Biomedical subjects

Seigo Nakamura

Publications and source records attributed to Seigo Nakamura.

7 recordsLinked to original sources

PubMed2025

Image-guided biopsy of breast lesions-when to use what biopsy technique.

In recent years, minimally invasive diagnostic options for breast lesions have expanded, but consensus on optimal biopsy techniques and imaging combinations remains lacking. This study, driven by an adapted RAND-UCLA Appropriateness Method and insights from eight experts in breast biopsy from across the world, aims to create consensus for selecting biopsy techniques. Highlighted findings suggest Vacuum-Assisted Biopsy (VAB) for lesions visible exclusively at mammography/tomosynthesis (with or without contrast enhancement) or MRI. Core-needle biopsy (CNB) takes precedence for masses over 5 mm visible under US. The selection of other biopsy techniques during US-guided procedures depends on lesion type, size, and sampling indication. VAB is preferred for smaller masses (< 5 mm), complex cystic and solid lesions with small solid parts, small intraductal masses, architectural distortions, and calcifications visible on US. In re-biopsy scenarios for inconclusive findings or high-risk lesions, the panel suggests two VAB extensions: Extended Vacuum-Assisted Biopsy (EVAB) for unambiguous lesion classification and Vacuum-Assisted Excision (VAE) for complete lesion removal. Furthermore, the panel provides detailed input on how to handle specific cases, such as re-biopsy for lobular neoplasia, flat epithelial atypia and atypical ductal hyperplasia. Surgical excision is advised for DCIS and benign or borderline phyllodes tumors found through initial CNB or VAB. In conclusion, an international expert group formulated recommendations on diagnostic breast biopsies under image guidance, aiming to ensure accurate diagnosis worldwide by providing practical advice on needle selection and biopsy approach. KEY POINTS: Evidence-based literature on the preferred biopsy technique and imaging combination for the diagnosis of breast lesions is sparse, and a general consensus is not available. The selection of biopsy technique for different image-guided procedures depends on lesion type, size, and sampling indication. This international expert panel consensus statement addresses standard approaches for varying biopsy indications.

Breast cancer↗

PubMed2003

Long-term results of breast-conserving treatment for early-stage breast cancer in Japanese women from multicenter investigation.

BACKGROUND: Although many clinical data regarding breast-conserving treatment have already been reported from European and North American countries, few clinical data with long-term follow-up have been reported from Japan. METHOD: We collected information on therapeutic and possible or developed prognostic factors and follow-up data for Japanese women who had received breast-conserving treatment consisting of wide excision of the primary tumor, axillary dissection and radiotherapy for unilateral breast cancer considered suitable for breast-conserving treatment from 18 Japanese major breast cancer treating hospitals; 1561 patients were registered. RESULTS: The median follow-up period was 77 months. Five-year disease-free and overall survival rates were 89.4 and 95.9%, respectively. The 5-year local recurrence-free rate was 96.3%. The patients with histologically positive margins (P < 0.0001) or estrogen receptor negative tumor (P = 0.0340) or younger than 40 years old (P < 0.0001) developed statistically significantly more local recurrences. Adjuvant endocrine therapy was essential for the estrogen receptor positive patients to have a lower local recurrence rate. Endocrine therapy did not change the local recurrence rate among estrogen receptor negative patients at all. Multivariate analysis showed histological margin status and the combination of estrogen receptor status and endocrine therapy were independent prognostic factors for local recurrence. CONCLUSION: The 5-year local recurrence rate of Japanese breast cancer patients who were treated with breast-conserving treatment using radiotherapy was 3.7%. Independent prognostic factors for local recurrence were histological margin status and the combination of estrogen receptor status and adjuvant endocrine therapy.

Adult↗

PubMed2002

Efficacy of 3D-MR mammography for breast conserving surgery after neoadjuvant chemotherapy.

BACKGROUND: One of the main roles of neoadjuvant chemotherapy for breast cancer is to shrink large tumors to increase patient eligibility for breast conserving surgery. Three dimensional MR Mammography (3D-MRM) can detect tumor extension more accurately compared with mammography and Ultrasonography (US). Therefore, the shrinkage pattern observed on 3D-MRM was analyzed with regard to several pathological factors. METHODS: A total of 27 breast cancer cases were examined by 3D-MRM before and after neoadjuvant chemotherapy. The volume reduction and shrinkage patterns were assessed and compared with the pathological diagnosis. RESULTS: There were two shrinkage patterns. Twelve of 25 evaluable breast cancers (48%) showed a concentric shrinkage pattern while 13 cases (52%) showed a dendritic shrinkage pattern. The cases with concentric shrinkage were good candidates for breast conserving surgery, But tumors showing dendritic shrinkage often had positive margins necessitating mastectomy. Pathologically, tumors with a papillotubular pattern, Estrogen receptor (ER) positivity, low nuclear grade and c-erbB 2 negativity tended to show dendritic shrinkage. CONCLUSIONS: 3D-MRM is a useful modality for evaluating whether breast conserving surgery can be safely done in the neoadjuvant setting.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed2002

3D imaging of intraductal spread of breast cancer and its clinical application for navigation surgery.

BACKGROUND: To perform optimal tumor resection of breast cancer, preoperative information concerning intraductal spread of cancer (ISC) is very important. METHODS: To detect ISC, three-dimensional (3D) imaging methods including helical CT, MRI, and ultrasound were examined in patients with primary breast cancer by comparison with multi-sliced pathological specimens. RESULTS: The sensitivity of each modality for detecting ISC was 64.7%, 90.2% and 78.6%, and the specificity was 97.1%, 62.9% and 100%, respectively. Subsequently, the potential of each modality for navigation in breast conserving surgery was assessed. Three-dimensional helical CT navigation could reduce the positive rate of the specimen margins, and 3D MRI navigation using a special mapping sheet enabled removal of non-palpable breast cancer without positive margins in 66.7% of patients preliminarily. Real-time 3D ultrasound images correlated with the resected tumor size, with the difference between the two less than 2 cm in 72.7 % of the patients with ISC. CONCLUSION: Three-dimensional images from each modality were reliable enough for diagnosis of tumor spread, and surgical navigation using these images seemed to have potential clinical application for breast conserving surgery. Prospective studies for navigation surgery with more patients are needed.

Breast Neoplasms↗

PubMed2002

Distribution of alpha-1 adrenoceptor subtypes in RNA and protein in rabbit eyes.

We investigated subtypes of alpha-1 adrenoceptor (AR) in rabbit ocular tissues using reverse transcription-polymerase chain reaction (RT - PCR), in situ hybridization (ISH) and binding studies. Competitive RT - PCR assays specific for the subtypes of alpha-1 AR revealed that the mRNA expression of alpha-1a AR was dominant, and that of each alpha-1b and alpha-1d was less than 10% and 0.5% of total alpha-1 ARs mRNA, respectively, in the iris, ciliary body, choroid and retina. In alpha-1a AR splice isoform-specific RT - PCR assays, we found a distinct proportion of each isoform mRNA in the iris, ciliary body and choroid. The results of the ISH assays for alpha-1a AR subtype showed that hybridization signals were clearly observed in the iris dilator muscle and in the epithelium of the ciliary processes. In binding studies, alpha-1A AR was a dominant subtype in the iris, choroid and retina in contrast to the ciliary body that had more alpha-1B than alpha-1A AR subtype at protein level.

Adrenergic alpha-Antagonists↗

PubMed2002

[Post launch studies].

Evidence Based Medicine (EBM) is a growing concept in Japan as it is elsewhere. Central to improving the use of EBM is generation of data through well conducted controlled clinical studies. There are many problems associated with conduct of clinical studies after launch in Japan, and many initiatives are ongoing to improve the situation. Development of Clinical Research Coordinators (CRO) and central Data Management centers are key to improving the quality of clinical research in Japan. Currently Japan has an undeveloped legal system with regard to post-launch trials and off-label use of registered drugs. There is no reimbursement for off-label and various restrictions imposed on the recipients of the Ministry of Health, Labour and Welfare's (MHLW) funds. Maybe the biggest problem is the high cost of post-marketing studies sponsored by pharmaceutical manufacturers. A high quality system to support post launch clinical studies need a solid financial base. There is a need for a suitable review system for investigator initiated multi-centre studies, as the current IRB system is not sufficient. There are also challenges regarding the differences, perceived or real, in treatment practice and available registrations in Japan and in the West, causing problems in choosing suitable comparators and study designs. At the present time it is not clear whether investigator initiated trials will be acceptable for registration purposes in Japan. The agreed first priority is to build a suitable and strong infrastructure within the academic community to support researchers to investigate important questions with or without pharmaceutical company support. Despite all these issues, several groundbreaking projects are under way throughout Japan, in many different areas and by different collaborative groups, some with government support. In fact, researcher-initiated clinical trials achieved a rapid growth in Japan in the past year.

Clinical Trials as Topic↗

PubMed2002

[Image-guided breast conserving surgery based on 3D-MRI].

Surgery for breast cancer has changed markedly during the past 20 years. Radical mastectomy, referred to as Halstead's operation, is not commonly performed at present, while breast-conserving surgery (BCS) has become the standard therapy for early breast cancer. In the era of BCS, preoperative evaluation of tumor extension is extremely important. Three-dimensional magnetic resonnance imaging(3D-MRI) is a promising diagnostic method to confirm tumor extension compared with other conventional methods (mammography and ultrasound). Therefore, 3-D MRI can be used to assist image-guided surgery for nonpalpable tumors, which are detected as clustered microcalcifications, or in clinical complete response cases after neoadjuvant chemotherapy.

Breast Neoplasms↗