Keiichi Kubota

Dr. Keiichi Kubota

Tohto Bunkyo Hospital, Bunkyo City, Tokyo 113-0034, Japan

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 August 2013 in Journal of Hepato-Biliary-Pancreatic Sciences
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Journal Article
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Keiichi KubotaKeiichi Kubota
Keiichi Kubota
YNYasuni Nakanuma
Yasuni Nakanuma
FKFukuo Kondo
Fukuo Kondo
HHHiroyuki Hachiya
Hiroyuki Hachiya
MMMasaru Miyazaki
Masaru Miyazaki
KIKazuo Inui
Kazuo Inui

8 June 2020 in Journal of Hepato-Biliary-Pancreatic Sciences
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Journal Article
Closed access
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Keiichi KubotaKeiichi Kubota
Keiichi Kubota
JJJin‐Young Jang
Jin‐Young Jang
YNYasuni Nakanuma
Yasuni Nakanuma
KJKee‐Taek Jang
Kee‐Taek Jang
YHYasuo Haruyama
Yasuo Haruyama
MUMichiaki Unno
Michiaki Unno

9 December 2020 in Journal of Clinical Medicine
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Journal Article
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YNYasuni Nakanuma
Yasuni Nakanuma
KUKatsuhiko Uesaka
Katsuhiko Uesaka
YKYuko Kakuda
Yuko Kakuda
TSTakashi Sugino
Takashi Sugino
Keiichi KubotaKeiichi Kubota
Keiichi Kubota
TTTakuro Terada
Takuro Terada
Intraductal papillary neoplasm of the bile duct (IPNB), a pre-invasive neoplasm of the bile duct, is being established pathologically as a precursor lesion of invasive cholangiocarcinoma (CCA), and at the time of surgical resection, approximately half of IPNBs show stromal invasion (IPNB associated with invasive carcinoma). IPNB can involve any part of the biliary tree. IPNB shows grossly visible, exophytic growth in a dilated bile duct lumen, with histologically villous/papillary neoplastic epithelia with tubular components covering fine fibrovascular stalks. Interestingly, IPNB can be classified into four subtypes (intestinal, gastric, pancreatobiliary and oncocytic), similar to intraductal papillary mucinous neoplasm of the pancreas (IPMN). IPNBs are classified into low-grade and high-grade based on lining epithelial features. The new subclassification of IPNB into types 1 (low-grade dysplasia and high-grade dysplasia with regular architecture) and 2 (high-grade dysplasia with irregular architecture) proposed by the Japan–Korea pathologist group may be useful in the clinical field. The outcome of post-operative IPNBs is more favorable in type 1 than type 2. Recent genetic studies using next-generation sequencing have demonstrated the existence of several groups of mutations of genes: (i) IPNB showing mutations in KRAS, GNAS and RNF43 belonged to type 1, particularly the intestinal subtype, similar to the mutation patterns of IPMN; (ii) IPNB showing mutations in CTNNB1 and lacking mutations in KRAS, GNAS and RNF43 belonged to the pancreatobiliary subtype but differed from IPMN. IPNB showing mutation of TP53, SMAD4 and PIK3CA might reflect complicated and other features characterizing type 2. The recent recognition of IPNBs may facilitate further clinical and basic studies of CCA with respect to the pre-invasive and early invasive stages.

