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Featured researches published by Jun Obata.


European Urology | 2014

The Predictive Value of C-reactive Protein for Prognosis in Patients with Upper Tract Urothelial Carcinoma Treated with Radical Nephroureterectomy: A Multi-institutional Study

Nobuyuki Tanaka; Eiji Kikuchi; Suguru Shirotake; Kent Kanao; Kazuhiro Matsumoto; Hiroaki Kobayashi; Yasumasa Miyazaki; Hiroki Ide; Jun Obata; Katsura Hoshino; Nozomi Hayakawa; Yujiro Ito; Takeo Kosaka; Kiichiro Kodaira; Masafumi Oyama; Akira Miyajima; Tetsuo Momma; Ken Nakagawa; Munehisa Ueno; Mototsugu Oya

BACKGROUND Few studies have discussed the prognostic impact of serum C-reactive protein (CRP) level in upper tract urothelial carcinoma (UTUC). OBJECTIVE To investigate whether the perioperative level of CRP provides additional prognostic information following radical nephroureterectomy (RNU). DESIGN, SETTING, AND PARTICIPANTS A total of 564 patients with UTUC from a retrospective multi-institutional cohort were included. The median follow-up was 32 mo. INTERVENTION All patients underwent RNU without neoadjuvant chemotherapy, while 106 patients (18.8%) received adjuvant chemotherapy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Associations between perioperative CRP level and outcome were assessed using multivariate analysis. A serum CRP level >0.50mg/dl was defined as elevated. RESULTS AND LIMITATIONS Preoperative CRP (pre-CRP) level was elevated in 136 patients (24.1%). Multivariate analysis showed that pre-CRP elevation was an independent predictor of subsequent disease recurrence (hazard ratio [HR]: 1.47 for CRP 0.51-2.00; HR: 1.89 for CRP >2.00). Five-year recurrence-free survival rates were 69.2% in patients with pre-CRP levels ≤ 0.50 mg/dl, 54.3% in patients with pre-CRP levels between 0.51 and 2.00 mg/dl, and 35.4% in patients with pre-CRP levels >2.00 mg/dl (p<0.001). Similar results were found in cancer-specific mortality, showing that pre-CRP elevation was an independent predictor of worse outcome (HR: 1.74 for CRP 0.51-2.00; HR: 2.31 for CRP >2.00). In a subgroup analysis of the elevated pre-CRP group, postoperative normalisation of CRP level was an independent predictor of better outcome. This study is limited by its retrospective nature as well as its heterogeneous group of patients and variable follow-up protocols resulting from the multi-institution design. CONCLUSIONS Serum CRP may become a possible biomarker in UTUC, suggesting that patients with an elevated pre-CRP level could be predicted to have subsequent disease recurrence and cancer-specific mortality, while postoperative normalisation of CRP level was an independent predictor for prognosis.


BJUI | 2013

Patient characteristics and outcomes in metastatic upper tract urothelial carcinoma after radical nephroureterectomy: the experience of Japanese multi‐institutions

Nobuyuki Tanaka; Eiji Kikuchi; Kent Kanao; Kazuhiro Matsumoto; Hiroaki Kobayashi; Yasumasa Miyazaki; Hiroki Ide; Jun Obata; Katsura Hoshino; Suguru Shirotake; Nozomi Hayakawa; Takeo Kosaka; Akira Miyajima; Tetsuo Momma; Ken Nakagawa; Shintaro Hasegawa; Yosuke Nakajima; Mototsugu Oya

To investigate oncological outcomes and prognostic factors in patients with upper tract urothelial carcinoma (UTUC) who experienced disease recurrence after radical nephroureterectomy (RNU). Few studies have focused on the clinical courses of patients who experienced disease recurrence after RNU.


Japanese Journal of Clinical Oncology | 2011

Neoadjuvant gemcitabine plus cisplatin for muscle-invasive bladder cancer

Gou Kaneko; Eiji Kikuchi; Kazuhiro Matsumoto; Jun Obata; So Nakamura; Akira Miyajima; Mototsugu Oya

