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Dive into the research topics where Hiroki Izumi is active.

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Featured researches published by Hiroki Izumi.


International Journal of Oncology | 2015

A novel point-of-care system for high-speed real-time polymerase chain reaction testing for epidermal growth factor receptor mutations in bronchial lavage fluids after transbronchial biopsy in patients with non-small cell lung cancer

Tomohiro Sakamoto; Masahiro Kodani; Miyako Takata; Hiroki Chikumi; Masaki Nakamoto; Shizuka Nishii-Ito; Yasuto Ueda; Hiroki Izumi; Haruhiko Makino; Hirokazu Touge; Kenichi Takeda; Akira Yamasaki; Masaaki Yanai; Natsumi Tanaka; Tadashi Igishi; Eiji Shimizu

Epidermal growth factor receptor (EGFR) gene mutation testing is essential for choosing appropriate treatment options in patients with advanced non-small cell lung cancer (NSCLC). However, a time delay occurs between histological diagnosis and molecular diagnosis in clinical situations. To minimize this delay, we developed a novel point-of-care test for EGFR mutations, based on a high-speed real-time polymerase chain reaction (PCR) system designated here as ultrarapid PCR combined with highly accurate bronchoscopic sampling. We investigated whether our system for detecting EGFR mutations was valid by comparing test results with those obtained using a commercialized EGFR mutation test. We obtained small amounts of bronchial lavage fluids after transbronchial biopsies (TBBs) were performed on enrolled patients (n=168) who underwent endobronchial ultrasonography using a guide sheath (EBUS-GS). EGFR mutation analysis was performed by ultrarapid PCR immediately after EBUS-GS-TBBs were obtained (on the same day). After pathological diagnoses of NSCLC, EGFR mutation status in formalin-fixed, paraffin- embedded samples was confirmed by the PCR-invader method, and the concordance rates between the PCR methods were compared. The total diagnostic yield of EBUS-GS-TBB was 91.0%. The positive concordance rates for detecting 19del and L858R with the ultrarapid PCR and PCR-invader methods were both 100%. Negative concordance rates were 97.2 and 98.1%, respectively. We also demonstrated a dramatic effect of early erlotinib administration, based on ultrarapid PCR results, for a 52-year-old woman suffering from respiratory failure due to severe intrapulmonary metastases with poor performance status. In conclusion, ultrarapid PCR combined with EBUS-GS-TBB enabled rapid and reliable point-of-care testing for EGFR mutations.


Human genome variation | 2017

A novel SLC34A2 mutation in a patient with pulmonary alveolar microlithiasis

Hiroki Izumi; Jun Kurai; Masahiro Kodani; Masanari Watanabe; Akihiro Yamamoto; Eiji Nanba; Kaori Adachi; Tadashi Igishi; Eiji Shimizu

Pulmonary alveolar microlithiasis (PAM) is a rare autosomal recessive disease caused by mutations in SLC34A2 and characterized by intra-alveolar accumulation of microliths. We diagnosed a case of PAM in a 27-year-old Japanese female and identified a novel mutation in SLC34A2 (c.1390 G>C [G464R] in exon 12).


Molecular and Clinical Oncology | 2016

Pulmonary intravascular large B-cell lymphoma successfully treated with rituximab, cyclophosphamide, vincristine, doxorubicin and prednisolone immunochemotherapy: Report of a patient surviving for over 1 year.

Shizuka Nishii-Ito; Hiroki Izumi; Hirokazu Touge; Kenichi Takeda; Yuzuru Hosoda; Akira Yamasaki; Satoshi Kuwamoto; Eiji Shimizu; Toru Motokura

A 73-year-old man with a history of lethargy, fever and dyspnea was admitted to Tottori University Hospital. A computed tomography (CT) scan revealed splenomegaly and diffusely spreading ground-glass opacities (GGOs) in both lungs. A video-assisted thoracoscopic surgery (VATS)-guided lung biopsy revealed intravascular proliferation of large atypical lymphoid cells in the arteries, veins and alveolar walls. The patient was diagnosed with intravascular large B-cell lymphoma (IVLBCL); he received 6 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone (R-CHOP) immunochemotherapy and has remained in complete remission for >1 year. Although IVLBCL is a rare disease, it should be considered in the differential diagnosis of pulmonary diffuse lesions that present with GGOs on CT scans.


