Mizuki Onozawa

Dr. Mizuki Onozawa

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 March 2021 in Cancer Science
Verified
Journal Article
Open access
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JLjasmine Lim
jasmine Lim
MOMizuki Onozawa
Mizuki Onozawa
MSMarniza Saad
Marniza Saad
TOTeng Aik Ong
Teng Aik Ong
TSThe A‐CaP (Asian Prostate Cancer) Study
The A‐CaP (Asian Prostate Cancer) Study
HAHideyuki Akaza
Hideyuki Akaza
The number of newly diagnosed prostate cancer cases varies across Asia, with higher mortality‐to‐incidence ratio reported in developing nations. Androgen deprivation therapy (ADT), alone or in combination, remains the mainstay of first‐line treatment for advanced prostate cancer. Key findings of extensive research and randomized controlled trials have shaped current clinical practice and influenced clinical guideline recommendations. We describe here the recent trend of ADT in newly diagnosed prostate cancer for Asia focusing on Japan (high‐income country) and Malaysia (middle‐income country) based on the Asian Prostate Cancer (A‐CaP) Study. The combination of radiotherapy and ADT or ADT alone was common in patients with intermediate‐to‐high risk localized and locally advanced disease. For metastatic prostate cancer, maximum androgen blockade (gonadotrophin‐releasing hormone [GnRH] agonist/antagonist plus antiandrogen) was prevalent among the Japanese patients while primary ADT alone with GnRH agonist/antagonist was widely practiced in the Malaysian cohort. Upfront combined therapy (ADT plus docetaxel or androgen receptor pathway inhibitor) has significantly improved the outcomes of patients with metastatic castration‐naïve prostate cancer. Its application, however, remains low in our cohorts due to patients’ financial capacity and national health insurance coverage. Early detection remains the cornerstone in prostate cancer control to improve treatment outcome and patient survival.

27 August 2018 in Cancer Medicine
Verified
Journal Article
Open access
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MOMizuki Onozawa
Mizuki Onozawa
HAHideyuki Akaza
Hideyuki Akaza
SHShiro Hinotsu
Shiro Hinotsu
MOMototsugu Oya
Mototsugu Oya
OOOsamu Ogawa
Osamu Ogawa
TTTaiji Tsukamoto
Taiji Tsukamoto
Background: This study investigated how differences in the method of the first‐line androgen deprivation therapy (ADT) affected the time to castration‐resistant prostate cancer. Methods: The Japan Study Group of Prostate Cancer compiled a nationwide community‐based database on prostate cancer patients who underwent ADT. That database included 13 774 patients who were started on ADT by surgical or medical castration alone (monotherapy group, 5395 cases) or ADT in combination with a nonsteroidal anti‐androgen (combined androgen blockade (CAB) group, 8379 cases). We used logistic regression analysis with background factors as independent factors to calculate propensity scores in regard to selection of CAB. Next, for 8826 cases of propensity score‐matched patients, we compared the survival rates in the two groups. Results: The CAB group showed a significantly better progression‐free survival (PFS) rate (65.6% vs 59.6% at 5 years; median time to progression, 11.6 vs 7.1 years; hazard ratio in the CAB group: 0.78, with a 95% confidence interval of 0.72 to 0.84; P < 0.001). In subgroup analysis based on the background factors, the PFS rate was generally better in the CAB group in all risk subgroups except for those having significant risk factors. Conclusion: Propensity score matching analysis revealed the prolongation of PFS by CAB in prostate cancer patients without significant risk factors. It would possible to decide the type of the first‐line ADT according to the prostate cancer risk.

