Search PubMed⌕ Search

Biomedical subjects

Yasuo Miyoshi

Publications and source records attributed to Yasuo Miyoshi.

At least 55 records · Page 3Linked to original sources
PubMed2003

Association of serum estrone levels with estrogen receptor-positive breast cancer risk in postmenopausal Japanese women.

PURPOSE: Several reports have demonstrated the association between high serum estrogens levels and breast cancer risk in postmenopausal women. It is hypothesized that breast cancers arising in postmenopausal women with high serum estrogens levels are more likely to be estrogen receptor (ER)-positive. Thus, we have investigated whether or not high serum estrone (E(1)) levels are associated with ER-positive breast cancer risk in postmenopausal women. EXPERIMENTAL DESIGN: A case-control study was conducted on 71 cases (postmenopausal breast cancer patients) and 73 controls (postmenopausal healthy women). Serum E(1) levels were examined in their association with breast cancer risk after adjustment for the various epidemiological risk factors. In addition, clinicopathological characteristics of breast cancers arising in the women with high E(1) levels were investigated. RESULTS: Women in the high tertile of E(1) levels had a significantly (P < 0.01) increased risk of breast cancer as compared with women in the low tertile [odds ratio (OR), 4.14; 95% confidence interval (CI), 1.44-11.87]. Subset analysis according to the ER status showed that women in the high tertile of E(1) levels had a significantly increased risk for ER-positive breast cancer (OR, 23.79; 95% CI, 3.50-161.59) but not for ER-negative breast cancer (OR, 1.45; 95% CI, 0.41-5.15) as compared with women in the low tertile. Tumor size and lymph node status were not significantly different between women in the high tertile and those in the intermediate and low tertiles. But the frequency of low-histological-grade tumors and ER-positive tumors (88 and 67%, respectively) showed a greater trend toward an increase (P = 0.06 and P = 0.07, respectively) in women in the high tertile than those (69 and 46%, respectively) in the intermediate and low tertiles. In addition, ER levels in ER-positive tumors were significantly (P < 0.05) higher in women in the high tertile (245.3 +/- 37.1 fmol/mg protein) than those in the intermediate and low tertiles (134.0 +/- 31.3 fmol/mg protein). CONCLUSIONS: Postmenopausal women with high serum E(1) levels have a significantly increased risk for ER-positive, but not ER-negative, breast cancer. Breast cancers arising in women with high E(1) levels show a high ER positivity as well as high ER content. Measurement of serum E(1) levels would be clinically useful in the selection of postmenopausal women who can benefit from prophylactic use of tamoxifen because tamoxifen can prevent ER-positive, but not ER-negative, breast cancer.

Aged↗
PubMed2003

High expression of steroid sulfatase mRNA predicts poor prognosis in patients with estrogen receptor-positive breast cancer.

PURPOSE: Prognostic significance of the intratumoral mRNA expression of three enzymes related to in situ estrogen biosynthesis, i.e., aromatase, sulfatase, and 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1), was evaluated in patients with invasive breast cancer. EXPERIMENTAL DESIGN: Aromatase, sulfatase, and 17beta-HSD1 mRNA levels in tumor tissues (n = 181) and normal breast tissues (n = 34) were examined by a quantitative, real-time PCR assay and compared with various clinicopathological factors as well as prognosis. RESULTS: The sulfatase mRNA levels, but not the aromataseor 17beta-HSD1 mRNA levels, were significantly associated with lymph node metastases (P < 0.005), histological grade III (P < 0.001), and poor prognosis (P < 0.005). The association between the sulfatase mRNA and poor prognosis was found to be significant (P < 0.001) only in patients with estrogen receptor (ER)-positive tumors but not in ER negative tumors. In ER-positive tumors, the sulfatase mRNA levels was a significant prognostic factor independent of the lymph node status and histological grade by multivariate analysis. CONCLUSIONS: The sulfatase mRNA levels can serve as a significant, independent prognostic factor only in ER-positive tumors. It is speculated that the up-regulation of sulfatase mRNA levels leads to a high intratumoral estrogen concentration and, thus, an enhanced stimulation of tumor growth through ERs.

