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Hayashi H, Sugawara S, Fukuda Y, Sato Y, Miura S, Ota K, Ozawa Y, Hara S, Tanizaki J, Azuma K, Omori S, Tachihara M, Nishino K, Hosokawa S, Chiba Y, Haratani K, Sakai K, Nishio K, Yamamoto N, Nakagawa K. A randomized phase II study comparing nivolumab (NIVO) with carboplatin-pemetrexed (CbPEM) for patients (pts) with EGFR mutation-positive non-small cell lung cancer (NSCLC) who acquire resistance to tyrosine kinase inhibitors (TKIs) not due to a secondary T790M mutation (WJOG8515L). J Clin Oncol 2021. [DOI: 10.1200/jco.2021.39.15_suppl.9037] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
9037 Background: Although the efficacy of antibodies to programmed cell death–1 (PD-1) appears to be less pronounced in patients with NSCLC harboring epidermal growth factor receptor gene ( EGFR) mutations, patients who develop disease progression (PD) to TKIs due to mechanisms other than secondary T790M mutation of EGFR might be more likely to benefit from NIVO. Here, we report the results of first randomized phase II trial to compare NIVO with the CbPEM in those population. Methods: Pts with advanced EGFR mt NSCLC who experienced PD after EGFR-TKIs were randomized 1:1 to NIVO or CbPEM. Eligibility criteria included the treatment history with TKIs as follow; no evidence of T790M after PD on 1st/2nd generation (gen) TKIs (A) after PD on 3rd gen TKIs as a 2nd line for T790M positive tumor (B) or 3rd gen TKIs as a front-line (C). The primary end point is progression-free survival (PFS) and biomarker analysis were included for exploratory analysis. Results: A total of 102 patients was randomized. Median PFS and overall survival (OS) were 1.7 and 20.7 months (mo), respectively, for NIVO arm (n = 52) versus 5.6 and 19.9 months for CbPEM (n = 50) (Hazard ratio [HR] = 1.92 and 0.88, respectively). Overall response rate and duration of response were 9.6% and 5.3 months for NIVO and 36.0% and 5.5 months for CbPEM. PD-L1 expression on tumor cells and tumor mutation burden (TMB) were evaluated in 77 (TPS 0%. 1-49%, > 50%, n = 46, 20, and 11) and 50 (Median TMB 6.2mt/mb). Immune-related gene expression profiling was under evaluation and the results will be demonstrated in the meeting. The efficacy of NIVO in PD-L1 strong positive (>50%, n = 8) and no evidence of T790M after PD on 1st/2nd gen TKIs (n = 29) was tended to be better than their counterparts. There was no significant correlation between TMB and the efficacy of NIVO. Pneumonitis was observed in one patient (1.0%) for NIVO arm and no new safety signals were noted. Conclusions: NIVO was not associated with longer PFS than CbPEM in selected pts with advanced EGFR mt NSCLC. OS was similar between groups. Baseline PD-L1 status and genetic alteration features may be relevant predictive markers to select pts who would benefit from NIVO. Clinical trial information: jRCTs051180133. [Table: see text]
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Ochi N, Ichihara E, Takigawa N, Harada D, Inoue K, Shibayama T, Hosokawa S, Kishino D, Harita S, Oda N, Hara N, Hotta K, Maeda Y, Kiura K. The effects of antibiotics on the efficacy of immune checkpoint inhibitors in patients with non-small-cell lung cancer differ based on PD-L1 expression. Eur J Cancer 2021; 149:73-81. [PMID: 33838391 DOI: 10.1016/j.ejca.2021.02.040] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 01/22/2021] [Accepted: 02/24/2021] [Indexed: 01/22/2023]
Abstract
BACKGROUND Immune checkpoint inhibitors (ICIs) are essential for treatment of various malignancies, including non-small-cell lung cancer (NSCLC). Recently, several studies have shown that the gut microbiome plays an important role in ICI treatment of solid cancers, and antibiotic (ATB) use had a negative impact on the outcomes of ICI treatment via dysbiosis in the gut. However, whether this is applicable to NSCLC remains unclear. The impact of ATBs based on PD-L1 expression also remains unclear. METHODS We retrospectively reviewed the medical records of patients with NSCLC who received ICI monotherapy (anti-PD-1 or anti-PD-L1 antibody) at nine institutions from December 2015 to May 2018. Outcomes with use of ATBs during the 2 months before or a month after initiation of ICI treatment, including progression-free survival (PFS) and overall survival (OS), were investigated using the Kaplan-Meier method. Multivariate analysis was also conducted using a Cox proportional hazards model. RESULTS A total of 531 patients were included in this study, among whom 98 (18.5%) received ATBs before or after ICI treatment. ATB use was significantly associated with a shorter median OS (11.7 months in the ATB group vs. 16.1 months in the non-ATB group; p = 0.028), whereas the difference in PFS was not significant (3.5 months in both the groups; p = 0.287). We next investigated the association based on PD-L1 expression in the 265 patients for whom PD-L1 expression was determined. There was no significant difference in the median OS or PFS between patients with NSCLC and PD-L1 expression <50% receiving ATBs and those not receiving ATBs (PFS: 3.3 vs. 2.8 months, p = 0.88; OS: 9.5 vs. 17.1 months, p = 0.24). Conversely, patients with NSCLC and PD-L1 expression ≥50% receiving ATBs showed significantly shorter median PFS and OS (PFS: 4.2 vs. 9.4 months, p = 0.012; OS: 11.9 vs. 28.4 months, p = 0.011). The impact of ATBs in patients with NSCLC and PD-L1 expression ≥50% was more significant than that in the entire cohort. CONCLUSIONS Our results indicate that the impact of ATB use on the efficacy of ICIs differed based on PD-L1 expression in patients with advanced NSCLC. A negative impact of ATB use was found in patients with NSCLC and PD-L1 expression ≥50% but not in those with PD-L1 expression <50%.
