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Featured researches published by Naohiro Koyasaki.


Breast Cancer Research and Treatment | 1991

Breast deformity, its correction, and assessment of breast conserving surgery

Masakuni Noguchi; Yasuo Saito; Yusuke Mizukami; Akitaka Nonomura; Nagayoshi Ohta; Naohiro Koyasaki; Takao Taniya; Itsuo Miyazaki

A combination of quadrantectomy, axillary dissection, and radiotherapy (QUART) is the regimen most favored by Japanese surgeons among a variety of breast conserving therapies currently available against breast cancer. Unfortunately, extensive resections such as quadrantectomy often give poor local cosmetic results in patients with small breasts. With the aim of improving the cosmetic aspect after an extensive resection, immediate transposition of the latissimus dorsi muscle (LDM) was carried out in breast conserving surgery. To date, twenty-one patients have been entered in this study. Post-quadrantectomy breast deformity was not corrected in six patients including one with bilateral breast cancers, but was corrected by transposition of a part of LDM in 14 other patients. In the last patient, who also had bilateral breast cancers, the right breast was treated by QUART and the left breast by subcutaneous mastectomy followed by transposition of LDM. The cosmetic outcome for these patients was assessed both subjectively and objectively; the objective assessment used a Moire topography camera. The postoperative appearance and topography revealed a satisfactory symmetry of breasts in the transposed patients, especially those with small breasts, when compared with non-transposed patients. It may be concluded that the transposition of LDM is useful in preventing breast deformity following an extensive resection in breast conserving surgery.


Cancer | 1992

C-erbB-2 oncoprotein expression Versus internal mammary lymph node metastases as additional prognostic factors in patients with axillary lymph node-positive breast cancer

Masakuni Noguchi; Naohiro Koyasaki; Nagayoshi Ohta; Hirohisa Kitagawa; Mitsuharu Earashi; Michael Thomas; Itsuo Miyazaki; Yuji Mizukami

The relationship was assessed between c‐erbB‐2 oncoprotein expression and other prognostic factors in breast cancer, such as axillary and internal mammary node metastases. The value of these indicators was analyzed in estimating prognosis, especially in patients with axillary node‐positive breast cancer. These results showed that c‐erbB‐2 is significantly related to clinical stage and axillary node metastases. A univariate study revealed that disease‐free and overall survival were correlated significantly with clinical stage, tumor size, axillary and internal mammary node metastases, and 21N status. Among the patients with axillary node involvement, however, 21N status did not appear to be a significant additional prognostic factor. Internal mammary node metastases were significant. In a multivariate study, only axillary and internal mammary node metastases were significant prognostic factors for either the entire group of patients or those with positive axillary nodes. Therefore, axillary node dissection and biopsy of the internal mammary nodes may provide important prognostic information for patients with breast cancer.


Cancer | 1991

Reappraisal of internal mammary node metastases as a prognostic factor in patients with breast cancer

Masakuni Noguchi; Nagayoshi Ohta; Naohiro Koyasaki; Takao Taniya; Itsuo Miyazaki; Yuji Mizukami

Clinical, histologic, and biologic prognostic factors were examined in 144 patients with invasive breast cancer. It was determined whether variable prognostic factors, especially internal mammary lymph node metastases, would serve as a basis for the prognosis of breast cancer. In a univariate study, overall survival was significantly correlated with tumor size, axillary lymph node status, axillary and internal mammary lymph node metastases, and DNA ploidy status. Especially among patients with one to three positive axillary nodes, survival in case of internal mammary involvement were significantly lower than without internal mammary involvement. In a multivariate study, only axillary and internal mammary lymph node metastases were recognized as important, independent prognostic factors of survival, but neither axillary lymph node status nor DNA ploidy status appeared as important prognostic factors. It was concluded that internal mammary lymph node metastases is additional prognostic factor, especially in patients with one to three positive axillary nodes. Because axillary and internal mammary lymph node metastases could not be predicted from their clinical assessment, axillary lymph node dissection and biopsy of internal mammary nodes may be a useful staging procedure for these patients.


Breast Cancer Research and Treatment | 1991

Lymph node metastases versus DNA ploidy as prognostic factors for invasive ductal carcinoma of the breast

Masakuni Noguchi; Takao Taniya; Nagayoshi Ohta; Naohiro Koyasaki; Itsuo Miyazaki; Yuji Mizukami

We evaluated the relationship between the DNA ploidy status and other variable prognostic factors, especially regional lymph node metastases, in 121 patients with invasive ductal carcinoma of breast, together with the value of these factors in estimating the prognosis of breast cancer. The ploidy status was diploid in 40% of the patients, and aneuploid in 60%. A significantly higher incidence of aneuploidy was found in patients with more than 4 positive axillary lymph nodes, positive internal mammary lymph nodes, or clinical stage 3 of malignancy. In a univariate study, overall survival and disease-free survival were significantly correlated with axillary and internal mammary lymph node metastases, tumor size, and clinical stage of malignancy. The disease-free survival rates for the diploid group tended to be somewhat higher than those for the aneuploid group of patients without axillary lymph node metastases. In the multivariate analysis, however, only axillary lymph node metastasis was significantly correlated with overall survival and disease-free survival. There was also a trend for the internal mammary lymph node metastases to be correlated with survival. As the DNA ploidy status was closely correlated with the axillary and internal mammary lymph node metastases, it did not appear to be an independent prognostic factor in this small series.


