Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Kentaro Yamazaki is active.

Publication


Featured researches published by Kentaro Yamazaki.


The New England Journal of Medicine | 2015

Randomized Trial of TAS-102 for Refractory Metastatic Colorectal Cancer

Robert J. Mayer; Eric Van Cutsem; Alfredo Falcone; Takayuki Yoshino; R. Garcia-Carbonero; Nobuyuki Mizunuma; Kentaro Yamazaki; Yasuhiro Shimada; Josep Tabernero; Yoshito Komatsu; Alberto Sobrero; Eveline Boucher; Marc Peeters; Ben Tran; Heinz-Josef Lenz; Alberto Zaniboni; Howard S. Hochster; James M. Cleary; Hans Prenen; Fabio Benedetti; Hirokazu Mizuguchi; Lukas Makris; Masanobu Ito; Atsushi Ohtsu

BACKGROUND Early clinical trials conducted primarily in Japan have shown that TAS-102, an oral agent that combines trifluridine and tipiracil hydrochloride, was effective in the treatment of refractory colorectal cancer. We conducted a phase 3 trial to further assess the efficacy and safety of TAS-102 in a global population of such patients. METHODS In this double-blind study, we randomly assigned 800 patients, in a 2:1 ratio, to receive TAS-102 or placebo. The primary end point was overall survival. RESULTS The median overall survival improved from 5.3 months with placebo to 7.1 months with TAS-102, and the hazard ratio for death in the TAS-102 group versus the placebo group was 0.68 (95% confidence interval [CI], 0.58 to 0.81; P<0.001). The most frequently observed clinically significant adverse events associated with TAS-102 were neutropenia, which occurred in 38% of those treated, and leukopenia, which occurred in 21%; 4% of the patients who received TAS-102 had febrile neutropenia, and one death related to TAS-102 was reported. The median time to worsening performance status (a change in Eastern Cooperative Oncology Group performance status [on a scale of 0 to 5, with 0 indicating no symptoms and higher numbers indicating increasing degrees of disability] from 0 or 1 to 2 or more) was 5.7 months with TAS-102 versus 4.0 months with placebo (hazard ratio, 0.66; 95% CI, 0.56 to 0.78; P<0.001). CONCLUSIONS In patients with refractory colorectal cancer, TAS-102, as compared with placebo, was associated with a significant improvement in overall survival. (Funded by Taiho Oncology-Taiho Pharmaceutical; RECOURSE ClinicalTrials.gov number, NCT01607957.).


Lancet Oncology | 2015

Ramucirumab versus placebo in combination with second-line FOLFIRI in patients with metastatic colorectal carcinoma that progressed during or after first-line therapy with bevacizumab, oxaliplatin, and a fluoropyrimidine (RAISE): a randomised, double-blind, multicentre, phase 3 study

Josep Tabernero; Takayuki Yoshino; Allen Lee Cohn; Radka Obermannova; G. Bodoky; R. Garcia-Carbonero; Tudor Ciuleanu; David Craig Portnoy; Eric Van Cutsem; Axel Grothey; Jana Prausová; Pilar Garcia-Alfonso; Kentaro Yamazaki; Philip Clingan; Sara Lonardi; Tae Won Kim; Lorinda Simms; Shao Chun Chang; Federico Nasroulah

BACKGROUND Angiogenesis is an important therapeutic target in colorectal carcinoma. Ramucirumab is a human IgG-1 monoclonal antibody that targets the extracellular domain of VEGF receptor 2. We assessed the efficacy and safety of ramucirumab versus placebo in combination with second-line FOLFIRI (leucovorin, fluorouracil, and irinotecan) for metastatic colorectal cancer in patients with disease progression during or after first-line therapy with bevacizumab, oxaliplatin, and a fluoropyrimidine. METHODS Between Dec 14, 2010, and Aug 23, 2013, we enrolled patients into the multicentre, randomised, double-blind, phase 3 RAISE trial. Eligible patients had disease progression during or within 6 months of the last dose of first-line therapy. Patients were randomised (1:1) via a centralised, interactive voice-response system to receive 8 mg/kg intravenous ramucirumab plus FOLFIRI or matching placebo plus FOLFIRI every 2 weeks until disease progression, unacceptable toxic effects, or death. Randomisation was stratified by region, KRAS mutation status, and time to disease progression after starting first-line treatment. The primary endpoint was overall survival in the intention-to-treat population. This study is registered with ClinicalTrials.gov, number NCT01183780.ld FINDINGS We enrolled 1072 patients (536 in each group). Median overall survival was 13·3 months (95% CI 12·4-14·5) for patients in the ramucirumab group versus 11·7 months (10·8-12·7) for the placebo group (hazard ratio 0·844 95% CI 0·730-0·976; log-rank p=0·0219). Survival benefit was consistent across subgroups of patients who received ramucirumab plus FOLFIRI. Grade 3 or worse adverse events seen in more than 5% of patients were neutropenia (203 [38%] of 529 patients in the ramucirumab group vs 123 [23%] of 528 in the placebo group, with febrile neutropenia incidence of 18 [3%] vs 13 [2%]), hypertension (59 [11%] vs 15 [3%]), diarrhoea (57 [11%] vs 51 [10%]), and fatigue (61 [12%] vs 41 [8%]). INTERPRETATION Ramucirumab plus FOLFIRI significantly improved overall survival compared with placebo plus FOLFIRI as second-line treatment for patients with metastatic colorectal carcinoma. No unexpected adverse events were identified and toxic effects were manageable. FUNDING Eli Lilly.