13 April 2025 in Japanese Journal of Clinical Oncology
Verified
Journal Article
Open access
MOMizuki Onozawa
Mizuki Onozawa
TKTaketo Kawai
Taketo Kawai
SHShiro Hinotsu
Shiro Hinotsu
ASAtsushi Saito
Atsushi Saito
TMTakeshi Mitomi
Takeshi Mitomi
J(Japan Study Group of Prostate Cancer (J-CaP)
Japan Study Group of Prostate Cancer (J-CaP)
Background: The optimal treatment sequence of approved therapies for castration-resistant prostate cancer (PC) is unclear. This study assessed real-world patient characteristics, treatment patterns, and effectiveness in patients with castration-resistant PC in Japan. Methods: Using data from the Japan Study Group of Prostate Cancer registry (2016–2018), this retrospective study included patients with ≥1 record of: primary androgen-deprivation therapy for hormone-sensitive PC and clinical progression to castration-resistant PC during primary androgen-deprivation therapy. The primary outcomes were patient characteristics, treatment patterns, and treatment duration. Other outcomes were overall survival (OS), cancer-specific survival (CSS), time to disease progression, and time to second disease progression. Results: A total of 600 patients were included. The mean age was 75.3 (SD: 7.9) years at PC diagnosis. The median prostate-specific antigen level was 135.5 (IQR: 37.3–542.2) ng/mL. The most common first-line castration-resistant PC treatments were enzalutamide (30%), docetaxel (20%), abiraterone (18%), flutamide (12%), and bicalutamide (8.7%). The most common second-line treatments were enzalutamide (28.5%), abiraterone (21.9%), and docetaxel (16.6%). The median treatment duration for enzalutamide, docetaxel, abiraterone, and flutamide was 254.0, 176.0, 197.0, and 111.5 days, respectively. Across all treatments, the median OS, CSS, time to disease progression, and second disease progression was 1028.0, 1239.0, 616.0, and 887.0 days, respectively. Conclusion: Androgen receptor signaling inhibitors and docetaxel were the most common first- and second-line castration-resistant PC treatments. Enzalutamide was the preferred androgen receptor signaling inhibitor with the longest treatment duration.

23 September 2022 in Japanese Journal of Clinical Oncology
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Journal Article
Closed access
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KTKozaburo Tanuma
Kozaburo Tanuma
KKKoji Kawai
Koji Kawai
SNSatoshi Nitta
Satoshi Nitta
MSMasanobu Shiga
Masanobu Shiga
TKTakashi Kawahara
Takashi Kawahara
JMJun Miyazaki
Jun Miyazaki
The International Germ Cell Cancer Collaborative Group Update Consortium showed the improved survival of patients with a non-seminomatous germ cell tumor. We updated the survival data of the non-seminomatous germ cell tumor patients treated at our hospital. We analyzed the outcomes of 138 patients treated in 1981–2018. We compared the survival of the patients treated in the early (1981–99) and later (2000–18) periods and determined the groups’ progression-free survival and overall survival using the Kaplan–Meier method. We used a web-based application of the International Germ Cell Cancer Collaborative Group Update model to calculate each patient’s predicted 3-year progression-free survival. The 5-year progression-free survival rates of the good, intermediate and poor prognosis groups were 91, 83 and 64%, and their 5-year overall survival rates were 97, 89 and 82%, respectively. There were no significant differences in the progression-free survival or overall survival of the good and intermediate prognosis groups by treatment year. The 5-year progression-free survival of the poor prognosis group was almost identical in both treatment year (60 and 65%, respectively). By contrast, the 5-year overall survival in the later period (85%) was higher than that in the early period (70%). The median-predicted 3-year progression-free survival rates of the good, intermediate and poor prognosis groups were 92, 83 and 51% (P < 0.01), respectively. The concordance index for the good, intermediate and poor prognosis groups were 0.56, 0.79 and 0.67, respectively. The survival of our poor prognosis non-seminomatous germ cell tumor patients improved over time. The 5-year overall survival of patients treated in 2000–18 reached 85%.

