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Dive into the research topics where Shigeyoshi Iwamoto is active.

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Featured researches published by Shigeyoshi Iwamoto.


Lancet Oncology | 2013

Leucovorin, fluorouracil, and oxaliplatin plus bevacizumab versus S-1 and oxaliplatin plus bevacizumab in patients with metastatic colorectal cancer (SOFT): an open-label, non-inferiority, randomised phase 3 trial

Yasuhide Yamada; Daisuke Takahari; Hiroshi Matsumoto; Hideo Baba; Masato Nakamura; Kazuhiro Yoshida; Motoki Yoshida; Shigeyoshi Iwamoto; Ken Shimada; Yoshito Komatsu; Yasutsuna Sasaki; Taroh Satoh; Keiichi Takahashi; Hideyuki Mishima; Kei Muro; Masahiko Watanabe; Yuh Sakata; Satoshi Morita; Yasuhiro Shimada; Kenichi Sugihara

BACKGROUND Studies done in Asia have shown that a regimen of S-1 plus oxaliplatin (SOX) has promising efficacy and safety in patients with metastatic colorectal cancer. We aimed to establish whether SOX plus bevacizumab is non-inferior to mFOLFOX6 (modified regimen of leucovorin, fluorouracil, and oxaliplatin) plus bevacizumab as first-line chemotherapy for metastatic colorectal cancer. METHODS We undertook an open-label, non-inferiority, randomised phase 3 trial in 82 sites in Japan. We enrolled individuals aged 20-80 years who had metastatic colorectal cancer, had an Eastern Cooperative Oncology Group performance status of 0 or 1, had assessable lesions, had received no previous chemotherapy or radiotherapy, could take drugs orally, and had adequate organ function. Eligible patients were randomly assigned (1:1) to receive either mFOLFOX6 plus bevacizumab (on day 1 of each 2-week cycle, 5 mg/kg intravenous infusion of bevacizumab and a simultaneous intravenous infusion of 85 mg/m(2) oxaliplatin, 200 mg/m(2)l-leucovorin, 400 mg/m(2) bolus fluorouracil, and 2400 mg/m(2) infusional fluorouracil) or SOX plus bevacizumab (on day 1 of each 3-week cycle, 7·5 mg/kg intravenous infusion of bevacizumab and 130 mg/m(2) intravenous infusion of oxaliplatin; assigned dose of S-1 twice a day from after dinner on day 1 to after breakfast on day 15, followed by 7-day break). Randomisation was done centrally with the minimisation method, with stratification by institution and whether postoperative adjuvant chemotherapy had been given. Participants, investigators, and data analysts were not masked to treatment assignment. The primary endpoint was progression-free survival (PFS), which was defined as the interval between enrolment and progressive disease (≥20% increase in sum of longest dimensions of target lesions from baseline, or appearance of new lesions) or death, whichever came first. The primary analysis was done by modified intention to treat. This trial is registered with the Japan Pharmaceutical Information Center, number JapicCTI-090699. FINDINGS Between Feb 1, 2009, and March 31, 2011, 512 patients underwent randomisation. 256 patients assigned to receive SOX plus bevacizumab and 255 assigned to receive mFOLFOX6 plus bevacizumab were included in the primary analysis. Median PFS was 11·5 months (95% CI 10·7-13·2) in the group assigned to mFOLFOX6 plus bevacizumab and 11·7 months (10·7-12·9) in the group assigned to SOX plus bevacizumab (HR 1·04, 95% CI 0·86-1·27; less than non-inferiority margin of 1·33, pnon-inferiority=0·014). The most common haematological adverse events of grade 3 or higher were leucopenia (21 [8%] of 249 patients given mFOLFOX6 plus bevacizumab included in safety analysis vs six [2%] of 250 given SOX plus bevacizumab; p=0·0029) and neutropenia (84 [34%] vs 22 [9%]; p<0·0001). Grade 3 or higher anorexia (13 [5%] vs three [1%]; p=0·019) and diarrhoea (23 [9%] vs seven [3%]; p=0·0040) were significantly more common in patients given SOX plus bevacizumab than in those given mFOLFOX6 plus bevacizumab. We recorded seven treatment-related deaths (three in the group given mFOLFOX6 plus bevacizumab; four in that given SOX plus bevacizumab). INTERPRETATION SOX plus bevacizumab is non-inferior to mFOLFOX6 plus bevacizumab with respect to PFS as first-line treatment for metastatic colorectal cancer, and could become standard treatment in Asian populations. FUNDING Taiho.