Cancer Science | 2011

Genotype-directed, dose-finding study of irinotecan in cancer patients with UGT1A1*28 and/or UGT1A1*6 polymorphisms.

Taroh Satoh; Takashi Ura; Yasuhide Yamada; Kentaro Yamazaki; Toshimasa Tsujinaka; Munakata M; Tomohiro Nishina; Shu Okamura; Taito Esaki; Yasutsuna Sasaki; Wasaburo Koizumi; Yoshihiro Kakeji; Naoki Ishizuka; Ichinosuke Hyodo; Yuh Sakata

Irinotecan‐induced severe neutropenia is associated with homozygosity for the UGT1A1*28 or UGT1A1*6 alleles. In this study, we determined the maximum‐tolerated dose (MTD) of irinotecan in patients with UGT1A1 polymorphisms. Patients who had received chemotherapy other than irinotecan for metastatic gastrointestinal cancer were enrolled. Patients were divided into three groups according to UGT1A1 genotypes: wild‐type (*1/*1); heterozygous (*28/*1, *6/*1); or homozygous (*28/*28, *6/*6, *28/*6). Irinotecan was given every 2 weeks for two cycles. The wild‐type group received a fixed dose of irinotecan (150 mg/m2) to serve as a reference. The MTD was guided from 75 to 150 mg/m2 by the continual reassessment method in the heterozygous and homozygous groups. Dose‐limiting toxicity (DLT) and pharmacokinetics were evaluated during cycle 1. Of 82 patients enrolled, DLT was assessable in 79 patients (wild‐type, 40; heterozygous, 20; and homozygous, 19). Dose‐limiting toxicity occurred in one patient in the wild‐type group, none in the heterozygous group, and six patients (grade 4 neutropenia) in the homozygous group. In the homozygous group, the MTD was 150 mg/m2 and the probability of DLT was 37.4%. The second cycle was delayed because of neutropenia in 56.3% of the patients given the MTD. The AUC0–24 h of SN‐38 was significantly greater (P < 0.001) and more widely distributed in the homozygous group. Patients homozygous for the UGT1A1*28 or UGT1A1*6 allele can receive irinotecan in a starting dose of 150 mg/m2, but many required dose reductions or delayed treatment in subsequent cycles. UMIN Clinical Trial Registration number: UMIN000000618. (Cancer Sci 2011; 102: 1868–1873)


Gastric Cancer | 2009

Weekly paclitaxel for heavily treated advanced or recurrent gastric cancer refractory to fluorouracil, irinotecan, and cisplatin

Rai Shimoyama; Hirofumi Yasui; Narikazu Boku; Yusuke Onozawa; Shuichi Hironaka; Akira Fukutomi; Kentaro Yamazaki; Keisei Taku; Takashi Kojima; Nozomu Machida; Akiko Todaka; Hideharu Tomita; Takeshi Sakamoto; Takahiro Tsushima

