 is ...

Introduction Malignant pleural mesothelioma (MPM) is a highly aggressive malignancy in which the mitogen-activated protein kinase pathway plays a critical role in the regulation of tumorigenesis. Hyaluronic acid (HA) is a major component of the extracellular matrix, and elevated HA levels with a concurrent increase in malignant properties are associated with MPM. Methods We evaluated the effects of trametinib, a mitogen-activated protein kinase (MEK) inhibitor, and 4-methylumbelliferone (4-MU), an HA synthesis inhibitor, alone and in combination on MPM cells in vitro and in vivo. We studied the effects of trametinib, 4-MU, and their combination on MPM cells by using cell viability assays, Western blot analysis, and a mouse xenograft model. Results Trametinib and 4-MU exhibited antiproliferative activity in MPM cells. Trametinib blocked MEK-dependent extracellular signal-regulated kinase (ERK) phosphorylation and decreased CD44 expression in a concentration-dependent manner. Trametinib inhibited the expression of Fra-1 (the activator protein 1 [AP1] component), inhibited ERK phosphorylation, and decreased CD44 expression. 4-MU inhibited ERK phosphorylation but not CD44 expression. In a mouse xenograft model, trametinib and 4-MU alone suppressed tumor growth compared with a control. The combination had a greater inhibitory effect than either monotherapy. Immunohistochemical analysis showed that trametinib treatment alone significantly reduced expression of programmed cell death 1 ligand 1. Furthermore, the combination of trametinib and 4-MU resulted in higher expression of programmed cell death 1 and programmed cell death 1 ligand 1 than did the 4-MU treatment alone. Conclusions Our results suggest that trametinib and 4-MU are promising therapeutic agents in MPM and that further study of the combination is warranted.

Background: The prognosis of Malignant pleural mesothelioma (MPM) is very poor, the new drug for MPM is need. IL-6 in serum with MPM patients is high, IL-6/Stat3 pathway is activated. We investigated that Stat3 is the potential target for the treatment of MPM. Methods: Cell viability was assayed with Cell Counting Kit-8 (CCK-8: WST-8 Dojindo). MPM cells (NCI-H28, NCI-H226, NCI-H2052, NCI-H2452, MSTO-211H) were seeded into 96-wellplates. After the treatment with Stat3 inhibitor (BBI-608). Cell Counting Kit-8 solution was added to each well of the plate and measured the absorbance using a microplate reader. The levels of phosphorylated Stat3 (p-Stat3) were measured in cell lysates using an InstantOne ELISA assays (eBioscience). The translocated p-Stat3, c-Myc were analyzed by Confocal immunofluorescent. In vivo study, H226 cells were injected into the subcutaneous over the flank region of nude mice. Mice were randomly assigned into four groups (5 mice each group) 1) vehicle control 2) treated with BBI-608 3) Radiation 4) BBI608/RT. Tumor is measured twice per week. Results: BBI-608 inhibited MPM cell lines (NCI-H28, NCI-H226, NCI-H2052, NCI-H2452, MSTO-211H) viability in a dose-dependent manner. The level of p-Stat3 was decreased 90% by BBI-608 10μM treatment in H226. Untreated H226, p-stat3 was observed in cytoplasma and localized in the nucleus. As compared with untreated cells, p-stat3, c-Myc were decrease in cytoplasma and was not localized in the nucleus with BBI-608 treated cells. BBI-608 suppressed tumor growth (p Conclusion: In this study, we have shown that BBI-608 inhibited the proliferation of all MPM cell (epithelial, biphasic, sarcomatoid) lines and inhibited Stat3 phosphorylation and blocked the translocation to the nucleus. We also demonstrated that BBBI-608 completely suppressed tumor growth with radiation in mouse model. Furthermore, Stat3 inhibitor with Radiation Therapy (START) is promising in MPM therapy. Citation Format: Seiji Matsumoto, Hiroshi Doi, Tohoru Nakamichi, Ayumi Kuroda, Masaki Hashimoto, Teruhisa Takuwa, Nobuyuki Kondo, Seiki Hasegawa. Stat3 inhibitor (BBI-608) with radiation therapy is promising in malignant pleural mesothelioma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2488.

e20082Background: The retinoblastoma (Rb) protein binds E2F transcription factors in the G1 phase to inhibit the activity of the Rb protein, thereby blocks the cell from initiating DNA replication....

Purpose Surgical treatment of lung cancer in patients receiving hemodialysis carries a high risk because of poor cardiac function and a fragile electrolyte balance. Because the number of patients receiving hemodialysis has increased, the proportion of such patients with lung cancer is expected to rise. However, few studies have examined the results of surgery for lung cancer in hemodialysis patients, especially by video-assisted thoracoscopic surgery (VATS). Methods We conducted a retrospective analysis of 5 hemodialysis patients who underwent VATS for lung cancer. Results All patients were men, and the mean age was 70.4 years. The operative procedure was lobectomy in 4 patients and segmentectomy in 1. During the perioperative period, none required urgent hemodialysis. There were no critical complications and in-hospital deaths. Three of the 5 patients are currently alive and recurrence-free. One patient died of recurrence at 4 month after surgery, and the other patient died at 17 months after surgery without cancer recurrence. Conclusions VATS appears to be a safe procedure for hemodialysis patients with lung cancer, and the long-term outcome is satisfactory.

