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Dive into the research topics where Yuhei Ohkubo is active.

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Featured researches published by Yuhei Ohkubo.


International Journal of Urology | 2008

Lymphovascular invasion is an independent predictor of prostate-specific antigen failure after radical prostatectomy in patients with pT3aN0 prostate cancer

Shinya Yamamoto; Satoru Kawakami; Junji Yonese; Yasuhisa Fujii; Yuhei Ohkubo; Taisuke Suyama; Yoshinobu Komai; Toshiki Kijima; Yuichi Ishikawa; Iwao Fukui

Objectives:  To investigate the association of lymphovascular invasion (LVI) in radical prostatectomy (RP) specimens with prostate‐specific antigen (PSA) failure in patients with pT3aN0 prostate cancer (PCA).


Urology | 2008

Prognostic Significance of Cancer Volume Involving Seminal Vesicles in Patients With pT3bpN0 Prostate Cancer

Shinya Yamamoto; Satoru Kawakami; Junji Yonese; Yasuhisa Fujii; Tetsuro Tsukamoto; Yuhei Ohkubo; Yoshinobu Komai; Yuichi Ishikawa; Iwao Fukui

OBJECTIVES To investigate the prognostic effect of the prostate cancer (PCa) volume involving the seminal vesicles (CVSVs) in the radical prostatectomy specimen from patients with Stage pT3bpN0 PCa. METHODS We retrospectively reviewed the clinical records of 27 patients with Stage pT3bpN0 PCa who had undergone radical prostatectomy alone. We measured the CVSVs using a grid method on the glass slide under microscopic inspection and investigated the association of the CVSVs with clinicopathologic variables. RESULTS Prostate-specific antigen (PSA) failure was confirmed in 11 of the 27 patients (41%) during a median follow-up of 34 months. The 3-year PSA failure-free survival rate was 48%. The median CVSVs was 1.14 cm(3). On univariate analysis, a CVSVs of >1.63 cm(3) was associated with positive surgical margins (P = .018), bilateral seminal vesicle involvement (P = .03), a long maximal tumor dimension (P = .031), and a greater preoperative PSA level (P = .0007). The 3-year PSA failure-free survival rate for those with a CVSVs of <or=1.63 cm(3) vs >1.63 cm(3) was 80% and 0%, respectively (P = .0009). On multivariate analysis, only the PSA level and CVSVs were identified as significant and independent predictors of PSA failure. Stratifying patients into 3 risk groups by these predictors, the PSA failure-free survival rate for patients with a PSA level >or=10 ng/mL and a CVSVs of >1.63 cm(3) was significantly worse than for any other group. CONCLUSIONS The CVSVs is useful and invaluable as an independent predictor of PSA failure in patients with Stage pT3bpN0 PCa. The measurement of the CVSVs is simple and helped to determine the indication for adjuvant treatment after radical prostatectomy.


Cancer | 2006

Phase I/II study of a combined gemcitabine, etoposide, and cisplatin chemotherapy regimen for metastatic urothelial carcinoma.

Tetsuro Tsukamoto; Junji Yonese; Yuhei Ohkubo; Iwao Fukui

The authors attempted to determine the maximum tolerated dose (MTD) of gemcitabine in combination with etoposide and cisplatin as a chemotherapy regimen and investigated the safety and antitumor activity with the recommended doses of gemcitabine with etoposide and cisplatin for patients with metastatic urothelial carcinoma.


Japanese Journal of Clinical Oncology | 2009

Risk Stratification of High-grade Prostate Cancer Treated with Antegrade Radical Prostatectomy with Intended Wide Resection

Shinya Yamamoto; Satoru Kawakami; Junji Yonese; Yasuhisa Fujii; Tetsuro Tsukamoto; Yuhei Ohkubo; Yoshinobu Komai; Yuichi Ishikawa; Iwao Fukui

OBJECTIVE The aim of this study was to assess the surgical outcome of high-grade prostate cancer (PCA) treated with antegrade radical prostatectomy with intended wide resection (aRP) and to establish the risk stratification. METHODS A consecutive 77 Japanese patients with Gleason score 8-10 PCA were treated with aRP alone and excluding patients with persistently elevated prostate-specific antigen (PSA), prospectively observed without any treatment until PSA failure was confirmed. PSA failure-free, cancer-specific and overall survival curves were generated with Kaplan-Meier method and the difference between groups was assessed with log-rank test. Coxs proportional hazards model was used to elucidate predictors of PSA failure. RESULTS During a median follow-up of 6 years, PSA failure was observed in 41 (53%) of the 77 patients. Five- and 10-year PSA failure-free survival rates of the entire cohort were 44.6% and 40.1%, respectively. Both overall and cancer-specific survival rates of the entire cohort at 5 and 10 years were 96.8% and 87.9%, respectively. In a multivariate analysis, PSA (P = 0.008), specimen confinement (SC) (P = 0.006) and persistently elevated PSA after aRP were identified as significant and independent predictors of PSA failure. When stratifying patients into three risk groups according to PSA level and SC status, PSA failure-free survival rate in patients with PSA < 10 ng/ml and specimen-confined disease (SCD) was significantly better than that in those of any other groups. CONCLUSIONS Good prognosis can be expected in patients with high-grade PCA treated with aRP alone when PSA < 10 ng/ml and the tumor was removed as an SCD.