Molecular and Clinical Oncology | 2017

Development of fever following first administration of zoledronate as a prognostic factor in advanced non‑small cell lung cancer patients with bone metastases

Hiroki Izumi; Tadashi Igishi; Akira Yamasaki; Kennichi Takeda; Masaaki Yanai; Natsumi Tanaka; Tomohiro Sakamoto; Shizuka Ito; Hirokazu Touge; Masahiro Kodani; Shingo Matsumoto; Yuji Kawasaki; Eiji Shimizu

Nitrogen-containing bisphosphonates (N-BPs), which are usually used for the treatment of advanced cancer with bone metastasis, occasionally cause fever following the first administration. However, it is unclear as to how the development of fever following the first administration of N-BP is associated with clinical outcome. The aim of the present study was to determine the prognostic value of the development of fever following the first administration of N-BP in advanced non-small cell lung cancer patients with bone metastases. The present study reviewed the data of 46 patients with advanced non-small cell lung cancer who were administered zoledronate (ZOL), an N-BP, for bone metastasis, between March 2009 and March 2011 in the Department of Medical Respirology at Tottori University Hospital. Clinicopathological factors were evaluated using univariate and multivariate analyses, and these factors were compared between the fever and non-fever groups. Of the 46 patients, 15 (32.6%) developed fever following the first administration of ZOL. No significant differences were observed in the clinicopathological characteristics between the two groups. The overall survival in the fever group was significantly longer compared with the non-fever group (median survival time: 33.4 vs. 15.7 months, P=0.04), and the development of fever following the first ZOL administration was independently associated with longer overall survival. The development of fever following the first ZOL administration was an independent prognostic factor in advanced non-small cell lung cancer patients with bone metastases. Thus, ZOL-associated fever may be a predictive factor for an undefined, survival-promoting effect of ZOL.


Lung Cancer | 2018

Acute-phase reaction induced by zoledronate and its effect on prognosis of patients with advanced non-small cell lung cancer

Hiroki Izumi; Akira Yamasaki; Kenichi Takeda; Masahiro Kodani; Hirokazu Touge; Natsumi Tanaka; Masaaki Yanai; Yasuto Ueda; Tomohiro Sakamoto; Shizuka Nishii-Ito; Haruhiko Makino; Kosuke Yamaguchi; Tadashi Igishi; Eiji Shimizu

OBJECTIVES Zoledronate (ZOL) is usually used for prevention of skeletal-related events in cancer patients with bone metastases. The first administration of ZOL is occasionally associated with development of acute-phase reaction (APR), which is due to activation of γδ T cells. ZOL-related APR was associated with better overall survival (OS) of patients with non-small cell lung cancer (NSCLC) in our previous retrospective study. However, it remains to be clarified whether γδ T cells are more activated in patients who experienced ZOL-related APR, and whether γδ T cell activation is involved in prolongation of OS. MATERIALS AND METHODS Twenty-three patients with advanced NSCLC were recruited between 2012 and 2014 in this study. We administered ZOL to participants with standard care. The patient characteristics, change in γδ T cell counts and cytokines, OS, and skeletal-related event-free survival were compared between patients with APR (APR group) and those without APR (non-APR group). RESULTS Ten patients (43.5%) experienced a ZOL-related APR. The number of γδ T cells at baseline in the APR group was significantly higher than that in the non-APR group. Serum interleukin-6 and tumor necrosis factor-α in the APR group were significantly increased, but no change in the number of γδ T cells was observed after the first administration of ZOL in both groups. OS in the APR group was significantly longer than that in the non-APR group (median survival time: 23.1 vs. 14.5 months, p < 0.01). CONCLUSION We showed that APR is related to higher numbers of γδ T cells at baseline and increased cytokines after the first ZOL administration, but not to proliferative responses of γδ T cells. In addition, better OS was observed in the APR group. Therefore, the number of γδ T cells might be a prognostic marker in patients with NSCLC.


Clinical Lung Cancer | 2018

Case ReportSquamous Cell Carcinoma Transformation from EGFR-mutated Lung Adenocarcinoma: A Case Report and Literature Review

Hiroki Izumi; Akira Yamasaki; Yasuto Ueda; Takashi Sumikawa; Hiroyuki Maeta; Shu Nakamoto; Eiji Shimizu

Epidermal growth factor receptor (EGFR)-mutated nonesmall-cell lung cancer responds dramatically to initial EGFR tyrosine kinase inhibitors (TKIs), although acquired resistance develops in w1 year. Osimertinib, one of the T790M-specific EGFR TKIs, results in a favorable response in EGFR-mutated NSCLC that has developed acquired resistance with a secondary T790M mutation. We report a rare case of EGFR-mutated stage IB lung adenocarcinoma with a point mutation in exon 21 (L858R) in a 68-year-old man that showed histologic transformation to squamous cell carcinoma (SCC) concurrently with secondary T790M mutation and responded to osimertinib. T790M-specific third-generation EGFR TKIs, including osimertinib, could be a promising strategy for EGFR T790M mutation-positive NSCLC, regardless of the histologic findings.


