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Featured researches published by Akira Arimoto.


Journal of Hepato-biliary-pancreatic Sciences | 2014

Case series of 17 patients with cholangiocarcinoma among young adult workers of a printing company in Japan.

Shoji Kubo; Yasuni Nakanuma; Shigekazu Takemura; Chikaharu Sakata; Yorihisa Urata; Akinori Nozawa; Takayoshi Nishioka; Masahiko Kinoshita; Genya Hamano; Hiroaki Terajima; Gorou Tachiyama; Yuji Matsumura; Terumasa Yamada; Hiromu Tanaka; Shoji Nakamori; Akira Arimoto; Norifumi Kawada; Masahiro Fujikawa; Hiromitsu Fujishima; Yasuhiko Sugawara; Shogo Tanaka; Hideyoshi Toyokawa; Yuko Kuwae; Masahiko Ohsawa; Shinichiro Uehara; Kyoko Kogawa Sato; Tomoshige Hayashi; Ginji Endo

An outbreak of cholangiocarcinoma occurred among workers in the offset color proof‐printing department at a printing company in Japan. The aim of this study was to clarify the characteristics of the patients with cholangiocarcinoma.


International Journal of Oncology | 2013

Effect of transcatheter arterial chemoembolization prior to surgical resection for hepatocellular carcinoma

Hiroki Nishikawa; Akira Arimoto; Tomoko Wakasa; Ryuichi Kita; Toru Kimura; Yukio Osaki

The aim of the present study was to evaluate the influence of preoperative transcatheter arterial chemoembolization (TACE) on survival after surgical resection (SR) for hepatocellular carcinoma (HCC). Two hundred and thirty-five HCC patients who underwent SR with curative intent were analyzed. Overall survival (OS), recurrence-free survival (RFS) and complication rates were compared between the TACE (n=110) and control groups (n=125). Moreover, TACE subjects were classified into TACE responders (n=85) and TACE non-responders (n=25), according to the therapeutic efficacy of pretreatment TACE, and the factors contributing to OS and RFS after SR were analyzed using univariate and multivariate analyses. The 1-, 3- and 5-year OS rates were 87.4, 76.0 and 62.5%, respectively, in the TACE group and 94.9, 79.0 and 57.8%, respectively, in the control group (P=0.674). The corresponding RFS rates at 1, 3 and 5 years were 73.3, 48.9 and 33.2%, respectively, in the TACE group and 73.3, 29.4 and 16.3%, respectively, in the control group (P=0.062). No TACE-related serious adverse events (SAEs) were observed. There were no significant differences between the groups in terms of surgery-related SAEs (P=0.714), operation time (P=0.881), blood loss during surgery (P=0.334) and hospitalization period (P=0.447). Multivariate analyses identified TACE responder, TACE non-responder, total bilirubin ≥1 mg/dl, serum albumin ≥4 g/dl, pretreatment α-fetoprotein (AFP) level ≥100 ng/ml and microscopic vascular invasion as significant prognostic factors linked to OS. TACE non-responder, tumor number (multiple) and pretreatment AFP level ≥100 ng/ml were significant adverse prognostic factors linked to RFS. In conclusion, TACE is a safe procedure in patients with HCC, and the efficacy of TACE prior to surgery may be associated with clinical outcomes after SR.


Journal of Cancer | 2013

Comparison of clinical characteristics and survival after surgery in patients with non-B and non-C hepatocellular carcinoma and hepatitis virus-related hepatocellular carcinoma.

Hiroki Nishikawa; Akira Arimoto; Tomoko Wakasa; Ryuichi Kita; Toru Kimura; Yukio Osaki

Background and aims: We compared clinicopathologic data and long-term clinical outcomes among patients with non-B and non-C hepatocellular carcinoma (NBNC-HCC) who underwent curative resection (group A, n=129), those with hepatitis B virus-related HCC (group B, n=62) and those with hepatitis C virus-related HCC (group C, n=284). Methods: Clinicopathologic characteristics and cumulative overall survival (OS) and recurrence-free survival (RFS) after curative resection were compared among the three groups. Results: The proportion of patients with non-liver cirrhosis (LC) or diabetes mellitus in group A was significantly higher than that in group B or group C. The mean maximum tumor size in group A was significantly larger than that of group B or group C. Cumulative 3-year OS rates after resection were 76% in group A, 79% in group B and 72% in group C (A vs. B, P=0.638; A vs. C, P=0.090; B vs. C, P=0.091; overall significance, P=0.088). The corresponding RFS rates after resection were 38% in group A, 36% in group B and 36% in group C (A vs. B, P=0.528; A vs. C, P=0.281; B vs. C, P=0.944; overall significance, P=0.557). In subgroup analyses in patients with LC, in those without LC and in those who satisfied the Milan criteria, similar results were obtained, i.e., the difference among the three groups did not reach significance in terms of OS and RFS. Conclusion: Long-term clinical outcomes in patients NBNC-HCC after curative resection were comparable to those in patients with hepatitis virus-related HCC after curative resection.


