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Featured researches published by Masahiro Oikawa.


Lung Cancer | 2012

Clinical and molecular analysis of synchronous double lung cancers

Junichi Arai; Tomoshi Tsuchiya; Masahiro Oikawa; Koji Mochinaga; Tomayoshi Hayashi; Koh-ichiro Yoshiura; Kazuhiro Tsukamoto; Naoya Yamasaki; Keitaro Matsumoto; Takuro Miyazaki; Takeshi Nagayasu

BACKGROUND Since multiple lung cancer treatment strategies differ, it is essential for clinicians to be able to distinguish between separate primary lesions and metastasis. In the present study, we used array comparative genomic hybridization (aCGH) and somatic mutation (epidermal growth factor receptor: EGFR) to analyze genomic alteration profiles in lung cancer patients. To validate the consistency among the pathological assessments and clarify the clinical differences between double primary lesions and metastasis, we also examined synchronous double lung cancer clinical data. METHODS Between January 1970 and March 2010, 2215 patients with lung cancer underwent surgical resection at Nagasaki University Hospital. We performed molecular analysis of 12 synchronous double lung cancer patients without lymph node metastasis (intrapulmonary metastasis in the same lobe (pm1): n=6, primary: n=6). We then evaluated the clinical outcomes of patients with pathologically diagnosed synchronous double lung cancers (intrapulmonary metastasis (pm): n=80, primary: n=39) and other T3 tumors (n=230). RESULTS Examination of the concordance rate (CR) of the copy number changes (CNCs) for paired tumors showed that the metastasis group was larger than the primary group (55.5% vs. 19.6%, p=0.04). Pathological diagnosis and molecular classification were the same in 10 out of 12 cases (83%). As compared to the primary group, there tended to be an inferior 5-year survival curve for the pm group. However, in N0 patients, the survival curve for the pm group overlapped the primary group, while the survival rate of the pm1 group was much higher than that of other T3 group (p<0.01). CONCLUSIONS Both pathological and molecular assessment using aCGH adapted in the current study appeared to have a consistency. Pathological pm1(T3)N0 patients may have a better prognosis than other T3N0 patients.


Radiation Oncology | 2011

Significance of genomic instability in breast cancer in atomic bomb survivors: analysis of microarray-comparative genomic hybridization.

Masahiro Oikawa; Koh-ichiro Yoshiura; Hisayoshi Kondo; Shiro Miura; Takeshi Nagayasu; Masahiro Nakashima

BackgroundIt has been postulated that ionizing radiation induces breast cancers among atomic bomb (A-bomb) survivors. We have reported a higher incidence of HER2 and C-MYC oncogene amplification in breast cancers from A-bomb survivors. The purpose of this study was to clarify the effect of A-bomb radiation exposure on genomic instability (GIN), which is an important hallmark of carcinogenesis, in archival formalin-fixed paraffin-embedded (FFPE) tissues of breast cancer by using microarray-comparative genomic hybridization (aCGH).MethodsTumor DNA was extracted from FFPE tissues of invasive ductal cancers from 15 survivors who were exposed at 1.5 km or less from the hypocenter and 13 calendar year-matched non-exposed patients followed by aCGH analysis using a high-density oligonucleotide microarray. The total length of copy number aberrations (CNA) was used as an indicator of GIN, and correlation with clinicopathological factors were statistically tested.ResultsThe mean of the derivative log ratio spread (DLRSpread), which estimates the noise by calculating the spread of log ratio differences between consecutive probes for all chromosomes, was 0.54 (range, 0.26 to 1.05). The concordance of results between aCGH and fluorescence in situ hybridization (FISH) for HER2 gene amplification was 88%. The incidence of HER2 amplification and histological grade was significantly higher in the A-bomb survivors than control group (P = 0.04, respectively). The total length of CNA tended to be larger in the A-bomb survivors (P = 0.15). Correlation analysis of CNA and clinicopathological factors revealed that DLRSpread was negatively correlated with that significantly (P = 0.034, r = -0.40). Multivariate analysis with covariance revealed that the exposure to A-bomb was a significant (P = 0.005) independent factor which was associated with larger total length of CNA of breast cancers.ConclusionsThus, archival FFPE tissues from A-bomb survivors are useful for genome-wide aCGH analysis. Our results suggested that A-bomb radiation may affect the increased amount of CNA as a hallmark of GIN and, subsequently, be associated with a higher histologic grade in breast cancer found in A-bomb survivors.


