Masanori Nakamura

Osaka City University, Ōsaka-shi, Osaka-fu, Japan

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Publications (13)3.56 Total impact

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    ABSTRACT: Although papillary thyroid microcarcinoma (PTMC) has an excellent prognosis, certain cases exhibit aggressive clinical manifestations. In this study, we assessed the expression of E-cadherin and Ki-67 in primary PTMC tumors and metastatic lymph nodes, in order to investigate the mechanism underlying the mainly indolent but potentially malignant nature of PTMC. A total of 93 PTMC patients treated in our institute were included in this study. All primary tumors and 57 metastatic lymph nodes were immunohistochemically stained and a total of 73 tumors (78.5%) were positive for E-cadherin. E-cadherin expression was significantly less common at the invasive front (58.1%, P<0.01) compared to that at the center of the tumor. Tumors that had lost E-cadherin expression at the invasive front frequently presented with lymph node metastasis (70.6%). Small tumors (≤5 mm diameter) expressed E-cadherin significantly more frequently compared with larger tumors (P=0.04); however, no other particular characteristic was found to correlate with the status of E-cadherin expression in the primary tumors. E-cadherin expression was detected in 49 (86.0%) of the 57 metastatic foci and correlated significantly with the expression status at the invasive front of the tumor (P=0.02). The Ki-67 index was universally low and was not correlated with the clinicopathological characteristics or the E-cadherin expression of the tumors. These results suggested that cancer cells in the metastatic lymph nodes exhibit indolent characteristics, similar to those of the primary PTMC. However, the metastatic cancer cells may have already completed the process of epithelial-to-mesenchymal transition (EMT) and mesenchymal-to-epithelial transition (MET), suggesting an innate malignant potential.
    Molecular and Clinical Oncology 03/2014; 2(2):226-232.
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    ABSTRACT: Anaplastic thyroid cancer (ATC) is thought to often be transformed from pre-existing differentiated thyroid cancer. It is one of the most aggressive malignancies and has a dismal prognosis due to its resistance to multimodal therapies. Basic exploratory studies using authentic ATC cell lines that retain its clinical features are necessary. We investigated the characteristics of seven ATC cell lines newly established at our institute to confirm their possible utility for basic studies. Seven distinct cell lines from six patients were established. Their molecular characteristics and sensitivities to cytotoxic anti-cancer drugs were investigated and compared with each other, and with the clinical features of the original tumors. All cells showed extensive chromosomal abnormality and Pax8 expression, indicating human thyroid follicular cell origin. Vascular endothelial growth factor was secreted from all cells, suggesting possible candidacy for targeted therapy. Vimentin was expressed, but E-cadherin expression was lost in all cells but OCUT-1C, which showed different features from those of OCUT-1F derived from the same tumor, suggesting a mixture of cancer cell clones with various degrees of differentiation within a single ATC tumor. Cells were likely to show sensitivity for taxanes, indicating the usefulness of taxanes as the first-line chemotherapy. OCUT-2, a cell line with both B-Raf and PI3 KCA mutation, demonstrated the importance of molecular target-oriented therapy. Basic studies using authentic ATC cell lines retaining the clinical features of the original tumor are useful models for investigating the mechanism of anaplastic transformation and exploring novel therapeutic strategies.
    World Journal of Surgery 12/2013; 38(3). · 2.35 Impact Factor
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    ABSTRACT: We report a case of emergency resection of a giant gastrointestinal stromal tumor of the stomach associated with hemorrhagic shock. A 79-year-old woman was admitted to our hospital because of massive hematemesis. Laboratory analysis revealed a hemoglobin level of 6.5 g/dL. Abdominal computed tomography (CT) and upper gastrointestinal endoscopy revealed a submucosal tumor, 12 cm in diameter, in the fornix of the stomach. As a Dieulafoy-like lesion was present, we attempted coagulation hemostasis in the exposed blood vessels. Endoscopic hemostasis was not successful. The patient went into hemorrhagic shock. Emergency surgery was performed: total gastrectomy with distal pancreatosplenectomy. The resected specimen measured 10×12×7 cm and was hard. Immunohistologically, the tumor was positive for c-kit and CD34 and negative for alpha smooth muscle actin (αSMA), desmin, and S-100. Histological examination revealed that the patient had a high-risk gastrointestinal stromal tumor of the stomach with no nodal metastasis. The postoperative course was uneventful and the patient has remained alive without recurrence for 4 years.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2013; 40(12):2185-7.