17-Hydroxysteroid Dehydrogenases↗
PubMed2002

Influence of adjuvant tamoxifen treatment on bone mineral density and bone turnover markers in postmenopausal breast cancer patients in Japan.

The effect of adjuvant tamoxifen treatment on bone mineral density (BMD) and bone turnover markers was studied in postmenopausal breast cancer patients. The relationship of tamoxifen's effect with the genetic polymorphisms of estrogen receptor (ER)-alpha and ER-beta gene was also studied. Twenty-one postmenopausal breast cancer patients were given tamoxifen (20 mg/day) as the adjuvant treatment after the surgery. BMD of the lumbar supine (dual emission X-rays absorptiometry) and bone resorption (deoxypyridinoline, aminoterminal telopeptide of type I collagen, and carboxyterminal telopeptide of type I collagen) and formation (propeptide of type I procollagen, osteocalcin, and bone-specific alkaline phosphatase) markers were examined at baseline (before the surgery), 6 and 12 months after the start of tamoxifen treatment. Genetic polymorphisms analyzed were TA dinucleotide repeats polymorphism in the promoter region and PvuII and XbaI restriction fragment length polymorphism for the ER-alpha gene and the CA dinucleotide repeats polymorphism in the intron 5 for the ER-beta gene. Tamoxifen significantly increased BMD of the lumbar spine at both 6 (P<0.01) and 12 months (P<0.01) after the start of tamoxifen as compared with that at baseline. The mean percent increase in BMD was 3.3% at 6 months and 2.7% at 12 months. All bone resorption and formation markers significantly decreased at both 6 and 12 months. Among the four genetic polymorphisms studied, only ER-beta CA repeat polymorphism was found to be significantly associated with BMD at 12 months, i.e. BMD of the 21 CA repeats allele carriers was significantly higher than that of the non-carriers (P=0.025). These results suggest that tamoxifen increases BMD of the lumbar supine by reducing the bone turnover in postmenopausal breast cancer patients, and this bone restoring effect of tamoxifen is more marked in ER-beta 21 CA repeats allele carriers than non-carriers.

Age Factors↗
PubMed2002

Mutational analysis of the class I beta-tubulin gene in human breast cancer.

Non-small cell lung cancers have a high incidence of somatic mutations of the beta-tubulin (class I) gene, suggesting involvement in the acquisition of resistance to taxanes, which exert their effects through binding to beta-tubulin. Since taxanes are often used in the treatment of breast cancer, we carried out a mutational analysis of the class I beta-tubulin (GenBank accession AF070600) gene in breast cancer. We paid special attention to the primer design so as not to amplify the pseudogenes. We identified 1 somatic mutation, codon 306 [Arg (CGC) to Cys (TGC)], and 2 genetic polymorphisms, codon 217 [Leu (CTG) to Leu (CTA)] and (C to T) at 57 bases downstream from exon 4. Our results suggest that acquisition of resistance to taxanes is unlikely to be explained by somatic mutations of the class I beta-tubulin gene in most breast cancers. In addition, the overestimation of the incidence of somatic mutations of the class I beta-tubulin gene due to the pseudogenes is discussed.

Base Sequence↗
PubMed2002

High BRCA2 mRNA expression predicts poor prognosis in breast cancer patients.