Journal of Human Genetics | 2015

Germline mutations causing familial lung cancer

Koichi Tomoshige; Keitaro Matsumoto; Tomoshi Tsuchiya; Masahiro Oikawa; Takuro Miyazaki; Naoya Yamasaki; Hiroyuki Mishima; Akira Kinoshita; Toru Kubo; Kiyoyasu Fukushima; Koh-ichiro Yoshiura; Takeshi Nagayasu

Genetic factors are important in lung cancer, but as most lung cancers are sporadic, little is known about inherited genetic factors. We identified a three-generation family with suspected autosomal dominant inherited lung cancer susceptibility. Sixteen individuals in the family had lung cancer. To identify the gene(s) that cause lung cancer in this pedigree, we extracted DNA from the peripheral blood of three individuals and from the blood of one cancer-free control family member and performed whole-exome sequencing. We identified 41 alterations in 40 genes in all affected family members but not in the unaffected member. These were considered candidate mutations for familial lung cancer. Next, to identify somatic mutations and/or inherited alterations in these 40 genes among sporadic lung cancers, we performed exon target enrichment sequencing using 192 samples from sporadic lung cancer patients. We detected somatic ‘candidate’ mutations in multiple sporadic lung cancer samples; MAST1, CENPE, CACNB2 and LCT were the most promising candidate genes. In addition, the MAST1 gene was located in a putative cancer-linked locus in the pedigree. Our data suggest that several genes act as oncogenic drivers in this family, and that MAST1 is most likely to cause lung cancer.


International Journal of Cancer | 2014

Novel diagnostic procedure for determining metastasis to sentinel lymph nodes in breast cancer using a semi-dry dot-blot method

Ryota Otsubo; Masahiro Oikawa; Hiroshi Hirakawa; Kenichiro Shibata; Kuniko Abe; Tomayoshi Hayashi; Naoe Kinoshita; Kazuto Shigematsu; Toshiko Hatachi; Hiroshi Yano; Megumi Matsumoto; Katsunori Takagi; Tomoshi Tsuchiya; Koichi Tomoshige; Masahiro Nakashima; Hideki Taniguchi; Takeyuki Omagari; Noriaki Itoyanagi; Takeshi Nagayasu

We developed an easy, quick and cost‐effective detection method for lymph node metastasis called the semi‐dry dot‐blot (SDB) method, which visualizes the presence of cancer cells with washing of sectioned lymph nodes by anti‐pancytokeratin antibody, modifying dot‐blot technology. We evaluated the validity and efficacy of the SDB method for the diagnosis of lymph node metastasis in a clinical setting (Trial 1). To evaluate the validity of the SDB method in clinical specimens, 180 dissected lymph nodes from 29 cases, including breast, gastric and colorectal cancer, were examined. Each lymph node was sliced at the maximum diameter and the sensitivity, specificity and accuracy of the SDB method were determined and compared with the final pathology report. Metastasis was detected in 32 lymph nodes (17.8%), and the sensitivity, specificity and accuracy of the SDB method were 100, 98.0 and 98.3%, respectively (Trial 2). To evaluate the efficacy of the SDB method in sentinel lymph node (SLN) biopsy, 174 SLNs from 100 cases of clinically node‐negative breast cancer were analyzed. Each SLN was longitudinally sliced at 2‐mm intervals and the sensitivity, specificity, accuracy and time required for the SDB method were determined and compared with the intraoperative pathology report. Metastasis was detected in 15 SLNs (8.6%), and the sensitivity, specificity, accuracy and mean required time of the SDB method were 93.3, 96.9, 96.6 and 43.3 min, respectively. The SDB method is a novel and reliable modality for the intraoperative diagnosis of SLN metastasis.


Diagnostic Molecular Pathology | 2013

A predictive factor of the quality of microarray comparative genomic hybridization analysis for formalin-fixed paraffin-embedded archival tissue.

