Details of a Researcher - Oya, Mototsugu

Papers - Oya, Mototsugu

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Prognostic value of neutrophil-to-lymphocyte ratio in patients with metastatic renal cell carcinoma treated with first-line and subsequent second-line targeted therapy

Tanaka Nobuyuki, Mizuno Ryuichi, Yasumizu Yota, Ito Keiichi, Shirotake Suguru, Masunaga Ayako, Ito Yujiro, Miyazaki Yasumasa, Hagiwara Masayuki, Kanao Kent, Mikami Shuji, Nakagawa Ken, Momma Tetsuo, Masuda Takeshi, Asano Tomohiko, Oyama Masafumi, Oya Mototsugu

Urologic Oncology: Seminars and Original Investigations 35 ( 2 ) 39.e19 - 39.e28 2017.02

ISSN 1078-1439

Purpose The International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) risk model has been designed for prognostification in patients with metastatic renal cell carcinoma (mRCC) treated with targeted therapy. One factor is neutrophil count; however, increasing evidence has suggested the superiority of neutrophil-to-lymphocyte ratio (NLR) for predicting outcome. In this study, we evaluate the prognostic effect of NLR levels on patients with mRCC treated with targeted therapy, and then we compare the predictive accuracy of the IMDC risk model and its modified one by using NLR, instead of neutrophil count. Patients and method A total of 277 patients are included for the analysis. All patients underwent targeted therapies and associated outcome are assessed using multivariate analysis. Results Pretreatment NLR levels are elevated in 30.3% and 23.1% of patients in the first-line and subsequent second-line setting, respectively. Kaplan-Meier curves reveal that elevated pretreatment NLR is significantly associated with poor overall survival (OS) since first-line (P<0.001) and second-line targeted therapy administration (P<0.001). Also, multivariate analyses show that elevated pretreatment NLR is an independent predictor for poor OS since first-line and second-line targeted therapy administration. The addition of NLR to the IMDC risk model, instead of neutrophil count, significantly improves the predictive accuracy for OS, and estimated gain is 1.7% and 6.2% in first-line and second-line targeted therapy, respectively. Conclusion Changes in NLR levels could be predictive for prognosis in patients with mRCC treated with first-line and second-line targeted therapy. The addition of NLR significantly improves the predictive accuracy of the IMDC risk model in the first-line and subsequent second-line setting.

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IJU this issue

Oya Mototsugu

International Journal of Urology 24 ( 2 ) 93 2017.02

ISSN 0919-8172

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Immunohistochemistry of aldosterone synthase leads the way to the pathogenesis of primary aldosteronism

Nishimoto, Koshiro, Koga, Minae, Seki, Tsugio, Oki, Kenji, Gomez-Sanchez, Elise P., Gomez-Sanchez, Celso E., Naruse, Mitsuhide, Sakaguchi, Tomokazu, Morita, Shinya, Kosaka, Takeo, Oya, Mototsugu, Ogishima, Tadashi, Yasuda, Masanori, Suematsu, Makoto, Kabe, Yasuaki, Omura, Masao, Nishikawa, Tetsuo, Mukai, Kuniaki

MOLECULAR AND CELLULAR ENDOCRINOLOGY 441 ( C ) 124 - 133 2017.02

Research paper (scientific journal), ISSN 0303-7207

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Diagnosis of Renal Angiomyolipomas: Classic, Fat-Poor, and Epithelioid Types

Jinzaki, Masahiro, Silverman, Stuart G., Akita, Hirotaka, Mikami, Shuji, Oya, Mototsugu

SEMINARS IN ULTRASOUND CT AND MRI 38 ( 1 ) 37 - 46 2017.02

Research paper (scientific journal), ISSN 0887-2171

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Role of metastasectomy in patients with metastatic renal cell carcinoma

Takamatsu Kimiharu, Oya Mototsugu

Japanese Journal of Clinical Urology 71 ( 13 ) 1096 - 1100 2017.01

ISSN 0385-2393

Novel algorithm for management of acute epididymitis

Hongo Hiroshi, Kikuchi Eiji, Matsumoto Kazuhiro, Yazawa Satoshi, Kanao Kent, Kosaka Takeo, Mizuno Ryuichi, Miyajima Akira, Saito Shiro, Oya Mototsugu

