Yoichi Arai

Tohoku University, Japan

Are you Yoichi Arai?

Claim your profile

Publications (408)1255.73 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: To assess the risk factors for biochemical recurrence in D'Amico intermediate-risk prostate cancer patients treated using radical prostatectomy. We retrospectively reviewed the medical records of 1268 men with prostate cancer treated using radical prostatectomy without neoadjuvant therapy. The association between various risk factors and biochemical recurrence was then statistically evaluated. The Kaplan-Meier method, log-rank tests and Cox proportional hazards models were used for statistical analysis. In the intermediate-risk group, 96 patients (14.5%) experienced biochemical recurrence during a median follow up of 41 months. In the intermediate-risk group, preoperative prostate-specific antigen level, prostate volume and prostate-specific antigen density were significant preoperative risk factors for biochemical recurrence, whereas other factors including age, primary Gleason 4, clinical stage >T2 and percentage of positive biopsies were not. In multivariate analysis, higher preoperative prostate-specific antigen level and density, and a smaller prostate volume were independent risk factors for biochemical recurrence in the intermediate-risk group. Biochemical recurrence-free survival of patients in the intermediate-risk group with a higher prostate-specific antigen level and density (≥15 ng/mL, ≥0.6 ng/mL/cm(3) , respectively), and lower prostate volume (≤10 mL) was comparable with that of high-risk group individuals (P = 0.632, 0.494 and 0.961, respectively). Preoperative prostate-specific antigen, prostate volume and prostate-specific antigen density are significant risk factors for biochemical recurrence in D'Amico intermediate-risk prostate cancer patients treated using radical prostatectomy. Using these variables, a subset of the intermediate-risk patients can be identified as having equivalent outcomes to high-risk patients. © 2015 The Japanese Urological Association.
    International Journal of Urology 08/2015; DOI:10.1111/iju.12898 · 2.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Adrenal venous sampling (AVS) is critical to determine the subtype of primary aldosteronism (PA). "Central" AVS, that is, the collection of effluents from bilateral adrenal central veins, sometimes does not allow differentiation between bilateral aldosterone-producing adenomas (APA) and idiopathic hyperaldosteronism (IHA). To establish the best treatment course, we have developed "segmental AVS"; that is, we collect effluents from the tributaries of central veins to determine the intra-adrenal sources of aldosterone overproduction. We then evaluated the clinical utility of this novel approach in the diagnosis and treatment of PA. We performed central and/or segmental AVS in 297 PA patients, and assessed the accuracy of diagnosis based on the results of central (n=138, 46.5%) and segmental AVS (n=159, 53.5%) by comparison with those of clinicopathological evaluation of resected specimens. Segmental AVS demonstrated both elevated and attenuated secretion of aldosterone from APA and non-tumorous segments, respectively, in patients with bilateral APA and recurrent APA. These findings were completely confirmed by detailed histopathological examination after surgery. Segmental AVS, but not central AVS, also served to identify APA located distal from the central vein. Compared to central AVS, segmental AVS served to identify APA in some patients and its use should expand the pool of patients eligible for adrenal sparing surgery through the identification of unaffected segments, despite the fact that segmental AVS requires more expertise and time. Especially, this new technique could enormously benefit patients with bilateral or recurrent APA because of the preservation of non-tumorous glandular tissue.
    European Journal of Endocrinology 07/2015; 173(4). DOI:10.1530/EJE-14-1161 · 4.07 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Adrenocortical carcinoma (ACC) is a malignant neoplasm often associated with an aggressive biological behavior. The histologic differentiation between ACC and adrenocortical adenoma (ACA) is largely determined by employing the Weiss criteria, although this classification may not apply to all the cases. Additionally, various genomic features of ACC could be an auxiliary mode to establish the diagnosis of ACC. Most ACC cases are hormonally functional, and immunohistochemical analysis of steroidogenic enzymes has provided pivotal information as to the analysis of intratumoral production of corticosteroids. This article summarizes the current status of the histopathological diagnosis, molecular pathogenesis, and hormonal features of ACC. Copyright © 2015 Elsevier Inc. All rights reserved.