Kenjiro Nakao; Masahiro Oikawa; Junichi Arai; Zhanna Mussazhanova; Hisayoshi Kondo; Kazuko Shichijo; Masahiro Nakashima; Tomayoshi Hayashi; Koh-ichiro Yoshiura; Toshiko Hatachi; Takeshi Nagayasu

Utilizing formalin-fixed paraffin-embedded (FFPE) archival tissue, the most common form of tissue preservation in routine practice, for cytogenetic analysis using microarray comparative genomic hybridization (aCGH) remains challenging. We searched for a predictive factor of the performance of FFPE DNA in aCGH analysis. DNA was extracted from 63 FFPE archival tissue samples of various tissue types (31 breast cancers, 24 lung cancers, and 8 thyroid tumors), followed by aCGH analysis using high-density oligonucleotide microarrays. Tumor DNA from matched frozen samples and from FFPE samples after whole-genome amplification were also analyzed in 2 and 4 case, respectively. The derivative log ratio spread (DLRSpread) was used to assess the overall quality of each aCGH result. The DLRSpread correlated significantly with the double-stranded DNA ratio of tumor DNA, storage time, and the degree of labeling with Cy5 (P<0.0001; correlation coefficients=−0.796, 0.551, −0.481, respectively). Stepwise multiple linear regression analysis revealed that the double-stranded DNA ratio of tumor DNA is the most significant predictive factor of DLRSpread (regression coefficient=−0.4798; P=<0.0001). The cytogenetic profiles of FFPE and matched frozen samples showed good concordance. Although the double-stranded DNA ratios were increased after whole-genome amplification, the DLRSpread was not improved. The double-stranded DNA ratio can be used to predict the performance of aCGH analysis for DNA from FFPE samples. Using this quality metric, valuable FFPE archival tissue samples can be utilized for aCGH analysis.


Breast Journal | 2011

Intracystic Papillary Carcinoma of Breast Harbors Significant Genomic Alteration Compared with Intracystic Papilloma: Genome-wide Copy Number and LOH Analysis Using High-Density Single-Nucleotide Polymorphism Microarrays

Masahiro Oikawa; Takeshi Nagayasu; Hiroshi Yano; Tomayoshi Hayashi; Kuniko Abe; Akira Kinoshita; Koh-ichiro Yoshiura

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Breast Cancer | 2016

Aromatase inhibitors with or without luteinizing hormone-releasing hormone agonist for metastatic male breast cancer: report of four cases and review of the literature.

Sayaka Kuba; Mayumi Ishida; Masahiro Oikawa; Yoshiaki Nakamura; Kosho Yamanouchi; Eriko Tokunaga; Kenichi Taguchi; Taito Esaki; Susumu Eguchi; Shinji Ohno

Abstract The roles of aromatase inhibitors (AIs) and luteinizing hormone–releasing hormone (LH–RH) agonists in the management of male breast cancer remain uncertain, with no reports in Japanese men. We report four Japanese male patients with metastatic breast cancer treated with AIs with or without an LH–RH agonist, and consider the relationship between treatment effect and estradiol (E2) concentration. Three patients were initially treated with AI alone after selective estrogen receptor modulators (SERMs), and one received AIs plus an LH–RH agonist after a SERM. Two patients treated with an AI alone responded, one patient with E2 levels below the lower assay limit and the other with levels above the limit. The other treated with an AI alone experienced progression regardless of the E2 levels below the lower assay limit, however, responded after the addition of an LH–RH agonist. E2 concentrations were related to the efficacy of treatment in one patient. The patient initially treated with an AI plus an LH–RH agonist also responded. No grade 3 or 4 adverse events were observed in any of the patients treated with AIs with or without an LH–RH agonist. AIs with or without an LH–RH agonist offer an effective treatment option for hormone receptor-positive metastatic male breast cancer.


Journal of Surgical Oncology | 2016

Evaluation of totally implantable central venous access devices with the cephalic vein cut-down approach: Usefulness of preoperative ultrasonography

Ryota Otsubo; Toshiko Hatachi; Ken-ichiro Shibata; Takuya Yoshida; Hironosuke Watanabe; Masahiro Oikawa; Megumi Matsumoto; Hiroshi Yano; Hideki Taniguchi; Takeshi Nagayasu

The aims of this retrospective study, were to evaluate totally implantable central venous access device (TICVAD) implantation and to validate the efficacy of preoperative ultrasonography.