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    ABSTRACT: Aspiration biopsy cytology (ABC) is commonly performed for the diagnosis of thyroid tumor. Because ABC may not provide sufficient tissue for pathological diagnosis, we performed needle biopsy using a Monopty Biopsy Instrument for the accurate diagnosis of thyroid cancer. Furthermore, it is difficult to safely perform a core needle biopsy (CNB) for the diagnosis of breast cancer in the thyroid gland region. In this study, we evaluated the feasibility of using a Monopty Biopsy Instrument as an alternative to conventional ABC or CNB for the biopsy-based diagnosis of thyroid cancer. Twenty patients with clinically suspected thyroid cancer were enrolled, and all patients were thoroughly examined. Seven cases of thyroid cancer were diagnosed, of which 5 cases were papillary carcinoma and 2 were undifferentiated carcinoma.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2012; 39(12):2407-9.
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    ABSTRACT: In the early stages of breast cancer when axillary lymph node dissection is avoidable, we performed same day surgery with a breast-conserving operation following sentinel lymph node navigation biopsy under local anesthesia. Initial sentinel lymph node biopsy under local anesthesia is performed to avoid false-negative sentinel lymph node metastasis. Resected sentinel lymph nodes were examined in fixed sections by hematoxylin-eosin staining and immunohistochemistry. The enrolled subjects were 20 patients with breast cancer whose diagnoses were confirmed before treatment. Two (10.0%) patients had metastasis.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2012; 39(12):1914-6.
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    ABSTRACT: Case: The patient was an 82-year-old woman. Three years ago, she was aware of a tumor in her left breast that was gradually increasing in size and bleeding, prompting her to visit our hospital. Ultrasonography showed an irregular and low- echoic mass with a skin ulcer of about 2×2 cm in size in the left breast A area. Skin biopsy examination indicated adenocarcinoma, estrogen receptor-positive, progesterone receptor-positive, and human epidermal growth factor receptor type 2-negative. An overall examination did not show a distant metastasis. We diagnosed left breast cancer (luminal A type) with T4bN0M0, stage IIIB. We administered tamoxifen at a dose of 20 mg/day. After 8 months of tamoxifen treatment, no signs of an apparent mass were observed by palpation and ultrasonography. The effect of tamoxifen was considered a clinical complete response (CR). The patient did not experience any adverse events during treatment. Although CR was maintained for nearly 6 years by continuation of hormone therapy, tumor growth was observed after 6 years and 9 months. We performed partial resection of the left breast under local anesthesia. At present, 3 months after the operation, our patient is alive with no recurrence. We conclude that hormone (tamoxifen) therapy is a useful treatment for elderly postmenopausal woman with estrogen receptor-positive advanced breast cancer.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2012; 39(12):2039-41.
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    ABSTRACT: Carcinomatous meningitis due to breast cancer is comparatively rare in Japan. Here, we report 4 cases of carcinomatous meningitis due to breast cancer. Meningeal metastasis was present in only 1 of the 4 cases, and the other 3 cases were associated with brain metastasis. Meningeal metastasis frequently causes symptoms associated with intracranial hypertension. Gadolinium-enhanced magnetic resonance imaging and cerebrospinal fluid cytology were useful for the diagnosis of meningeal metastasis. Multidisciplinary therapy, such as radiation and chemotherapy, was performed. Two of the 4 patients were treated with combined intrathecal administration of methotrexate and whole brain radiation. The quality of life was improved by multidisciplinary therapy.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2012; 39(12):1917-9.
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    ABSTRACT: Case: A 104-year-old female patient with a left breast mass was admitted to our hospital. Ultrasonography showed an irregular and low-echoic mass of about 2.4×2.4×1.4 cm size in the left breast EAC area. Core needle biopsy examination indicated invasive ductal carcinoma of the breast: ER (+), PR (+), and HER2 (-). An overall examination did not show a distant metastasis. We diagnosed her with left breast cancer(luminal A type) T2N0M0, stage IIA. We administered anastrozole at a dose of 1 mg/day. After 6 months, the primary tumor diameter was reduced to 2.1 cm, and the effect of anastrozole was considered a clinical partial response. The patient did not experience any adverse events during treatment. The partial response was maintained for about 2 years. We experienced a successful case of a super-elderly breast cancer patient treated with anastrozole. We conclude that hormone therapy is a useful treatment for super-elderly postmenopausal women with estrogen receptor-positive breast cancer.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2012; 39(12):2042-4.