European Journal of Gastroenterology & Hepatology | 2013

Surgical resection for hepatocellular carcinoma: clinical outcomes and safety in elderly patients.

Hiroki Nishikawa; Akira Arimoto; Tomoko Wakasa; Ryuichi Kita; Toru Kimura; Yukio Osaki

Objectives The aim of this study was to compare the clinical outcomes and safety of surgical resection for hepatocellular carcinoma between patients older than 75 years of age (elderly group) and those younger than 75 years (control group). Methods A total of 92 patients were included in the elderly group and 206 patients were included in the control group. Clinical outcomes including overall survival, recurrence-free survival, and safety were compared between these two groups after initial surgery. Results The mean (±SD) observation periods were 2.5±1.8 years in the elderly group and 3.1±2.2 years in the control group. The 1, 3, and 5-year overall survival rates after surgery were 90.0, 73.3, and 43.0%, respectively, in the elderly group and 91.0, 77.5, and 64.4%, respectively, in the control group (P=0.188). The corresponding recurrence-free survival rates were 66.3, 38.8, and 26.2%, respectively, in the elderly group and 66.3, 38.8, and 22.2%, respectively, in the control group (P=0.634). Multivariate analysis identified a total bilirubin level greater than 1.0 mg/dl (P=0.003), a serum albumin level greater than 4.0 g/dl (P=0.005), an &agr;-fetoprotein level greater than 100 ng/ml (P<0.001), and microvascular invasion (P<0.001) as significant factors linked to overall survival, and tumor number (P=0.014) and microvascular invasion (P=0.008) were significant factors associated with recurrence-free survival. There was no significant difference between the two groups in terms of surgery-related serious adverse events (P>0.999). Conclusion Surgical resection appears to be a safe and feasible procedure for the treatment of hepatocellular carcinoma in elderly patients.


Hepatology Research | 2014

Effect of nucleoside analog use in patients with hepatitis B virus‐related hepatocellular carcinoma

Hiroki Nishikawa; Norihiro Nishijima; Akira Arimoto; Tadashi Inuzuka; Ryuichi Kita; Toru Kimura; Yukio Osaki

To examine the effect of nucleoside analog (NA) therapy on clinical outcome in patients with hepatitis B virus (HBV)‐related hepatocellular carcinoma (HCC) who underwent curative therapy.


Oncology Letters | 2013

Prognostic factors in patients with hepatitis B virus-related hepatocellular carcinoma undergoing nucleoside analog antiviral therapy

Hiroki Nishikawa; Norihiro Nishijima; Akira Arimoto; Tadashi Inuzuka; Ryuichi Kita; Toru Kimura; Yukio Osaki

In the present era of entecavir (ETV) use for chronic hepatitis B (CHB), the prognostic factors in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) remain unclear. The aims of the present study were to investigate the prognostic factors in patients with HBV-related HCC treated with ETV who underwent curative therapy. A total of 74 HBV-related HCC patients treated with ETV who underwent curative therapy were analyzed. Predictive factors associated with overall survival (OS) and recurrence-free survival (RFS) were examined using univariate and multivariate analysis. Our study population included 49 males and 25 females with a median age of 62 years. The median observation period was 3.4 years (range, 0.2–11.5 years). The 1-, 3- and 5-year cumulative OS rates were 100, 89.8 and 89.8%, respectively. The corresponding RFS rates were 82.8, 52.1 and 25.6%, respectively. In this study, 73 patients (98.6%) achieved an HBV DNA level of <400 copies/ml during the follow-up period. No viral breakthrough hepatitis, as defined by 1 log increase from nadir, was observed during ETV therapy. According to multivariate analysis, only hepatitis B e antigen (HBeAg) positivity was significantly associated with OS [hazard ratio (HR), 0.058; 95% confidence interval (CI), 0.005–0.645; P=0.020)], whereas HCC stage (HR, 0.359; 95% CI, 0.150–0.859; P=0.021), HBeAg positivity (HR, 0.202; 95% CI, 0.088–0.463; P<0.001) and γ-glutamyl transpeptidase ≥50 IU/l (HR, 0.340; 95% CI, 0.152–0.760; P=0.009) were significant predictive factors linked to RFS. In conclusion, HBeAg positivity was significantly associated with OS and RFS in HBV-related HCC patients treated with ETV who underwent curative therapy. In such patients, close observation is required, even after curative therapy for HCC.


