Mizuno, Ryuichi



School of Medicine, Department of Urology (Shinanomachi)


Associate Professor

Academic Background 【 Display / hide

  • 1992.04

    Keio University, 医学部

    University, Graduated


Papers 【 Display / hide

  • Castration-resistant prostate cancer patients who had poor response on first androgen deprivation therapy would obtain certain clinical benefit from early docetaxel administration

    Shigeta K., Kosaka T., Hongo H., Yanai Y., Matsumoto K., Morita S., Mizuno R., Shinojima T., Kikuchi E., Oya M.

    International Journal of Clinical Oncology (International Journal of Clinical Oncology)  24 ( 5 ) 546 - 553 2019.05

    ISSN  13419625

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    © 2019, Japan Society of Clinical Oncology. Background: Our specific aim was to investigate the prognostic value of effective duration of first androgen deprivation therapy (ADT) and to evaluate the clinical impact on early docetaxel administration with oncological outcomes in castration-resistant prostate cancer (CRPC) patients treated with docetaxel. Methods: We identified 148 mCRPC patients who were treated with 75 mg/m 2 docetaxel. We defined 16 months as the threshold for the effective duration of ADT, and defined 12 months as the cut-off time for starting docetaxel from the onset of CRPC. Univariate and multivariate analyses were conducted to investigate the prognostic indicators that influenced the survival outcomes. Results: Overall, 81 (54.7%) patients died. The median 1st ADT response was 22.2 months and the median time interval from CRPC onset to docetaxel treatment was 11.7 months. Multivariate analysis indicated that visceral metastasis, bone metastasis extent of disease (EOD) ≥ 2, and effective duration of ADT < 16 months were the independent prognostic indicators for progression-free survival (PFS). Referring to cancer-specific survival (CSS), besides visceral metastasis and effective duration of ADT < 16 months, late docetaxel treatment ≥ 12 months became as the predictors for poor prognosis. Among the ADT poor-responder group (ADT < 16 months), Kaplan–Meier method showed that 1-year and 2-year CSS rates were 96.0% and 80.0% in the patients who introduced docetaxel in early setting (< 12 months), which were significantly higher than those who introduced in late settings (93.6% and 30.8%, respectively, p < 0.001). Conclusion: CRPC patients who had poor response during 1st ADT would obtain survival benefit by introducing docetaxel treatment in early stage.

  • Ⅳ. Current Economic Issues in Treatment for Metastatic Renal Cell Carcinoma

    Mizuno R., Oya M.

    Gan to kagaku ryoho. Cancer &amp; chemotherapy (Gan to kagaku ryoho. Cancer &amp; chemotherapy)  46 ( 1 ) 50 - 53 2019.01

    ISSN  03850684

  • Impact of inflammatory marker levels one month after the first-line targeted therapy initiation on progression-free survival prediction in patients with metastatic clear cell renal cell carcinoma

    Ito K., Masunaga A., Tanaka N., Mizuno R., Shirotake S., Yasumizu Y., Ito Y., Miyazaki Y., Hagiwara M., Kanao K., Mikami S., Momma T., Masuda T., Nakagawa K., Oyama M., Asano T., Oya M.

    Japanese Journal of Clinical Oncology (Japanese Journal of Clinical Oncology)  49 ( 1 ) 69 - 76 2019

    ISSN  03682811

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    © The Author(s) 2018. Published by Oxford University Press. All rights reserved. Objectives: Progression-free survival of first-line targeted therapy greatly influences the survival of patients with metastatic renal cell carcinoma. We evaluated whether post-treatment inflammatory markers and lactate dehydrogenase levels had impacts on progression-free survival prediction in addition to those of conventional predictors. Methods: Two hundred and fifteen patients whose tumors were clear cell type and in whom first-line targeted therapies could be continued for >1 month were evaluated. Pretreatment clinical factors, pathological factors and laboratory data 1 month after targeted therapy initiation—including inflammatory markers (neutrophil count, neutrophil-to-lymphocyte ratio and C-reactive protein) and lactate dehydrogenase—were reviewed. To identify progression-free survival predictors, multivariate analyses were done. Results: The 1-year progression-free survival rate was 47%. Female gender, Karnofsky performance status <80%, time from diagnosis to systemic treatment <12 months, pretreatment C-reactive protein >3.0 mg/dl and post-treatment neutrophil-to-lymphocyte ratio >3.0 were independent predictors for progression-free survival. In contrast, neither C-reactive protein increase nor neutrophil-to-lymphocyte ratio increase after targeted therapy initiation were independent predictors. Pretreatment lactate dehydrogenase, post-treatment lactate dehydrogenase and lactate dehydrogenase decline were not independent predictors. When all patients were stratified by these independent factors into three groups (0 risk vs. 1 or 2 risks vs. 3 or more risks), there were significant differences in progression-free survival rates between the groups (P < 0.0001). Furthermore, there were also significant differences in overall survival rates between the groups (P < 0.0001). Conclusions: Integration of post-treatment neutrophil-to-lymphocyte ratio value with pretreatment factors may lead to the establishment of effective predictive model for disease progression in patients with metastatic clear cell renal cell carcinoma who received first-line targeted therapies.

  • Prediction of extraprostatic extension by MRI tumor contact length: difference between anterior and posterior prostate cancer

    Matsumoto K., Akita H., Narita K., Hashiguchi A., Takamatsu K., Takeda T., Kosaka T., Mizuno R., Kikuchi E., Oya M., Jinzaki M.

