Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where Tomoko Wakasa is active.

Publication


Featured researches published by Tomoko Wakasa.


Cancer Science | 2011

Prognostic significance of tumor/stromal caveolin-1 expression in breast cancer patients

Nian-Song Qian; Takayuki Ueno; Nobuko Kawaguchi-Sakita; Masahiro Kawashima; Noriyuki Yoshida; Yoshiki Mikami; Tomoko Wakasa; Masayuki Shintaku; Shigeru Tsuyuki; Takashi Inamoto; Masakazu Toi

Caveolin‐1 (Cav‐1) has been extensively characterized in cancer biological research. However, the role of Cav‐1 in the interaction between tumor and stromal cells remains unclear. In the present study, we examined Cav‐1 expression in tumor cells and stromal cells in breast cancer tissue by immunohistochemical analysis and evaluated its prognostic value in a training cohort. Immunohistochemical analysis of Cav‐1 expression was scored as (++), (+) or (−) according to the proportion of positively stained tumor cells (T) and stromal cells (S). Correlation analysis between tumor/stromal Cav‐1 expression and clinicopathological parameters revealed that only T(++) Cav‐1 status was positively associated with tumor size and histological nodal status (P = 0.019 and 0.021, respectively). Univariate analysis revealed that combined T(++)/S(−) status was significantly correlated with unfavorable prognostic outcomes (P < 0.001). Multivariate analysis demonstrated that this combined status is an independent prognostic factor for primary breast cancer (P = 0.002). Clinical outcomes in different subgroups of breast cancer patients were also strictly dependent on this combined status (P < 0.05). The prognostic value of T(++)/S(−) Cav‐1 status was also validated in the testing cohort. Collectively, our data indicate that high Cav‐1 expression in tumor cells and lack of this expression in stromal cells could help identify a particular subgroup of breast cancer patients with potentially poor survival. Further studies are required to understand the regulatory mechanism of Cav‐1 in the tumor microenvironment. (Cancer Sci 2011; 102: 1590–1596)


Histopathology | 2009

Reappraisal of synchronous and multifocal mucinous lesions of the female genital tract: a close association with gastric metaplasia

Yoshiki Mikami; Takako Kiyokawa; Yuko Sasajima; Norihiro Teramoto; Tomoko Wakasa; Kenichi Wakasa; Sakae Hata

Aims:  To describe the gastric phenotype of synchronous mucinous metaplasia and neoplasms of the female genital tract (SMMN–FGT).


International Journal of Oncology | 2013

Effect of transcatheter arterial chemoembolization prior to surgical resection for hepatocellular carcinoma

Hiroki Nishikawa; Akira Arimoto; Tomoko Wakasa; Ryuichi Kita; Toru Kimura; Yukio Osaki

The aim of the present study was to evaluate the influence of preoperative transcatheter arterial chemoembolization (TACE) on survival after surgical resection (SR) for hepatocellular carcinoma (HCC). Two hundred and thirty-five HCC patients who underwent SR with curative intent were analyzed. Overall survival (OS), recurrence-free survival (RFS) and complication rates were compared between the TACE (n=110) and control groups (n=125). Moreover, TACE subjects were classified into TACE responders (n=85) and TACE non-responders (n=25), according to the therapeutic efficacy of pretreatment TACE, and the factors contributing to OS and RFS after SR were analyzed using univariate and multivariate analyses. The 1-, 3- and 5-year OS rates were 87.4, 76.0 and 62.5%, respectively, in the TACE group and 94.9, 79.0 and 57.8%, respectively, in the control group (P=0.674). The corresponding RFS rates at 1, 3 and 5 years were 73.3, 48.9 and 33.2%, respectively, in the TACE group and 73.3, 29.4 and 16.3%, respectively, in the control group (P=0.062). No TACE-related serious adverse events (SAEs) were observed. There were no significant differences between the groups in terms of surgery-related SAEs (P=0.714), operation time (P=0.881), blood loss during surgery (P=0.334) and hospitalization period (P=0.447). Multivariate analyses identified TACE responder, TACE non-responder, total bilirubin ≥1 mg/dl, serum albumin ≥4 g/dl, pretreatment α-fetoprotein (AFP) level ≥100 ng/ml and microscopic vascular invasion as significant prognostic factors linked to OS. TACE non-responder, tumor number (multiple) and pretreatment AFP level ≥100 ng/ml were significant adverse prognostic factors linked to RFS. In conclusion, TACE is a safe procedure in patients with HCC, and the efficacy of TACE prior to surgery may be associated with clinical outcomes after SR.


Journal of Cancer | 2013

Comparison of clinical characteristics and survival after surgery in patients with non-B and non-C hepatocellular carcinoma and hepatitis virus-related hepatocellular carcinoma.