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Hosokawa S, Mizuta K. Pulsatile tinnitus with a whitish mass in the middle ear. Eur Ann Otorhinolaryngol Head Neck Dis 2021; 138:413-414. [PMID: 33736967 DOI: 10.1016/j.anorl.2020.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 08/06/2020] [Accepted: 09/04/2020] [Indexed: 10/21/2022]
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Morita A, Hosokawa S, Yamada K, Umeno T, Kano H, Kayatani H, Shiojiri M, Sakugawa M, Bessho A. Dacomitinib as a retreatment for advanced non-small cell lung cancer patient with an uncommon EGFR mutation. Thorac Cancer 2021; 12:1248-1251. [PMID: 33651475 PMCID: PMC8046035 DOI: 10.1111/1759-7714.13897] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 02/04/2021] [Accepted: 02/04/2021] [Indexed: 12/19/2022] Open
Abstract
In non‐small cell lung cancer (NSCLC), uncommon epidermal growth factor receptor (EGFR) mutations are mutations other than Ex19 deletion and Ex21 L858R, which are common mutations highly sensitive to EGFR‐tyrosine kinase inhibitors. Afatinib, a second‐generation EGFR‐tyrosine kinase inhibitor, has been shown to be effective in patients with uncommon mutations. Dacomitinib, another second‐generation EGFR‐tyrosine kinase inhibitor, has not previously been shown to be effective in patients with uncommon mutations. Here, we report the efficacy of dacomitinib for uncommon EGFR mutations in a 71‐year‐old woman diagnosed with metastatic lung adenocarcinoma with uncommon EGFR mutation (Ex18 G719A). Afatinib was administered as the first‐line treatment, and a remarkable antitumor effect was observed. However, the tumor grew after 14 months. Pemetrexed plus carboplatin followed by pemetrexed, docetaxel, atezolizumab and S‐1 were performed in sequence. Although approximately four years had passed since the start of treatment, her physical condition was good. The patient started dacomitinib as the sixth‐line treatment. Lesions were markedly reduced and treatment with dacomitinib was continued for 7.8 months. Dacomitinib is a possible treatment option for NSCLC with uncommon mutations.
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Harada D, Isozaki H, Kozuki T, Yokoyama T, Yoshioka H, Bessho A, Hosokawa S, Takata I, Takigawa N, Hotta K, Kiura K. Crizotinib for recurring non-small-cell lung cancer with EML4-ALK fusion genes previously treated with alectinib: A phase II trial. Thorac Cancer 2021; 12:643-649. [PMID: 33470536 PMCID: PMC7919114 DOI: 10.1111/1759-7714.13825] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 12/22/2020] [Accepted: 12/22/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The efficacy of crizotinib treatment for recurring EML4-ALK-positive non-small cell lung cancer (NSCLC) previously treated with alectinib is unclear. Based on our preclinical findings regarding hepatocyte growth factor/mesenchymal epithelial transition (MET) pathway activation as a potential mechanism of acquired resistance to alectinib, we conducted a phase II trial of the anaplastic lymphoma kinase/MET inhibitor, crizotinib, in patients with alectinib-refractory, EML4-ALK-positive NSCLC. METHODS Patients with ALK-rearranged tumors treated with alectinib immediately before enrolling in the trial received crizotinib monotherapy. The objective response rate was the primary outcome of interest. RESULTS Nine (100%) patients achieved a partial response with alectinib therapy with a median treatment duration of 6.7 months. Crizotinib was administered with a median treatment interval of 50 (range, 20-433) days. The overall response rate was 33.3% (90% confidence interval [CI]: 9.8-65.5 and 95% CI: 7.5-70.1), which did not reach the predefined criteria of 50%. Two (22%) patients who achieved a partial response had brain metastases at baseline. Progression-free survival (median, 2.2 months) was not affected by the duration of treatment with alectinib. The median survival time was 24.1 months. The most common adverse events were an increased aspartate transaminase/alanine transaminase (AST/ALT) ratio (44%) and appetite loss (33%); one patient developed transient grade 4 AST/ALT elevation, resulting in treatment discontinuation. Other adverse events were consistent with those previously reported; no treatment-related deaths occurred. CONCLUSIONS Although the desired response rate was not achieved, crizotinib monotherapy following treatment with alectinib showed efficacy alongside previously described adverse events.