Diseases of The Colon & Rectum | 2002

Changing Site Distribution of Colorectal Cancer in Japan

Hideho Takada; Tsunehide Ohsawa; Shigeyoshi Iwamoto; Ryo Yoshida; M. Nakano; Seiki Imada; Kazuhiko Yoshioka; Masashi Okuno; Yoshiro Masuya; Kenji Hasegawa; Naoko Kamano; Koshiro Hioki; Tetsuichiro Muto; Yasuo Koyama

AbstractPURPOSE: In North America and other high-risk areas, there has been a proximal shift in the subsite distribution of colorectal cancer. We wanted to determine whether any similar change has occurred in Japan, and where the incidence of this disease has increased sharply. METHODS: Data from the Reports of the Japanese Society for Cancer of the Colon and Rectum were used to analyze the time trend of colorectal cancer in Japan between 1974 and 1994 according to the patients’ age at diagnosis and sex, and the site of the tumor within the colon or rectum. RESULTS: The percentage of patients over the age of 70, especially females, increased. The increase in the percentage of right-sided colon cancer in colorectal cancer cases was accompanied by a continuous decline in the percentage of rectal cancer in both sexes at all ages. In general, the percentage of right-sided colon cancer in colon cancer cases was stable in men, but increased in women. The rate among patients older than 70 years increased in men, but predominated and remained stable in women. No proximal shift in colon cancer was found in either sex under the age of 69. CONCLUSION: These findings indicated that a proximal shift in the subsite distribution of colorectal cancer has occurred in Japan. This rightward shift of colorectal cancer is due to the decreasing proportion of rectal cancer. Furthermore, the increasing proportion of older patients, especially females, may be another major determinant of the changing colon cancer subsite distribution.


Nutrition and Cancer | 1998

Effects of fatty acids on liver metastasis of ACL‐15 rat colon cancer cells

Shigeyoshi Iwamoto; Hideto Senzaki; Yasuhiko Kiyozuka; Eliko Ogura; Hideho Takada; Koshiro Hioki; Airo Tsubura

The effects of eicosapentaenoic acid [EPA; n-3 polyunsaturated fatty acid (PUFA)], linoleic acid (LA; n-6 PUFA), and palmitic acid (PA; saturated fatty acid) on 1,2-dimethylhydrazine-induced F344 rat colon carcinoma cells (ACL-15) were investigated in vivo and in vitro. The number and size of liver metastatic foci via a superior mesenteric vein injection of ACL-15 cells in F344 rats were significantly inhibited in the EPA-treated group compared with the LA-treated group (p < 0.01); the PA-treated animals and those fed commercial rodent chow (standard diet) demonstrated intermediate values. In a dot immunoblotting assay, vascular cell adhesion molecule 1 expression on ACL-15 cells was downregulated by EPA-ethyl ester treatment and upregulated by LA-ethyl ester treatment compared with the untreated control cells, whereas the expression of matrix metalloproteinase 1 and 2 was not influenced by the fatty acid ethyl esters. In a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, EPA-ethyl ester suppressed ACL-15 cell growth in a schedule-dependent manner, and LA-ethyl ester showed schedule-dependent stimulation. In contrast, PA demonstrated no regulatory effect on cell growth at lower concentrations (< or = 5 mg/ml) but concentration-dependent inhibition at higher concentrations. According to our in vivo cell kinetic study, the difference in tumor growth at the metastatic site was due to different tumor cell proliferation rates; the cell loss rate was not altered. Therefore, the inhibitory effect of liver metastasis on ACL-15 cells by EPA can be explained by a decreased ability of tumor cell adhesion to the capillary bed (low expression of vascular cell adhesion molecule 1) and a lower potential of tumor cell proliferation (low mitotic rate) at the secondary site.