    Endocrinology & Metabolism Clinics of North America 06/2015; 44(2):399-410. DOI:10.1016/j.ecl.2015.02.007 · 3.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To clarify the significance of the International Germ Cell Cancer Collaborative Group classification in the 2000s, especially in intermediate- and poor-prognosis testicular germ cell tumor in Japan. We retrospectively analyzed 117 patients with intermediate- and poor-prognosis testicular non-seminomatous germ cell tumor treated at five university hospitals in Japan between 2000 and 2010. Data collected included age, levels of tumor markers, spread to non-pulmonary visceral metastases, treatment details and survival. The median follow-up period of all patients was 57 months. A total of 50 patients (43%) were classified as having intermediate prognosis, and 67 patients (57%) as poor prognosis according to the International Germ Cell Cancer Collaborative Group classification. As first-line chemotherapy, 92 patients (79%) received bleomycin, etoposide and cisplatin. Of all patients, 74 patients (63%) received second-line chemotherapy. The most commonly used second-line chemotherapy regimens were a combination of taxanes, ifosfamide and platinum in 49 cases (66%). Overall, 33 patients (28%) received third-line chemotherapy. A total of 88 patients (75%) underwent post-chemotherapy surgery. The 5-year overall survival for intermediate (n = 50) and poor prognosis (n = 67) was 89% and 83% (P = 0.21), respectively. In poor prognosis patients, patients with two or more risk factors (any of high lactic dehydrogenase, alpha-fetoprotein and human chorionic gonadotropin levels, and presence of non-pulmonary visceral metastases) had significantly worse survival than those with only one risk factor (71% and 91%, respectively, P = 0.01). The 5-year overall survivals of poor-prognosis testicular non-seminomatous germ cell tumor patients reached 83%. Further stratification of poor-prognosis patients based on a number of risk factors has the potential to further identify those with poorer prognosis. © 2015 The Japanese Urological Association.
    International Journal of Urology 06/2015; DOI:10.1111/iju.12844 · 2.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Prostate needle biopsy plays a pivotal role not only in the diagnosis but also the management of patients with prostate cancer. Prostate cancer is often multifocal and diagnosis of the lesion could therefore be difficult with diagnostic imaging only; thus, multiple core biopsies are taken from several different regions of the prostate. In current practice, 10- or 12-core needle biopsy is considered the clinical standard. Several techniques have been reported to improve the orientation of the specimens, but tissue marking, which could theoretically provide important information on the location of the lesion in the prostate, has been rarely reported. Therefore, in this study, we evaluated the clinical significance of systematic 12-core needle biopsy with tissue marking for preoperative prediction of lesion sites and clinicopathological features of patients. We evaluated 93 patients who underwent 12-core prostate biopsy and subsequent radical prostatectomy. We correlated the biopsy results to the prostate sites in which biopsies were performed and prognostic factors of the patients, especially the degree of extraprostatic extension (EPE) obtained in surgical specimens. Among 253 cancer foci detected in 93 prostatectomy specimens, 168 (66.4%) foci were detected by biopsy. All patients had proven cancer. EPE-positive cancers were associated with a larger number of positive cores, larger tumor length, and higher percentage of cancer tissue in the corresponding cores. Systematic 12-core prostate biopsy with tissue marking is useful for preoperative detection of cancer foci and provides valuable information that enables effective surgical strategies.
    The Tohoku Journal of Experimental Medicine 05/2015; 236(1):55-61. DOI:10.1620/tjem.236.55 · 1.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To understand the current practice pattern of active surveillance using a nationwide survey among Japanese urologists. A new questionnaire about active surveillance was developed and mailed to 863 training institutes in January 2014. The questionnaire included indications for active surveillance, percentage of active surveillance for localized prostate cancer, problems with active surveillance, which protocol was used, timing of first repeat biopsy, use of prostate-specific antigen or doubling time and use of magnetic resonance imaging. A total of 2133 Japanese urologists in the 632 training institutes answered the questionnaire. The median age was 42 years (26-84 years). Of the responders, 26.9% had no use of active surveillance for localized prostate cancer. The Prostate Cancer Research International: Active Surveillance criteria were most frequently used (29.7%), followed by a low-risk group without a definitive follow-up protocol (29.4%). Regarding repeat biopsy, 40.6% carried it out at 1 year after active surveillance initiation, but 24.1% did not usually carry it out and 31.8% carried it out only when they considered it necessary. Magnetic resonance imaging was used routinely in 22.2% and as required in 67.6%. Re-biopsy or magnetic resonance imaging was less carried out in general hospitals than in universities. The percentage of no usual repeat biopsy was significantly higher in urologists who had more than 10 years of experience. Repeat biopsies (60.3%), inadequate inclusion criteria (49.9%), psychological burden for patients (43.7%), unexpected progression (41.1%) and unknown long-term outcomes (40.6%) were considered the major problems of active surveillance in the responders. The practice pattern of active surveillance varies widely among Japanese urologists. It is necessary to gain a correct understanding of active surveillance. © 2015 The Japanese Urological Association.