Respirology case reports | 2017

A case of lung abscess successfully treated by transbronchial drainage using a guide sheath: GS drainage for lung abscess

Hiroki Izumi; Masahiro Kodani; Shingo Matsumoto; Yuji Kawasaki; Tadashi Igishi; Eiji Shimizu

A 51‐year‐old man was diagnosed with colon cancer in September 2011, and a solitary pulmonary nodule was detected by computed tomography (CT) scan. We performed a transbronchial biopsy with endobronchial ultrasonography using a guide sheath (GS) and diagnosed lung metastasis of colon cancer. The patient experienced remittent fever after the biopsy in spite of intravenous antibiotic therapies. Moreover, his CT scan showed a large lung abscess at the biopsy site. We performed transbronchial drainage using a GS as salvage therapy. The bloody pus was successfully aspirated, and chest X‐ray following the procedure showed dramatic shrinkage of the abscess.


International Journal of Oncology | 2015

Favorable effect of the combination of vinorelbine and dihydropyrimidine dehydrogenase-inhibitory fluoropyrimidine in EGFR-mutated lung adenocarcinoma: Retrospective and in vitro studies

Hiroki Izumi; Hirokazu Touge; Tadashi Igishi; Haruhiko Makino; Shizuka Nishii-Ito; Miyako Takata; Hirofumi Nakazaki; Yasuto Ueda; Shingo Matsumoto; Masahiro Kodani; Jun Kurai; Kenichi Takeda; Tomohiro Sakamoto; Masaaki Yanai; Natsumi Tanaka; Chaitanya S. Nirodi; Eiji Shimizu

Although cytotoxic chemotherapy is essential in epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC), it is unclear which regimen is most effective. We retrospectively compared the efficacy of standard platinum-based chemotherapy with that of combination chemotherapy using vinorelbine (VNR) plus dihydropyrimidine dehydrogenase-inhibitory fluoropyrimidine (DIF) in EGFR-mutated lung adenocarcinomas, and we investigated a potential mechanism by which the combination chemotherapy of VNR + DIF was favorable in the treatment of EGFR-mutated lung adenocarcinoma in vitro. In our retrospective analysis, the response rate and disease control rate afforded by the VNR + DIF treatment tended to be better than those by platinum-based chemotherapy, and the progression-free survival of the 24 VNR + DIF-treated patients was significantly longer than that of the 15 platinum-based chemotherapy patients. In EGFR-mutated PC9 cells, VNR induced EGFR dephosphorylation at a clinically achievable concentration. 1BR3-LR cells, a line of fibroblast cells transfected with a mutant EGFR construct, were completely resistant to gefitinib in the medium containing 10% fetal bovine serum (FBS), whereas the sensitivity of these cells to gefitinib was increased in 0.5% FBS-containing medium. Similarly, the sensitivity of 1BR3-LR cells to VNR was increased when they were cultured in low-serum condition. In addition, sodium orthovanadate (Na3VO4) inhibited the EGFR dephosphorylation induced by VNR or gefitinib and suppressed the cell growth inhibition by these agents in PC9 cells. VNR and gefitinib showed synergistic cell growth inhibition in combination with 5-fluorouracil (5-FU) in PC9 cells. We propose that the EGFR dephosphorylation induced by VNR is related to cell growth inhibitory activity of VNR, and that this is one of the mechanisms of the synergistic effect of VNR + 5-FU in EGFR-mutated lung cancer cells. In conclusion, the combination chemotherapy of VNR + DIF may be a promising treatment for NSCLC patients with EGFR mutations.


International Journal of Oncology | 2014

Synergistic cell growth inhibition by the combination of amrubicin and Akt-suppressing agents in K-ras mutation-harboring lung adenocarcinoma cells: Implication of EGFR tyrosine kinase inhibitors

Shizuka Ito; Tadashi Igishi; Miyako Takata; Yasuto Ueda; Shingo Matsumoto; Masahiro Kodani; Kenichi Takeda; Hiroki Izumi; Tomohiro Sakamoto; Kosuke Yamaguchi; Haruhiko Makino; Hirokazu Touge; Hiroki Chikumi; Eiji Shimizu


Internal Medicine | 2010

Small cell lung cancer complicated by pulmonary sarcoidosis.

Hirokazu Tokuyasu; Hiroki Izumi; Natsuko Mukai; Kenichi Takeda; Yasuto Sakaguchi; Noritaka Isowa; Eiji Shimizu

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