International Journal of Urology 24 ( 1 ) 82 - 87 2017.01

ISSN 0919-8172

Objectives: To identify predictive factors for the severity of epididymitis and to develop an algorithm guiding decisions on how to manage patients with this disease. Methods: A retrospective study was carried out on 160 epididymitis patients at Keio University Hospital. We classified cases into severe and non-severe groups, and compared clinical findings at the first visit. Based on statistical analyses, we developed an algorithm for predicting severe cases. We validated the algorithm by applying it to an external cohort of 96 patients at Tokyo Medical Center. The efficacy of the algorithm was investigated by a decision curve analysis. Results: A total of 19 patients (11.9%) had severe epididymitis. Patient characteristics including older age, previous history of diabetes mellitus and fever, as well as laboratory data including a higher white blood cell count, C-reactive protein level and blood urea nitrogen level were independently associated with severity. A predictive algorithm was created with the ability to classify epididymitis cases into three risk groups. In the Keio University Hospital cohort, 100%, 23.5%, and 3.4% of cases in the high-, intermediate-, and low-risk groups, respectively, became severe. The specificity of the algorithm for predicting severe epididymitis proved to be 100% in the Keio University Hospital cohort and 98.8% in the Tokyo Medical Center cohort. The decision curve analysis also showed the high efficacy of the algorithm. Conclusions: This algorithm might aid in decision-making for the clinical management of acute epididymitis.

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Imaging features of renal cell carcinoma differential diagnosis, staging, and posttreatment evaluation

Jinzaki Masahiro, Akita Hirotaka, Oya Mototsugu

139 - 176 2017.01

With the widespread use of ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI), there has been an increase in the detection of various subtypes of renal cell carcinomas (RCCs) and benign renal tumors. The differentiation of RCCs from benign tumors such as fat-poor angiomyolipoma and oncocytoma is very important to prevent unnecessary surgery. In addition, the recent progress of therapies to treat RCCs, including nephronsparing surgery, percutaneous ablative procedures, and targeted antiangiogenic therapies, has increased the need for the accurate determination of subtypes and staging. With the development of imaging modalities, there have been significant improvements in correlating preoperative imaging with pathologic characteristics. Many studies performed within the last two decades have helped to clarify diagnostic imaging clues for both cystic and solid renal tumors. In this chapter, we discuss the current status of US, CT, and MRI for the detection and differential diagnosis of renal tumors as well as staging, postprocedural imaging, and imaging for the targeted antiangiogenic treatment of RCC.

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Refractory mechanisms

Oya Mototsugu, Shinojima Toshiaki, Mizuno Ryuichi

351 - 367 2017.01

Vascular endothelial growth factor (VEGF)-targeted agents have brought significant progress in pharmacotherapy of advanced renal cell carcinoma (RCC). Some RCCs, however, appear to have innate resistance to treatment. Moreover, majority of patients who primarily respond to VEGF-targeted therapy eventually develop disease progression after prolonged treatment. The mechanism of resistance is supposed to be so multifactorial that it cannot be explained by single molecular events. Despite various factors including cytokines, bone marrowderived cells, microenvironment, and genetic or epigenetic abnormality could be involved, tumor hypoxia seems to play one of crucial roles in most of the processes. The multiple mechanism in developing drug resistance might just represent the diversity of cellular response to hypoxia and nutrient deprivation, induced by the disruption of the blood vessels. In this chapter we comprehensively review current efforts aiming to clarify these process and to develop pharmacological strategies leading to overcome the drug resistance in RCC.

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Headache caused by brain metastases of castration-resistant prostate cancer during cabazitaxel therapy

Watanabe Keitaro, Kosaka Takeo, Hongo Hiroshi, Tamaki Satoshi, Oya Mototsugu

Keio Journal of Medicine 66 ( 4 ) 65 - 71 2017.01

ISSN 0022-9717

We describe the case of a 55-year-old man who underwent four cycles of cabazitaxel therapy for castration- resistant prostate cancer (CRPC). After the fourth cycle of cabazitaxel, the patient experienced severe headaches. Brain gadolinium (Gd) contrast-enhanced magnetic resonance imaging (MRI) revealed multiple brain metastases. A few days later, the patient suffered impaired consciousness that progressed rapidly. The patient was treated for the symptoms of increased intracranial pressure and underwent whole-brain radiation. One month later, the patient’s consciousness level and headache had improved. Although brain metastases of prostate cancer are rare, the possibility of brain metastases should be considered for prostate cancer patients, especially when a CRPC patient complains of headache. Additionally, even if major conditions such as cerebral hemorrhage are excluded by the use of non-contrast enhanced computed tomography, brain Gd contrast-enhanced MRI should be performed in consideration of the possibility of brain metastases of prostate cancer.