Surgery Today | 1991

A multivariate study of the relationship between regional lymph node metastases and prognosis in patients with operable breast cancer

Masakuni Noguchi; Takao Taniya; Naohiro Koyasaki; Nagayoshi Ohta; Itsuo Miyazaki

In order to evaluate the prognostic importance of clinical and histological node information, we made univariate and multivariate analyses of regional lymph node metastases in 223 patients with operable breast cancer who were surgically treated from 1973 to 1985. Clinical axillary node status, histological involvement of the axillary lymph nodes, their anatomical levels and numbers, and histological involvement of the internal mammary lymph nodes were selected as evaluating prognostic factors. The histological presence or absence of axillary node involvement, especially at the distal level, proved to be the most important prognostic factor. However, neither the anatomical level nor the number of histologically involved axillary lymph nodes appeared to be an important prognostic factor. On the other hand, histological involvement of the internal mammary nodes appeared to be an important and independent prognostic factor. Therefore, we concluded that axillary lymph node dissection with a biopsy of the internal mammary nodes would provide more accurate information about the prognosis of patients with operable breast cancer.


Molecular and Cellular Endocrinology | 1993

Influence of hormones on tumor growth, cell kinetics, estrogen receptor and insulin-like growth factor-I-related protein of human breast cancer (MCF-7) cells transplanted in nude mice

Masakuni Noguchi; Michael Thomas; Naohiro Koyasaki; Nagayoshi Ohta; Takao Taniya; Hirohisa Kitagawa; Itsuo Miyazaki; Yusuke Mizukami

The influence of estrogens and tamoxifen on estrogen receptor (ER)-positive human breast cancer (MCF-7) cells transplanted into athymic nude mice was investigated. The mice were divided into the following three groups: (1) an E2 group with mice receiving 17 beta-estradiol dipropionate; (2) a TAM group with mice receiving tamoxifen; (3) a control group with mice given no hormone. (1) Tumor growth was significantly increased in the E2 group, but significantly decreased in the TAM group compared to control; (2) the tumor contents of insulin-like growth factor-I (IGF-I) and the rate of IGF-I-positive cells were significantly lower in the E2 group, but significantly higher in the TAM groups compared to control; (3) the IGF-I-positive cell rates were in significant inverse correlation with the [3H]thymidine-labeled cell rates in the E2, TAM and control groups. Thus, the tumor contents of IGF-I and the rate of IGF-I-positive cells were inversely correlated to the tumor growth and the [3H]thymidine-labeled cell rate in this in vivo study, although IGF-I is known to be a mitogen for breast cancer cells in vitro. Further studies are necessary to answer the questions as to the in vivo roles of immunoreactive IGF-I in ER-positive breast cancer.


Japanese Journal of Cancer Research | 1991

Effects of Hormones on Tumor Growth and Immunoreactive Insulin–like Growth Factor–1 of Estrogen Receptor–positive Human Breast Cancer (MCF‐7) Transplanted in Nude Mice

Masakuni Noguchi; Naohiro Koyasaki; Itsuo Miyazaki; Yuji Yuji

The effects of estrogens and tamoxifen were analyzed on estrogen receptor–positive human breast cancer (MCF–7) transplanted into athymic nude mice. It was found that (1) the tumor growth and the proportion of 3H–thymidine –labeled cells were significantly increased in the 17β– estradiol dipropionate (E2) group, but significantly decreased In the tamoxifen (TAM) group with respect to the control group, and (2) the tumor content of insulin–like growth factor–1 (IGF–1) and the rate of IGF–1–positive cells were significantly lower in the E2 group, but significantly higher in the TAM group than in the control group. It was concluded that the tumor content of IGF–1 and the proportion of IGF–I–positive cells were inversely correlated to the tumor growth and the 3H–thymidine labeling index in vivo,


Surgery Today | 1992

The relationship between lymph node metastases and DNA-ploidy status as prognostic factors in invasive breast cancer

Masakuni Noguchi; Nagayoshi Ohta; Naohiro Koyasaki; Takao Taniya; Itsuo Miyazaki; Yuji Mizukami

We evaluated the relationship between the regional lymph node metastases and the DNA ploidy status in 207 patients with invasive breast cancer, as well as their prognostic values in estimating the prognosis of breast cancer. A significantly higher incidence of aneuploidy was found in patients with a large T3 or T4 tumor, a positive axillary lymph node status, more than 4 positive axillary lymph nodes or positive internal mammary lymph nodes. In a univariate study, the overall survival was significantly correlated with tumor size, axillary lymph node status, axillary and internal mammary lymph node metastases, and DNA ploidy status. In the multivariate analysis, however, only axillary and internal mammary lymph node metastases were recognized as important independent prognostic factors on survival. In this series, the DNA ploidy status did not appear to be an independent prognostic factor either in the entire series or in negative axillary node patients, since it was closely correlated with the axillary or internal mammary lymph node metastases, and the axillary node negative patients had an extremely favorable prognosis.


Archives of Surgery | 1993

Internal mammary nodal status is a more reliable prognostic factor than DNA ploidy and c-erb B-2 expression in patients with breast cancer.

Masakuni Noguchi; Naohiro Koyasaki; Nagayoshi Ohta; Hirohisa Kitagawa; Mitsuharu Earashi; Michael Thomas; Itsuo Miyazaki; Yuji Mizukami


Cancer Research | 1991

Effects of the prostaglandin synthetase inhibitor indomethacin on tumorigenesis, tumor proliferation, cell kinetics, and receptor contents of 7,12-dimethylbenz(a)anthracene-induced mammary carcinoma in Sprague-Dawley rats fed a high- or low-fat diet.

Masakuni Noguchi; Takao Taniya; Naohiro Koyasaki; Takeo Kumaki; Itsuo Miyazaki; Yuji Mizukami

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