5 July 2023 in Japanese Journal of Clinical Oncology
Verified
Journal Article
Open access
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STSatoru Taguchi
Satoru Taguchi
MOMizuki Onozawa
Mizuki Onozawa
SHShiro Hinotsu
Shiro Hinotsu
TKTaketo Kawai
Taketo Kawai
TMTakeshi Mitomi
Takeshi Mitomi
HKHaruki Kume
Haruki Kume
This multicenter, retrospective, observational study investigated baseline characteristics and clinical outcomes in patients with hormone-sensitive prostate cancer who received primary androgen deprivation therapy, using Japan Study Group of Prostate Cancer registry data. Among patients in the Japan Study Group of Prostate Cancer registry, those who initiated primary androgen deprivation therapy and were aged 20 years or older were enrolled in this study. The primary endpoint was time to disease progression, defined as time from primary androgen deprivation therapy initiation to either prostate-specific antigen or clinical progression. Secondary endpoints included prostate-specific antigen progression-free survival, prostate-specific antigen response (90% or greater reduction from baseline) and distribution of second-line treatment. Of the 2494 patients (goserelin, n = 564; leuprorelin, n = 1148; surgical castration, n = 161; degarelix, n = 621), those who received degarelix had higher prostate-specific antigen levels and Gleason scores and were at a more advanced clinical stage than those receiving goserelin or leuprorelin. The median time to disease progression (identical to the prostate-specific antigen progression-free survival result) was not reached for goserelin and leuprorelin, 52.7 months for surgical castration and 54.0 months for degarelix. Although baseline prostate-specific antigen values in the degarelix cohort were higher than those of the leuprorelin or goserelin cohorts, prostate-specific antigen responses were not different among the three cohorts. Regarding second-line treatment, the largest patient group received degarelix followed by leuprorelin (n = 195). This study clarified patient characteristics and long-term effectiveness of primary androgen deprivation therapy in real-world clinical practice. Japanese urologists appear to select appropriate primary androgen deprivation therapy based on patient background and tumour characteristics, with degarelix largely reserved for higher risk patients.

24 October 2020 in Cancer Medicine
Verified
Journal Article
Open access
PDF file
JLjasmine Lim
jasmine Lim
SHShiro Hinotsu
Shiro Hinotsu
MOMizuki Onozawa
Mizuki Onozawa
RMRohan Malek
Rohan Malek
MSMurali Sundram
Murali Sundram
HAHideyuki Akaza
Hideyuki Akaza
The J‐CAPRA score is an assessment tool which stratifies risk and predicts outcome of primary androgen deprivation therapy (ADT) using prostate‐specific antigen, Gleason score, and clinical TNM staging. Here, we aimed to assess the generalisability of this tool in multi‐ethnic Asians. Performance of J‐CAPRA was evaluated in 782 Malaysian and 16,946 Japanese patients undergoing ADT from the Malaysian Study Group of Prostate Cancer (M‐CaP) and Japan Study Group of Prostate Cancer (J‐CaP) databases, respectively. Using the original J‐CAPRA, 69.6% metastatic (M1) cases without T and/or N staging were stratified as intermediate‐risk disease in the M‐CaP database. To address this, we first omitted clinical T and N stage variables, and calculated the score on a 0–8 scale in the modified J‐CAPRA scoring system for M1 patients. Notably, treatment decisions of M1 cases were not directly affected by both T and N staging. The J‐CAPRA score threshold was adjusted for intermediate (modified J‐CAPRA score 3–5) and high‐risk (modified J‐CAPRA score ≥6) groups in M1 patients. Using J‐CaP database, validation analysis showed that overall survival, prostate cancer‐specific survival, and progression‐free survival of modified intermediate and high‐risk groups were comparable to those of original J‐CAPRA (p > 0.05) with Cohen's coefficient of 0.65. Around 88% M1 cases from M‐CaP database were reclassified into high‐risk category. Modified J‐CAPRA scoring system is instrumental in risk assessment and treatment outcome prediction for M1 patients without T and/or N staging.