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Preface

Oya Mototsugu

v - vii 2017.01

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Purified protein derivative skin test reactions are associated with clinical outcomes of patients with nonmuscle invasive bladder cancer treated with induction bacillus Calmette-Guérin therapy

Niwa Naoya, Kikuchi Eiji, Matsumoto Kazuhiro, Kosaka Takeo, Mizuno Ryuichi, Oya Mototsugu

Urologic Oncology: Seminars and Original Investigations (Urologic Oncology: Seminars and Original Investigations) 36 ( 2 ) 77.e15 - 77.e21 2017.01

Research paper (scientific journal), Joint Work, ISSN 1078-1439

Objectives: To investigate the relationship between purified protein derivative (PPD) skin test reactions before bacillus Calmette-Guérin (BCG) therapy and the clinical outcomes of BCG-naïve nonmuscle invasive bladder cancer patients treated with adjuvant BCG therapy. Materials and methods: A total of 288 nonmuscle invasive bladder cancer patients subjected to the PPD skin test before BCG therapy were included. PPD skin test reactions were categorized into 3 groups: positive, slightly positive, and negative. The presence of an induration was positive. If an induration was absent, erythema of 10. mm or more and less than 10. mm corresponded to slightly positive and negative, respectively. Results: A total of 66 (22.9%), 149 (51.7%), and 73 (25.3%) patients exhibited a positive, slightly positive, and negative to PPD skin test, respectively. The 5-year recurrence-free survival rate of patients with positive PPD skin test reactions was 89.4 ± 4.1%, which was significantly higher than those of patients with slightly positive (65.5 ± 4.2%, P = 0.001) and negative reactions (56.4 ± 6.6%, P<0.001). A multivariate Cox regression analysis revealed that a positive PPD skin test reaction was independently associated with tumor recurrence (hazard ratio of 0.233, P<0.001), but not with stage progression. The incidence of fever persisting for more than 2 days or fever of ≥38°C was significantly higher in patients with a positive PPD skin test reaction (18.2%) than in patients with slightly positive (8.7%) and negative PPD skin test reactions (4.1%). Conclusions: The PPD skin test reactions before BCG therapy may predict clinical outcomes following BCG therapy and help clinicians counsel patients exhibiting strong therapeutic effects with BCG therapy and potentially major BCG-related side effects.

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The Conditional Survival with Time of Intravesical Recurrence of Upper Tract Urothelial Carcinoma

Shigeta Keisuke, Kikuchi Eiji, Hagiwara Masayuki, Ando Toshiyuki, Mizuno Ryuichi, Abe Takayuki, Mikami Shuji, Miyajima Akira, Nakagawa Ken, Oya Mototsugu

Journal of Urology (ELSEVIER SCIENCE INC) 198 ( 6 ) 1278 - 1285 2017

ISSN 0022-5347

Purpose: Since conditional survival analysis provides better estimates of survival time at each followup, we assessed changes in conditional intravesical recurrence-free survival rates after radical nephroureterectomy. We also sought to determine how the impact of well-known risk factors evolves with time, particularly in patients with localized upper tract urothelial carcinoma. Materials and Methods: We identified 364 patients with Ta-3N0M0 localized upper tract urothelial carcinoma who underwent open or laparoscopic radical nephroureterectomy at 1 of our 3 institutions. Conditional intravesical recurrence-free and cancer specific survival rates were calculated using the Kaplan-Meier method. The changing impact of parameters on intravesical recurrence with time was assessed by multivariate Cox regression analysis. Results: Intravesical recurrence after radical nephroureterectomy was detected in 176 patients (48.4%) and 93 (25.5%) died of localized upper tract urothelial carcinoma. Five-year intravesical recurrence-free and cancer specific survival rates after surgery were 41.5% and 72.9%, respectively. Based on 1, 2, 3 and 4-year survivorship the 5-year conditional intravesical recurrence-free survival rate increased from 41.5% to 60.5%, 73.4%, 79.5% and 96.7%, respectively. The 5-year conditional cancer specific survival rate also improved from 72.9% to 78.4%, 85.4%, 90.9% and 95.5% at 1, 2, 3 and 4 years, respectively. The effects of well-known predictive factors on estimated conditional survival decreased with time for intravesical recurrence. In contrast, the impact of T2 or lower pathological stage and laparoscopic radical nephroureterectomy sustained statistical power with time. Conclusions: Conditional survival analysis revealed that the probability of intravesical recurrence-free survival increased with time in patients with localized Ta-3N0M0 upper tract urothelial carcinoma after radical nephroureterectomy. Patients with T2 or lower T stage who undergo laparoscopic radical nephroureterectomy may be recommended for longer followup to detect subsequent intravesical recurrence.