BackgroundAlthough triweekly administration of paclitaxel is approved for gastric cancer in Japan, currently, the drug is often delivered with a weekly schedule because of the equivalent efficacy and lesser toxicity of this dosing schedule as compared with the triweekly administration schedule. Weekly administration of paclitaxel as second-line or first-line chemotherapy for gastric cancer has been reported to yield a response rate of about 20%. Because there has been no report of the efficacy of weekly paclitaxel in the third-line setting, this retrospective study investigated the efficacy and toxicities of weekly paclitaxel used in the third-line setting for the treatment of gastric cancer refractory to all three key drugs, fluorouracil, irinotecan, and cisplatin, used in clinical practice.MethodsIn 85 patients with advanced or recurrent histologically confirmed gastric adenocarcinoma who had failed to respond to prior chemotherapy regimens containing fluorouracil, irinotecan, and cisplatin, paclitaxel (80 mg/m2) was administered weekly, three times, for 3 weeks out of 4.ResultsThe median number of courses was 3 (range, 1–38). The overall response rate was 23.2% (19/82) in the patients with measurable lesions, and ascites disappeared in 15 of 48 patients (31.3%). Progression-free survival was 105 days and the median survival time was 201 days from the initiation of paclitaxel administration. Grade 3 or 4 leukopenia, neutropenia, anemia, and thrombocytopenia were observed in 25 (29%), 25 (29%), 37 (44%), and 3 (4%) patients. Other, nonhematological, toxicities were nausea, vomiting, anorexia, sensory neuropathy, fatigue, and febrile neutropenia.ConclusionWeekly paclitaxel administration shows activity against advanced gastric cancer also in the third-line setting.


Annals of Oncology | 2016

Randomized phase III study of bevacizumab plus FOLFIRI and bevacizumab plus mFOLFOX6 as first-line treatment for patients with metastatic colorectal cancer (WJOG4407G)

Kentaro Yamazaki; Mituhiro Nagase; Hiroshi Tamagawa; Saori Ueda; Takao Tamura; Kohei Murata; T. Eguchi Nakajima; Eishi Baba; Miho Tsuda; Toshikazu Moriwaki; Taito Esaki; Yukikazu Tsuji; Kei Muro; Koichi Taira; Tadamichi Denda; S. Funai; Katsunori Shinozaki; Hiroyuki Yamashita; Nobuo Sugimoto; Tatsuya Okuno; Tomohiro Nishina; M. Umeki; Tadahisa Kurimoto; Tetsuji Takayama; A. Tsuji; Motoki Yoshida; Ayumu Hosokawa; Y. Shibata; K. Suyama; Mayuko Okabe

BACKGROUND FOLFIRI and FOLFOX have shown equivalent efficacy for metastatic colorectal cancer (mCRC), but their comparative effectiveness is unknown when combined with bevacizumab. PATIENTS AND METHODS WJOG4407G was a randomized, open-label, phase III trial conducted in Japan. Patients with previously untreated mCRC were randomized 1:1 to receive either FOLFIRI plus bevacizumab (FOLFIRI + Bev) or mFOLFOX6 plus bevacizumab (mFOLFOX6 + Bev), stratified by institution, adjuvant chemotherapy, and liver-limited disease. The primary end point was non-inferiority of FOLFIRI + Bev to mFOLFOX6 + Bev in progression-free survival (PFS), with an expected hazard ratio (HR) of 0.9 and non-inferiority margin of 1.25 (power 0.85, one-sided α-error 0.025). The secondary end points were response rate (RR), overall survival (OS), safety, and quality of life (QoL) during 18 months. This trial is registered to the University Hospital Medical Information Network, number UMIN000001396. RESULTS Among 402 patients enrolled from September 2008 to January 2012, 395 patients were eligible for efficacy analysis. The median PFS for FOLFIRI + Bev (n = 197) and mFOLFOX6 + Bev (n = 198) were 12.1 and 10.7 months, respectively [HR, 0.905; 95% confidence interval (CI) 0.723-1.133; P = 0.003 for non-inferiority]. The median OS for FOLFIRI + Bev and mFOLFOX6 + Bev were 31.4 and 30.1 months, respectively (HR, 0.990; 95% CI 0.785-1.249). The best overall RRs were 64% for FOLFIRI + Bev and 62% for mFOLFOX6 + Bev. The common grade 3 or higher adverse events were leukopenia (11% in FOLFIRI + Bev/5% in mFOLFOX6 + Bev), neutropenia (46%/35%), diarrhea (9%/5%), febrile neutropenia (5%/2%), peripheral neuropathy (0%/22%), and venous thromboembolism (6%/2%). The QoL assessed by FACT-C (TOI-PFC) and FACT/GOG-Ntx was favorable for FOLFIRI + Bev during 18 months. CONCLUSION FOLFIRI plus bevacizumab was non-inferior for PFS, compared with mFOLFOX6 plus bevacizumab, as the first-line systemic treatment for mCRC. CLINICAL TRIALS NUMBER UMIN000001396.