Digestive Diseases and Sciences | 2010

Timing of Resection for Synchronous Liver Metastases from Colorectal Cancer

Masaki Kaibori; Shigeyoshi Iwamoto; Morihiko Ishizaki; Kosuke Matsui; Takamichi Saito; Kazuhiko Yoshioka; Yoshinori Hamada; A.-Hon Kwon

BackgroundThis study aimed to compare the surgical outcome and long-term survival between simultaneous and delayed resection of liver metastases from colorectal cancer (LM), and to identify the factors influencing hepatic disease-free survival in patients with synchronous LM.MethodsSeventy-four patients with LM were divided into two groups, i.e., 32 patients who underwent hepatectomy at the time of colorectal surgery (simultaneous group) and 42 patients who underwent delayed liver resection (delayed group).ResultsThe hepatic disease-free survival rates of patients from the delayed group with either ≥3 or <3 liver metastases were significantly better than that of the simultaneous group. Multivariate analysis showed that simultaneous resection was one of three independent prognostic indicators with an influence on hepatic disease-free survival. In 13 of the 42 (31%) patients from the delayed group, new metastatic lesions were found in the same and/or different segments after re-evaluation during the interval between operations. These patients had a higher incidence of poorly differentiated or mucinous adenocarcinoma, shorter interval between procedures, and larger tumors than patients without tumor progression.ConclusionsTumor progression could be recognized and occult metastases were detected during the interval between operations. Delayed resection of synchronous LM may be useful to reduce the risk of rapid recurrence in the remnant liver. Patients with poorly differentiated or mucinous adenocarcinoma and those with larger tumors who undergo delayed liver resection should receive neoadjuvant chemotherapy during the interval between operations.


Japanese Journal of Clinical Oncology | 2011

The Importance of Evaluation of DNA Amplificability in KRAS Mutation Testing with Dideoxy Sequencing using Formalin-fixed and Paraffin-embedded Colorectal Cancer Tissues

Naoko Okayama; Mitsuaki Nishioka; Shoichi Hazama; Kouhei Sakai; Yutaka Suehiro; Masato Maekawa; Junichi Sakamoto; Shigeyoshi Iwamoto; Takeshi Kato; Hideyuki Mishima; Masaaki Oka; Yuji Hinoda

OBJECTIVE We evaluated DNA amplificability to achieve a 100% success rate in KRAS mutation testing with dideoxy sequencing using formalin-fixed and paraffin-embedded colorectal cancer tissue samples obtained from a recent clinical trial. METHODS We evaluated the effects of deparaffinization, formalin fixation or storage time, and amplicon size on the amplificability of DNAs extracted from 19 formalin-fixed and paraffin-embedded colorectal cancer tissue samples. We subjected to KRAS mutation analysis 112 samples from metastatic colorectal cancer patients in 31 hospitals enrolled in a Phase II trial of a second-line FOLFIRI (5-fluorouracil+ leucovorin + irinotecan) + cetuximab regimen. RESULTS Deparaffinization, formalin fixation and storage times did not appear to affect the recovery and amplificability of DNAs. However, amplicon size had a remarkable effect on the amplificability of DNAs. The smaller fragments with a size of ≤278 bp (96-278 bp) were successfully amplified with polymerase chain reaction in all samples tested, whereas the larger fragments with a size of ≥298 bp (298-565 bp) were not amplified. All samples from our clinical trial were successfully analyzed using three sets of primers with the amplicon sizes of 201, 221 and 240 bp, and KRAS mutations in exons 2 and 3 were detected in 49 of the 112 cases (43.8%). CONCLUSIONS These data suggest that the evaluation of DNA amplificability and amplicon size is important for the success of mutation detection tests such as the KRAS test with dideoxy sequencing using formalin-fixed and paraffin-embedded tissue samples in the clinical setting.