Hiroki Nishikawa; Akira Arimoto; Tomoko Wakasa; Ryuichi Kita; Toru Kimura; Yukio Osaki

Background and aims: We compared clinicopathologic data and long-term clinical outcomes among patients with non-B and non-C hepatocellular carcinoma (NBNC-HCC) who underwent curative resection (group A, n=129), those with hepatitis B virus-related HCC (group B, n=62) and those with hepatitis C virus-related HCC (group C, n=284). Methods: Clinicopathologic characteristics and cumulative overall survival (OS) and recurrence-free survival (RFS) after curative resection were compared among the three groups. Results: The proportion of patients with non-liver cirrhosis (LC) or diabetes mellitus in group A was significantly higher than that in group B or group C. The mean maximum tumor size in group A was significantly larger than that of group B or group C. Cumulative 3-year OS rates after resection were 76% in group A, 79% in group B and 72% in group C (A vs. B, P=0.638; A vs. C, P=0.090; B vs. C, P=0.091; overall significance, P=0.088). The corresponding RFS rates after resection were 38% in group A, 36% in group B and 36% in group C (A vs. B, P=0.528; A vs. C, P=0.281; B vs. C, P=0.944; overall significance, P=0.557). In subgroup analyses in patients with LC, in those without LC and in those who satisfied the Milan criteria, similar results were obtained, i.e., the difference among the three groups did not reach significance in terms of OS and RFS. Conclusion: Long-term clinical outcomes in patients NBNC-HCC after curative resection were comparable to those in patients with hepatitis virus-related HCC after curative resection.


European Journal of Gastroenterology & Hepatology | 2013

Surgical resection for hepatocellular carcinoma: clinical outcomes and safety in elderly patients.

Hiroki Nishikawa; Akira Arimoto; Tomoko Wakasa; Ryuichi Kita; Toru Kimura; Yukio Osaki

Objectives The aim of this study was to compare the clinical outcomes and safety of surgical resection for hepatocellular carcinoma between patients older than 75 years of age (elderly group) and those younger than 75 years (control group). Methods A total of 92 patients were included in the elderly group and 206 patients were included in the control group. Clinical outcomes including overall survival, recurrence-free survival, and safety were compared between these two groups after initial surgery. Results The mean (±SD) observation periods were 2.5±1.8 years in the elderly group and 3.1±2.2 years in the control group. The 1, 3, and 5-year overall survival rates after surgery were 90.0, 73.3, and 43.0%, respectively, in the elderly group and 91.0, 77.5, and 64.4%, respectively, in the control group (P=0.188). The corresponding recurrence-free survival rates were 66.3, 38.8, and 26.2%, respectively, in the elderly group and 66.3, 38.8, and 22.2%, respectively, in the control group (P=0.634). Multivariate analysis identified a total bilirubin level greater than 1.0 mg/dl (P=0.003), a serum albumin level greater than 4.0 g/dl (P=0.005), an &agr;-fetoprotein level greater than 100 ng/ml (P<0.001), and microvascular invasion (P<0.001) as significant factors linked to overall survival, and tumor number (P=0.014) and microvascular invasion (P=0.008) were significant factors associated with recurrence-free survival. There was no significant difference between the two groups in terms of surgery-related serious adverse events (P>0.999). Conclusion Surgical resection appears to be a safe and feasible procedure for the treatment of hepatocellular carcinoma in elderly patients.


Annals of Nuclear Medicine | 2007

Comparison of dynamic FDG-microPET study in a rabbit turpentine-induced inflammatory model and in a rabbit VX2 tumor model.

Yoshimasa Hamazawa; Koichi Koyama; Terue Okamura; Tomoko Wakasa; Tomohisa Okuma; Yasuyoshi Watanabe; Yuichi Inoue

Purpose: We investigated the optimum time for the differentiation tumor from inflammation using dynamic FDG-microPET scans obtained by a MicroPET P4 scanner in animal models.Materials and Methods: Forty-six rabbits with 92 inflammatory lesions that were induced 2, 5, 7, 14, 30 and 60 days after 0.2 ml (Group 1) or 1.0 ml (Group 2) of turpentine oil injection were used as inflammatory models. Five rabbits with 10 VX2 tumors were used as the tumor model. Helical CT scans were performed before the PET studies. In the PET study, after 4 hours fasting, and following transmission scans and dynamic emission data acquisitions were performed until 2 hours after intravenous FDG injection. Images were reconstructed every 10 minutes using a filtered-back projection method. PET images were analyzed visually referring to CT images. For quantitative analysis, the inflammation-to-muscle (I/M) ratio and tumor-to-muscle (T/M) ratio were calculated after regions of interest were set in tumors and muscles referring to CT images and the time-I/M ratio and time-T/M ratio curves (TRCs) were prepared to show the change over time in these ratios. The histological appearance of both inflammatory lesions and tumor lesions were examined and compared with the CT and FDG-microPET images.Results: In visual and quantitative analysis, All the I/M ratios and the T/M ratios increased over time except that Day 60 of Group 1 showed an almost flat curve. The TRC of the T/M ratio showed a linear increasing curve over time, while that of the I/M ratios showed a parabolic increasing over time at the most. FDG uptake in the inflammatory lesions reflected the histological findings. For differentiating tumors from inflammatory lesions with the early image acquired at 40 min for dual-time imaging, the delayed image must be acquired 30 min after the early image, while imaging at 90 min or later after intravenous FDG injection was necessary in single-time-point imaging.Conclusion: Our results suggest the possibility of shortening the overall testing time in clinical practice by adopting dual-time-point imaging rather than single-time-point imaging.