9 June 2008 in BMC Cancer
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HKHiroaki Kijima
Hiroaki Kijima
TSTokihiko Sawada
Tokihiko Sawada
NTNaohisa Tomosugi
Naohisa Tomosugi
Keiichi KubotaKeiichi Kubota
Keiichi Kubota
Background: The present study evaluated the expression of hepcidin mRNA in hepatocellular carcinoma (HCC). Methods: Samples of cancerous and non-cancerous liver tissue were taken from 40 patients with HCC who underwent hepatectomy. Expression of hepcidin mRNA was evaluated by real-time PCR, and compared in tumors differing in their degree of differentiation, number of tumors, and vessel invasion. Correlations between hepcidin expression and the interval until HCC recurrence, and the serum concentration of hepcidin were evaluated, together with the expression of mRNAs for other iron metabolism molecules, ferroportin and transferrin receptor 2 (Trf2). Results: Hepcidin mRNA expression in non-cancerous and cancerous tissues was 1891.8 (32.3–23187.4) and 53.4 (1.9–3185.8), respectively (P < 0.0001). There were no significant differences in hepcidin expression among tumors differing in their degree of differentiation, number of tumors, or vessel invasion. There was no significant correlation between hepcidin expression and the interval until HCC recurrence. The serum concentration of hepcidin-25 was not correlated with hepcidin-mRNA expression. Finally, there were no significant differences in the expression of mRNA for ferroportin and Trf2 between cancerous and non-cancerous tissues. Conclusion: Expression of hepcidin mRNA is strikingly suppressed in cancerous, but not in non-cancerous tissues, in patients with HCC, irrespective of ferroportin or Trf2 expression. Uniform suppression of hepcidin may be linked to the development of HCC.

1 January 2007 in World Journal of Gastroenterology
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Journal Article
Open access
Keiichi KubotaKeiichi Kubota
Keiichi Kubota
JKJunji Kita
Junji Kita
KRKyu Rokkaku
Kyu Rokkaku
YIYoshimi Iwasaki
Yoshimi Iwasaki
TSTokihiko Sawada
Tokihiko Sawada
TFTakahiro Fujimori
Takahiro Fujimori
Ectopic hepatocellular carcinoma arising from pancreas: A case report and review of the literature

26 May 2020 in British Journal of Surgery
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Journal Article
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WKWooil Kwon
Wooil Kwon
HKHongbeom Kim
Hongbeom Kim
YHY. Han
Y. Han
YHY. J. Hwang
Y. J. Hwang
SKS G Kim
S G Kim
JJJ.‐Y. Jang
J.‐Y. Jang
Background In gallbladder cancer, stage T2 is subdivided by tumour location into lesions on the peritoneal side (T2a) or hepatic side (T2b). For tumours on the peritoneal side (T2a), it has been suggested that liver resection may be omitted without compromising the prognosis. However, data to validate this argument are lacking. This study aimed to investigate the prognostic value of tumour location in T2 gallbladder cancer, and to clarify the adequate extent of surgical resection. Methods Clinical data from patients who underwent surgery for gallbladder cancer were collected from 14 hospitals in Korea, Japan, Chile and the USA. Survival and risk factor analyses were conducted. Results Data from 937 patients were available for evaluation. The overall 5‐year disease‐free survival rate was 70·6 per cent, 74·5 per cent for those with T2a and 65·5 per cent among those with T2b tumours (P = 0·028). Regarding liver resection, extended cholecystectomy was associated with a better 5‐year disease‐free survival rate than simple cholecystectomy (73·0 versus 61·5 per cent; P = 0·012). The 5‐year disease‐free survival rate was marginally better for extended than simple cholecystectomy in both T2a (76·5 versus 66·1 per cent; P = 0·094) and T2b (68·2 versus 56·2 per cent; P = 0·084) disease. Five‐year disease‐free survival rates were similar for extended cholecystectomies including liver wedge resection versus segment IVb/V segmentectomy (74·1 versus 71·5 per cent; P = 0·720). In multivariable analysis, independent risk factors for recurrence were presence of symptoms (hazard ratio (HR) 1·52; P = 0·002), R1 resection (HR 1·96; P = 0·004) and N1/N2 status (N1: HR 3·40, P < 0·001; N2: HR 9·56, P < 0·001). Among recurrences, 70·8 per cent were metastatic. Conclusion Tumour location was not an independent prognostic factor in T2 gallbladder cancer. Extended cholecystectomy was marginally superior to simple cholecystectomy. A radical operation should include liver resection and adequate node dissection.