The prognostic significance of BRCA2 mRNA levels in tumor tissues was studied in sporadic breast cancer patients. BRCA2 mRNA levels were determined by real-time PCR. Histologic grade III tumors showed significantly (p = 0.001) higher BRCA2 mRNA levels (0.828 +/- 0.102 BRCA2/beta-glucuronidase mRNA ratio, mean +/- SE) than histologic grade I and II tumors (0.438 +/- 0.055) and estrogen receptor (ER)-negative tumors (0.773 +/- 0.102) showed a nonsignificant (p = 0.072) trend toward an increase in BRCA2 mRNA levels compared to ER-positive tumors (0.541 +/- 0.079). Other clinicopathologic parameters, such as menopausal status, lymph node status and tumor size, were not significantly associated with BRCA2 mRNA levels. Patients with high BRCA2 mRNA levels showed a significantly (p = 0.006) lower 5-year disease free survival rate (63%) than those with low levels (94%). Lymph node metastases, ER negativity and high histologic grade were also significantly (p < 0.05) associated with poor prognosis. Multivariate analysis revealed that BRCA2 mRNA levels were a significant prognostic factor, being independent of the other conventional prognostic factors. Our results suggest that BRCA2 mRNA levels might serve as a clinically useful prognostic factor in breast cancer patients.

BRCA2 Protein↗
PubMed2002

Molecular classification of primary breast tumors possessing distinct prognostic properties.

The natural progression of breast cancer differs greatly between patients; the precise prediction of this disease course will improve the efficacy of therapeutics. Gene expression profiling may elucidate the undiscovered biological variations between seemingly similar cancers, leading to a new cancer classification system valuable in accurate diagnosis. The expression levels of 2412 genes, derived from 98 cancer samples, were precisely recorded by a high throughput RT-PCR technique, adapter-tagged competitive PCR. Subsequent cluster analysis revealed a molecular profile, correlating with estrogen receptor levels and the presence of lymph node metastases. We analyzed 301 cancer samples for the expression patterns of 21 genes critical in this categorization. The classification of the samples into three major groups was verified utilizing principal component analysis. This molecular classification system correlated significantly with early recurrence, independent of lymph node status. This malignant potential is associated with the expression levels of a group of genes, which comprise a set of candidates potentially useful in diagnostic prediction. These genes and the associated control mechanisms may also be effective therapeutic targets.

Breast Neoplasms↗
PubMed2002

Prediction of response to docetaxel by CYP3A4 mRNA expression in breast cancer tissues.

We studied the relationship between response of breast cancer to docetaxel (DOC) or cylophosphamide + epirubucin (CE) treatment and CYP3A4 mRNA expression in breast tumors. CYP3A4 inactivates DOC but not E, which is a predominant effector in CE treatment. Twenty patients with locally advanced breast tumors and 18 patients with locally recurrent tumors underwent tumor biopsy before chemotherapy, and CYP3A4 mRNA expression levels in tumor tissues were assayed by real-time quantitative polymerase chain reaction. Twenty-three patients were treated with DOC (60 mg/m(2) q3w) and 15 patients were treated with CE (C 600 mg/m(2) and E 60 mg/m(2) q3w). Patients with low CYP3A4 mRNA levels (n = 14) exhibited a significantly (p < 0.01) higher response rate (71%) to DOC treatment than those (n = 9) with high CYP3A4 mRNA levels (response rate, 11%). Positive predictive value, negative predictive value and diagnostic accuracy of CYP3A4 mRNA levels in the prediction of response to DOC were 71, 89, and 78%, respectively. However, no significant association was observed between CYP3A4 mRNA expression and response to CE treatment. These results suggest that intratumoral CYP3A4 mRNA levels might be useful as a predictor of response to DOC treatment, but not to CE treatment, in breast cancer patients. The increased inactivation of DOC by CYP3A4 in tumor tissues may play some role in the acquisition of resistance to DOC.

Adult↗
PubMed2002

Adjuvant hormonal therapy.