Japanese Journal of Clinical Oncology | 2012

Safety, Efficacy and Pharmacokinetics of Neratinib (HKI-272) in Japanese Patients with Advanced Solid Tumors: A Phase 1 Dose-escalation Study

Yoshinori Ito; Mitsukuni Suenaga; Kiyohiko Hatake; Shunji Takahashi; Masahiro Yokoyama; Yusuke Onozawa; Kentaro Yamazaki; Shuichi Hironaka; Kiyoshi Hashigami; Hirotaka Hasegawa; Nobuko Takenaka; Narikazu Boku

OBJECTIVE Neratinib (HKI-272), a potent, irreversible, small-molecule, orally administered, pan-ErbB inhibitor that blocks signal transduction via inhibition of three epidermal growth factor receptors [ErbB1, ErbB2 (Her2) and ErbB4], is being developed for the treatment of solid tumors, including breast cancer. This Phase 1 dose-escalation study assessed the safety, tolerability, maximum-tolerated dose, antitumor activity and pharmacokinetics of neratinib in Japanese patients with advanced solid tumors. METHODS Patients received neratinib 80, 160, 240 or 320 mg orally; each patient enrolled in only one dose cohort. Patients received a single dose in week 1, followed by daily continuous doses. Blood samples collected were on days 1 and 21 for pharmacokinetic analyses. RESULTS Twenty-one patients were enrolled (3 breast cancer; 17 colorectal cancer; 1 gastric cancer). Neratinib-related adverse events (all grades) included diarrhea (20 patients), fatigue (14 patients), nausea and abdominal pain (9 patients each) and anorexia (8 patients). Grade ≥3 neratinib-related adverse events in two or more patients were diarrhea and anorexia (two patients each). Dose-limiting toxicities were diarrhea and anorexia (two patients, 320 mg dose). The maximum-tolerated dose and recommended dose was neratinib 240 mg once daily. Of 21 evaluable patients, 2 with breast cancer had partial response, 3 had stable disease ≥24 weeks, 7 had stable disease ≥16 weeks and 9 had progressive disease. Pharmacokinetic analyses indicated that neratinib exposures increased with dose. CONCLUSIONS The safety, efficacy and pharmacokinetic profiles of neratinib are consistent with those reported for non-Japanese patients and warrant further investigation of neratinib in Japanese patients with solid tumors.


Journal of Gastroenterology | 2002

Carcinoma of duodenum arising from Brunner's gland

Kimishige Akino; Yoshihiro Kondo; Atsumori Ueno; Kentaro Yamazaki; Masayo Hosokawa; Hideki Shimoji; Takeya Adachi; Saho Honda; Shingo Ichiyanagi; Yoshikazu Akahonai; Yasunori Fujisawa; Hiroaki Takahashi; Yoshiaki Arimura; Takao Endo; Kohzoh Imai

Primary carcinoma of the duodenum is a rare lesion. In conjunction with the widespread use of panendoscopy, reported cases of carcinoma of the duodenum have recently increased. Although benign hyperplasia of Brunners gland is well documented, duodenal carcinoma originating in Brunners gland is extremely rare, and, consequently, there is little data on the morphological or histochemical characteristics. We report here a case of early duodenal carcinoma arising from Brunners gland, whose origin was proven by mucin immunohistochemistry.


Japanese Journal of Clinical Oncology | 2010

S-1 Monotherapy as Second-line Treatment for Advanced Pancreatic Cancer after Gemcitabine Failure

Akiko Todaka; Akira Fukutomi; Narikazu Boku; Yusuke Onozawa; Shuichi Hironaka; Hirofumi Yasui; Kentaro Yamazaki; Keisei Taku; Nozomu Machida; Takeshi Sakamoto; Hideharu Tomita

OBJECTIVE No standard salvage chemotherapy regimen has been established for patients with advanced pancreatic cancer after failure of gemcitabine-based treatment. Although a Phase II study of S-1 monotherapy was conducted in patients with gemcitabine-refractory advanced pancreatic cancer, the number of patients enrolled was small. METHODS We retrospectively reviewed 84 consecutive patients who received S-1 monotherapy as a second-line treatment after gemcitabine failure at the Shizuoka Cancer Center between May 2004 and April 2008. The selection criteria in this study were age 20-75 years, ECOG performance status <or=2 and preserved organ functions. S-1 was administered orally twice a day at a dose of 40 mg/m(2) for 28 days, followed by 14-day rest. RESULTS Fifty-two patients were selected for the analysis. Out of the 47/52 patients with measurable lesions, only 2 patients (4%) showed a partial response and 15 patients (32%) showed stable disease. The median progression-free survival was 2.1 months and the median overall survival was 5.8 months, with a 1-year survival rate of 12%. The common grade 3/4 toxicities were diarrhea (8%), anorexia (6%), fatigue (6%), anemia (6%) and leucopenia (4%). CONCLUSIONS S-1 monotherapy is marginally effective and well tolerated in the second-line setting in patients with gemcitabine-refractory advanced pancreatic cancer.


