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Dive into the research topics where Keitaro Matsumoto is active.

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Featured researches published by Keitaro Matsumoto.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2006

Video-assisted thoracic surgery lobectomy reduces the morbidity after surgery for stage I non-small cell lung cancer

Masashi Muraoka; Tadayuki Oka; Shinji Akamine; Tsutomu Tagawa; Akihiro Nakamura; Satoshi Hashizume; Keitaro Matsumoto; Masato Araki; Yutaka Tagawa; Takeshi Nagayasu

OBJECTIVE We conducted this study to evaluate the surgical invasiveness and the safety of video-assisted thoracic surgery lobectomy for stage I lung cancer. METHODS Video-assisted thoracic surgery lobectomies were performed on 43 patients with clinical stage IA non-small cell lung cancer. We compared the surgical invasiveness parameters with 42 patients who underwent lobectomy by conventional thoracotomy. RESULTS Intraoperative blood loss was significantly less than that in the conventional thoracotomy group (151+/-149 vs. 362+/-321 g, p<0.01). Chest tube duration (3.0+/-2.1 vs. 3.9+/-1.9 days) was significantly shorter than those in the conventional thoracotomy group (p<0.05). The visual analog scale which was evaluated as postoperative pain level on postoperative day 7, maximum white blood count and C-reactive protein level were significantly lower than those in the conventional thoracotomy group (p<0.05). The morbidity rate was significantly lower than that in the conventional thoracotomy group (25.6% vs. 47.6%, p<0.05). Sputum retention and arrhythmia were significantly less frequent than in the conventional thoracotomy group (p<0.05). We experienced no operative deaths in both groups. CONCLUSION We conclude that video-assisted thoracic surgery lobectomy for stage I non-small cell lung cancer patients is a less invasive and safer procedure with a lower morbidity rate compared with lobectomy by thoracotomy.


Lung Cancer | 2012

Clinical and molecular analysis of synchronous double lung cancers

Junichi Arai; Tomoshi Tsuchiya; Masahiro Oikawa; Koji Mochinaga; Tomayoshi Hayashi; Koh-ichiro Yoshiura; Kazuhiro Tsukamoto; Naoya Yamasaki; Keitaro Matsumoto; Takuro Miyazaki; Takeshi Nagayasu

BACKGROUND Since multiple lung cancer treatment strategies differ, it is essential for clinicians to be able to distinguish between separate primary lesions and metastasis. In the present study, we used array comparative genomic hybridization (aCGH) and somatic mutation (epidermal growth factor receptor: EGFR) to analyze genomic alteration profiles in lung cancer patients. To validate the consistency among the pathological assessments and clarify the clinical differences between double primary lesions and metastasis, we also examined synchronous double lung cancer clinical data. METHODS Between January 1970 and March 2010, 2215 patients with lung cancer underwent surgical resection at Nagasaki University Hospital. We performed molecular analysis of 12 synchronous double lung cancer patients without lymph node metastasis (intrapulmonary metastasis in the same lobe (pm1): n=6, primary: n=6). We then evaluated the clinical outcomes of patients with pathologically diagnosed synchronous double lung cancers (intrapulmonary metastasis (pm): n=80, primary: n=39) and other T3 tumors (n=230). RESULTS Examination of the concordance rate (CR) of the copy number changes (CNCs) for paired tumors showed that the metastasis group was larger than the primary group (55.5% vs. 19.6%, p=0.04). Pathological diagnosis and molecular classification were the same in 10 out of 12 cases (83%). As compared to the primary group, there tended to be an inferior 5-year survival curve for the pm group. However, in N0 patients, the survival curve for the pm group overlapped the primary group, while the survival rate of the pm1 group was much higher than that of other T3 group (p<0.01). CONCLUSIONS Both pathological and molecular assessment using aCGH adapted in the current study appeared to have a consistency. Pathological pm1(T3)N0 patients may have a better prognosis than other T3N0 patients.