Recently, the guidelines for adjuvant hormonal therapy for primary breast cancer were presented at the National Institute of Health Consensus Development Conference in November 2000 and at the 7th International Conference on Adjuvant Therapy of Primary Breast Cancer in February 2001. Adjuvant hormonal therapy should be offered basically to all patients with tumors expressing estrogen receptor (ER) and/or progesterone receptor (PR), assessed by immunohistochemistry. The consensus statements recommended 5 years of tamoxifen as standard hormonal therapy for both premenopausal and postmenopausal patients with ER and/or PR positive tumors. Ovarian ablation or suppression of ovarian function combined with tamoxifen is a treatment of choice for premenopausal patients with high-risk endocrine-responsive tumors. The selection of hormonal therapies and their combination with chemotherapy should be decided according to the assessment of risk of relapse, side effects, and patients' condition and preference.

Antineoplastic Agents, Hormonal↗
PubMed2002

Overview: video-assisted breast surgery.

Since 1992, video-assisted surgery for the breast has been developed mainly in the field of plastic surgery, notably in breast augmentation surgery. Today, video-assisted surgery, indicating partial or total endoscopic surgery, can be performed for the treatment of both benign and malignant breast tumors to improve the cosmetic outcome. Although, in some respects, this kind of surgery for malignant tumors is still experimental, it is feasible enough for clinical use, and is expected to become one of the standard operations for breast cancer.

Breast Neoplasms↗
PubMed2002

[Genetic test and prophylactic treatment in breast cancer families].

Fifteen (13.3%) and 21 (18.6%) deleterious germline mutations were identified in BRCA1, and BRCA2 genes among 113 Japanese breast cancer families. We found a BRCA1 codon 63 (nucleotide 307) nonsense mutation and a 4-bp deletion at codon 1858 (nucleotide 5802) of BRCA2 in 4 and 7 independent families, respectively. Haplotype analysis has revealed that these two mutations were founder mutations. Lifetime risk of breast cancer in BRCA1 or BRCA2 mutation carriers was estimated at nearly 80%, and that of ovarian cancer in BRCA1 mutation carriers was about 40%. A questionnaire survey as to the genetic testing (BRCA1 and BRCA2) and prevention was carried out with 146 healthy women (hospital workers or medical students) and 84 breast cancer patients. About 80% of healthy women as well as breast cancer patients responded positively to the genetic testing, based on the assumption their's was a breast cancer family, and about 20% of each group answered that they would opt for prophylactic mastectomy and oophorectomy if they were found to be germline mutation carriers. These results indicate that genetic testing and prophylactic surgery would be acceptable among a considerable number of Japanese women, and seem to support the establishment an infrastructure for genetic testing in Japan.

Adult↗
PubMed2002

High expression of Wilms' tumor suppressor gene predicts poor prognosis in breast cancer patients.

PURPOSE: The prognostic significance of the Wilms' tumor suppressor gene(WT1) mRNA expression was evaluated in patients with invasive breast cancer. EXPERIMENTAL DESIGN: WT1 mRNA expression in tumor tissues (n = 99) was examined by a quantitative, real-time PCR assay. RESULTS: No significant association was observed between WT1 mRNA levels and clinicopathological parameters such as menopausal status, tumor size, lymph node status, histological grade, and estrogen receptor status. Five-year disease-free survival rate of patients with high WT1 mRNA levels (62.6%) was significantly (P < 0.05) poorer than those with low WT1 mRNA levels (77.2%). Lymph node metastasis (P < 0.05), high histological grade (P < 0.01), and estrogen receptor negativity (P < 0.05) were also significantly associated with poor prognosis, respectively. Multivariate analysis revealed that WT1 mRNA levels were a significant prognostic factor, independent of the other conventional prognostic factors. CONCLUSIONS: These results suggest that measurement of WT1 mRNA levels in tumor tissues might be useful as a new prognostic factor in breast cancer patients.

Adult↗
PubMed2002

[Application of endoscopic surgery for breast cancer treatment].