Surgery Today | 1999

A solitary fibrous tumor in the perianal region with a 13-year follow-up: Report of a case

Ryo Yoshida; Hideho Takada; Shigeyoshi Iwamoto; Yasunari Uedono; Hiroshi Kawanishi; Kazuhiko Yoshioka; Yasushi Nakane; Koshiro Hioki; Noriko Sakaida; Akiharu Okamura

A case of a solitary fibrous tumor (SFT) of the perianal region in a 62-year-old man is reported herein. The patient had undergone an abdominoperineal excision of the rectum for an anorectal tumor 13 years previously, and had been referred to our hospital for a perineal mass. Computerized tomography and angiography revealed a markedly hypervascular tumor measuring 11×8 cm in size in the pelvic cavity. After preoperative radiotherapy (total 58 Gy) and the embolization of the feeding arteries, he underwent an en bloc excision of the tumor. Microscopically, the tumor was composed of spindle shaped cells with a “patternless” arrangement in a collagenous background. There was immunohistochemical evidence that these cells were strongly positive for CD34, thus suggesting the tumor to be SFT. The previously resected anorectal tumor showed similar histological and immunohistochemical findings. The patient’s recovery was uneventful.


Annals of Oncology | 2015

FOLFIRI plus bevacizumab as second-line therapy in patients with metastatic colorectal cancer after first-line bevacizumab plus oxaliplatin-based therapy: the randomized phase III EAGLE study

Shigeyoshi Iwamoto; Takao Takahashi; Hiroshi Tamagawa; Masato Nakamura; Yoshinori Munemoto; Tatsuya Kato; Taishi Hata; Tadamichi Denda; Yoshitaka Morita; Michio Inukai; Katsuyuki Kunieda; Naoki Nagata; Kiyotaka Kurachi; Kenji Ina; M. Ooshiro; Tatsu Shimoyama; Hideo Baba; Koji Oba; Junichi Sakamoto; Hideyuki Mishima

EAGLE was a randomized, multicenter phase III study which evaluated the superiority of bevacizumab 10 mg/kg plus FOLFIRI compared with bevacizumab 5 mg/kg plus FOLFIRI in patients with mCRC previously treated with first-line bevacizumab plus an oxaliplatin-based regimen. The results suggest that the higher 10 mg/kg dose offers no clear clinical benefit compared with bevacizumab 5 mg/kg in this setting.


Surgery Today | 1999

Malignant hemangioendothelioma of the small intestine: Report of a case

Ryo Yoshida; Hideho Takada; Shigeyoshi Iwamoto; Takashi Mouri; Yasunari Uedono; Hiroshi Kawanishi; Koshiro Hioki; Noriko Sakaida; Akiharu Okamura

A case of malignant hemangioendothelioma (MH) of the small intestine in a 27-year-old woman is reported herein. The patient developed acute abdominal symptoms during investigations for anemia, weight loss, anorexia, and recurrent gastrointestinal bleeding. An emergency laparotomy revealed perforation of a jejumal tumor. The results of a histopathological study of the resected small bowel segment were interpreted as MH with lymph node involvement. Following this case report, a review of the relevant literature on small intestinal MH is presented.


Cancer Medicine | 2016

Retrospective analysis of bevacizumab-induced hypertension and clinical outcome in patients with colorectal cancer and lung cancer.