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Obstructive azoospermia caused by low ligation of varicocele: A case report

Hagiuda, Jun, Ishikawa, Hiromichi, Hagiwara, Masayuki, Kono, Hidaka, Nakagawa, Ken, Oya, Mototsugu

SYSTEMS BIOLOGY IN REPRODUCTIVE MEDICINE (TAYLOR & FRANCIS INC) 63 ( 5 ) 338 - 339 2017

Research paper (scientific journal), ISSN 1939-6368

© 2017 Taylor & Francis. Varicocele is commonly observed in male partners of infertile couples. The surgical ligation of varicoceles under microscopy can be safely performed by a skilled andrologist with most patients subsequently experiencing an improvement in semen quality. This is the first case in which obstructive azoospermia occurred after high inguinal varicocelectomy. The vas deferens was disrupted near the internal inguinal ring by fibrous tissue. A vasovasostomy was performed and semen parameters subsequently recovered.

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Overall survival of first-line axitinib in metastatic renal cell carcinoma

Oya Mototsugu, Tomita Yoshihiko, Fukasawa Satoshi, Shinohara Nobuo, Habuchi Tomonori, Rini Brian I., Fujii Yosuke, Kamei Yoichi, Umeyama Yoshiko, Bair Angel H., Uemura Hirotsugu

Cancer Science 2017

ISSN 1347-9032

Subgroup analyses of a randomized global phase II study of axitinib showed objective response rate of 66% and median progression-free survival of 27.6 months in treatment-naïve Japanese patients with metastatic renal cell carcinoma (RCC). This analysis evaluated overall survival (OS) and safety in 44 Japanese patients and compared the results with 169 non-Japanese patients. In addition, baseline characteristics for predictive factors that may influence OS in first-line metastatic RCC were explored in all patients using a Cox proportional hazard model. With median follow-up of 33 months, fewer than half (16 of 44) of the Japanese patients had died and median OS was not reached (95% confidence interval [CI], 38.8 months-not estimable), whereas 107 of 169 (63%) non-Japanese patients had died and median OS was 33.9 months (95% CI, 28.9-42.7). Estimated 1-year, 2-year and 3-year survival probability (95% CI) was 86.4% (76.2-96.5), 75.0% (62.2-87.8) and 68.2% (54.4-81.9), respectively, in Japanese patients, and was higher than that in non-Japanese patients (75.1% [68.4-81.8], 62.1% [54.5-69.7] and 47.2% [39.3-55.1], respectively). The updated safety analysis did not reveal any new adverse events of concern among Japanese or non-Japanese patients. The multivariate analysis identified that lower baseline Eastern Cooperative Oncology Group performance status, lower baseline tumor burden, and longer time from histopathological diagnosis to treatment were significant positive predictors of OS. The current analysis confirmed the clinical activity of axitinib in treatment-naïve Japanese patients with metastatic RCC, with an acceptable toxicity profile.

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Cost analysis of leuprorelin acetate in Japanese prostate cancer patients: comparison between 6-month and 3-month depot formulations

Goto, Rei, Uda, Akihito, Hiroi, Shinzo, Iwasaki, Kosuke, Takashima, Kenta, Oya, Mototsugu