International Journal of Clinical Oncology | 2007

Successful 2-year-long remission following repeated salvage surgery in a patient with chemotherapy-resistant metastatic nonseminomatous germ cell tumor

Hideki Takeshita; Junji Yonese; Yasuhisa Fujii; Satoru Kawakami; Yoshinobu Komai; Yuhei Ohkubo; Shinya Yamamoto; Yuichi Ishikawa; Yasuyuki Seto; Shigekazu Ohyama; Iwao Fukui

A 34 year-old man with a diagnosis of nonseminomatous testicular cancer with retroperitoneal lymph node metastasis (T1N3M0S2, stage IIIb; intermediate prognosis, made after right inguinal orchiectomy was performed) was referred to our hospital after having had a total of eight courses of systemic chemotherapy and external-beam radiotherapy to the retroperitoneal region in the previous 1 year. His serum α-fetoprotein (AFP) level remained elevated. Two courses of paclitaxel, etoposide, and cisplatin combined chemotherapy (TEP; paclitaxel 120 mg/m2 day 1, etoposide 80 mg/m2 days 2–5, cisplatin 20 mg/m2 days 2–5) failed to normalize the AFP level. During the following 2 years he underwent salvage surgery four times; infrarenal retroperitoneal lymph node dissection (RPLND), left neck lymph node dissection, thoracic duct excision, and suprarenal RPLND. Viable cancer cells were found in all surgically resected specimens, except for the neck lymph node specimen. The serum AFP level was normalized and he has been well without relapse for 2 years after the last surgery. The present case suggests that repeated salvage surgery may be beneficial in selected patients with a chemotherapy-resistant metastatic germ cell tumor.


International Journal of Clinical Oncology | 2006

Possibility of recovery of estrogen sensitivity following high-dose glucocorticoid therapy in a patient with hormone-refractory prostate cancer

Shinya Yamamoto; Jyunji Yonese; Satoru Kawakami; Tetsuro Tsukamoto; Yuhei Ohkubo; Manabu Tatokoro; Iwao Fukui

A 74-year-old man underwent irradiation therapy (RT) to the prostate bed because of prostate-specific antigen (PSA) failure after retropubic radical prostatectomy (RRP). Six months after the RT, a solitary bone metastasis developed in the third thoracic vertebra, and hormonal therapy (HT) was initiated. Three years later, following the loss of response to all hormonal agents, including oral estrogen and glucocorticoid therapy, paraplegia developed, due to a spinal metastasis. RT and high-dose glucocorticoid therapy were given for the spinal metastasis. Diethylstilbestrol diphosphate (DES-DP) was given continuously during this treatment, except for a 1-month period when the patient had pneumonia. After the RT and high-dose glucocorticoid therapy, his serum PSA decreased, from 308 to 36.99 ng/ml. In accordance with the 1-month discontinuation, and then resumption of DES-DP, the serum PSA levels went up and down. So we suspected that the tumor had recovered sensitivity to DES-DP with the high-dose glucocorticoid therapy. With a further decrease of serum PSA to 2.12 ng/ml, he has been alive for more than 3 years to date since the diagnosis of hormone-refractory prostate cancer (HRPCA). To our knowledge, there have been no reports showing such a marked recovery of hormone-sensitivity in HRPCA. No optimal therapy has yet been established for HRPCA; therefore, high-dose glucocorticoid therapy in combination with DES-DP warrants further study.


European Urology | 2007

Preoperative Serum Testosterone Level as an Independent Predictor of Treatment Failure following Radical Prostatectomy

Shinya Yamamoto; Junji Yonese; Satoru Kawakami; Yuhei Ohkubo; Manabu Tatokoro; Yoshinobu Komai; Hideki Takeshita; Yuichi Ishikawa; Iwao Fukui


Archive | 2008

Biopsy and Pathological Predictors of Outcome Prognostic Significance of Cancer Volume Involving Seminal Vesicles in Patients With pT3bpN0 Prostate Cancer

Shinya Yamamoto; Satoru Kawakami; Junji Yonese; Yasuhisa Fujii; Tetsuro Tsukamoto; Yuhei Ohkubo; Yoshinobu Komai; Yuichi Ishikawa; Iwao Fukui


Urology | 2007

MP-18.09: Treatment results of patients with seminal vesicle invasion (pT3b) undergoing radical prostatectomy with wide resection

Iwao Fukui; Jyunji Yonese; Satoru Kawakami; Yasuhisa Fujii; Shinya Yamamoto; Yuhei Ohkubo


The Japanese Journal of Urology | 2004

[The result of VIP chemotherapy as an induction therapy in 6 patients with non-seminomatous extragonadal germ cell tumor].

Mizuaki Sakura; Tetsurou Tsukamoto; Junji Yonese; Masayuki Nakaishi; Yuhei Ohkubo; Takuya Maezawa; Keita Takimoto; Iwao Fukui; Ken Nakagawa; Sakae Okumura; Yuichi Ishikawa; Nozomu Aoki

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Iwao Fukui

Japanese Foundation for Cancer Research

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Shinya Yamamoto

Japanese Foundation for Cancer Research

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Junji Yonese

Japanese Foundation for Cancer Research

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Satoru Kawakami

Japanese Foundation for Cancer Research

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Yasuhisa Fujii

Tokyo Medical and Dental University

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Yoshinobu Komai

Japanese Foundation for Cancer Research

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Tetsuro Tsukamoto

Japanese Foundation for Cancer Research

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Hideki Takeshita

Japanese Foundation for Cancer Research

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Jyunji Yonese

Japanese Foundation for Cancer Research

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