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Dive into the research topics where Masataka Yoshimoto is active.

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Featured researches published by Masataka Yoshimoto.


Cancer | 2006

Ipsilateral breast tumor recurrence (IBTR) after breast-conserving treatment for early breast cancer : Risk factors and impact on distant metastases

Yoshifumi Komoike; Futoshi Akiyama; Yuichi Iino; Tadashi Ikeda; Sadako Akashi-Tanaka; Shozo Ohsumi; Mikihiro Kusama; Muneaki Sano; Eisei Shin; Kimito Suemasu; Hiroshi Sonoo; Tetsuya Taguchi; Tsunehiro Nishi; Reiki Nishimura; Shunsuke Haga; Keiichi Mise; Takayuki Kinoshita; Shigeru Murakami; Masataka Yoshimoto; Hideaki Tsukuma; Hideo Inaji

The clinical features of ipsilateral breast tumor recurrence (IBTR) after breast conserving therapy (BCT) for early stage breast cancer were analyzed from long‐term follow‐up of BCT in Japan. The purpose of this study was to clarify risk factors of IBTR and the impact of IBTR on development of distant metastases in this ethnic group.


Breast Cancer Research and Treatment | 2000

Surgical treatment of hepatic metastases from breast cancer.

Masataka Yoshimoto; Takashi Tada; Mitsue Saito; Kaoru Takahashi; Masujiro Makita; Yoshihiro Uchida; Fujio Kasumi

We have performed a retrospective study to evaluate whether surgical treatment is beneficial in patients with hepatic metastases from breast cancer. Between September 1985 and September 1998, 25 patients with hepatic metastases (14 solitary and 11 multiple), eight of whom had extrahepatic metastases, underwent hepatectomy. All of the detectable liver metastasis were resected in all of the cases. There were no severe postoperative complications. All but one of the patients received adjunctive polychemotherapy after the hepatectomy. After the hepatectomy, recurrent tumors were detected in 18 of the patients, being located in the liver in 12 (67%) of them. Overall, however, hepatectomy ensured that the liver was clinically recurrence-free for a median of 24 months (range 2–132 months). Eleven patients died of recurrent tumors, two died of other causes and the remaining 12 are currently alive. The 2- and 5-year cumulative survival rates after hepatectomy were 71% and 27%, respectively, and the median survival duration was 34.3±3.2 months, much better than the period of 8.5 months for another series of patients treated with standard or non-surgical therapies at our institution. The number and the size of hepatic metastases, the interval between treatment of the primary lesion and hepatectomy, and the existence of extrahepatic metastasis were not adverse prognostic factors. In conclusion, our data, although limited and highly selective, suggest that surgical treatment of hepatic metastases from breast cancer may prolong survival in certain subgroups of patients to a greater extent than standard or non-surgical therapies.


Genes, Chromosomes and Cancer | 1998

Mapping of a new target region of allelic loss to a 2-cM interval at 22q13.1 in primary breast cancer.

Aritoshi Iida; Keisuke Kurose; Rie Isobe; Futoshi Akiyama; Goi Sakamoto; Masataka Yoshimoto; Fujio Kasumi; Yusuke Nakamura; Mitsuru Emi

Allelic losses on chromosome arm 22q are frequently observed in human meningiomas and in carcinomas of the colon, ovary, and breast. Among 140 primary breast cancers we examined for loss of heterozygosity (LOH) at 16 polymorphic loci on the long arm of chromosome 22, 56 (40%) showed LOH for at least one locus. Eleven of these tumors had retained heterozygosity for markers proximal to the NF2 locus but showed LOH for markers distal to NF2. Deletion mapping indicated a new common region of deletion, 2‐cM in extent, at q13.1 between Interleukin 2 receptor β (IL2RB) and D22S279. Our results raise the possibility that one or more tumor suppressor genes associated with breast cancer may exist at 22q13.1. Comparison of these results with clinicohistological data indicated that allelic losses on 22q tend to occur more frequently in tumors of malignant histological types. Genes Chromosomes Cancer 21:108–112, 1998.