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Hosokawa S, Ichihara E, Bessho A, Harada D, Inoue K, Shibayama T, Kishino D, Harita S, Ochi N, Oda N, Hara N, Hotta K, Maeda Y, Kiura K. Impact of previous thoracsic radiation therapy on the efficacy of immune checkpoint inhibitors in advanced non-smasll-cell lung cancer. Jpn J Clin Oncol 2021; 51:279-286. [PMID: 33049757 DOI: 10.1093/jjco/hyaa180] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/23/2020] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES Studies investigating the association between radiation therapy and the efficacy of immune checkpoint inhibitors in advanced non-small-cell lung cancer have provided inconsistent results, likely due to relatively small cohort sizes. This study investigated the effect of previous thoracic radiation therapy on the efficacy of immune checkpoint inhibitor therapy in a large non-small-cell lung cancer cohort. PATIENTS AND METHODS We conducted a retrospective cohort study using data from 531 non-small-cell lung cancer patients who received monotherapy with programmed cell death protein 1/programmed death-ligand 1 inhibitors at nine institutions. The effects of thoracic radiation therapy on the efficacy of immune checkpoint inhibitors were investigated. RESULTS A total of 531 non-small-cell lung cancer patients treated with immune checkpoint inhibitors were included in this study. The progression-free survival period was significantly longer in patients that had received thoracic radiation therapy before immune checkpoint inhibitor therapy compared to those without previous thoracic radiation therapy (median progression-free survival 5.0 vs. 3.0 months, P = 0.0013). A multivariate analysis showed that thoracic radiation therapy was an independent predictive factor of improved progression-free survival (hazard ratio of progression-free survival: 0.79, P = 0.049). In contrast, extra-thoracic radiation therapy was associated with inferior outcomes (median progression-free survival 3.0 vs. 4.2 months, P = 0.0008). CONCLUSION Previous thoracic radiation therapy, but not prior extra-thoracic radiation therapy, enhanced the efficacy of anti-programmed cell death protein 1/programmed death-ligand 1 therapy in non-small-cell lung cancer patients.
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Ikeda S, Kato T, Kenmotsu H, Ogura T, Iwasawa S, Sato Y, Harada T, Kubota K, Tokito T, Okamoto I, Furuya N, Yokoyama T, Hosokawa S, Iwasawa T, Yamanaka T, Okamoto H. A Phase 2 Study of Atezolizumab for Pretreated NSCLC With Idiopathic Interstitial Pneumonitis. J Thorac Oncol 2020; 15:1935-1942. [PMID: 32858235 PMCID: PMC7446731 DOI: 10.1016/j.jtho.2020.08.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 07/26/2020] [Accepted: 08/16/2020] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Interstitial pneumonia (IP) is one of the most common and poor prognostic comorbidities in patients with NSCLC and a known risk factor for pneumonitis. Atezolizumab monotherapy is an established treatment for recurrent NSCLC and reported to have a lower risk of pneumonitis than programmed cell death protein 1 inhibitors. This study aimed to assess the safety and efficacy of atezolizumab monotherapy in patients with pretreated advanced or recurrent NSCLC with idiopathic IP. METHODS Patients with advanced or recurrent NSCLC with comorbid idiopathic, chronic fibrotic IP with % forced vital capacity of greater than 70% and no history of immune checkpoint inhibitors were enrolled. The patients received atezolizumab (1200 mg) every 3 weeks until the discontinuation criteria were met. The primary end point of this study was the 1-year survival rate. A sample size of 38 patients was set. RESULTS This study was terminated early owing to high incidence of pneumonitis. A total of 17 patients were enrolled, with a median age of 70 years. The median % forced vital capacity and % diffusing capacity for carbon monoxide at baseline were 85.4% and 54.4%, respectively. The incidence of pneumonitis was 29.4% (5 of 17) for all grades, 23.5% (4 of 17) for grade greater than or equal to 3, and 5.9% (1 of 17) for grade 5. A total of 57.1% patients (4 of 7) with honeycomb lung developed pneumonitis with a grade greater than or equal to 3, whereas only one patient (10%) without honeycomb lung (n = 10) with grade 1 pneumonitis was found. CONCLUSIONS Patients with NSCLC with comorbid IP as defined by the selection criteria for this study might have an increased risk of immune checkpoint inhibitor-induced pneumonitis.
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Otani S, Sasaki J, Nakahara Y, Fukui T, Igawa S, Naoki K, Bessho A, Hosokawa S, Fukamatsu N, Nakamura Y, Kasai T, Sugiyama T, Tokito T, Seki N, Hamada A, Okamoto H, Masuda N. Phase II study of amrubicin plus erlotinib in previously treated, advanced non-small cell lung cancer with wild-type epidermal growth factor receptor (TORG1320). Invest New Drugs 2020; 39:530-536. [PMID: 33159674 DOI: 10.1007/s10637-020-01031-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Accepted: 10/28/2020] [Indexed: 10/23/2022]
Abstract
Background Amrubicin (AMR) is a completely synthetic 9-aminoanthracycline and clinically active against non-small cell lung cancer (NSCLC). We conducted a phase I study of AMR and erlotinib (ERL) combination therapy in previously treated patients with advanced NSCLC and have already reported the safety and effectiveness. Methods We conducted a multi-center, single-arm phase II trial to evaluate the efficacy of AMR and ERL combination therapy in patients with previously treated, advanced NSCLC harboring wild-type EGFR, PS 0-1 and < 75 years of age. Patients were treated at 3-week intervals with AMR plus ERL. The primary endpoint was the PFS, and the secondary endpoints were the response rate (RR), disease control rate (DCR), overall survival (OS) and toxicity. The trough ERL concentration (Ctrough) was measured as an exploratory study to analyze the relationship between the efficacy/safety and pharmacokinetics. Results From June 2013 to July 2016, 25 patients were enrolled in this trial. The PFS according to the central test was 3.6 months (95% confidence interval 2.1-5.1). The RR and DCR were 24.0% and 64.0%, respectively. We had no treatment-related deaths in this study. Conclusions The PFS of AMR and ERL combination therapy was superior to that of AMR monotherapy in the historical setting, but the primary endpoint was not met in this trial. In our study, the pharmacokinetic analysis showed that the Ctrough of ERL was elevated with combination therapy. This combination therapy might be a viable treatment for previously treated NSCLC patients without a driver oncogene mutation. Clinical trial information UMIN 000010582.