Journal of Clinical Neuroscience | 2008

Ependymal cyst in the lumbar spine associated with cauda equina compression

Minori Kato; Hiroaki Nakamura; Eisuke Suzuki; Hidetomi Terai; Kenichi Wakasa; Tomoko Wakasa; Kunio Takaoka

There are many reports of extradural ependymal cysts in the literature; however, reports of intradural ependymal cysts are very rare and there has been no prior mention of an ependymal cyst originating from the filum terminale. In this report we present the case of a 31-year-old woman with an ependymal cyst that caused cauda equina compression, and discuss the clinical profile of the case in terms of symptoms, diagnostic images, pathohistological findings, and surgical procedures. To our knowledge, this is the first report of an ependymal cyst that caused cauda equina compression. The cyst was successfully treated by excision of the cyst during careful intraoperative monitoring to prevent neurological damage to the conus medullaris and cauda equina.


Digestive Endoscopy | 2014

Dense-type crypt opening seen on magnifying endoscopy with narrow-band imaging is a feature of gastric adenoma

Takashi Kanesaka; Akira Sekikawa; Takehiko Tsumura; Takanori Maruo; Yukio Osaki; Tomoko Wakasa; Masayuki Shintaku; Kenshi Yao

Magnifying endoscopy with narrow‐band imaging (ME‐NBI) can visualize crypt openings (CO) as slit‐like structures in gastric epithelial neoplasia. Visualization of numerous CO is characteristic of low‐grade adenoma (LGA). The aim of the present study was to investigate whether visualization of CO by ME‐NBI is useful for discriminating between LGA and early gastric cancer (EGC).


Gastroenterology Research and Practice | 2013

The Relation between Obesity and Survival after Surgical Resection of Hepatitis C Virus-Related Hepatocellular Carcinoma

Hiroki Nishikawa; Akira Arimoto; Tomoko Wakasa; Ryuichi Kita; Toru Kimura; Yukio Osaki

Background and Aims. We aimed to investigate the relationship between obesity and survival in hepatitis C virus-(HCV-) related hepatocellular carcinoma (HCC) patients who underwent curative surgical resection (SR). Methods. A total of 233 patients with HCV-related HCC who underwent curative SR were included. They included 60 patients (25.8%) with a body mass index (BMI) of > 25 kg/m2 (obesity group) and 173 patients with a BMI of < 25 kg/m2 (control group). Overall survival (OS) and recurrence-free survival (RFS) rates were compared. Results. The median follow-up periods were 3.6 years in the obesity group and 3.1 years in the control group. The 1-, 3-, and 5-year cumulative OS rates were 98.3%, 81.0%, and 63.9% in the obesity group and 90.0%, 70.5%, and 50.3% in the control group (P = 0.818). The corresponding RFS rates were 70.1%, 27.0%, and 12.0% in the obesity group and 70.1%, 39.0%, and 21.7% in the control group (P = 0.124). There were no significant differences between the obesity group and the control group in terms of blood loss during surgery (P = 0.899) and surgery-related serious adverse events (P = 0.813). Conclusions. Obesity itself did not affect survival in patients with HCV-related HCC after curative SR.


Endocrine Journal | 2015

Prognostic classification of thyroid follicular cell tumors using Ki-67 labeling index: Risk stratification of thyroid follicular cell carcinomas [Review]

Kennichi Kakudo; Tomoko Wakasa; Yoshio Ohta; Katsunari Yane; Yasuhiro Ito; Hiroyuki Yamashita

This review emphasizes that the so-called high-risk thyroid carcinoma is not a distinct tumor entity, but a group of tumors with different histologies. High-grade histological features, such as tumor necrosis, increased mitoses, and nuclear pleomorphism, together with high Ki-67 labeling index (more than 10%), are good indicators of high-risk thyroid carcinoma and suggest a possible risk for anaplastic transformation. This review proposes the stratification of patients with thyroid carcinoma into low-, moderate-, and high-risk groups based on Ki-67 labeling index, which should be useful for the clinical management of patients, even after initial surgery. Currently, both the aggressive variant of papillary carcinoma and poorly differentiated carcinoma are aggressively treated by a completion of total thyroidectomy with prophylactic lymph node dissection followed by radioactive iodine treatment. Therefore, patients with moderate-risk or high-risk thyroid carcinoma based on Ki-67 labeling index should also be considered candidates for this treatment strategy.

Collaboration


Dive into the Tomoko Wakasa's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Kennichi Kakudo

Wakayama Medical University

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Researchain Logo
Decentralizing Knowledge