KTKazumasa Torimoto

Kazumasa Torimoto

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Previous Organizations / Institutes

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Kazumasa Torimoto has a total of 256 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Characteristics of Children Successfully Treated for Daytime Urinary Incontinence

    by Yosuke Morizawa, Kosuke Mieda, Akira Tachibana, Mitsuru Tomizawa, Kenta Onishi, Shunta Hori, Daisuke Gotoh, Yasushi Nakai, Makito Miyake, Kazumasa Torimoto, et al.

    Objective: A stepwise approach is recommended for the treatment of daytime urinary incontinence, with standard urotherapy as the first‐line treatment, followed by pharmacological treatment when standard urotherapy is unsuccessful. This study was aimed at characterizing and comparing children with an overactive bladder and daytime urinary incontinence who became continent solely on standard urotherapy and those who achieved continence on a combination of standard urotherapy and pharmacological treatment.Methods: This retrospective study included 221 patients with complete continence during the day.Results: Of these patients, 104 (47%) were successfully treated with standard urotherapy, and 117 (53%) required pharmacological treatment. Children who achieved continence on a combination of standard urotherapy and pharmacological treatment had significantly more baseline incontinence episodes during the daytime (p = 0.001) and lower voided volumes (voided volume/estimated bladder capacity: 37 and 42 mL respectively, p = 0.0085) compared with children who were treated with standard urotherapy only. Half the patients underwent an initial screening, including the use of a bladder diary, without the need for time‐consuming and complex urotherapy.Conclusions: Most children achieved daytime continence solely through standard urotherapy. Additionally, half of the patients achieved continence at the initial screening, including the use of the bladder diary. Children requiring additional pharmacological treatment to achieve continence have more severely overactive bladders.


  • Open Access

    Immunosuppressant-Induced Alteration of Gut Microbiota Causes Loss of Skeletal Muscle Mass: Evidence from Animal Experiments Using Mice and Observational Study on Humans

    by Mitsuru Tomizawa, Shunta Hori, Tatsuo Yoneda, Fumisato Maesaka, Sayuri Onishi, Takuto Shimizu, Kenta Onishi, Yosuke Morizawa, Daisuke Gotoh, Yasushi Nakai, et al.

    Background/Objectives: The number of older adults requiring a kidney transplant (KT) is increasing; hence, postoperative sarcopenia prevention is necessary. KT recipients require permanent oral immunosuppressants (ISs), and the gut microbiota (GM) plays a role in various systemic diseases. However, few studies have evaluated post-kidney transplantation frailty and the associations among ISs, GM, and muscle mass alterations. Therefore, we investigated the effects of ISs on GM and skeletal muscle mass in mice and human KT recipients. Methods: Mice were treated with six different ISs, and their skeletal muscle mass, GM diversity, and colonic mucosal function were assessed. Human KT recipients and donors were monitored before and after surgery for 1 year, and GM diversity was evaluated before and 1 month after surgery. Results: The abundance of Akkermansia, crypt depth, and mucin 2 expression were lower in tacrolimus- and prednisolone-treated mice. The psoas muscle volume changes at 1 month and 1 year after surgery were lower in KT recipients than in donors. Furthermore, the beta diversity was significantly different between the operative groups (p = 0.001), and the KT group showed the lowest Shannon index. Conclusions: The findings of this study indicate potential links among ISs, GM, and muscle mass decline. Further investigation is required to improve therapeutic strategies and patient outcomes.

  • Intraoperative tumor capsule injury in patients with renal cell carcinoma receiving partial nephrectomy

    by Takuto Shimizu, Makito Miyake, Kazuki Ichikawa, Nobutaka Nishimura, Mitsuru Tomizawa, Kenta Onishi, Shunta Hori, Yosuke Morizawa, Daisuke Gotoh, Yasushi Nakai, et al.