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Kano H, Ichihara E, Harada D, Inoue K, Kayatani H, Hosokawa S, Kishino D, Watanabe K, Ochi N, Oda N, Hara N, Ninomiya K, Hotta K, Maeda Y, Kiura K. Utility of immune checkpoint inhibitors in non-small-cell lung cancer patients with poor performance status. Cancer Sci 2020; 111:3739-3746. [PMID: 32726470 PMCID: PMC7540975 DOI: 10.1111/cas.14590] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/04/2020] [Accepted: 07/17/2020] [Indexed: 12/26/2022] Open
Abstract
Most clinical trials of non‐small‐cell lung cancer (NSCLC) exclude patients with poor ECOG performance status (PS). Thus, the efficacy of immune checkpoint inhibitors (ICIs) in patients with poor PS remains unclear. Herein, we used data from a retrospective cohort to assess the potential clinical benefits of ICIs in NSCLC patients with poor PS. Data from NSCLC patients who received ICI monotherapy at 9 institutions between December 2015 and May 2018 were retrospectively analyzed. After excluding 4 patients who lacked PS data, a total of 527 ICI‐treated patients, including 79 patients with PS 2 or higher, were used for our analyses. The progression‐free survival (PFS) and overall survival (OS) of patients with PS 2 or higher were significantly shorter compared with those of PS 0‐1 patients (median PFS, 4.1 vs 2.0 months; P < .001 and median OS, 17.4 vs 4.0 months; P < .001). Among NSCLC patients with programmed cell death protein‐ligand 1 (PD‐L1) expression of 50% or higher who were treated with pembrolizumab as first‐line therapy, the median PFS times of patients with PS 2 and 0‐1 were 7.3 and 8.1 months, respectively. There was no significant difference in PFS between patients with PS 2 and 0‐1 (P = .321). Although poor PS was significantly associated with worse outcomes in NSCLC patients treated with ICIs, pembrolizumab as a first‐line treatment in NSCLC patients expressing high levels of PD‐L1 could provide a clinical benefit, even in patients with PS 2.
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Ichihara E, Harada D, Inoue K, Shibayama T, Hosokawa S, Kishino D, Harita S, Ochi N, Oda N, Hara N, Hotta K, Maeda Y, Kiura K. Characteristics of patients with EGFR-mutant non-small-cell lung cancer who benefited from immune checkpoint inhibitors. Cancer Immunol Immunother 2020; 70:101-106. [PMID: 32648165 DOI: 10.1007/s00262-020-02662-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Accepted: 07/03/2020] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Immune checkpoint inhibitors (ICIs) are less effective in non-small-cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) mutations. However, a small percentage of patients with EGFR-mutant NSCLC do respond, and the characteristics of these patients are not known. Here, we identify the characteristics of patients who may respond to ICI therapy for EGFR-mutant NSCLC. PATIENTS AND METHODS The medical records of NSCLC patients with EGFR mutations who received PD-1/PD-L1 antibody monotherapy at nine institutions were reviewed. RESULTS In total, 58 patients with EGFR-mutant NSCLC were analyzed. Various clinical factors such as smoking history and EGFR mutation type were not associated with progression-free survival (PFS) of ICIs, while the PFS of prior EGFR tyrosine kinase inhibitors (TKIs) was inversely associated with that of ICIs. Patients who responded to prior EGFR TKIs for > 10 months exhibited a significantly shorter response to ICIs compared to those who had responded for ≤ 10 months (PFS of ICI: 1.6 vs. 1.9 months; hazard ratio: 2.54; 95% confidence interval 1.26-5.12; p = 0.009). However, patients who responded to ICIs for > 6 months responded to prior EGFR TKIs for significantly shorter periods compared to those who responded to ICIs for ≤ 6 months (PFS of prior EGFR TKI: 5.3 vs. 12.1 months; log-rank test: p = 0.0025). CONCLUSION The duration of response to prior EGFR TKIs could be a predictive marker of ICI therapy in EGFR-mutant NSCLC patients.
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Miyamoto S, Azuma K, Ishii H, Bessho A, Hosokawa S, Fukamatsu N, Kunitoh H, Ishii M, Tanaka H, Aono H, Nakahara Y, Kusaka K, Hosomi Y, Kikuchi N, Mori Y, Itani H, Hamada A, Yamada K, Okamoto H. Low-Dose Erlotinib Treatment in Elderly or Frail Patients With EGFR Mutation-Positive Non-Small Cell Lung Cancer: A Multicenter Phase 2 Trial. JAMA Oncol 2020; 6:e201250. [PMID: 32407455 DOI: 10.1001/jamaoncol.2020.1250] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Importance Although the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors for EGFR gene mutation-positive non-small cell lung cancer is well established, optimal dosing remains to be established, especially in elderly or frail patients. Objective To investigate the efficacy and safety of low-dose erlotinib in elderly or frail patients with EGFR mutation-positive non-small cell lung cancer. Design, Setting, and Participants Single-arm phase 2 trial with the Southwest Oncology Group (SWOG) 2-stage design that enrolled frail patients from 21 Japanese institutions after meeting the inclusion criteria. Chemotherapy-naive patients with EGFR-activating mutation-positive non-small cell lung cancer who were considered frail based on age, the Charlson Comorbidity Index, and Eastern Cooperative Oncology Group performance status were eligible for the study. Interventions Patients were initially administered 50 mg/d erlotinib for 4 weeks, which was modified based on response or adverse events. Dose increase was permitted for patients with stable disease after 4 weeks. Main Outcomes and Measures The primary end point was the independent review committee-confirmed objective response rate (ORR) at the dose of 50 mg/d. The study also evaluated the pharmacokinetics of low-dose erlotinib and influence of ABCB1 gene polymorphisms. Results Eighty patients were enrolled, with a median (range) age of 80 (49-90) years; 54 (68%) were men. An independent review committee confirmed a significant ORR of 60.0% (90% CI, 50.2%-69.2%). The disease control rate was 90.0% (90% CI, 82.7%-94.9%), median progression-free survival was 9.3 months (95% CI, 7.2-11.4 months), and median overall survival was 26.2 months (95% CI, 21.9-30.4 months). Mild adverse events were observed in some participants, with few patients exhibiting grade 3 or greater adverse events. Low-dose erlotinib treatment was temporarily suspended for 10 patients owing to adverse events. Five of 80 patients (6%) had their erlotinib dose reduced to 25 mg because of oral mucositis, paronychia, erythema multiforme, diarrhea, and anorexia. Two patients discontinued treatment because of adverse events (cutaneous ulcer and bone infection, and oral mucositis, respectively). There were no cases of interstitial lung disease or treatment-related deaths. The median (range) erlotinib plasma concentration was measured at 685 (153-1950) ng/mL. Seventy-three patients discontinued study treatment owing to disease progression (n = 60), death (n = 3), AEs (n = 4), and patient requests (n = 6). No clear association was observed between the pharmacokinetics of low-dose erlotinib and the treatment outcome. Conclusions and Relevance Low-dose erlotinib appears to be safe and effective in elderly or frail patients with EGFR mutation-positive non-small cell lung cancer and can be a valid treatment option. Trial Registration UMIN-CTR Identifier: UMIN000015949.