European Journal of Cardio-Thoracic Surgery | 2016

Intraoperative diagnosis of lymph node metastasis in non-small-cell lung cancer by a semi-dry dot-blot method

Koichi Tomoshige; Tomoshi Tsuchiya; Ryota Otsubo; Masahiro Oikawa; Naoya Yamasaki; Keitaro Matsumoto; Takuro Miyazaki; Tomayoshi Hayashi; Naoe Kinoshita; Atsushi Nanashima; Takeshi Nagayasu

OBJECTIVES Sublobar resection procedures, such as segmentectomy and wedge resection, can be used for resectable lung cancer when the cancer is small or the condition of the patient is poor. In such cases, intraoperative lymph node (LN) exploration is necessary to avoid incomplete resection of potential N1 or N2 disease. The semi-dry dot-blotting (SDB) method was developed to detect intraoperative LN metastasis as a quick, cost-effective procedure that does not require special technical expertise. This study examined whether SDB can sufficiently identify LN metastasis in lung cancer patients. METHODS This study prospectively examined 147 LNs from 50 lung cancer patients who underwent surgery at Nagasaki University Hospital between April 2011 and June 2013. The SDB method uses antigen-antibody reactions with anti-pancytokeratin as the primary antibody and detects cancer cells using chromogen. To identify LN metastases, each LN was examined by the SDB method during surgery along with intraoperative pathological diagnosis (ope-Dx) and permanent pathological diagnosis (permanent-Dx). RESULTS Compared with permanent-Dx, SDB offered 94.7% sensitivity, 97.7% specificity and 97.2% accuracy, while ope-Dx exhibited 84.2% sensitivity, 100% specificity and 98.0% accuracy. For 3 cases, micrometastases were detected by the SDB method but not by ope-Dx. Three LNs from lobar stations showed pseudo-positive results by the SDB method because of the presence of alveolar epithelium. CONCLUSIONS The SDB method offers acceptably high accuracy in detecting LN metastasis, especially for mediastinal LNs, and represents a potential alternative for the intraoperative diagnosis of LN metastasis, even in the absence of a pathologist.


Breast Cancer | 2017

Cytogenetic analysis of metaplastic squamous cell carcinoma of the breast inter- and intratumoral heterogeneity

Masahiro Oikawa; Akiko Igawa; Kenichi Taguchi; Kimiko Baba; Mayumi Ishida; Sayuri Akiyoshi; Hiroshi Yano; Takeshi Nagayasu; Shinji Ohno; Eriko Tokunaga

BackgroundSquamous cell carcinoma (SCC) of the breast is a rare and generally aggressive disease that accounts for less than 0.1% of all breast carcinomas. Although SCCs have distinct morphological features, their origin and cytogenetic profile are not well understood.MethodsFive patients with SCC were studied. The tumor area that was predominantly composed of SCC components was macrodissected and DNA was extracted. In three cases, an invasive or noninvasive ductal carcinoma of no special type (NST) component was also present. NST-component DNA was also extracted. The tumor DNA was used for array comparative genomic hybridization analysis using a high-density oligonucleotide microarray. The cytogenetic profile of the SCC components was compared with each other and with the paired NST component in three of the five cases.ResultsThe cytogenetic profile of the SCC components indicated large intertumoral heterogeneity. There were between 2 and 160 copy number alterations per case, and no common copy number alterations were identified. The cytogenetic profiles of the paired SCC and NST components were similar but not identical. Although, in one case, a larger number of copy number aberrant regions were detected in the SCC component than the NST component. In this case, all the NST component aberrations were present in the SCC component. This implies that the SCC component originated from the NST component. There were no common SCC component-specific aberrations in the three NST-component cases.ConclusionOur results demonstrate the cytogenetic inter- and intratumoral heterogeneity of SCC of the breast. Our comparison of cytogenetic profiles indicated that the SCC component originated from the NST component in one case.

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