Leukemia | 1997

Morphological subtyping of acute myeloid leukemia with maturation (AML-M2): homogeneous pink-colored cytoplasm of mature neutrophils is most characteristic of AML-M2 with t(8;21)

Hideo Nakamura; Kazutaka Kuriyama; Naoki Sadamori; Mariko Mine; Takahiro Itoyama; Ippei Sasagawa; Keitaro Matsumoto; Tsuji Y; Norio Asou; Kageyama Si; Hisashi Sakamaki; Nobuhiko Emi; Ryuzo Ohno; Masao Tomonaga

Morphologic and cytochemical features of 30 acute myeloid leukemia subtype M2 (AML-M2) patients with t(8;21) were compared with those of 50 AML-M2 patients without t(8;21). It was disclosed that irregular nuclear shape, Auer bodies, and at least 90% myeloperoxidase positivity in blast cells, and pseudo-Pelger-Huët anomaly of the nuclei and homogeneous pink-colored cytoplasm of mature neutrophils were observed in 90–100% of the t(8;21)+ patients. The percentages of patients showing these features were significantly (P < 0.01) lower in the t(8;21)− group. Among these morphological features, homogeneous pink-colored cytoplasm of mature neutrophils is most characteristic of t(8;21)+ AML-M2, because it was seen in 90% of the t(8;21)+ patients but in only 2% of the t(8;21)− patients. Conversely, pale-colored cytoplasm without any granules in mature neutrophils or dyserythropoietic features was observed in 84% of the t(8;21)− patients, but in none of the t(8;21)+ patients. These data suggest that it is possible to subtype AML-M2 patients morphologically by the recognition of homogeneous pink-colored or pale-colored cytoplasm of mature neutrophils and dyserythropoietic features. Thus, the morphologic subtyping of AML-M2 can be utilized alone or in combination with chromosomal or molecular subtyping for biological and clinical studies of AML with maturation.


International Journal of Oncology | 2013

High expression of trimethylated histone H3 at lysine 27 predicts better prognosis in non-small cell lung cancer.

Xiaohui Chen; Ning Song; Keitaro Matsumoto; Atsushi Nanashima; Takeshi Nagayasu; Tomayoshi Hayashi; Mingang Ying; Daisuke Endo; Zhiren Wu; Takehiko Koji

Epigenetic parameters such as DNA methylation and histone modifications play pivotal roles in carcinogenesis. Global histone modification patterns have been implicated as possible predictors of cancer recurrence and prognoses in a great variety of tumor entities. Our study was designed to evaluate the association among trimethylated histone H3 at lysine 27 (H3K27me3), clinicopathological variables and outcome in early-stage non-small cell lung cancer (NSCLC). The expression of H3K27me3 and its methyl-transferase, enhancer of zeste homolog 2 (EZH2) together with proliferating cell nuclear antigen (PCNA) were evaluated by immunohistochemistry in normal lung tissue (n=5) and resected NSCLC patients (n=42). In addition, the specificity of antibody for H3K27me3 was tested by western blot analysis. The optimal cut-off point of H3K27me3 expression for prognosis was determined by the X-tile program. The prognostic significance was determined by means of Kaplan-Meier survival estimates and log-rank tests. As a result, enhanced trimethylation of H3K27me3 was correlated with longer overall survival (OS) and better prognosis (P<0.05). Moreover, both univariate and multivariate analyses indicated that H3K27me3 level was a significant and independent predictor of better survival (hazard ratio, 0.187; 95% confidence interval, 0.066-0.531, P=0.002). Furthermore, H3K27me3 expression was positively correlated with DNA methylation level at CCGG sites while reversely related to EZH2 expression (P<0.05). In conclusion, H3K27me3 level defines unrecognized subgroups of NSCLC patients with distinct epigenetic phenotype and clinical outcome, and can probably be used as a novel predictor for better prognosis in NSCLC patients.


European Journal of Cardio-Thoracic Surgery | 2015

Inflammation-based scoring is a useful prognostic predictor of pulmonary resection for elderly patients with clinical stage I non-small-cell lung cancer

Takuro Miyazaki; Naoya Yamasaki; Tomoshi Tsuchiya; Keitaro Matsumoto; Masaki Kunizaki; Daisuke Taniguchi; Takeshi Nagayasu