Endoscopic breast surgery has the advantage that it can be performed from a small, inconspicuous incision remote from the lesion. The cosmetic outcome is an important factor in the selection of the surgical technique as in addition to the oncologic effect on breast cancer. From this point of view, endoscopic partial mastectomy should be performed in patients with small tumors, especially those located in the upper quadrants. The approach should be selected for each case considering the size and location of the tumor. For patients with multiple tumors or with tumors accompanied by extended intraductal components, endoscopic total glandectomy or subcutaneous mastectomy with breast reconstruction is a good choice. Patients with a tumor located near the skin or invading the skin are not candidates for endoscopic surgery. Endoscopic axillary dissection is still controversial in its advantages compared with conventional surgery. To avoid surgical complications and an increase in the local failure rate of breast cancer, selection of patients and the surgical technique must be considered carefully.

Breast Neoplasms↗
PubMed2001

Combined hepatocellular/cholangiocellular carcinoma with sarcomatoid features: genetic analysis for histogenesis.

The histogenesis of sarcomatoid transformation in hepatocellular carcinomas (HCCs) and cholangiocellular carcinomas (CCCs) remains unclear. In the current case, microsatellite loss of heterozygosity (LOH) assay and mutational analysis of the p53 gene with immunohistochemical examination were performed to investigate the histogenesis of each component. The tumor was composed of two parts: one part comprised poorly differentiated HCC (HCC portion), while the other part included undifferentiated, sarcomatoid HCC and CCC (combined portion). LOH at D8S555 was detected in both portions. 1-bp cytosine was deleted at codon 241 of exon 7 of the p53 gene in the combined portion. Immunohistochemically, p53 accumulated in the nuclei of undifferentiated, sarcomatoid HCC and CCC cells, suggesting that the p53 gene mutation might be common in these components. These results support the hypothesis that undifferentiated, sarcomatoid HCC and CCC could be offspring from the original HCC.

Journal Article↗
PubMedDate not supplied

Acceleration of chromosomal instability of BRCA1-associated hereditary breast cancers by p53 abnormality.

Chromosomal instability (CIN) of BRCA1-associated hereditary breast cancers was studied by fluorescence in situ hybridization of chromosomes 1, 11, and 17. CIN values (the percentage of cells with a nonmodal chromosome) were obtained for each of three chromosomes, and their average was finally used as the CIN value of the sample. BRCA1-associated tumors showed a significantly (p = 0.0089) higher CIN value than normal breast tissues (24.3 +/- 4.3, n = 7, vs. 9.2 +/- 1.1, n = 6, mean +/- SE). In addition, BRCA1-associated tumors with positive p53 immunostaining showed a significantly (p = 0.0018) higher CIN value than those with negative p53 immunostaining (35.7 +/- 3.5, n = 3, vs. 15.8 +/- 1.3, n = 4). These results demonstrate that a loss of BRCA1 function results in the growth of breast cancers with CIN, and this phenotype is further accelerated by p53 abnormality.

Adult↗
PubMedDate not supplied

Breast cancer risk associated with CYP1A1 genetic polymorphisms in Japanese women.

Although several reports are available on the association between CYP1A1 polymorphisms and breast cancer risk in Caucasian women, it has never been reported in Japanese women. Since breast cancer incidence and clinicopathologic features of breast cancers are different between Japanese and Caucasian women, it is conceivable that the risk factors of breast cancer might also differ. In addition, a preliminary study has shown that the frequencies of the variant allele in the CYP1A1 gene are different among ethnic groups. Therefore, in the present study, we investigated the association of CYP1A1 polymorphisms with breast cancer risk in Japanese women. The association of two CYP1A1 polymorphisms, that is, 3' noncoding region (6235(T/C)) and codon 462 (Ile/Val), with breast cancer risk was analyzed by a case-control study (195 cases and 272 controls). Variant allele 6235C carriers at the 3' noncoding region polymorphism showed a significantly (p < 0.01) reduced breast cancer risk (odds ratio 0.60; 95% CI 0.41-0.88) as compared with noncarriers, and variant allele 462Val carriers at the codon 462 polymorphism also showed a significantly (p < 0.05) reduced risk (odds ratio 0.66; 95% CI 0.45-0.96) as compared with noncarriers. The relationship between the genetic polymorphisms and clinicopathologic characteristics of breast cancers was also investigated. Variant allele 6235C carriers showed a significantly (p < 0.02) higher positivity of lymph node metastasis than noncarriers (54% versus 36%), and tumors measuring less than 2 cm were significantly (p < 0.03) more frequently observed in variant allele 462Val carriers than noncarriers (50% versus 33%). These results suggest that the CYP1A1 polymorphisms would be useful for predicting breast cancer risk as well as some tumor characteristics in Japanese women.