    Objective: We investigated the impact of intraoperative tumor capsule injury (TCI) during robot‐assisted partial nephrectomy (RAPN) or laparoscopic partial nephrectomy (LPN) on oncological outcomes, as well as underlying factors of intraoperative TCI for improving surgical outcomes.Methods: A total of 253 patients who underwent RAPN or LPN between 2010 and 2022 were retrospectively analyzed and were divided into two groups: non‐TCI and TCI groups. The background was compared between two groups. We investigated the surgical records or video to evaluate TCI and seek the possible causes for TCI. Multivariate logistic regression analysis was performed to identify prognostic factors for cancer recurrence.Results: Of the 253 patients, 227 have renal cell carcinoma (RCC), with 29 patients having TCI. The TCI group had larger tumors, a lower rate of trifecta achievement, higher bleeding, higher T stage, and a lower rate of clear cell RCC (ccRCC) histological types as compared to non‐TCI group. Disease recurrence rate was 13.8% with TCI and 1.0% with non‐TCI (odds ratio 15.7; 95% confidence interval, 2.73–90.1; p = 0.003). Univariate and multivariate analyses confirmed TCI as an independent prognostic factor for disease‐free survival. Compared with ccRCC, non‐clear cell RCC (non‐ccRCC) was found to have a higher probability of TCI and a significantly thinner capsule thickness on pathological evaluation.Conclusion: TCI had a negative impact on oncological outcomes. Surgeons should consider thickness of tumor capsules, especially in cases with non‐ccRCC, to minimize the risk of TCI during partial nephrectomy.


  • Feasibility of approximate measurement of bladder volume in children using the Lilium α‐200 portable bladder scanner

    by Yosuke Morizawa, Shunta Hori, Daisuke Gotoh, Yasushi Nakai, Kazumasa Torimoto, Kiyohide Fujimoto


  • Difference of oncological efficacy between two immune checkpoint inhibitors following first-line platinum-based chemotherapy in patients with unresectable, metastatic, advanced urothelial carcinoma: a multicenter real-world Japanese cohort

    by Makito Miyake, Nobutaka Nishimura, Yuki Oda, Tatsuki Miyamoto, Kota Iida, Kuniaki Inoue, Akira Tachibana, Takanosuke Yoshikawa, Keichi Sakamoto, Mikiko Ohnishi, et al.

    Background Maintenance avelumab is currently recommended for patients with unresectable and/or metastatic (mUC) achieving at least stable disease (SD) on first-line platinum-based chemotherapy (1L-CT). Pembrolizumab is an alternative therapeutic avenue for this patient cohort in clinical practice. We investigated real-world data, focusing on the correlation between response to 1L-CT and oncological efficacy of subsequent immune checkpoint inhibitor (ICI) therapy with avelumab or pembrolizumab. Methods A multicenter database registered 626 patients with mUC diagnosed from 2008–2023; among these, 175 receiving 2–6 cycles of 1L-CT followed by ICI therapy. Patients were categorized based on response to 1L-CT using the Response Evaluation Criteria in Solid Tumors (v1.1). Objective response rate on ICI, progression to ICI-free survival (ICI-PFS), and overall survival from start of 1L-CT were compared between avelumab-treated and pembrolizumab-treated patients in each response subgroup. Results ICI-PFS was significantly longer in patients achieving partial response on 1L-CT and subsequently receiving pembrolizumab compared to those receiving avelumab. Notably, patients achieving SD on 1L-CT and subsequently receiving pembrolizumab manifested significantly higher objective response rate (14% and 41%, respectively) and prolonged ICI-PFS relative to those receiving avelumab. In contrast, overall survival did not delineate difference between patients treated with avelumab versus pembrolizumab. Similar findings were discerned in the subanalysis of patients having favorable SD (tumor shrinkage, from − 29 to 0%) and unfavorable SD (tumor enlargement, from + 1 to + 19%) on 1L-CT. Conclusions Our study provides real-world evidence regarding difference of oncological efficacy between maintenance avelumab and subsequent pembrolizumab in patients with mUC who achieved partial response or SD on 1L-CT.


  • Open Access

    Routine Surveillance of Upper Urinary Tract Imaging for Diagnosing Upper Urinary Tract Urothelial Cancer Recurrence in Patients with Nonmuscle Invasive Bladder Cancer

    by Nobutaka Nishimura, Makito Miyake, Tatsuki Miyamoto, Takuto Shimizu, Tomomi Fujii, Yosuke Morizawa, Shunta Hori, Daisuke Gotoh, Yasushi Nakai, Kazumasa Torimoto, et al.

    Background. Although routine surveillance imaging to examine upper urinary tract urothelial cancer recurrence during follow-up of nonmuscle invasive bladder cancer is recommended, its necessity remains invalidated. A single-institute long-term follow-up cohort study to evaluate the clinical impact of routine surveillance imaging and identify risk factors for upper urinary tract urothelial cancer recurrence after nonmuscle invasive bladder cancer treatment was conducted. Methods and Materials. A retrospective chart review of 864 patients with primary nonmuscle invasive bladder cancer who underwent initial transurethral resection of bladder tumor between 1980 and 2020 was conducted. The opportunities to diagnose its recurrence were examined. Moreover, oncological outcomes included upper urinary tract urothelial cancer recurrence-free survival and overall survival. Results. Of 864 patients, 19 (2.2%) experienced upper urinary tract urothelial cancer recurrence. Among 19 patients, recurrence was detected through routine imaging in 12 (63.2%), cystoscopy in 2 (10.5%), urine cytology in 2 (10.5%), and presence of gross hematuria in 1 (5.3%). All patients had high- or highest-risk NMIBC at diagnosis of primary nonmuscle invasive bladder cancer. On multivariate Fine-Gray proportional regression analyses, a tumor size of ≥30 mm and carcinoma in situ were independently associated with short upper urinary tract urothelial cancer recurrence-free survival ( and 0.0089, respectively). Conclusion. Most patients experiencing upper urinary tract urothelial cancer recurrence were diagnosed by routine surveillance imaging, suggesting its clinical importance, especially for patients with nonmuscle invasive bladder cancer accompanied by a tumor size of ≥30 mm and carcinoma in situ.


  • Open Access

    Intravesical Injection of OnabotulinumtoxinA (Botulinum Toxin Type A) in Japanese Patients With Refractory Overactive Bladder

    by Daisuke Gotoh, Kazumasa Torimoto, Norimi Takamatsu, Kenta Onishi, Yosuke Morizawa, Shunta Hori, Yasushi Nakai, Makito Miyake, Kiyohide Fujimoto

    Background/Aim: Botulinum toxin intravesical injection therapy (hereafter, botulinum therapy) is approved in Japan for treating urinary urgency, frequency, and urinary incontinence due to refractory overactive bladder or neurogenic bladder. Although botulinum therapy is classified as urinary incontinence surgery, it is minimally invasive, effective, and safe. However, there are few reports on the actual use of botulinum therapy and examination of its effects and side-effects. Herein, we report real-world data on botulinum therapy. Patients and Methods: Patients who received botulinum therapy for refractory overactive bladder at the Nara Medical University and affiliated facilities from May 2020 to May 2022 were enrolled. The patient background, treatment efficacy, and safety were retrospectively reviewed. Results: Twenty-three cases of refractory overactive bladder (age: 68.4±14.1 years; 7 males, 16 females; 17 outpatient, 6 hospitalized) were enrolled. Pretreatment, the overactive bladder symptom score (OABSS) was 10.1±2.7, and post-void residual urine volume was 27.1±31.6 ml. Botulinum was administered once, twice, thrice, and four times in 11, eight, three, and one cases, respectively. OABSS decreased to 6.1±3.2 2 weeks after botulinum therapy (p<0.0001), and the effect persisted at 6.6±3.2 after 12 weeks (p<0.0001). Post-void residual urine volume increased to 74.6±79.2 ml after 2 weeks (p=0.0010), but subsequently improved to 33.9±42.0 ml after 12 weeks (p=0.0002). Adverse events included post-void residual urine volume of 200 ml or more in three patients (7.5%) and urinary retention grade 2 in two (5.0%). Conclusion: Botulinum therapy is effective and relatively safe for refractory overactive bladders.


