Kazuyuki Numakura

Dr. Kazuyuki Numakura

orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

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

Representative Publications

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4 January 2012 in World Journal of Surgical Oncology
Verified
Journal Article
Open access
PDF file
SNShintaro Narita
Shintaro Narita
NTNorihiko Tsuchiya
Norihiko Tsuchiya
TKTeruaki Kumazawa
Teruaki Kumazawa
SMShinya Maita
Shinya Maita
KNKazuyuki Numakura
Kazuyuki Numakura
THTomonori Habuchi
Tomonori Habuchi
Background: To assess the outcome of neoadjuvant chemohormonal therapy comprising complete androgen blockade followed by treatment with docetaxel and estramustine phosphate before radical prostatectomy in Japanese patients with a high risk of localized prostate cancer (PCa). Methods: Complete androgen blockade followed by 6 cycles of docetaxel (30 mg/m2) with estramustine phosphate (560 mg) were given to 18 PCa patients before radical prostatectomy. Subsequently, the clinical and pathological outcomes were analyzed. Results: No patients had severe adverse events during chemohormonal therapy, and hence they were treated with radical prostatectomy. Two patients (11.1%) achieved pathological complete response. Surgical margins were negative in all patients. At a median follow-up of 18 months, 14 patients (77.8%) were disease-free without PSA recurrence. All 4 patients with PSA recurrence had pathologic T3b or T4 disease and 3 of these 4 patients had pathologic N1 disease. Conclusion: We found that neoadjuvant chemohormonal therapy with complete androgen blockade followed by treatment with docetaxel and estramustine phosphate before radical prostatectomy was safe, feasible, and associated with favorable pathological outcomes in patients with a high risk of localized PCa.

11 March 2021 in BMC Cancer
Verified
Journal Article
Open access
PDF file
OGon behalf of the Japanese Urological Oncology Group
on behalf of the Japanese Urological Oncology Group
Makito MiyakeMakito Miyake
Makito Miyake
KIKota Iida
Kota Iida
NNNobutaka Nishimura
Nobutaka Nishimura
TMTatsuki Miyamoto
Tatsuki Miyamoto
HNHiroyuki Nishiyama
Hiroyuki Nishiyama
Background: To explore possible solutions to overcome chronic Bacillus Calmette–Guérin (BCG) shortage affecting seriously the management of non-muscle invasive bladder cancer (NMIBC) in Europe and throughout the world, we investigated whether non-maintenance eight-dose induction BCG (iBCG) was comparable to six-dose iBCG plus maintenance BCG (mBCG). Methods: This observational study evaluated 2669 patients with high- or highest-risk NMIBC who treated with iBCG with or without mBCG during 2000–2019. The patients were classified into five groups according to treatment pattern: 874 (33%) received non-maintenance six-dose iBCG (Group A), 405 (15%) received six-dose iBCG plus mBCG (Group B), 1189 (44%) received non-maintenance seven−/eight-dose iBCG (Group C), 60 (2.2%) received seven−/eight-dose iBCG plus mBCG, and 141 (5.3%) received only ≤5-dose iBCG. Recurrence-free survival (RFS), progression-free survival, and cancer-specific survival were estimated and compared using Kaplan–Meier analysis and the log-rank test, respectively. Propensity score-based one-to-one matching was performed using a multivariable logistic regression model based on covariates to obtain balanced groups. To eliminate possible immortal bias, 6-, 12-, 18-, and 24-month conditional landmark analyses of RFS were performed. Results: RFS comparison confirmed that mBCG yielded significant benefit following six-dose iBCG (Group B) in recurrence risk reduction compared to iBCG alone (groups A and C) before (P < 0.001 and P = 0.0016, respectively) and after propensity score matching (P = 0.001 and P = 0.0074, respectively). Propensity score-matched sequential landmark analyses revealed no significant differences between groups B and C at 12, 18, and 24 months, whereas landmark analyses at 6 and 12 months showed a benefit of mBCG following six-dose iBCG compared to non-maintenance six-dose iBCG (P = 0.0055 and P = 0.032, respectively). There were no significant differences in the risks of progression and cancer-specific death in all comparisons of the matched cohorts. Conclusions: Although non-maintenance eight-dose iBCG was inferior to six-dose iBCG plus mBCG, the former might be an alternative remedy in the BCG shortage era. To overcome this challenge, further investigation is warranted to confirm the real clinical value of non-maintenance eight-dose iBCG.