Journal of Human Genetics | 2000

Identification of Rad51 alteration in patients with bilateral breast cancer

Masahiro Kato; Ken Ichi Yano; Fumie Matsuo; Hiroko Saito; Toyomasa Katagiri; Hitoshi Kurumizaka; Masataka Yoshimoto; Fujio Kasumi; Futoshi Akiyama; Goi Sakamoto; Hirokazu Nagawa; Yusuke Nakamura; Yoshio Miki

AbstractThe human Rad51 gene, HsRAD51, is a homolog of RecA of Escherichia coli and functions in recombination and DNA repair. BRCA1 and BRCA2 proteins form a complex with Rad51, and these genes are thought to participate in a common DNA damage response path-way associated with the activation of homologous recombination and double-strand break repair. Additionally, we have shown that the pattern of northern blot analysis of the Rad51 gene is closely similar to those of the BRCA1 and BRCA2 genes. It is therefore possible that alterations of the Rad51 gene may be involved in the development of hereditary breast cancer. To investigate this possibility, we screened Japanese patients with hereditary breast cancer for Rad51 mutations and found a single alteration in exon 6. This was determined to be present in the germline in two patients with bilateral breast cancer, one with synchronous bilateral breast cancer and the other with synchronous bilateral multiple breast cancer. In both patients, blood DNAs showed a G-to-A transition in the second nucleotide of codon 150, which results in the substitution of glutamine for arginine. As this alteration was not present in any patients with breast or colon cancer examined, we assume that this missense alteration is likely to be a disease-causing mutation.


World Journal of Surgery | 2005

Hepatic Resection for Metastatic Breast Cancer: Prognostic Analysis of 34 Patients

Yoshihiro Sakamoto; Junji Yamamoto; Masataka Yoshimoto; Fujio Kasumi; Tomoo Kosuge; Norihiro Kokudo; Masatoshi Makuuchi

Liver metastasis of breast cancer is considered a generalized disease, and surgical treatment is rarely discussed. Thirty-four patients who underwent 35 hepatectomies for liver metastases of breast cancer between 1985 and 2003 were analyzed. The median interval between the breast surgery and relapse in the liver was 1.9 years (0–20 years). The liver was the first site of recurrence in 25 patients. Fifteen clinicopathologic factors were evaluated using univariate and multivariate analyses to predict survival after hepatic resection. No patients died because of the surgery. The median survival was 36 months (1 month to 20 years). The overall and disease-free 5-year survival rates after hepatectomy for breast metastases were 21% and 16%, respectively. Four patients survived more than 5 years. The presence of extrahepatic recurrence prior to hepatectomy was the only significant prognostic factor according to the analyses, and the 5-year survival rate of patients without extrahepatic disease was 31%. No patient who had hilar lymph node metastasis survived more than 5 years. In the absence of extrahepatic recurrence, surgical resection of liver metastasis from breast cancer can offer an acceptable prognosis and should not be avoided in selected patients.


Journal of Clinical Oncology | 2009

Oral Uracil and Tegafur Compared With Classic Cyclophosphamide, Methotrexate, Fluorouracil As Postoperative Chemotherapy in Patients With Node-Negative, High-Risk Breast Cancer: National Surgical Adjuvant Study for Breast Cancer 01 Trial

Toru Watanabe; Muneaki Sano; Shigemitsu Takashima; Tomoki Kitaya; Yutaka Tokuda; Masataka Yoshimoto; Norio Kohno; Kazuhiko Nakagami; Hiroji Iwata; Kojiro Shimozuma; Hiroshi Sonoo; Hitoshi Tsuda; Goi Sakamoto; Yasuo Ohashi