Pancreas | 2011

Risk factors of familial pancreatic cancer in Japan: Current smoking and recent onset of diabetes

Hiroyuki Matsubayashi; Atsuyuki Maeda; Hideyuki Kanemoto; Katsuhiko Uesaka; Kentaro Yamazaki; Shuichi Hironaka; Yuji Miyagi; Hisatomo Ikehara; Hiroyuki Ono; Alison P. Klein; Michael Goggins

Objectives: In western countries, 7% to 10% of patients with pancreatic cancer (PC) have a familial predisposition to their disease. The aim of this study was to determine the familial susceptibility to PC in Japan. Methods: Five hundred seventy-seven patients with PC and 577 age- and gender-matched controls were analyzed for cancer history in their first-degree relative(s) (FDRs) and demographic factors. Results: The patients with PC were more likely to have an FDR with PC (6.9%) than the controls (2.9%; odds ratio [OR], 2.5; P = 0.02). Three patients (0.5%), but none of the controls, had a family history of PC in multiple FDRs. Smoking, especially current smoking (OR, 1.5; P = 0.005), and diabetes mellitus (OR: 1.7, P = 0.001) were also associated with PC. The odds increased up to 10-fold if the patients were positive for these 3 factors. The patients with familial PC were more likely to be current smokers (40%) and to have diabetes mellitus (32.5%) than the sporadic cases (30.1% and 20.1%; OR, 1.6 and 1.9). Conclusions: A family history of PC is a risk of PC in Japan (6.9%) as is a personal history of diabetes and smoking. It is prudent to inform the kindred of patients with familiar PC of the risk of smoking and to follow carefully if they develop diabetes.Abbreviations: PC - pancreatic cancer, FDR - first-degree relative, OR - odds ratio, FPC - familial pancreatic cancer, DM - diabetes mellitus, SIR - standardized incidence rate, IPMN - intraductal papillary mucinous neoplasm, MDCT - multidetector computed tomography, US - ultrasound, NFPTR - National Familial Pancreas Tumor Registry


Cancer Science | 2015

Japanese Society of Medical Oncology Clinical Guidelines: RAS (KRAS/NRAS) mutation testing in colorectal cancer patients

H. Taniguchi; Kentaro Yamazaki; Takayuki Yoshino; Kei Muro; Yasushi Yatabe; Toshiaki Watanabe; Hiromichi Ebi; Atsushi Ochiai; Eishi Baba; Katsuya Tsuchihara

The Japanese guidelines for the testing of KRAS mutations in colorectal cancer have been used for the past 5 years. However, new findings of RAS (KRAS/NRAS) mutations that can further predict the therapeutic effects of anti‐epidermal growth factor receptor (EGFR) antibody therapy necessitated a revision of the guidelines. The revised guidelines included the following five basic requirements for RAS mutation testing to highlight a patient group in which anti‐EGFR antibody therapy may be ineffective: First, anti‐EGFR antibody therapy may not offer survival benefit and/or tumor shrinkage to patients with expanded RAS mutations. Thus, current methods to detect KRAS exon 2 (codons 12 and 13) mutations are insufficient for selecting appropriate candidates for this therapy. Additional testing of extended KRAS/NRAS mutations is recommended. Second, repeated tests are not required for the detection; tissue materials of either primary or metastatic lesions are applicable for RAS mutation testing. Evaluating RAS mutations prior to anti‐EGFR antibody therapy is recommended. Third, direct sequencing with manual dissection or allele‐specific PCR‐based methods is currently applicable for RAS mutation testing. Fourth, thinly sliced sections of formalin‐fixed, paraffin‐embedded tissue blocks are applicable for RAS mutation testing. One section stained with H&E should be provided to histologically determine whether the tissue contains sufficient amount of tumor cells for testing. Finally, RAS mutation testing must be performed in laboratories with appropriate testing procedures and specimen management practices.

Collaboration


Dive into the Kentaro Yamazaki's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar

Narikazu Boku

St. Marianna University School of Medicine

View shared research outputs
Top Co-Authors

Avatar

Hirofumi Yasui

Shiga University of Medical Science

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Kei Muro

Sapporo Medical University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Kensei Yamaguchi

Japanese Foundation for Cancer Research

View shared research outputs
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge