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Dive into the research topics where Koji Kitada is active.

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Featured researches published by Koji Kitada.


Clinical Cancer Research | 2012

Impact of expression of human epidermal growth factor receptors EGFR and ERBB2 on survival in stage II/III gastric cancer.

Masanori Terashima; Koji Kitada; Atsushi Ochiai; Wataru Ichikawa; Issei Kurahashi; Shinichi Sakuramoto; Hitoshi Katai; Takeshi Sano; Hiroshi Imamura; Mitsuru Sasako

Purpose: EGF receptor (EGFR) and HER2 positivity are considered to be negative prognostic factors in gastric cancer. Biomarker analysis was conducted to evaluate the impact of EGFR and HER2 expression on the outcome of patients enrolled in the Adjuvant Chemotherapy Trial of TS-1 for Gastric Cancer (ACTS-GC), a randomized controlled trial comparing postoperative adjuvant S-1 therapy with surgery alone in 1,059 patients with stage II/III gastric cancer. Experimental Design: Formalin-fixed, paraffin-embedded surgical specimens were retrospectively examined in 829 patients (78.3%). The effects of EGFR and HER2 positivity on survival were analyzed on the basis of the 5-year survival data from the study. EGFR positivity was defined as an immunohistochemistry (IHC) score of 3+, and HER2 positivity as an IHC score of 3+ or an IHC score of 2+ with a positive dual-color in situ hybridization status. Results: EGFR and HER2 were positive in 75 (9.0%) and 113 (13.6%) patients, respectively. The overall and relapse-free survival rates were significantly lower in EGFR-positive patients than in EGFR-negative patients, whereas they were similar in HER2-positive and HER2-negative patients. Multivariate analysis showed that EGFR positivity correlated with poor outcomes [HR = 1.504; 95% confidence interval (CI) = 1.020–2.149; P = 0.040]. Treatment with S-1 improved survival compared with surgery alone, irrespective of EGFR and HER2 status. Conclusions: EGFR positivity, but not HER2 positivity, was associated with poor patient outcomes after curative resection of stage II/III gastric cancer. There was no interaction between S-1 and EGFR or HER2 status with respect to survival outcome. Clin Cancer Res; 18(21); 5992–6000. ©2012 AACR.


Oncotarget | 2017

TOP2A, GGH, and PECAM1 are associated with hematogenous, lymph node, and peritoneal recurrence in stage II/III gastric cancer patients enrolled in the ACTS-GC study

Masanori Terashima; Wataru Ichikawa; Atsushi Ochiai; Koji Kitada; Issei Kurahashi; Shinichi Sakuramoto; Hitoshi Katai; Takeshi Sano; Hiroshi Imamura; Mitsuru Sasako

BACKGROUND To identify factors related to relapse sites, we carried out an exploratory biomarker analysis of data from the Adjuvant Chemotherapy Trial of TS-1 for Gastric Cancer study, which is a randomized, controlled trial comparing postoperative adjuvant S-1 therapy with surgery alone in 1,059 patients with stage II/III gastric cancer. PATIENTS AND METHODS Surgical specimens from 829 patients were retrospectively examined, and 63 genes involved in a variety of biological processes were analyzed by quantitative real-time PCR. Gene expression normalized to reference genes was categorized as lower or higher than the median, and association with relapse sites was analyzed based on 5-year relapse-free survival. RESULTS Hematogenous, lymph node, and peritoneal recurrence developed in 72, 105, and 138 of the 829 patients, respectively; hazard ratios were 0.79 (95% confidential interval: 0.54-1.16), 0.51 (0.31-0.82), and 0.60 (0.42-0.84), respectively. Expression of platelet/endothelial cell adhesion molecule 1 (PECAM1) and topoisomerase II alpha (TOP2A) was strongly correlated with hematogenous recurrence and peritoneal recurrence, respectively (false discovery rate = 7.7×10-5 and 0.002, respectively). Gamma-glutamyl hydrolase (GGH) expression was moderately correlated with lymph node recurrence (false discovery rate = 0.34). Relapse-free survival was worse in patients expressing high levels of PECAM1 (hazard ratio = 2.37, 1.65-3.41), TOP2A (hazard ratio = 2.35, 1.55-3.57), or GGH (hazard ratio = 1.87, 1.13-3.08), respectively. A multivariate analysis revealed that these were stronger independent risk factors than tumor histological type. CONCLUSION In patients with stage II/III gastric cancer, TOP2A, GGH, and PECAM1 levels in primary tumors are linked to high risk of hematogenous, lymph node, and peritoneal recurrence, respectively.Background To identify factors related to relapse sites, we carried out an exploratory biomarker analysis of data from the Adjuvant Chemotherapy Trial of TS-1 for Gastric Cancer study, which is a randomized, controlled trial comparing postoperative adjuvant S-1 therapy with surgery alone in 1,059 patients with stage II/III gastric cancer. Patients and Methods Surgical specimens from 829 patients were retrospectively examined, and 63 genes involved in a variety of biological processes were analyzed by quantitative real-time PCR. Gene expression normalized to reference genes was categorized as lower or higher than the median, and association with relapse sites was analyzed based on 5-year relapse-free survival. Results Hematogenous, lymph node, and peritoneal recurrence developed in 72, 105, and 138 of the 829 patients, respectively; hazard ratios were 0.79 (95% confidential interval: 0.54–1.16), 0.51 (0.31–0.82), and 0.60 (0.42–0.84), respectively. Expression of platelet/endothelial cell adhesion molecule 1 (PECAM1) and topoisomerase II alpha (TOP2A) was strongly correlated with hematogenous recurrence and peritoneal recurrence, respectively (false discovery rate = 7.7×10−5 and 0.002, respectively). Gamma-glutamyl hydrolase (GGH) expression was moderately correlated with lymph node recurrence (false discovery rate = 0.34). Relapse-free survival was worse in patients expressing high levels of PECAM1 (hazard ratio = 2.37, 1.65–3.41), TOP2A (hazard ratio = 2.35, 1.55–3.57), or GGH (hazard ratio = 1.87, 1.13–3.08), respectively. A multivariate analysis revealed that these were stronger independent risk factors than tumor histological type. Conclusion In patients with stage II/III gastric cancer, TOP2A, GGH, and PECAM1 levels in primary tumors are linked to high risk of hematogenous, lymph node, and peritoneal recurrence, respectively.


Gastric Cancer | 2017

Impact of insulin-like growth factor-1 receptor and amphiregulin expression on survival in patients with stage II/III gastric cancer enrolled in the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer.

Wataru Ichikawa; Masanori Terashima; Atsushi Ochiai; Koji Kitada; Issei Kurahashi; Shinichi Sakuramoto; Hitoshi Katai; Takeshi Sano; Hiroshi Imamura; Mitsuru Sasako

BackgroundExploratory biomarker analysis was conducted to identify factors related to the outcomes of patients with stage II/III gastric cancer using data from the Adjuvant Chemotherapy Trial of S-1 for Gastric Cancer, which was a randomized controlled study comparing the administration of an orally active combination of tegafur, gimeracil, and oteracil with surgery alone.MethodsFormalin-fixed paraffin-embedded surgical specimens from 829 patients were retrospectively examined, and 63 genes were analyzed by quantitative real-time RT-PCR after TaqMan assay-based pre-amplification. Gene expression was normalized to the geometric mean of GAPDH, ACTB, and RPLP0 as reference genes, and categorized into low and high values based on the median. The impact of gene expression on survival was analyzed using 5-year survival data. The Benjamini and Hochberg procedure was used to control the false discovery rate.ResultsIGF1R and AREG were most strongly correlated with overall survival, which was significantly worse in high IGF1R patients than low IGF1R patients, but better in high AREG patients than low AREG patients. The hazard ratio for death in the analysis of overall survival (S-1 vs. surgery alone) was reduced in the high IGF1R group compared with the low IGF1R group and in the low AREG group compared with the high AREG group. There were no significant interaction effects.ConclusionIGF1R gene expression was associated with poor outcomes after curative resection of stage II/III gastric cancer, whereas AREG gene expression was associated with good outcomes. No significant interaction effect on survival was evident between S-1 treatment and gene expression.


Gastric Cancer | 2014

Evaluation of HER2-based biology in 1,006 cases of gastric cancer in a Japanese population

Masaki Aizawa; Akiko Nagatsuma; Koji Kitada; Takeshi Kuwata; Satoshi Fujii; Taira Kinoshita; Atsushi Ochiai


Gastric Cancer | 2014

Impact of the expression of thymidylate synthase and dihydropyrimidine dehydrogenase genes on survival in stage II/III gastric cancer

Mitsuru Sasako; Masanori Terashima; Wataru Ichikawa; Atsushi Ochiai; Koji Kitada; Issei Kurahashi; Shinichi Sakuramoto; Hitoshi Katai; Takeshi Sano; Hiroshi Imamura


Journal of Clinical Oncology | 2011

Impact of human epidermal growth factor receptor (EGFR) and ERBB2 (HER2) expressions on survival in patients with stage II/III gastric cancer, enrolled in the ACTS-GC study.

Masanori Terashima; Atsushi Ochiai; Koji Kitada; Wataru Ichikawa; Issei Kurahashi; Shinichi Sakuramoto; T. Fukagawa; Takeshi Sano; Hiroshi Imamura; Mitsuru Sasako


Journal of Clinical Oncology | 2012

Interaction between intratumoral ERCC1 expression and adjuvant treatment with S-1 on the survival of patients enrolled in the ACTS-GC study.

Koji Kitada; Atsushi Ochiai; Wataru Ichikawa; Masanori Terashima; Issei Kurahashi; Shinichi Sakuramoto; Hitoshi Katai; Takeshi Sano; Hiroshi Imamura; Mitsuru Sasako


Journal of Clinical Oncology | 2012

Impact of the gene expressions of thymidylate synthase and dihydropyrimidine dehydrogenase on survival in patients enrolled in the ACTS-GC study.

Mitsuru Sasako; Masanori Terashima; Wataru Ichikawa; Atsushi Ochiai; Koji Kitada; Issei Kurahashi; Shinichi Sakuramoto; Hitoshi Katai; Takeshi Sano; Hiroshi Imamura


The Japanese Journal of Gastroenterological Surgery | 2012

A Case of IgG4-related Sclerosing Cholangitis with Intrahepatic Bile Duct Stricture Mimicking Cholangiocarcinoma

Koji Kitada; Naoto Gotohda; Daisuke Nobuoka; Yuichiro Kato; Takahiro Kinoshita; Shinichiro Takahashi; Masaru Konishi; Taira Kinoshita


Journal of Clinical Oncology | 2013

Expression analysis of MET, EGFR, and HER2, and K-ras mutation status in patients with stage II/III gastric cancer enrolled in the ACTS-GC study.

Atsushi Ochiai; Koji Kitada; Wataru Ichikawa; Masanori Terashima; Issei Kurahashi; Hitoshi Katai; Ryoji Kushima; Mitsuru Sasako

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Masanori Terashima

Fukushima Medical University

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Mitsuru Sasako

Hyogo College of Medicine

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Wataru Ichikawa

Saitama Medical University

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Takeshi Sano

Japanese Foundation for Cancer Research

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