PURPOSE The primary aim of this study was to compare the effectiveness of oral uracil-tegafur (UFT) with that of classical cyclophosphamide, methotrexate, and fluorouracil (CMF) given as postoperative adjuvant treatment to women with node-negative, high-risk breast cancer. PATIENTS AND METHODS Women with node-negative, high-risk breast cancer were randomly assigned to receive either 2 years of UFT or six cycles of CMF after surgery. The primary end point was relapse-free survival (RFS). Overall survival (OS), toxicity, and quality of life (QOL) were secondary end points. The hypothesis was that UFT was not inferior to CMF in terms of RFS. RESULTS Between October 1996 and April 2001, a total of 733 patients were randomly assigned to receive either treatment. The median follow-up time was 6.2 years. The RFS rates at 5 years were 88.0% in the CMF arm and 87.8% in the UFT arm. OS rates were 96.0% and 96.2%, respectively. The hazard ratios of the UFT arm relative to the CMF arm were 0.98 for RFS (95% CI, 0.66 to 1.45; P = .92) and 0.81 for OS (95% CI, 0.44 to 1.48; P = .49). The toxicity profiles differed between the two groups. The QOL scores were better for patients given UFT than those given CMF. CONCLUSION RFS and OS with oral UFT were similar to those with classical CMF. Given the higher QOL scores, oral UFT is a promising alternative to CMF for postoperative adjuvant chemotherapy in women with node-negative, high-risk breast cancer.


Cancer | 1998

Allelic Loss on Chromosome 1p Is Associated with Progression and Lymph Node Metastasis of Primary Breast Carcinoma

Kazuhiro Tsukamoto; B S Noriko Ito; Masataka Yoshimoto; Fujio Kasumi; Futoshi Akiyama; Goi Sakamoto; Yusuke Nakamura; Mitsuru Emi

Frequent allelic losses on the short arm of chromosome 1 have been observed in a wide variety of human tumors. Cytogenetic and molecular genetic studies in breast carcinomas have shown frequent alterations on chromosome 1, involving loss of 1p or gain of 1q.


Cancer | 1999

Localization of a tumor suppressor gene associated with the progression of human breast carcinoma within a 1‐cm interval of 8p22–p23.1

Takashi Yokota; Masataka Yoshimoto; Futoshi Akiyama; Goi Sakamoto; Fujio Kasumi; Yusuke Nakamura; Mitsuru Emi

Frequent allelic losses on the short arm of chromosome 8 in several types of human cancers, and deletion maps of this region in tumor DNAs, have suggested that 8p harbors one or more genes that are important for suppressing tumorigenesis in the tissues in question.


British Journal of Cancer | 1997

Localization of a breast cancer tumour-suppressor gene to a 3-cM interval within chromosomal region 16q22.

Aritoshi Iida; R Isobe; Masataka Yoshimoto; Fujio Kasumi; Yusuke Nakamura; Mitsuru Emi

Allelic losses on chromosome 16q in tumour cells are frequent in a variety of malignancies, suggesting the presence of one or more tumour-suppressor genes in the region. Among 210 sporadic breast cancers we examined using 15 microsatellite markers on the long arm of chromosome 16, heterozygosity for at least one locus was lost in 141 (67%). Detailed deletion mapping revealed two distinct commonly deleted regions. One region was defined as a 3-cM interval flanked by markers D16S512 and D16S515 at 16q22; the second consisted of a 9.5-cM interval flanked by markers D16S498 and D16S303 at q24.3. Allelic loss on 16q was observed frequently in small tumours, tumours without lymph node metastasis and tumours of the non-invasive histological type as well as in tumours of more advanced phenotype, suggesting that inactivation of one of at least two tumour-suppressor genes on 16q plays a role in early stage breast carcinogenesis.


Cancer | 1993

Time dependency of the influence of prognostic factors on relapse in breast cancer.

Masataka Yoshimoto; Goi Sakamoto; Yasuo Ohashi

Background. A number of factors concerning the prognosis of cancer patients have been reported, but the evaluation of individual factors is not always consistent. The author considered that the discrepancies may lie in part in that factors may have a changing influence on relapse with time. The present study was intended to reveal the phenomenon and its clinical significance in patients with breast cancer.

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Goi Sakamoto

Japanese Foundation for Cancer Research

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Futoshi Akiyama

Japanese Foundation for Cancer Research

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Takuji Iwase

Japanese Foundation for Cancer Research

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Kaoru Takahashi

Japanese Foundation for Cancer Research

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Masujiro Makita

Japanese Foundation for Cancer Research

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Keiichiro Tada

Japanese Foundation for Cancer Research

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Seiichiro Nishimura

Japanese Foundation for Cancer Research

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