Aya Nakaya; Takayasu Kurata; Takashi Yokoi; Shigeyoshi Iwamoto; Yoshitaro Torii; Yuichi Katashiba; Makoto Ogata; Madoka Hamada; Masanori Kon; Shosaku Nomura

Bevacizumab(Avastin®), a humanized therapeutic monoclonal antibody that targets vascular endothelial growth factor, is widely used in cancer treatment. Patients who are treated with bevacizumab have an increased risk of developing systemic hypertension. However, the relationship between bevacizumab‐induced hypertension and clinical outcome remains unclear. We aimed to evaluate the effect of bevacizumab‐induced hypertension in terms of prognosis in patients with colorectal cancer and non‐small cell lung cancer. The study included 632 patients, 317 patients with non‐small cell lung cancer and 315 patients with colorectal cancer. All patients were treated with bevacizumab in combination with standard chemotherapy protocols, between April 2007 and December 2014. Blood pressure was measured before each treatment cycle. In the patient group with colorectal cancer, treated with bevacizumab, Grade 2–3 hypertension was present in 27.6%. In hypertensive patients with colorectal cancer, median overall survival was 42.6 months, compared with 20.6 months for normotensive patients in this group (P = 0.00071). In the patient group with non‐small cell lung cancer, treated with bevacizumab, Grade 2–3 hypertension was present in 20.5%. In hypertensive patients with non‐small cell lung cancer, median overall survival was 43.0 months, compared with 26.3 months for normotensive patients in this group (P = 0.00451). Patients who developed hypertension during treatment with bevacizumab for colorectal cancer and non‐small cell lung cancer had significantly prolonged overall survival when compared with normotensive patients. Bevacizumab‐induced hypertension may represent a biomarker for clinical benefit in cancer patients treated with bevacizumab.


Clinical Colorectal Cancer | 2016

A Phase II Study of XELOX and Cetuximab as First-Line Therapy in Patients With KRAS Wild Type Metastatic Colorectal Cancer (FLEET2 Study)

Shoichi Hazama; Hiromichi Maeda; Shigeyoshi Iwamoto; Ho Min Kim; Hiroyoshi Takemoto; Kenji Kobayashi; Junichi Sakamoto; Naoki Nagata; Koji Oba; Hideyuki Mishima

BACKGROUND Despite the comparable clinical benefit of XELOX (capecitabine with oxaliplatin) and FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin), the value of XELOX treatment in combination with cetuximab for metastatic colorectal cancer (mCRC) remains largely unknown. PATIENTS AND METHODS In this clinical trial we evaluated the efficacy and safety of weekly/biweekly cetuximab administration combined with biweekly XELOX in patients with previously untreated v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) wild type mCRC. The primary end point was response rate (RR) with confirmation, and the secondary end points included progression-free survival (PFS), overall survival (OS), disease control rate (DCR), dose intensity, and the safety of the protocol treatment. RESULTS Forty patients who fulfilled the inclusion criteria participated in this study. The median treatment cycle number was 8 and the median dose intensities were 218 mg/m2/wk for cetuximab, 34 mg/m2/wk for oxaliplatin, and 821 mg/m2/d for capecitabine. One patient showed complete response and partial response was observed in 19 patients, giving an overall RR of 50% (95% confidence interval [CI], 33.8%-66.2%). Stable disease was obtained in 13 patients, resulting in a DCR of 82.5% (95% CI, 67.2%-92.7%). The PFS was 6.5 months (95% CI, 3.5-9.6 months), and the OS was 24.3 months (95% CI, 14.9-33.7 months). The safety profile revealed the common Grade 3/4 adverse events to be acneiform eruption (12.5%), peripheral neuropathy (7.5%), and elevated alanine transaminase levels (7.5%). Grade 3/4 thrombocytopenia and neutropenia occurred only in 5.0% and 2.5% of the patients, respectively. Grade 1 hand-foot syndrome (HFS) was not uncommon (20%), whereas Grade 2/3 HFS occurred in only 3 patients (7.5%). No deaths were reported within 30 days of the last dose. CONCLUSION Cetuximab with XELOX showed a confirmed overall RR of 50%, which was within the previously reported range of RR. The safety profile showed an acceptable rate and severity of adverse events. In light of the several advantages of XELOX, including convenience and the reported cost-saving aspects, further study of this combination therapy is warranted.

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Yasushi Nakane

Kansai Medical University

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A-Hon Kwon

Kansai Medical University

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