    Prostate Cancer and Prostatic Diseases (Prostate Cancer and Prostatic Diseases)   2019

    ISSN  13657852

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    © 2019, Springer Nature America, Inc. Background: Tumor contact length (TCL) is defined as the extent of contact between prostate cancer and the prostatic capsule, and its predictive value for microscopic extraprostatic extension (EPE) has been reported. However, the impact of the zonal origin (anterior or posterior tumor) of the tumor on the diagnosis of EPE is controversial. Methods: We retrospectively analyzed the records of 233 consecutive patients who underwent preoperative MRI and radical prostatectomy. We designated their tumors as anterior or posterior, and evaluated the correlation between the TCL measured by MRI and microscopic EPE in the radical prostatectomy specimen. Then, we created the predicted probability curves for EPE versus TCL for anterior and posterior prostate cancer. Results: There were 109 patients (47%) with an anterior tumor and 124 patients (53%) with a posterior tumor. Postoperative pathological analysis confirmed pT3 in 18 patients (17%) with an anterior tumor and in 53 patients (43%) with a posterior tumor. Multivariate analysis demonstrated that the zonal origin of the tumor was an independent predictive factor for EPE. We developed separate probability curves of EPE versus TCL for anterior and posterior prostate cancer, which revealed that anterior tumors were less likely to invade the extraprostatic tissues. Among patients whose TCL was 10–20 mm, 9/32 patients (28%) with an anterior tumor had EPE compared with 24/45 patients (53%) with a posterior tumor (p = 0.036). The decision curve of this EPE predictive model had high clinical efficacy. Conclusions: Our results indicate that anterior tumors have more favorable pathological characteristics than posterior tumors with the same TCL measured by MRI. We constructed two separate predicted probability curves for EPE after discriminating anterior and posterior tumors, which will be useful for decision making in clinical practice.

  • The prognostic value of zonal origin and extraprostatic extension of prostate cancer for biochemical recurrence after radical prostatectomy

    Takamatsu K., Matsumoto K., Shojo K., Tanaka N., Takeda T., Morita S., Kosaka T., Mizuno R., Shinojima T., Kikuchi E., Asanuma H., Oya M.

    Urologic Oncology: Seminars and Original Investigations (Urologic Oncology: Seminars and Original Investigations)   2019

    ISSN  10781439

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    © 2019 Elsevier Inc. Objective: To investigate the influence of the zonal origin of prostate cancer and extraprostatic extension on biochemical recurrence (BCR). Patients and methods: We included 638 consecutive patients undergoing radical prostatectomy between 2005 and 2015 who did not receive neoadjuvant/adjuvant therapy. The largest lesion was defined as the index tumor. We categorized each patient into the transition zone (TZ) or peripheral zone (PZ) group based on the lesion where the index tumor existed. Differences in the BCR defined as increasing prostate-specific antigen rate between groups were examined by Kaplan-Meier analysis and the Cox proportional hazards model. Results: There were 293 (46%) patients with TZ cancer and 345 (54%) with PZ cancer. TZ cancer was significantly associated with a higher prostate-specific antigen (P = 0.012), lower biopsy positive core rate (P = 0.020), lower pathological Gleason score (P = 0.017), lower pathological stage (P = 0.002), and lower rate of seminal vesicle invasion (P = 0.002). During a median follow-up period of 59 months, 79 patients (12%) developed BCR. In the entire cohort, the PZ origin (hazard ratio: 1.68, P = 0.033) and extraprostatic extension were independent risk factors for BCR. The 3-, 5-, and 7-year BCR-free survival rates of patients with pT3a TZ cancer were 89%, 88%, and 86%, respectively, which were significantly better than those of patients with pT3a PZ cancer (80%, 74%, and 62%, P = 0.012), but were similar to those of the pT2 cancer cohort (92%, 91%, and 90%, P = 0.376). Conclusion: TZ cancer had more favorable pathological characteristics and oncological outcome than PZ cancer especially in pT3a cases.

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Reviews, Commentaries, etc. 【 Display / hide

Presentations 【 Display / hide

  • 放射線照射後の膀胱穿孔に伴う急性腎不全の一例

    Matsumoto Kazuhiro

    日本泌尿器科学会東京地方会 (第582回) , 


    Oral presentation (general)

  • 腎細胞癌におけるEts-1の発現


    第15回泌尿器科分子・細胞研究会 (京都) , 


    Oral presentation (general)

  • 膀胱癌診断における超拡大内視鏡Endocytoscopeの使用経験


    第19回日本Endourology・ESWL学会総会 (東京) , 


    Oral presentation (general)

  • 両側腎盂尿管術後精巣転移の1例


    第576回日本泌尿器科学会東京地方会 (東京) , 


    Poster presentation

  • 感度を90%にした場合の生検で見逃されると予想される前立腺癌の病理学的検討


    第93回日本泌尿器科学会総会 (東京) , 


    Poster presentation

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Research Projects of Competitive Funds, etc. 【 Display / hide

  • T細胞レパトアを組入れた進行性腎細胞癌に対する免疫チェックポイント阻害薬選択基準


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

  • リキッドバイオプシーによる進行性腎細胞癌新規分子標的治療アルゴリズムの確立


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator


Courses Taught 【 Display / hide











Courses Previously Taught 【 Display / hide

  • 泌尿器科学

    Keio University


    Full academic year