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Inui M, Kajihara Y, Tsuchiya Y, Hosokawa S, Matsuda K, Uchiyama H, Tsutsui S, Baron AQR. Peculiar temperature dependence of dynamical sound speed in liquid Se 50Te 50 by inelastic x-ray scattering. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:214003. [PMID: 31958784 DOI: 10.1088/1361-648x/ab6d8e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Inelastic x-ray scattering (IXS) measurements were carried out on liquid Se50Te50 at temperatures up to 1323 K to investigate how the atomic dynamics changes with temperature through the semiconductor-metal transition. The acoustic mode was clearly observed in the dynamic structure factor and its energy was determined using a damped harmonic oscillator model. The dynamical sound speed obtained by IXS for [Formula: see text] nm-1 was found to behave similarly to the temperature dependence of ultrasonic sound velocity with a minimum near the semiconductor metal transition. The results can be explained by taking liquid Se50Te50 to be an inhomogeneous liquid consisting of metallic and semiconducting domains whose size is approximately 3 nm. The relaxation time obtained from frequency dependence of the dynamical sound speed was on a picosecond time scale.
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Takafuji H, Ogura R, Izumi T, Hosokawa S. Paradoxical Embolism of Stroke-Related Patent Foramen Ovale in a Nonagenarian Woman. J Cardiovasc Echogr 2020; 29:172-174. [PMID: 32089998 PMCID: PMC7011487 DOI: 10.4103/jcecho.jcecho_35_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
There are few clinical reports of elderly patients with paradoxical embolism in the current literature. Herein, we describe the case of a nonagenarian patient with paradoxical embolism of stroke-related patent foramen ovale (PFO). A 95-year-old woman was admitted to our hospital because of dysarthria. Her medical history included cerebral infarction, hypertension, and dyslipidemia. Magnetic resonance imaging performed in the emergency room revealed cerebral infarction of the left temporal lobe. After hospitalization in the neurosurgery department, we performed further clinical investigations to diagnose the type of stroke. There was no significant stenosis with plaque of the carotid and cerebral arteries, and there were no sources of cardiac embolism or an episode of atrial arrhythmia. Transesophageal echocardiography (TEE) showed PFO with separation and the Eustachian valve. In addition, spontaneous bidirectional shunt flow through the PFO was detected by TEE with the patient at rest. Ultrasonography of the leg vein revealed a thrombus in the deep vein. Therefore, she was diagnosed as having paradoxical embolism of stroke-related PFO and prescribed a direct oral anticoagulant (DOAC). This very rare case in which stroke-related PFO was diagnosed in a nonagenarian patient demonstrates that PFO is the cause of paradoxical embolism of stroke regardless of age.