OBJECTIVES The number of elderly lung cancer patients requiring surgery has been increasing due to the ageing society and less invasive perioperative procedures. Elderly people usually have various comorbidities, but there are few simple and objective tools that can be used to determine prognostic factors for elderly patients with clinical stage I non-small-cell lung cancer (NSCLC). The aim of this retrospective study was to evaluate the prognostic factors of surgically treated, over 80-year old patients with clinical stage I NSCLC. METHODS The preoperative data of 97 over 80-year old patients with clinical stage I NSCLC were collected at Nagasaki University Hospital from 1990 to 2012. As prognostic factors, inflammation-based scoring systems, including the Glasgow Prognostic Score (GPS) determined by serum levels of C-reactive protein and albumin, the neutrophil lymphocyte ratio (NLR) and the platelet lymphocyte ratio (PLR) were evaluated, as well as other clinicopathological factors, including performance status, body mass index, carcinoembryonic antigen, Charlson comorbidity index and type of surgical procedure. RESULTS The median age was 82 (range, 80-93) years. There were 62 (64.0%) clinical stage IA cases and 35 IB cases. Operations included 64 (66.0%) lobectomies, 15 segmentectomies and 18 wedge resections. The pathological stage was I in 76 (78.4%) patients, II in 12 (12.4%), III in 8 (8.2%) and IV in 1 (1.0%). Twelve (12.4%) patients underwent mediastinal lymph node dissection. Overall survival and disease-specific 5-year survival rates were 55.5 and 70.0%, respectively. The average GPS score was 0.4 (0-2). Disease-specific 5-year survival was significantly longer with GPS 0 than with GPS 1-2. (74.2%, 53.7%, respectively, P = 0.03). Overall 5-year survival was significantly longer with GPS 0 than with GPS 1-2. (59.7%, 43.1%, respectively, P = 0.005). Both the NLR (median value = 1.9) and the PLR (median value = 117) were not correlated with disease-specific and overall 5-year survival. On multivariate analysis, pathological stage I (P = 0.01) and GPS 0 (P = 0.04, hazard ratio: 2.13, 95% confidence interval 1.036-4.393) were significant prognostic factors. CONCLUSIONS The preoperative GPS appears to be a useful predictor of overall survival and could be a simple prognostic tool for elderly patients with clinical stage I NSCLC.


The Journal of Thoracic and Cardiovascular Surgery | 2009

Keratinocyte growth factor accelerates compensatory growth in the remaining lung after trilobectomy in rats.

Keitaro Matsumoto; Takeshi Nagayasu; Yoshitaka Hishikawa; Tsutomu Tagawa; Takatomo Yamayoshi; Takafumi Abo; Shuichi Tobinaga; Katsuro Furukawa; Takehiko Koji

OBJECTIVE In rats pulmonary resection is followed by lung compensatory growth. However, the molecular mechanism underlying lung compensatory growth remains unclear. Keratinocyte growth factor is expressed in lung tissue and is considered a possible mitogen for lung epithelial cells. The objectives of this study were to define the role of keratinocyte growth factor and its receptor in rat lung compensatory growth after trilobectomy and the effect of exogenous keratinocyte growth factor gene transfection. METHODS Adult Lewis rats were used. Right trilobectomy was performed in the operation group and sham thoracotomy in the sham group. In the operation group, keratinocyte growth factor-FLAG or FLAG expression vector was transfected directly into the lung by means of electroporation. Expression of keratinocyte growth factor and its receptor and alveolar cell proliferation index based on proliferating cell nuclear antigen levels were measured in the right lung at day 14 after the operation. RESULTS Proliferating cell nuclear antigen, keratinocyte growth factor, and keratinocyte growth factor receptor expression in lung epithelial cells was significantly increased at day 4 after trilobectomy. Transfection of keratinocyte growth factor-FLAG expression vector resulted in further significant enhancement of proliferating cell nuclear antigen at day 4 after trilobectomy; however, the transfection of FLAG expression vector did not alter the enhancement of proliferating cell nuclear antigen. Exogenous expression of keratinocyte growth factor in the remaining lung by means of electroporation significantly augmented epithelial proliferation and decreased the average airspace distance (mean linear intercept). CONCLUSION Our results implicate keratinocyte growth factor in the induction of alveolar epithelial cell proliferation for compensatory lung growth and indicate that overexpression of keratinocyte growth factor in the remaining lung by means of electroporation significantly augmented lung epithelial proliferation.


The Annals of Thoracic Surgery | 2015

Airway stent insertion simulated with a three-dimensional printed airway model.

Takuro Miyazaki; Naoya Yamasaki; Tomoshi Tsuchiya; Keitaro Matsumoto; Katsunori Takagi; Takeshi Nagayasu

A 30-year-old man underwent right single-lung transplantation for chronic obstructive pulmonary disease. The bronchial anastomosis developed ischemic change, resulting in stenosis of the intermediate bronchus. A modified Y-shaped airway stent with the fabricated orifice of the upper lobe was inserted by rigid bronchoscopy. Before the operation, a three-dimensional printed bronchial model of this patient was made for surgical simulation. This model enabled us to perform the operation easily, quickly, and successfully. The patients condition improved after airway stent insertion. The three-dimensional printed airway model provided sufficient preoperative understanding of the patients anatomy for planning the surgical procedure.


Acta Histochemica Et Cytochemica | 2010

Expression of keratinocyte growth factor and its receptor in rat tracheal cartilage: possible involvement in wound healing of the damaged cartilage.