OBJECTIVE Downstaging by neoadjuvant chemotherapy improves the survival of patients with muscle-invasive bladder cancer. In salvage setting, gemcitabine plus cisplatin has demonstrated an efficacy similar to that of methotrexate, vinblastine, doxorubicin and cisplatin with less toxicity. Therefore, the application of neoadjuvant gemcitabine plus cisplatin is also being anticipated. METHODS Twenty-two patients who received neoadjuvant gemcitabine plus cisplatin were evaluated. The rate of downstaging, chemotherapy delivery profile and toxicity data were assessed. As comparator group, nine patients who were administered with neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin were evaluated. RESULTS A mean of 1.9 cycles of neoadjuvant gemcitabine plus cisplatin were performed. Achieved drug intensity for gemcitabine and cisplatin was 83.8 and 95.4%. Downstaging to pT0 and <pT2 was achieved in 50.0 and 63.6%. Grade 3 or 4 neutropenia, anemia, thrombocytopenia and febrile neutropenia appeared in 14.3, 2.4, 21.4 and 2.4%, respectively. Grade 3 or 4 non-hematologic toxicity was not observed. Thrombocytosis developed in 26.2%. A mean of 2.3 cycles of neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin were performed. The achieved drug intensities for methotrexate, vinblastine, doxorubicin and cisplatin were 59.6, 69.8, 100 and 88.6%. In patients treated with neoadjuvant methotrexate, vinblastine, doxorubicin and cisplatin, downstaging to pT0 and <pT2 was achieved in 22.2 and 44.4%. Grade 3 or 4 neutropenia, anemia and thrombocytopenia was present in 19.1, 9.5 and 4.8%. Grade 3 nausea developed in 28.6%. CONCLUSIONS The rate of downstaging by neoadjuvant gemcitabine plus cisplatin was comparable with that by methotrexate, vinblastine, doxorubicin and cisplatin. Gemcitabine plus cisplatin was associated with less non-hematologic toxicity than methotrexate, vinblastine, doxorubicin and cisplatin.


The Journal of Urology | 2015

Impact of an Adjuvant Chemotherapeutic Regimen on the Clinical Outcome in High Risk Patients with Upper Tract Urothelial Carcinoma: A Japanese Multi-Institution Experience

Suguru Shirotake; Eiji Kikuchi; Nobuyuki Tanaka; Kazuhiro Matsumoto; Yasumasa Miyazaki; Hiroaki Kobayashi; Hiroki Ide; Jun Obata; Katsura Hoshino; Gou Kaneko; Masayuki Hagiwara; Takeo Kosaka; Kent Kanao; Kiichiro Kodaira; Satoshi Hara; Masafumi Oyama; Tetsuo Momma; Akira Miyajima; Ken Nakagawa; Shintaro Hasegawa; Yosuke Nakajima; Mototsugu Oya

PURPOSE Current guidelines do not yet provide any recommendations for adjuvant chemotherapy in patients with upper tract urothelial carcinoma managed with radical nephroureterectomy. We evaluated whether an adjuvant chemotherapeutic regimen would affect the clinical outcome in patients with high risk upper tract urothelial carcinoma. MATERIALS AND METHODS We identified 873 patients who had undergone radical nephrouretectomy for localized upper tract urothelial carcinoma at 14 Japanese institutions between 1993 and 2011. We assessed whether the type of regimen, such as methotrexate, vinblastine, doxorubicin and cisplatin, and gemcitabine and cisplatin, in an adjuvant setting, could affect the subsequent clinical outcome of patients with upper tract urothelial carcinoma. RESULTS On multivariate analysis pathological T stage, tumor grade, lymphovascular invasion and lymph node involvement were prognostic factors for recurrence-free survival and cancer specific survival. We defined 229 patients with 3 or more of these factors as the high risk group. In an analysis according to adjuvant regimen, Kaplan-Meier curves showed that the 1 and 2-year recurrence-free survival rates in the methotrexate, vinblastine, doxorubicin and cisplatin treated group were 71.4% and 47.9%, which were significantly higher than in the gemcitabine and cisplatin treated group (48.2% and not reached, p=0.022) or those not treated with adjuvant chemotherapy (53.4% and 39.6%, p=0.039). Similar results were observed in terms of cancer specific survival. CONCLUSIONS Our study showed that pT3-4, tumor grade 3, positive lymphovascular invasion and lymph node involvement were independent risk factors for disease mortality in patients with upper tract urothelial carcinoma treated with radical nephroureterectomy. In the high risk group methotrexate, vinblastine, doxorubicin and cisplatin adjuvant chemotherapy contributed to improve subsequent mortality compared to gemcitabine and cisplatin or no adjuvant chemotherapy.


Urologic Oncology-seminars and Original Investigations | 2014

The predictive value of positive urine cytology for outcomes following radical nephroureterectomy in patients with primary upper tract urothelial carcinoma: A multi-institutional study1

Nobuyuki Tanaka; Eiji Kikuchi; Kent Kanao; Kazuhiro Matsumoto; Suguru Shirotake; Hiroaki Kobayashi; Yasumasa Miyazaki; Hiroki Ide; Jun Obata; Katsura Hoshino; Nozomi Hayakawa; Takeo Kosaka; Masafumi Oyama; Akira Miyajima; Tetsuo Momma; Ken Nakagawa; Masahiro Jinzaki; Yosuke Nakajima; Mototsugu Oya