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Hosokawa S, Nakanishi H, Mineta H. Glottic adhesion and stenosis in a patient with systemic lupus erythematosus. Lupus 2019; 29:98-99. [PMID: 31830424 DOI: 10.1177/0961203319894386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Konishi K, Kamiya M, Ishiba R, Komatsu T, Ikenohira T, Asao T, Ushio T, Yamashita S, Kosugi T, Okamura J, Hosokawa S, Mineta H, Goshima S, Nakamura K. PO-126: The treatment of IMRT vs 3DCRT for maxillary sinus cancer combination with intra-arterial cisplatin. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(20)30468-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Tsuchiya-Kawano Y, Sasaki T, Yamaguchi H, Hirano K, Horiike A, Satouchi M, Hosokawa S, Morinaga R, Komiya K, Inoue K, Fujita Y, Toyozawa R, Kimura T, Takahashi K, Nishikawa K, Kishimoto J, Nakanishi Y, Okamoto I. Updated Survival Data for a Phase I/II Study of Carboplatin plus Nab-Paclitaxel and Concurrent Radiotherapy in Patients with Locally Advanced Non-Small Cell Lung Cancer. Oncologist 2019; 25:475-e891. [PMID: 31649134 DOI: 10.1634/theoncologist.2019-0746] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Accepted: 09/30/2019] [Indexed: 12/21/2022] Open
Abstract
LESSONS LEARNED Updated survival data for a phase I/II study of carboplatin plus nab-paclitaxel and concurrent radiotherapy were collected. In the group of 58 patients who were enrolled at 14 institutions in Japan, the median overall survival was not reached and the 2-year overall survival rate was 66.1% (95% confidence interval, 52.1%-76.8%). Results reveal encouraging feasibility and activity for this regimen. BACKGROUND We report the updated survival data for a phase I/II study of carboplatin plus nab-paclitaxel (nab-P/C) and concurrent radiotherapy (CRT) in patients with locally advanced non-small cell lung cancer (NSCLC). METHODS Individuals between 20 and 74 years of age with unresectable NSCLC of stage IIIA or IIIB and a performance status of 0 or 1 were eligible for the study. Patients received weekly nab-paclitaxel at 50 mg/m2 for 6 weeks together with weekly carboplatin at an area under the curve (AUC) of 2 mg/ml/min and concurrent radiotherapy with 60 Gy in 30 fractions. This concurrent phase was followed by a consolidation phase consisting of two 3-week cycles of nab-paclitaxel (100 mg/m2 on days 1, 8, and 15) plus carboplatin (AUC of 6 on day 1). After the treatment, patients were observed off therapy. The primary endpoint of the phase II part of the study was progression-free survival (PFS). RESULTS Between October 2014 and November 2016, 58 patients were enrolled at 14 institutions in Japan, with 56 of these individuals being evaluable for treatment efficacy and safety. At the median follow-up time of 26.0 months (range, 4.0-49.6 months), the median overall survival (OS) was not reached (95% confidence interval [CI], 25.3 months to not reached) and the 2-year OS rate was 66.1% (95% CI, 52.1%-76.8%). The median PFS was 11.8 months (95% CI, 8.2-21.0 months), and the 2-year PFS rate was 35.9% (95% CI, 23.1%-48.9%). Subgroup analysis according to tumor histology or patient age revealed no differences in median PFS or OS. Long-term follow-up of toxicities did not identify new safety signals, and no treatment-related deaths occurred during the study period. CONCLUSION Concurrent chemoradiation with nab-P/C was safe and provided a long-term survival benefit for patients with locally advanced NSCLC.
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Takafuji H, Hosokawa S, Ogura R, Hiasa Y. Correction to: Percutaneous transcatheter closure of high-risk patent foramen ovale in the elderly. Heart Vessels 2019; 34:1663-1664. [PMID: 30989327 PMCID: PMC6732151 DOI: 10.1007/s00380-019-01408-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Otani S, Yamada K, Miyamoto S, Azuma K, Ishii H, Bessho A, Hosokawa S, Kunitoh H, Miyazaki K, Tanaka H, Miura S, Aono H, Nakahara Y, Kusaka K, Hosomi Y, Hamada A, Okamoto H. MA21.11 A Multicenter Phase II Study of Low-Dose Erlotinib in Frail Patients with EGFR Mutation-Positive, Non-Small Cell Lung Cancer: TORG1425. J Thorac Oncol 2019. [DOI: 10.1016/j.jtho.2019.08.681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Kawamura G, Okayama H, Kido S, Aono T, Matsuda K, Tanaka Y, Iseki Y, Hosokawa S, Kosaki T, Shigematsu T, Kawada Y, Hiasa G, Yamada T, Kazatani Y. P6005Incidence and clinical characteristics of coronary artery spasm in patients with out-of-hospital cardiac arrest. Eur Heart J 2019. [DOI: 10.1093/eurheartj/ehz746.0725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Substantial cases of out-of-hospital cardiac arrest (OHCA) due to acute coronary syndrome have been recognized thus far, but there have been few reports about the aetiology of patients with OHCA without the organic heart disease. Especially, coronary artery spasm would be one of the causes of OHCA.
Purpose
This study aimed to investigate causes of OHCA without the organic heart disease and to investigate the characteristics and angiographic findings of OHCA patients with vasospastic angina (VSA).
Methods
Between January 2010 and April 2018, 920 patients with OHCA caused by probable or definite cardiovascular disease were transferred to our hospital. Return of spontaneous contraction was successfully achieved in 151 patients, among whom diagnosis was made in 130 patients. First, we analysed the causes of OHCA in these patients. Second, we compared clinical and angiographic characteristics between the VSA group with OHCA (OHCA-VSA) and the VSA group without OHCA (stable VSA; n=72) from our database.
Results
Among the 130 patients, 95 (73%) had the organic heart disease; 72, acute coronary syndrome; 19, myocardial disease; 2, valvular heart disease; and 1, congenital heart disease. There were 35 patients (27%) without the organic heart disease. Nineteen patients had primary (i.e., Brugada syndrome, QT prolongation) or secondary arrhythmia (i.e. drug adverse effect). Electrocardiogram, coronary angiogram, and LV structure and function were normal in 35 patients. However, there were 16 patients (11%) with VSA defined by Japanese guideline. The OHCA-VSA group was significantly younger (50±14) than the stable VSA group (64±11, P=0.003). The incidence of diffuse-type spasm in the OHCA-VSA group (100%) was significantly higher than that in the stable VSA group (100% vs. 69%, P<0.05). In addition, the incidence of triple-vessel coronary spasm in the OHCA-VSA group was significantly higher than that in the stable VSA group (86% vs. 25%, P=0.003).
Conclusion
OHCA patients without the organic heart disease had considerable cases of VSA, in addition to primary or secondary arrhythmia. Furthermore, the severity of spasm in the OHCA-VSA group was more serious and extensive than in comparison with the stable VSA group.