  • Electroencephalography‐based investigation of the effects of oral desmopressin on improving slow‐wave sleep time in nocturnal polyuria patients (the DISTINCT study): A single‐arm, open‐label, single‐assignment trial

    by Kazumasa Torimoto, Daisuke Gotoh, Yasushi Nakai, Makito Miyake, Kiyohide Fujimoto

    Aims: To investigate changes in subjective and objective sleep quality after desmopressin administration in patients with nocturia due to nocturnal polyuria (NP) using electroencephalography (EEG) and the Pittsburgh sleep quality index (PSQI).Methods: Twenty male patients (≥65 years old) with NP participated in this study. The inclusion criteria were nocturnal frequency ≥ 2, NP index (NPi) ≥ 0.33, first uninterrupted sleep period (FUSP) ≤ 2.5 h, serum sodium concentration ≥ 135 mEq/L, and estimated glomerular filtration rate ≥ 50 mL/min/1.73 m2. Participants were given 50 μg of desmopressin to be taken orally once daily before bed. The primary endpoint was the change in the duration of slow‐wave sleep (nonrapid eye movement sleep stages 3 and 4), as evaluated by EEG 28 days from the baseline. The visual analog scale (VAS) was used as an additional indicator of sleep quality.Results: Analysis of data from 15 participants (median age: 74.0 [70.5, 76.0] years) revealed that from before to after desmopressin administration, significant decreases occurred in the median nocturnal frequency (3.0 [2.0, 4.0] to 1.5 [1.0, 2.0]) and NPi (0.445 [0.380, 0.475] to 0.360 [0.250, 0.430]). Furthermore, FUSP was significantly prolonged from 120.0 (94.0, 150.0) min to 210.0 (203.8, 311.3) min. Although the VAS scores improved, slow‐wave sleep duration and the PSQI global score showed no significant differences (68.50 [47.50, 75.50] and 48.00 [38.00, 66.50]; 5.0 [5.0, 10.0] and 7.0 [5.0, 9.0] min, respectively).Conclusion: Oral administration of 50 μg desmopressin improved nocturnal frequency and FUSP in older individuals with NP but did not significantly enhance sleep quality. In older adults, decreased nighttime urinary frequency may enhance quality of life; however, its influence on objective sleep quality may be limited.


  • Open Access

    Correction: Utility of a penile compression device for the quality of life in male patients with urinary incontinence after prostatectomy (the MORE study): a randomized prospective study

    by Daisuke Gotoh, Kazumasa Torimoto, Kenta Onishi, Yosuke Morizawa, Shunta Hori, Yasushi Nakai, Makito Miyake, Kiyohide Fujimoto

  • Open Access

    Impact of Complete Surgical Resection of Metastatic Lesions in Patients with Advanced Renal Cell Carcinoma in the Era of Tyrosine Kinase Inhibitors and Immune Checkpoint Inhibitors

    by Takuto Shimizu, Makito Miyake, Nobutaka Nishimura, Takanori Yoshida, Yoshitaka Itami, Akira Tachibana, Chihiro Omori, Yuki Oda, Mikiko Kohashi, Mitsuru Tomizawa, et al.

    Complete metastasectomy (CM) in metastatic renal cell carcinoma (mRCC) has demonstrated efficacy in the cytokine era, but its effectiveness in the era of tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs) remains unclear. A multi-institutional database included clinicopathological data of 367 patients with mRCC. Patients were divided into two groups: the CM group and the non-CM group. These two groups were compared before and after propensity score matching (PSM). Cox proportional hazard models were used to detect factors associated with disease-free survival (DFS) and overall survival (OS) from mRCC diagnosis. The CM group showed a significant association with longer overall survival compared to the non-CM group in the PSM-unadjusted cohorts (p < 0.001, hazard ratio 0.49, 95% confidence interval 0.35–0.69), but no superiority was noted in the adjusted cohorts. The median DFS after CM was 24 months, with no significant differences based on relapse timing. Notably, the international metastatic RCC database consortium risk categories and metastatic burden were associated with DFS. This study supports the potential of CM in mRCC management during the TKI/ICI era, although limitations including sample size and selection bias need to be considered.