JOURNAL OF MEDICAL ECONOMICS (TAYLOR & FRANCIS LTD) 20 ( 11 ) 1155 - 1162 2017

Research paper (scientific journal), ISSN 1369-6998

© 2017 Informa UK Limited, trading as Taylor & Francis Group. Aims: This study aimed to evaluate the economic value for leuprorelin acetate 6-month depot compared with leuprorelin acetate 3-month depot from a societal perspective in Japanese prostate cancer patients. Methods: The cost analysis estimated the reduction in direct and indirect costs as well as intangible costs saved by having one less injection. Claims data were used for the analyses of direct and indirect costs reduction. A discrete choice experiment based on a web-based survey estimated the monetary value of the intangible costs for one injection. Another web-based survey of prostate cancer patients, who had received treatment with leuprorelin acetate injections, was carried out to calibrate the results of the discrete choice experiment. Results: Reductions in medical costs and loss of productivity for having one less injection in prostate cancer patients receiving leuprorelin acetate were JPY 5,670 and JPY 1,723, respectively. Intangible costs saved by using a 6-month depot formulation instead of a 3-month depot formulation for the injection of leuprorelin acetate were estimated to be JPY 19,872, including the values for a reduction in pain (JPY 3,131), injection site reactions (JPY 11,545), waiting time (JPY 9,479), and subtracting the value of medical consultation (JPY 4,283). The total cost reduction for having one less injection was JPY 27,265. Limitations: The respondents from the internet panel provided by a survey company are not necessarily a representative population of Japanese society. Conclusions: Leuprorelin acetate 6-month depot has an advantage in monetary value in the reduction in medical costs, loss of productivity, and intangible costs for having one less injection in prostate cancer patients compared with leuprorelin acetate 3-month depot. In the costs for treating with leuprorelin acetate, the percentage of intangible costs might not be negligible. The intangible costs will probably be actively evaluated to proceed to patient-centered healthcare in society.

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Ra-223 SPECT for semi-quantitative analysis in comparison with Tc-99m HMDP SPECT

Owaki Yoshiki, Nakahara Tadaki, Kosaka Takeo, Fukada Junichi, Kumabe Atsuhiro, Ichimura Akira, Murakami Mikoto, Nakajima Kiyotaka, Fukushi Masahiro, Inoue Kazumasa, Oya Mototsugu, Jinzaki Masahiro

EJNMMI Research 7 2017

ISSN 2191-219X

Background: Image-based measurement of absorbed dose of Ra-223 dichloride may be useful in predicting therapeutic outcome in patients with castration-resistant prostate cancer (CRPC). In general, SPECT has been found to be more accurate than planar imaging in terms of lesion-based analysis. The aims of this study were to assess the feasibility and clinical usefulness of Ra-223 SPECT. The energy spectrum of Ra-223 and SPECT images of a cylindrical phantom with a hot rod were obtained to determine the collimator candidates and energy window settings suitable for clinical Ra-223 SPECT (basic study A). Another phantom with a tube-shaped chamber and two spheres simulating bowel activity and metastatic lesions in the lumbar spine was scanned with medium-energy general-purpose (MEGP) and high-energy general-purpose (HEGP) collimators (basic study B). Ten patients with CRPC underwent SPECT imaging 2 h after Ra-223 injection successively with MEGP and HEGP collimators in random order for 30 min each. Lesion detectability and semi-quantitative analyses of bone metastasis (i.e. lesion-to-background ratio (LBR)) were performed compared to Tc-99m HMDP SPECT. Results: Basic study A revealed that an 84-keV photopeak ± 20% using the HEGP collimator offers better SPECT image quality than the other imaging conditions. Basic study B showed that uptake in one of the spheres was overestimated by overlapped activity of the tube-shaped chamber in planar imaging whereas the spheres had similar counts and significantly higher sphere-to-background ratio in SPECT. On both planar and SPECT images, HEGP gave higher image contrast than MEGP (p < 0.01). In the clinical study, Ra-223 SPECT at 84 keV ± 20% depicted more lesions with the HEGP than with the MEGP collimator (51 vs 36, p = 0.013). There was a positive correlation between LBR in Tc-99m SPECT and in Ra-223 SPECT (r = 0.67 with the MEGP and 0.69 with the HEGP collimator, p < 0.01). LBRs were significantly higher with the HEGP than with the MEGP collimator (p < 0.01). Conclusions: We recommended the use of the HEGP collimator at 84 keV ± 20% for Ra-223 SPECT imaging. Lesion-based semi-quantitative analysis in the human study revealed a good correlation between Ra-223 and Tc-99m HMDP SPECT in the early phase (2–3 h post injection).

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Reactive oxygen species induction by cabazitaxel through inhibiting Sestrin-3 in castration resistant prostate cancer

Kosaka Takeo, Hongo Hiroshi, Miyazaki Yasumasa, Nishimoto Koshiro, Miyajima Akira, Oya Mototsugu