Tracheal stenosis after intubation is a fairly common complication, and treatment of such cases can be difficult. A 52-year-old woman was admitted to our hospital because of severe dyspnea. Seven years previously, she had suffered tracheal stenosis after tracheal intubation and had undergone tracheal resection and placement of a self-expandable metal stent. In this case, tracheal restenosis had occurred and we successfully treated the patient by insertion of a silicone T-tube after tracheotomy. Use of a T-tube is safe and effective for relief of tracheal restenosis after self-expandable metal stent placement.

Introduction: Malignant pleural mesothelioma (MPM) is a highly aggressive malignancy for which no targeted therapy exists. The mitogen-activated protein kinase (MAPK) pathway plays critical roles in the regulation of tumorigenesis in multiple solid tumors, including MPM. Trametinib, a selective MEK inhibitor, have a survival benefit in patients with V600 BRAF-mutant metastatic melanoma. The effect of trametinib on MPM cells has not been well studied. Hyaluronan (HA) is one of the major components of the extracellular matrix. MPM is in most cases associated with elevated amounts of HA, which has increased the malignant properties of MPM cells. The HA synthesis inhibitor 4-methylumbelliferone (4-MU) has antitumor effects in various malignant tumors, but its effect on MPM cells has not been well studied. Purpose: We evaluated the effects of trametinib, 4-MU and their combination on MPM cells in vitro and in vivo. Experimental Design: The effects of trametinib, 4-MU, and their combination on MPM cells were evaluated using cell viability assay, western blot analysis, and mouse xenograft model. Results: Trametinib exhibited an antiproliferative activity in all four MPM cell lines, NCI-H226, NCI-H2452, NCI-H2052, and MSTO-211H, with IC50 values ranging from 0.15 μM to 12.7 μM. Trametinib blocked the phosphorylation of ERK until 72 hours and decreased the expression of CD44 in a dose-dependent manner. In addition, the expression of CD44 was inhibited (48-72 hours) after the suppression of ERK phosphorylation by trametinib. 4-MU exhibited an antiproliferative activity in MPM cells. 4-MU inhibited ERK phosphorylation but not CD44 expression. In mouse xenograft model, trametinib and 4-MU suppressed tumor growth (trametinib vs. control, P < 0.0001; 4-MU vs. control, P < 0.01), and their combination suppressed more strongly (combination vs. trametinib, P < 0.01; combination vs. 4-MU, P < 0.0001; combination vs. control, P < 0.0001). Conclusions: Trametinib and 4-MU exhibited antitumor activities in MPM cell lines. Furthermore, their combination exhibited more potent antitumor activities. These results suggests that Trametinib and 4-MU are promising therapeutic agents in MPM, and these combination therapies may be effective for the treatment of MPM. Citation Format: Hiroyuki Cho, Seiji Matsumoto, Yoshiko Fujita, Ayumi Kuroda, Masaki Hashimoto, Teruhisa Takuwa, Toshi Menju, Makoto Sonobe, Nobuyuki Kondo, Hiroshi Date, Seiki Hasegawa. Antitumor effect of Trametinib, a selective MEK inhibitor, in combination with 4-methylumbelliferone, a hyaluronic acid synthesis inhibitor, in Malignant pleural mesothelioma cell lines. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2581. doi:10.1158/1538-7445.AM2015-2581

e18543 Background: The mTOR signal pathways are activated in a broad range of malignancies. Methods: A multimodality therapy consisting of induction chemotherapy , extrapleural pneumonectomy (EPP) ...

e18542 Background: Cisplatin plus pemtrexte is first line chemotherapy for Malignant Pleural Mesothelioma (MPM). In multimodality include extrapleural pneumonectomy (EPP), chemotherapy is essential...

Introducion: Malignant pleural mesothelioma (MPM) is a highly aggressive malignancy and there is no approved targeted therapy. The MAPK pathway plays critical roles in the regulation of cell proliferation, growth, differentiation, and survival in multiple solid tumors, including MPM. Trametinib, a selective MEK inhibitor, have a survival benefit in patients with V600 BRAF-mutant metastatic melanoma. FDA approved Trametinib for these patients in May 2013. The effect of Trametinib in MPM cells has not been well studied. Purpose: We examined the effects of Trametinib in MPM cells in vitro. Methods: To examine the effect of Trametinib on the proliferation of MPM cells, we performed cell proliferation assay using four MPM cell lines, NCI-H2452, NCI-H226, NCI-H2052 and MSTO-211H. To examine the effect of Trametinib on intracellular signaling, we performed Western blot analysis in NCI-H226 cell line. Results: Trametinib exhibited potent antiproliferative activity in all four MPM cell lines with IC50 values ranging from 0.5 μM to 44 μM. Trametinib blocked the phosphorylation of ERK until 72 hours and decreased the expression of CD44 in a dose-dependent manner. In addition, the expression of CD44 was inhibited (48-72 hours) after the suppression of ERK phosphorylation by Trametinib. Conclusions: Our results suggest that Trametinib is a promising therapeutic agent for MPM. Citation Format: Hiroyuki Cho, Seiji Matsumoto, Yoshiko Fujita, Ayumi Kuroda, Masaki Hashimoto, Teruhisa Takuwa, Toshi Menju, Makoto Sonobe, Nobuyuki Kondo, Hiroshi Date, Seiki Hasegawa. Antitumor activity of Trametinib, a MEK1/2 inhibitor, in malignant pleural mesothelioma cells in vitro. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 742. doi:10.1158/1538-7445.AM2014-742

7585 Background: Malignant Pleural Mesothelioma (MPM) is a rare disease with poor prognosis. The combination chemotherapy with cisplatin and pemetrexed is the first line of MPM. The AKT/mTOR (Mamma...