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Yokoyama T, Ninomiya K, Oze I, Hata T, Tanaka A, Bessho A, Hosokawa S, Kuyama S, Kudo K, Kozuki T, Harada D, Yasugi M, Murakami T, Nakanishi M, Takigawa N, Katsui K, Maeda Y, Hotta K, Kiura K. A randomized trial of sodium alginate prevention of radiation-induced esophagitis in patients with locally advanced NSCLC receiving concurrent chemoradiotherapy: OLCSG1401. Ann Oncol 2019. [DOI: 10.1093/annonc/mdz265.052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Horiike A, Kawano Y, Sasaki T, Yamaguchi H, Hirano K, Satouchi M, Hosokawa S, Morinaga R, Komiya K, Inonue K, Fujita Y, Toyozawa R, Kimura T, Takahashi K, Nishikawa K, Kishimoto J, Nakanishi Y, Okamoto I. Updated survival date of phase I/II study of carboplatin plus nab-paclitaxel and concurrent radiotherapy for patients with locally advanced non-small cell lung cancer. J Clin Oncol 2019. [DOI: 10.1200/jco.2019.37.15_suppl.8529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
8529 Background: Chemoradiation regimens of greater efficacy are needed for patients with locally advanced non–small cell lung cancer (NSCLC). Methods: Patients between 20 and 74 years of age with unresectable NSCLC of stage IIIA or IIIB and a performance status of 0 or 1 were eligible for the study. In the phase II part of the study, patients received weekly nab-paclitaxel at 50 mg/m2 together with weekly carboplatin at an area under the curve (AUC) of 2 mg mL–1 min and concurrent radiotherapy with 60 Gy in 30 fractions. This concurrent phase was followed by a consolidation phase consisting of two 3-week cycles of nab-paclitaxel plus carboplatin. The primary end point of the phase II part of the study was progression-free survival (PFS). Results: Between October 2014 and November 2016, 58 patients were enrolled at 14 institutions in Japan, with 56 of these individuals being evaluable for treatment efficacy and safety. At the median follow-up time of 26.0 months (range, 4.0 to 49.6 months), the median overall survival (OS) was not reached (95% confidence interval [CI], 25.3 months to not reached) and the 2-year OS rate was 66.1% (95% CI, 52.1% to 76.8 %). The median PFS was 11.8 months (60% CI, 10.6 to 16.8 months; 95% CI, 8.2 to 21.0 months). The overall response rate was 76.8% (95% CI, 64.2% to 85.9%), and the disease control rate was 94.6% (95% CI, 85.4% to 98.2%). Subgroup analysis according to histology or age revealed no significant differences in median PFS or OS. Common toxicities of grade 3 or 4 in the concurrent phase included leukopenia (60.7%) and neutropenia (28.6%). Pneumonitis of grade 3 was observed in two patients during the study period. No treatment-related deaths occurred. Conclusions: Our results reveal encouraging feasibility and activity for concurrent chemoradiation with nab-paclitaxel at 50 mg/m2 and carboplatin at an AUC of 2 mg mL–1 min in patients with locally advanced NSCLC. Clinical trial information: UMIN000012719.
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Ninomiya K, Hata T, Yoshioka H, Ohashi K, Bessho A, Hosokawa S, Ishikawa N, Yamasaki M, Shibayama T, Aoe K, Kozuki T, Harita S, Ueda Y, Murakami T, Fujimoto N, Yanai H, Toyooka S, Takata M, Hotta K, Kiura K. A Prospective Cohort Study to Define the Clinical Features and Outcome of Lung Cancers Harboring HER2 Aberration in Japan (HER2-CS STUDY). Chest 2019; 156:357-366. [PMID: 31072612 DOI: 10.1016/j.chest.2019.01.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/19/2018] [Accepted: 01/02/2019] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Human epidermal growth factor 2 (HER2) is a potential driver oncogene. Although HER2-targeted precision therapy has been tested in non-small cell lung cancer (NSCLC), the demographic characteristics of HER2-positive NSCLC have not been systematically defined. METHODS Patients with pathologically confirmed stage IIIB/IV or recurrent NSCLC, Eastern Cooperative Oncology Group performance status 0 to 2, were prospectively registered. HER2 immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) assays were performed to screen patients. HER2 mutations were identified by using direct gene sequencing. The aim of this study was to clarify the frequency, characteristics, and outcome of HER2-positive NSCLC. HER2 was defined as positive if the tumor harbored IHC3+, IHC2+/FISH+, or exon 20 insertion mutations. RESULTS Of the 1,126 tumors screened, 34 (3.0%) were IHC3+, and 34 (3.0%) were IHC2+/FISH+. Among the 724 epidermal growth factor receptor wild-type tumors, 21 (2.9%) were HER2-mutant tumors, including A775-G776insYVMA (n = 15). Interestingly, the IHC3+ tumors and mutant tumors were entirely exclusive. Female patients had HER2-mutant tumors more frequently, whereas both IHC3+ and IHC2+/FISH+ tumors were detected more often in male subjects and smokers. Patients with an HER2-aberrant tumor had a significantly worse prognosis than those with epidermal growth factor receptor-positive and anaplastic lymphoma kinase-positive tumors, possibly due to the low proportion that received HER2-targeted therapies (n = 15 [26%]) and low response rates of 0% and 14% in patients with HER2-overexpressing and HER2-mutant tumors, respectively. CONCLUSIONS This prospective large-scale cohort study is the first to show comprehensively the frequency and clinical demographic characteristics of those with HER2-positive advanced lung tumors in detail, providing critical historical data for future drug development against HER2-positive NSCLC. Future treatment strategies would be developed stratified according to the types of HER2 aberrations. TRIAL REGISTRY UMIN Registration No. 000017003; URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000019691.