Takafumi Abo; Takeshi Nagayasu; Yoshitaka Hishikawa; Tsutomu Tagawa; Atsushi Nanashima; Takatomo Yamayoshi; Keitaro Matsumoto; Shucai An; Takehiko Koji

Keratinocyte growth factor (KGF) is involved in the development and regeneration of a variety of tissues. To clarify the role of KGF in cartilage wound healing, we examined the expression of KGF and its receptor (KGFR) immunohistochemically in the wound healing area of rat tracheal cartilage, and the direct effect of recombinant KGF on the proliferation and differentiation of primary cultures of rat chondrocytes. KGF was found in the cytoplasm of both chondrocytes and perichondrial cells. On the other hand, KGFR was detected only in the plasma membrane of chondrocytes. Although the expression of KGF was similar in the cartilage and perichondrial area before and after injury, KGFR expression was induced after injury and limited to proliferating chondrocytes. The staining pattern of KGF and KGFR was same in the mature and the immature rat tracheal cartilage. Moreover, in vitro experiments using primary cultured chondrocytes revealed that KGF at 200 ng/ml significantly increased the number of chondrocytes (~1.5-fold), and significantly reduced acid mucopolysaccharide production. These results indicate that KGF stimulates chondrocyte proliferation, suggesting that KGF could therapeutically modulate the wound healing process in the tracheal cartilage.


The Annals of Thoracic Surgery | 2012

Three-Dimensional Computed Tomography for a Mediastinal Basal Pulmonary Artery

Keitaro Matsumoto; Naoya Yamasaki; Tomoshi Tsuchiya; Takuro Miyazaki; Koichi Tomoshige; Hideyuki Hayashi; Kazuto Ashizawa; Takeshi Nagayasu

Anatomic variations of the pulmonary artery increase the risks for vessel injury and critical mistakes during pulmonary artery resection. A patient who underwent left lower lobectomy for lung cancer with a mediastinal lingular and basal pulmonary artery that had been detected preoperatively by three-dimensional computed tomography is presented. During thoracoscopic surgery, the mediastinal basal pulmonary arteries were found with careful dissection. The pulmonary arteries were divided, and left lower lobectomy was performed safely. This rare variation of the left pulmonary artery is important to detect before lobectomy to ensure safe surgery. In such cases, three-dimensional computed tomography is necessary.


Clinical Lung Cancer | 2012

A Multicenter Phase II Study of Adjuvant Chemotherapy With Oral Fluoropyrimidine S-1 for Non–Small-Cell Lung Cancer: High Completion and Survival Rates

Tomoshi Tsuchiya; Takeshi Nagayasu; Naoya Yamasaki; Keitaro Matsumoto; Takuro Miyazaki; Tsutomu Tagawa; Akihiro Nakamura; Hiroyuki Minami; Hideki Taniguchi; Shinji Akamine; Hiroshi Hisano; Yoshitaka Taniguchi

BACKGROUND Oral adjuvant chemotherapy without hospitalization might reduce the physiological and psychological burden on patients if effectiveness could be guaranteed. We conducted a multicenter feasibility study using S-1, an oral derivative of 5-fluorouracil, as postoperative adjuvant chemotherapy in patients with curatively resected pathologically stage IB-IIIA non-small-cell lung cancer. PATIENTS AND METHODS Adjuvant chemotherapy comprised 8 courses (4-week administration, 2-week withdrawal) of S-1 at 80-120 mg per day. Fifty-one patients from 7 institutions were enrolled in this pilot study, from June 2005 to March 2007. The primary end point was the completion rate of scheduled adjuvant chemotherapy. Secondary end points were the incidence and grade of adverse reactions. RESULTS Fifty patients were eligible. The completion rate for the planned 8 courses of S-1 administration was 72.0% (36 patients). Total percentage administration amount was 71.1%. Grade 3 adverse reactions such as neutropenia (4.0%), anorexia (4.0%), thrombopenia (2.0%), anemia (2.0%), elevated total bilirubin (2.0%), hypokalemia (2.0%), nausea (2.0%), and diarrhea (2.0%) were observed, but no grade 4 adverse effects were encountered. Overall and relapse-free survival rates at 3 years were 87.7% and 69.4%, respectively. CONCLUSIONS Postoperative 1-year administration of S-1 seems feasible as oral adjuvant chemotherapy for lung cancer. The oral formulation and low incidence of adverse reactions permit treatment on an outpatient basis. The present study would be reasonable to follow up with a properly powered phase III trial.

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