BACKGROUND AND OBJECTIVE Few studies have addressed the predictive value of positive urine cytology for prognosis in patients with upper tract urothelial carcinoma (UTUC). We investigated whether the status of preoperative urine cytology could provide additional prognostic information following radical nephroureterectomy (RNU). MATERIALS AND METHODS The study included 474 patients with primary nonmetastatic UTUC (pTa-4N0M0) from a retrospective multi-institutional cohort. The median follow-up period was 35 months. Associations between the status of urine cytologic evaluation and outcomes were analyzed using multivariate Cox regression models. Urine cytology was evaluated preoperatively using voided samples. Disease recurrence was defined as any relapse in nonbladder lesions and was coded separately from intravesical recurrence. RESULTS Positive urine cytology was detected in 184 patients (38.8%) preoperatively. Disease recurrence occurred in 127 patients, while intravesical recurrence occurred in 219 patients; 83 patients died of UTUC during follow-up. Kaplan-Meier analysis revealed that only the incidence of intravesical recurrence was significantly associated with the status of urine cytologic evaluation (P = 0.024); the intravesical recurrence-free survival rates at 1 and 3 years following RNU were 61.4% and 46.2% in patients with positive urine cytology and 71.1% and 51.6% in their counterparts, respectively. Multivariate analysis showed that gender (hazard ratio [HR] = 1.74, 95% confidence interval [CI]; 1.28-2.43), tumor multifocality in RNU specimens (HR = 1.64, 95% CI; 1.09-2.47), and positive urine cytology (HR = 1.41, 95% CI; 1.08-1.85) were independent risk factors for subsequent intravesical recurrence. CONCLUSIONS The results showed the prognostic value of positive urine cytology in patients with primary UTUC, and preoperative positive urine cytology may be associated with a significant increase in the prevalence of intravesical recurrence following RNU.


Urologic Oncology-seminars and Original Investigations | 2013

C-reactive protein: A biomarker of survival in patients with localized upper tract urothelial carcinoma treated with radical nephroureterectomy

Jun Obata; Eiji Kikuchi; Nobuyuki Tanaka; Kazuhiro Matsumoto; Nozomi Hayakawa; Hiroki Ide; Akira Miyajima; Ken Nakagawa; Mototsugu Oya

BACKGROUND AND OBJECTIVE Serum C-reactive protein (CRP) is one particular marker of systemic inflammation, and an elevated CRP level is associated with poor outcome in various malignancies. While the clinical value of CRP levels in upper tract urothelial carcinoma (UTUC) has not yet been fully evaluated, we investigated the impact of CRP elevation as a biomarker of patient prognosis in UTUC. MATERIALS AND METHODS A total of 183 patients who underwent radical nephroureterectomy (RNU) for localized UTUC (pTa-4N0M0) were identified between 1993 and 2009. The associations between the levels of serum CRP and patient outcome were analyzed. RESULTS Thirty-three patients experienced disease recurrence, and 28 died of the disease during the median follow-up period of 39 months. Using the defined cutoff level of CRP >0.5 mg/dl as elevated, preoperative CRP (pre-CRP) levels were elevated in 42 patients (23.0%). Kaplan-Meier curves revealed that subsequent tumor recurrences and worse cancer-specific survival could be significantly predicted in the elevated pre-CRP group. The 5-year recurrence-free survival rate was 63.6% in the elevated pre-CRP group and 83.4% in their counterparts (P < 0.001), and the 5-year cancer-specific survival rate was 64.7% in the elevated pre-CRP group and 84.3% in their counterparts (P = 0.001). Multivariate analysis revealed that elevated pre-CRP, in addition to pathologic T stage, was an independent risk factor for subsequent disease recurrence (P = 0.003, hazard ration (HR) = 2.83), and the decrease in cancer-specific survival (P = 0.012, HR = 2.65). In subgroup analysis using patients with pT3 tumors or greater, multivariate analysis also showed that elevated pre-CRP was an independent risk factor for a decrease in both recurrence-free and cancer-specific survival. CONCLUSIONS Pre-CRP level was an independent predictor of patient survival in localized advanced UTUC. Patients with pre-CRP >0.5 mg/dl were strongly predicted to have worse prognostic outcomes following RNU. Due to its low cost and easy accessibility, CRP may be a useful biomarker for localized UTUC.


BJUI | 2016

Plasma fibrinogen level: an independent prognostic factor for disease‐free survival and cancer‐specific survival in patients with localised renal cell carcinoma

Jun Obata; Nobuyuki Tanaka; Ryuichi Mizuno; Kent Kanao; Shuji Mikami; Kazuhiro Matsumoto; Takeo Kosaka; Eiji Kikuchi; Masahiro Jinzaki; Mototsugu Oya

To investigate the impact of perioperative plasma fibrinogen level as a biomarker of oncological outcome in localised renal cell carcinoma (RCC).