18 May 2018 in Oncotarget
Verified
Journal Article
Open access
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KNKazuyuki Numakura
Kazuyuki Numakura
NFNobuhiro Fujiyama
Nobuhiro Fujiyama
MTMakoto Takahashi
Makoto Takahashi
RIRyoma Igarashi
Ryoma Igarashi
HTHiroshi Tsuruta
Hiroshi Tsuruta
THTomonori Habuchi
Tomonori Habuchi
Clinical implications of pharmacokinetics of sunitinib malate and N-desethyl-sunitinib plasma concentrations for treatment outcome in metastatic renal cell carcinoma patients Clinical implications of pharmacokinetics of sunitinib malate and N-desethyl-sunitinib plasma concentrations for treatment outcome in metastatic renal cell carcinoma patients

1 March 2013 in Anti-Cancer Drugs
Verified
Journal Article
Closed access
NTNorihiko Tsuchiya
Norihiko Tsuchiya
SNShintaro Narita
Shintaro Narita
TITakamitsu Inoue
Takamitsu Inoue
NHNaoko Hasunuma
Naoko Hasunuma
KNKazuyuki Numakura
Kazuyuki Numakura
THTomonori Habuchi
Tomonori Habuchi
The aim of this study was to evaluate the clinical factors, drug-related genetic polymorphisms, and human leukocyte antigen (HLA) types to determine the association with sorafenib-induced high-grade skin rash (HGSR) in Japanese patients with advanced renal cell carcinoma (RCC). A total of 55 patients with advanced RCC treated with sorafenib were analyzed retrospectively. Of these, 33 patients were subjected to HLA typing and polymorphism analyses of CYP3A5, ABCB1, ABCC2, and UGT1A1, which are involved in the metabolism and membrane transport of sorafenib. Grade 3 or higher SR developed in 12 (22%), and a higher incidence was observed in female patients than in male patients (40 vs. 15%, P=0.046). The initial dose, initial dose per body weight, and initial dose per body surface area in patients with HGSR were significantly higher than those in patients without HGSR. Patients with the ABCC2 -24CC genotype were at a significantly higher risk of SR than those with the CT genotype (35 vs. 0%, P=0.032). HLA-A*24 was significantly associated with the occurrence of HGSR (P=0.049). Our finding suggested that women, higher initial dose per body weight or body surface area, the ABCC2 -24CC genotype, and HLA-A*24 are associated with the risk of sorafenib-induced HGSR in Japanese RCC patients.

13 October 2021 in Current Oncology
Verified
Journal Article
Open access
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SNShintaro Narita
Shintaro Narita
MSMitsuru Saito
Mitsuru Saito
KNKazuyuki Numakura
Kazuyuki Numakura
THTomonori Habuchi
Tomonori Habuchi
Benign ureteroenteric anastomosis strictures (UESs) are one of many critical complications that may cause irreversible disability following robot-assisted radical cystectomy (RARC). Previous studies have shown that the incidence rates of UES after RARC can reach 25.3%, with RARC having higher UES incidence rates compared to open radical cystectomy. Various known and unknown factors are involved in the occurrence of UES. To minimize the incidence of UES after RARC, our group has standardized the procedure and technique for intracorporeal urinary diversion by applying the following five strategies: (1) wide delicate dissection of the ureter and preservation of the periureteral tissues; (2) gentle handling of the ureter and security of periureteral tissues at the anastomotic site; (3) use of indocyanine green to confirm good blood supply; (4) standardization of the ample ureteral spatulation length for Wallace ureteroenteric anastomosis through objective measurements; and (5) development of an institutional standardized procedure manual. This review focused on the incidence, etiology, prevention, and management of UES after RARC to bring attention to the incidence of this complication while also proposing standardized surgical procedures to minimize its incidence after RARC.

1 September 2023 in Current Oncology
Verified
Journal Article
Open access
PDF file
KNKazuyuki Numakura
Kazuyuki Numakura
MKMizuki Kobayashi
Mizuki Kobayashi
YMYumina Muto
Yumina Muto
HSHiromi Sato
Hiromi Sato
YSYuya Sekine
Yuya Sekine
THTomonori Habuchi
Tomonori Habuchi
A recent approach to radiotherapy for prostate cancer is the administration of high doses of radiation to the prostate while minimizing the risk of side effects. Thus, image-guided radiotherapy utilizes advanced imaging techniques and is a feasible strategy for increasing the radiation dose. New radioactive particles are another approach to achieving high doses and safe procedures. Prostate brachytherapy is currently considered as a combination therapy. Spacers are useful to protect adjacent organs, specifically the rectum, from excessive radiation exposure.