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Harada D, Kozuki T, Nogami N, Bessho A, Hosokawa S, Fukamatsu N, Hotta K, Ohashi K, Kubo T, Yoshioka H, Yokoyama T, Sone N, Kuyama S, Kudo K, Yasugi M, Takigawa N, Oze I, Kiura K. A phase I/II trial of weekly nab-paclitaxel for pretreated non-small-cell lung cancer patients without epidermal growth factor receptor mutations and anaplastic lymphoma kinase rearrangement. Asia Pac J Clin Oncol 2019; 15:250-256. [PMID: 30938103 PMCID: PMC6849786 DOI: 10.1111/ajco.13147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Accepted: 03/05/2019] [Indexed: 12/27/2022]
Abstract
Aim We investigated the efficacy, safety and optimal schedule of nanoparticle albumin‐bound paclitaxel monotherapy as second‐ or third‐line treatment for non‐small‐cell lung cancer patients without epidermal growth factor receptor mutation and anaplastic lymphoma kinase rearrangement. Methods Patients with pretreated advanced non‐small‐cell lung cancer without epidermal growth factor receptor mutation and anaplastic lymphoma kinase rearrangement were included. The patients were administered 100 mg/m2 of nanoparticle albumin‐bound paclitaxel on days 1, 8, 15 and 22 (level 0) or on days 1, 8 and 15 (level –1) every 4 weeks during phase I of the trial. The primary endpoint was objective response rate. The estimated objective response rate was 15% and the threshold was 5% with an α error of 0.05 and β error of 0.2 in phase II. Results The recommended schedule was determined as level –1 in phase I. The characteristics of the 55 patients enrolled in phase II were as follows: median age = 66 years, male/female = 40/15, second/third line = 34/21 and adenocarcinoma/squamous cell carcinoma/large cell carcinoma/others = 34/17/2/2. Objective response rate was 7.3% (95% confidence interval, 2.0–17.6%). Median progression‐free survival was 3.4 months. Treatment‐related grade 3 or 4 toxicities were neutropenia (36.4%), febrile neutropenia (5.5%) and pulmonary infection (3.6%). Three patients had grade 2 pneumonitis and one treatment‐related death occurred due to adult respiratory distress syndrome. Conclusion This study failed to meet predefined primary endpoints for pretreated patients with advanced non‐small‐cell lung cancer without epidermal growth factor receptor mutation and anaplastic lymphoma kinase rearrangement.
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Takafuji H, Hosokawa S, Ogura R, Hiasa Y. Efficacy and safety of percutaneous transcatheter aortic valvuloplasty prior to non-cardiac surgery in Japanese patients with severe aortic stenosis. Cardiovasc Interv Ther 2019; 34:352-357. [PMID: 30847654 PMCID: PMC6754350 DOI: 10.1007/s12928-019-00581-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 02/27/2019] [Indexed: 11/29/2022]
Abstract
This study aimed to investigate the efficacy of percutaneous transcatheter aortic valvuloplasty (PTAV) performed prior to non-cardiac surgery and the safety of non-cardiac surgery after PTAV in elderly Japanese patients. Between March 2012 and August 2018, 14 patients who underwent PTAVs prior to non-cardiac surgery were enrolled. The mean age was 82.2 ± 7.0 years. A total of 9 patients (64.3%) were women. A retrograde approach was selected for 57.1% of the patients. More than 75% of the procedures were performed using echocardiographic imaging. Echocardiographic data including the aortic valve area (AVA), peak aortic valve blood velocity flow (AVF), peak aortic valve pressure gradient (AVPG), and mean AVPG significantly improved after PTAV (AVA; from 0.54 ± 0.11 to 0.80 ± 0.13 cm2, peak AVF; from 4.6 ± 0.8 to 3.8 ± 0.7 m/s, peak AVG; from 87.9 ± 28.0 to 62.2 ± 19.9 mmHg, mean AVG; from 49.8 ± 18.9 to 35.7 ± 11.6 mmHg; p < 0.001, p < 0.001, p < 0.001, p = 0.0012, respectively). Neither complications related to the PTAV procedure nor procedural mortality were noted. Non-cardiac surgery after PTAV was safely performed; there were no significant adverse events during non-cardiac surgery and no in-hospital mortality occurred after non-cardiac surgery. PTAV prior to non-cardiac surgery in elderly Japanese patients with severe aortic stenosis is safe and effective. In addition, non-cardiac surgery after PTAV can be safety performed without adverse events.
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Inui M, Suekuni K, Kajihara Y, Hosokawa S, Takabatake T, Nakajima Y, Matsuda K, Ohara K, Uchiyama H, Tsutsui S. Static and dynamic structures of liquid Ba 8Ga 16Sn 30: a melt of the thermoelectric clathrate compounds. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:455101. [PMID: 30251705 DOI: 10.1088/1361-648x/aae3f3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
X-ray diffraction and inelastic x-ray scattering measurements of liquid Ba8Ga16Sn30 have been carried out to investigate local structure and atomic dynamics in the liquid. The pair distribution function shows shorter and longer interatomic distances in the first coordination shell. The dynamic structure factor exhibits the inelastic excitations on both sides of the quasielastic central peak. The inelastic excitations disperse with increasing the momentum transfer, suggesting the longitudinal acoustic mode. We found a low energy excitation in addition to the longitudinal acoustic excitation in the dynamic structure factor and it reminds us a strong relationship with a rattling motion of a guest (Ba) atom in the solid state. The temperature dependence of the pair distribution function and the longitudinal acoustic excitation energy is very weak in a range from 600 to 900 °C. The result suggests that Ba and other atoms in the melt are located around minimum positions of the effective pair potential approximated as a harmonic one.
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