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    ABSTRACT: We report a case of advanced follicular thyroid carcinoma with massive involvement of the great veins of the cervix and mediastinum, and extensive tumor thrombus growing intraluminally into the superior vena cava. The patient, a 70-year-old Japanese woman, was treated successfully by a cooperative surgical team of endocrine and cardiovascular surgeons. Total thyroidectomy with thrombectomy was performed via a minimum phlebotomy in the right brachiocephalic vein, sacrificing only the right internal jugular vein, achieving complete primary tumor resection. She recovered quickly without any complications, and received (131)I radioisotope ablation for her multiple lung metastases. At the time of writing, more than 12 months after surgery, she was well. These treatments thus achieved progression-free survival without impairing her quality of life. Following the case report, we discuss the surgical indications for locally advanced thyroid carcinoma involving the great veins of the mediastinum by reviewing previous reports.
    Surgery Today 11/2011; 42(2):185-90. · 1.21 Impact Factor
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    ABSTRACT: Tailor-made treatment for lymphoma has been proposed, based on the information on prognostic on predictors or on molecular targets. This recent evolutions necessitated the collection of sufficient tissue samples for their preoperative evaluation. Since needle biopsy or needle aspiration cytology may not provide enough tissue for histo-pathologic diagnosis, incisional and excisional biopsies are commonly performed. In this study, we applied a handheld vacuum-assisted biopsy (VAB) system, as an alternative to the conventional incisional and excisional biopsies, to evaluate its feasibility in the biopsy -based diagnosis of malignant lymphoma. The subjects were nine patients with clinically suspected malignant lymphoma. All of them were correctly diagnosed with a diagnostic accuracy of 100%, and lymphoma sub-types could be defined according to the New WHO classification. There was no complication associated with the procedure. Lymph node biopsy for diagnosis of malignant lymphoma using this minimally invasive VAB technique allows a simple and safe collection of sufficient samples with good-quality, and promises to contribute to a precise molecular-based diagnosis.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2011; 38(12):2526-8.
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    ABSTRACT: We studied and analyzed therapeutic outcomes of a radical surgery under local anesthesia for breast cancer in our department. Subjects were 42 patients with breast cancer whose diagnoses were definitely made before surgery. Indications were: localized DCIS diagnosed preoperatively; invasive carcinoma less than 3 cm in tumor diameter on ultrasound; and clinically tumors with negative axillary lymph nodes. Operative procedures included lumpectomy associated with sentinel lymph node navigation biopsy. We could perform the operation under local anesthesia in all of the 42 patients, and were not demanded to shift from local to general anesthesia. Two patients had sentinel lymph nodes metastasis. Surgical stumps were positive in 14 patients( 33.3%). None of serious complications were encountered. Today's radical operation under local anesthesia for breast cancer is a useful procedure as minimally invasive surgery as for the indications employed in this study.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2011; 38(12):2017-9.
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    ABSTRACT: CASE 1: A 59-year-old female patient with left inflammatory breast cancer (HER2 type) T4N1M0, stage III B. Although a partial response (PR) was observed after chemotherapy, an increase of the tumor was confirmed, and thus she underwent pectoralis-conserving mastectomy and immediate reconstruction with a rectus abdominis flap. After the surgery, the patient continued to undergo radiotherapy and administration of trastuzumab. At present, after 1 year and 3 months, she is alive with no recurrence. CASE 2: A 67-year-old female patient with left inflammatory breast cancer (triple negative) T4N2M0, stage III B. Since a variety of chemotherapeutics were ineffective, she underwent mastectomy with pectoralis resection and immediate reconstruction with a rectus abdominis flap to control pain/bleeding caused by the increased tumor. Although radiotherapy and chemotherapy were performed after the surgery, lung and hepatic metastases were developed 6 months after the surgery, and she died in the 10th month after the surgery. CONCLUSION: In mastectomy for inflammatory breast cancer, an immediate reconstruction with a muscle cutaneous flap enabled unhesitating mastectomy in a wide area, and thus we consider this will be a useful technique.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2011; 38(12):2165-7.
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    ABSTRACT: A 55-year-old woman was admitted to our hospital with a complaint of appetite loss and body weight loss. Upper digestive endoscopy showed a giant fold at the greater curvature stomach and diffused edematous gastric mucosa. Abdominal contrast CT demonstrated a significant thickening of the gastric wall and a large number of lymph node swelling. A clinical finding was Stage IIIB (T3N2M0) Type 4 gastric cancer of poorly differentiated adenocarcinoma. Total gastrectomy, splenectomy and D2 lymph node dissection were performed. Although there was no peritoneal dissemination, peritoneal lavage cytology was positive. After the operation, S-1 alone chemotherapy was administered for four years. No recurrence had occurred for about seven years and eight months after resection. However, the patient was pointed out the signs of recurrence (ascites and induration) by CT. Now, S-1 alone chemotherapy was performed again, and the patient has been in good health.
    Gan to kagaku ryoho. Cancer & chemotherapy 11/2010; 37(12):2436-8.