European urology focus | 2015

Impact of Combined Use of Blood-based Inflammatory Markers on Patients with Upper Tract Urothelial Carcinoma Following Radical Nephroureterectomy: Proposal of a Cumulative Marker Score as a Novel Predictive Tool for Prognosis

Nobuyuki Tanaka; Eiji Kikuchi; Kent Kanao; Kazuhiro Matsumoto; Suguru Shirotake; Yasumasa Miyazaki; Hiroaki Kobayashi; Gou Kaneko; Masayuki Hagiwara; Hiroki Ide; Jun Obata; Katsura Hoshino; Nozomi Hayakawa; Takeo Kosaka; Satoshi Hara; Ken Nakagawa; Masahiro Jinzaki; Mototsugu Oya

BACKGROUND Previous studies showed the prognostic impact of preoperative levels of neutrophil-to-lymphocyte ratio (NLR), plasma fibrinogen, and serum C-reactive protein (CRP) in surgically treated upper tract urothelial carcinoma; however, few papers have discussed the proper use of these indices. OBJECTIVE To investigate whether combinations of these three markers, as a cumulative marker score (CMS), improve the accuracy of prognostic models following radical nephroureterectomy (RNU). DESIGN, SETTING, AND PARTICIPANTS A total of 394 patients from multiple institutions were included. Median follow-up was 30 mo. INTERVENTION All patients underwent RNU without neoadjuvant chemotherapy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Associated outcomes were assessed using multivariate analysis. The CMS was defined as the number of elevated levels of preoperative NLR, plasma fibrinogen, and serum CRP. RESULTS AND LIMITATIONS Multivariate analyses revealed that an increasing CMS was independently associated with high rates of disease recurrence, cancer-specific mortality, and all-cause mortality following RNU. Addition of the CMS to a model that included standard clinicopathologic predictors significantly improved predictive accuracy by 2.7% for disease recurrence, 3.9% for cancer-specific mortality, and 4.0% for all-cause mortality, which were the highest among other prognostic models using each marker alone or combinations of two. The study is limited by its retrospective nature. CONCLUSIONS Although the use of each inflammatory marker alone may be as predictive as clinicopathologic indices for prognosis, combinations like CMS can provide more accurate prognostic models following RNU. PATIENT SUMMARY Elevation of blood-based inflammatory markers may be useful for predicting prognosis because of their low cost and accessibility. Among blood-based indices, we examined the efficacy of preoperative neutrophil-to-lymphocyte ratio, plasma fibrinogen, and serum C-reactive protein levels. Although use of each marker alone provides additional prognostic information, the combination of all three markers would be more predictive than any single marker or combinations of two.


Urology | 2013

Positive Posterior Margin of Needle Biopsy Cores Is an Independent Predictor for Extracapsular Extension in Retropubic Radical Prostatectomy

Hiroyuki Yamanaka; Kazuhiro Matsumoto; Jun Obata; Akiharu Ninomiya; Kiyoshi Mukai; So Nakamura

OBJECTIVE To introduce the new preoperative parameter as a predictor for extracapsular extension (ECE), we defined the presence of tumor at the stump of the rectum side on prostate needle biopsy as a positive posterior margin (PPM), and speculated that PPM is related to ECE. METHODS This retrospective study was conducted in 230 patients who underwent prostate needle biopsy and retropubic radical prostatectomy between 2001 and 2011. We analyzed the association between their clinicopathological parameters and ECE. RESULTS Multivariate analysis showed that the Gleason score (P = .023, odds ratio [OR] 1.433), serum prostate-specific antigen (PSA, P = .013, OR 1.040), clinical stage (P = .018, OR 2.162), and PPM (P = .013, OR 2.253) were significant independent predictors for ECE. Next, using these 4 preoperative risk factors, we were able to accurately predict their ECE. Patients with 0 or 1 risk factor had a low probability of ECE (13.0% and 18.5%, respectively). In contrast, the majority of patients who had 3 or 4 risk factors were found to have ECE (80.1% and 71.4%, respectively). CONCLUSION The data suggest that the Gleason score, serum PSA, clinical stage, and PPM may be independent predictors for the existence of ECE. This suggests that the posterior margin in biopsy specimens is a more reliable and clinically useful parameter when making decisions concerning the choice of treatments.


Luts: Lower Urinary Tract Symptoms | 2013

Who Would Benefit from Solifenacin Add‐On Therapy to Tamsulosin for Overactive Bladder Symptoms Associated with Benign Prostatic Hyperplasia?

Jun Obata; Kazuhiro Matsumoto; Hiroyuki Yamanaka; Akiharu Ninomiya; So Nakamura

Objectives: We evaluated the types of patient factors that influence the efficacy and safety of solifenacin add‐on therapy to tamsulosin in men with overactive bladder (OAB) associated with benign prostatic hyperplasia (BPH).

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Suguru Shirotake

Saitama Medical University

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