Oncotarget (IMPACT JOURNALS LLC) 8 ( 50 ) 87675 - 87683 2017

ISSN 1949-2553

Reactive oxygen species (ROS) production induced by taxanes in cancer cells may influence the taxane-induced cell death or the drug resistance. We investigated the correlation between the cytotoxic effect of taxanes and ROS production in human castration-resistant prostate cancer (CRPC) cell lines. Three human prostate cancer cell lines were treated with increasing concentrations of docetaxel or cabazitaxel in vitro. Cabazitaxel showed significantly higher cytotoxic efficacy than docetaxel in human CRPC cells, accompanied by elevated ROS production detected by FACS analysis. To investigate whether cabazitaxel-mediated cell death was caused by the ROS generation induced by cabazitaxel, we treated CRPC cells in the presence of antioxidant NAC. NAC reduced the cytotoxic effect induced by cabazitaxel. We found that ROS elimination by Sestrin-3 (SESN3) was significantly inhibited by cabazitaxel, but not by docetaxel. These results indicate higher sensitivity of human CRPC to cabazitaxel compared to docetaxel involves ROS production through inhibiting the expression of antioxidant enzyme SESN3.

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Renal dysfunction caused by urological cancer

Matsumoto Kazuhiro, Oya Mototsugu

Japanese Journal of Nephrology 59 ( 5 ) 606 - 609 2017

ISSN 0385-2385

Prognostic significance of erythrocyte protein band 4.1-like5 expression in upper urinary tract urothelial carcinoma

Daimon Tatsuaki, Kosaka Takeo, Kikuchi Eiji, Mikami Shuji, Miyazaki Yasumasa, Hashimoto Ari, Hashimoto Shigeru, Mizuno Ryuichi, Miyajima Akira, Okada Yasunori, Sabe Hisataka, Oya Mototsugu

Urologic Oncology: Seminars and Original Investigations 2016.12

ISSN 1078-1439

Objectives: The erythrocyte protein band 4.1-like5 (EPB4.1L5) regulates E-cadherin in cancer invasion and metastasis inducing epithelial-to-mesenchymal transition. This study aimed to investigate the biological significance of EPB4.1L5 in upper urinary tract urothelial carcinoma (UTUC). Methods: Retrospective analysis of the clinical records of 165 patients with UTUC (Ta-4N0M0) subjected to radical nephroureterectomy and immunohistochemical examination of EPB4.1L5 expression in those tissues. Results: The median follow-up period was 62.2 months (interquartile range = 77.0). The score of EPB4.1L5 significantly correlated with tumor grade, pathological T stage, and lymphovascular invasion (all P<0.001). The 5-year Kaplan-Meier recurrence-free survival and cancer-specific survival rates were 54.1% and 59.5% in patients with high EPB4.1L5 expression, compared with 81.6% and 87.2%, (all P<0.001) in their counterparts. Multivariate analyses revealed that high expression of EPB4.1L5 was one of the independent prognostic factors for tumor recurrence (P = 0.022, HR = 2.40) and cancer-specific survival (P = 0.015, HR = 2.94). Conclusion: High EPB4.1L5 expression was related to worse clinical outcome in patients with UTUC. These results indicated that EPB4.1L5 could provide prognostic information in patients with UTUC regarding epithelial-to-mesenchymal transition.

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Influence of physician years on urological journal publication productivity among Japanese urologists

Niwa Naoya, Kikuchi Eiji, Matsumoto Kazuhiro, Miyajima Akira, Oya Mototsugu

SpringerPlus 5 ( 1 ) 2016.12

ISSN 2193-1801

Purpose: To evaluate the urological journal publication productivity of Japanese urologists based on their physician years. Methods: All original articles written by Japanese urologists and published from Japanese institutions in 6 primary urological journals between 2010 and 2014 were reviewed (N = 529 articles). Results: The median post-graduate years of the first and corresponding authors of all articles were 16 and 21 years, respectively. The publication productivities of the first and corresponding authors peaked from 11 to 15 and both 16–20 and 21–25 post-graduate years, respectively. In 187 publications in which the first and corresponding authors were different, first and corresponding author publication productivities peaked from 11 to 15 and 21–25 post-graduate years, respectively. In 342 publications in which the first author served as the corresponding author, first author publication productivity peaked from 16 to 20 post-graduate years. Of all articles examined, 130 (24.6%) were written by young urologists who had obtained their national medical license not less than 11 years ago. Only 0.9% (5/529) of all articles were written by female Japanese urologists, who account for 5.0% (332/6,649) of all Japanese Board Certified Urologists. Conclusions: The present study revealed that from 11 to 15 post-graduate years was the most productive time for Japanese urologists as the first author of urological publications and also that the role in manuscript preparation changed with increases in physician years. These results provide an insight into reconstructing future post-graduate training and educational urological programs in Japan.

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