Journal of Hepato-biliary-pancreatic Sciences | 2016

Pathological spectrum of bile duct lesions from chronic bile duct injury to invasive cholangiocarcinoma corresponding to bile duct imaging findings of occupational cholangiocarcinoma

Masahiko Kinoshita; Shoji Kubo; Yasuni Nakanuma; Yasunori Sato; Shigekazu Takemura; Shogo Tanaka; Genya Hamano; Tokuji Ito; Hiroaki Terajima; Terumasa Yamada; Shoji Nakamori; Akira Arimoto; Masahiro Fujikawa; Yasuhiko Sugawara; Takatsugu Yamamoto; Makoto Abue; Kei Nakagawa; Michiaki Unno; Toru Mizuguchi; Kenji Takenaka; Ken Shirabe; Toshihiko Shibata

We aimed to identify the pathological characteristics of occupational cholangiocarcinoma.


Oncology Reports | 2015

Clinical significance of the FIB-4 index for non-B non-C hepatocellular carcinoma treated with surgical resection

Hiroki Nishikawa; Yukio Osaki; Hideyuki Komekado; Azusa Sakamoto; Sumio Saito; Norihiro Nishijima; Akihiro Nasu; Akira Arimoto; Ryuichi Kita; Toru Kimura

The aims of the present study were to examine the relationship between the preoperative FIB-4 index and background liver fibrosis in non-tumor parts obtained from surgical specimens and to investigate whether the FIB-4 index can be a useful predictor for non-B non-C hepatocellular carcinoma (NBNC-HCC) patients treated with surgical resection (SR). A total of 118 patients with NBNC-HCC treated with SR with curative intent were analyzed. Receiver operating characteristic (ROC) curve analysis was performed for calculating the area under the ROC (AUROC) for the FIB-4 index, aspartate aminotransferase (AST) to platelet ratio index, AST to alanine aminotransferase ratio, serum albumin, total bilirubin and platelet count for cirrhosis. We also examined predictors linked to overall survival (OS) and recurrence-free survival (RFS) after SR. The mean patient age was 68.9±9.0 years (93 males and 25 females) with a median observation period of 3.2 years. In extracted surgical specimens, background liver cirrhosis (F4) was observed in 39 patients (33.1%). The mean maximum tumor size was 5.7±3.2 cm. The mean body mass index was 24.3±3.9 kg/m2. The FIB-4 index yielded the highest AUROC for cirrhosis with a level of 0.887 at an optimal cut-off value of 2.97 (sensitivity, 92.3; specificity, 69.6%). In the multivariate analysis, serum α-fetoprotein >40 ng/ml (P=0.026) was the only significant independent predictor linked to OS, while tumor number (P=0.002) and FIB-4 index >2.97 (P=0.044) were significant factors linked to RFS. In conclusion, preoperative FIB-4 index can be a useful predictor for NBNC-HCC patients who undergo SR.


Gastroenterology Research and Practice | 2013

The Relation between Obesity and Survival after Surgical Resection of Hepatitis C Virus-Related Hepatocellular Carcinoma

Hiroki Nishikawa; Akira Arimoto; Tomoko Wakasa; Ryuichi Kita; Toru Kimura; Yukio Osaki

Background and Aims. We aimed to investigate the relationship between obesity and survival in hepatitis C virus-(HCV-) related hepatocellular carcinoma (HCC) patients who underwent curative surgical resection (SR). Methods. A total of 233 patients with HCV-related HCC who underwent curative SR were included. They included 60 patients (25.8%) with a body mass index (BMI) of > 25 kg/m2 (obesity group) and 173 patients with a BMI of < 25 kg/m2 (control group). Overall survival (OS) and recurrence-free survival (RFS) rates were compared. Results. The median follow-up periods were 3.6 years in the obesity group and 3.1 years in the control group. The 1-, 3-, and 5-year cumulative OS rates were 98.3%, 81.0%, and 63.9% in the obesity group and 90.0%, 70.5%, and 50.3% in the control group (P = 0.818). The corresponding RFS rates were 70.1%, 27.0%, and 12.0% in the obesity group and 70.1%, 39.0%, and 21.7% in the control group (P = 0.124). There were no significant differences between the obesity group and the control group in terms of blood loss during surgery (P = 0.899) and surgery-related serious adverse events (P = 0.813). Conclusions. Obesity itself did not affect survival in patients with HCV-related HCC after curative SR.


Journal of Hepato-biliary-pancreatic Sciences | 2014

Indication for neoadjuvant chemotherapy in patients with colorectal liver metastases based on a nomogram that predicts disease-free survival

Masayuki Okuno; Etsuro Hatano; Satoru Seo; Kojiro Taura; Kentaro Yasuchika; Akio Nakajima; Takefumi Yazawa; Hiroaki Furuyama; Hiroshi Kawamoto; Shintaro Yagi; Ryuta Nishitai; Takahisa Fujikawa; Akira Arimoto; Masazumi Zaima; Tsunehiro Yoshimura; Hiroaki Terajima; Satoshi Kaihara; Dai Manaka; Akira Tanaka; Shinji Uemoto

The purpose of this study was to validate the Beppu nomogram, which predicts disease‐free survival (DFS) after resection of colorectal liver metastases, and to investigate the efficacy of neoadjuvant chemotherapy based on the nomogram‐predicted recurrence risk.

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