Adult↗
PubMedDate not supplied

Preoperative evaluation of residual tumor extent by three-dimensional magnetic resonance imaging in breast cancer patients treated with neoadjuvant chemotherapy.

The purpose of this study was to evaluate the usefulness of three-dimensional magnetic resonance imaging (3D MRI) for the preoperative assessment of residual tumor extent in breast cancer patients treated with neoadjuvant chemotherapy (NAC). Thirty-eight breast cancer patients treated with NAC containing taxane and/or anthracycline for 3-6 months were enrolled in this study. Tumor size was measured by means of calipers, ultrasonography, and dynamic MRI before and after NAC. Three-dimensional maximum intensity projection MRIs to measure the tumor size were created for every case. The tumor size determined by calipers, ultrasonography, and 3D MRI after NAC was compared with that determined by pathologic examination. The tumor size determined by 3D MRI showed a strong correlation with that determined by pathologic examination (r = 0.896). Moderate, but significant correlations were found between measurements obtained with calipers and pathology (r = 0.554), and between ultrasonography and pathology (r = 0.484). The response rates to NAC were estimated at 84.2% with calipers, 58.0% with ultrasonography, and 44.7% with 3D MRI. Calipers and ultrasonography thus tended to overestimate the response to NAC compared to 3D MRI (p < 0.001 and 0.240, respectively). Three-dimensional MRI can visualize residual tumor extent after NAC more accurately than calipers and ultrasonography, and seems to be more reliable than other modalities for estimating response to NAC. It should also help surgeons with decision making for breast-conserving surgery after NAC.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

uPA receptor expression in benign and malignant thyroid tumors.

BACKGROUND: Urokinase type plasminogen activator receptor (uPAR) plays an important role in cancer invasion and metastasis. However, the uPAR expression has been rarely investigated in thyroid carcinomas. The aim of this study was to evaluate the clinical relevance of uPAR in thyroid tumors. MATERIALS AND METHODS: Samples included 53 benign tumors (follicular adenoma 34, Graves' disease 8, adenomatous goiter 7 and others 4) and 62 cancers (papillary thyroid cancer (PTC) 47, follicular TC (FTC) 5, medullary TC (MTC) 5 and anaplastic TC (ATC) 5). uPAR expression was prospectively investigated with a labeled streptavidin-biotin method using an anti-uPAR monoclonal antibody. Patients were classified into a low- and high-staining group according to the percentage of positive cells (cut-off value=10%). RESULTS: uPAR was more strongly expressed in thyroid cancers (35.5%) than benign tumors (7.5%). FTC had a significantly higher uPAR expression compared to follicular adenoma (p<0.01). The positivity of uPAR was as follows: PTC 36.2%, FTC 60%, MTC 0% and ATC 40%. In PTC, high uPAR expression was associated with poorly-differentiated PTC (p<0.01) while had a trend to develop more distant metastases than those with low uPAR expression (p=0.17, by the Kaplan-Meier method). CONCLUSION: This study has shown that uPAR expression might be useful for the discrimination between FTC and follicular adenoma and could possibly be used as a prognostic factor in PTC.

Adenocarcinoma, Follicular↗