    International Journal of Urology 05/2015; 14(2). DOI:10.1111/iju.12813 · 2.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Direct injection of an anticancer agent into a metastatic lymph node (LN) has not been used as a standard treatment because evidence concerning the efficacy of local administration of a drug into a metastatic LN has not been established. Here we show that the combination of intralymphatic drug delivery with nano/microbubbles (NMBs) and ultrasound has the potential to improve the chemotherapeutic effect. We delivered cis-diamminedichloroplatinum (II) (CDDP) into breast carcinoma cells in vitro and found that apoptotic processes were involved in the antitumor action. Next, we investigated the antitumor effect of intralymphatic chemotherapy with NMBs and ultrasound in an experimental model of LN metastasis using MXH10/Mo-lpr/lpr mice exhibiting lymphadenopathy. The combination of intralymphatic chemotherapy with NMBs and ultrasound has the potential to improve the delivery of CDDP into target LNs without damage to the surrounding normal tissues. The present study indicates that intralymphatic drug delivery with NMBs and ultrasound will potentially be of great benefit in the clinical setting.
    PLoS ONE 04/2015; 10(4):e0123619. DOI:10.1371/journal.pone.0123619 · 3.23 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Treatment for ruptured renal angiomyolipoma in pregnancy requires immediate and appropriate decision-making based on the condition of the mother and fetus, and gestational age. A 37-year-old woman at 25 weeks of pregnancy presented with severe right flank pain. Computed tomography showed a ruptured right renal angiomyolipoma (8 cm in diameter). The maternal and fetal conditions were stable. Transcatheter arterial embolization was carried out electively 4 days after the rupture. Minimization of radiation exposure to the fetus was achieved by X-ray shielding for the fetus, low-dose-rate fluoroscopy, minimal angiography imaging and a color Doppler ultrasonography-guided procedure. Although threatened premature labor occurred because of post-embolization syndrome, the pregnancy was continued until cesarean section at 37 weeks of pregnancy. © 2015 The Japanese Urological Association.
    International Journal of Urology 04/2015; 22(7). DOI:10.1111/iju.12775 · 2.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: About one third of renal cell carcinoma (RCC) patients exhibit metastasis upon initial presentation. However, the molecular basis for RCC metastasis is not fully understood. A ganglioside, disialosyl globopentaosylceramide (DSGb5), was originally isolated from RCC tissue extracts, and its expression is correlated with RCC metastatic potential. DSGb5 is synthesized by GalNAc α2,6-sialyltransferase VI (ST6GalNAcVI) and is expressed on the surface of RCC cells. Importantly, DSGb5 binds to sialic acid-binding Ig-like lectin-7 (Siglec-7) expressed on natural killer (NK) cells, thereby inhibiting NK-cell cytotoxicity. However, the role of DSGb5 in RCC progression remains obscure. To address this issue, we used ACHN cells derived from malignant pleural effusion of a patient with metastatic RCC. Using the limiting dilution method, we isolated three independent clones with different DSGb5 expression levels. Comparison of these clones indicated that the cloned cells with high DSGb5 expression levels exhibited greater migration potential, compared to the clone with low DSGb5 expression levels. In contrast, DSGb5 expression levels exerted no significant effect on cell proliferation. We then established the ACHN-derived cell lines that stably expressed siRNA against ST6GalNAcVI mRNA or control siRNA. Importantly, the ST6GalNAcVI-knockdown cells expressed low levels of DSGb5. We thus demonstrated the significantly decreased migration potential of the ST6GalNAcVI-knockdown cells with low DSGb5 expression levels, compared to the control siRNA-transfected cells expressing high DSGb5 levels, but no significant difference in the cell proliferation. Thus, DSGb5 expression may ensure the migration of RCC cells. We propose that DSGb5 expressed on RCC cells may determine their metastatic capability.
    The Tohoku Journal of Experimental Medicine 04/2015; 236(1):1-7. DOI:10.1620/tjem.236.1 · 1.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The pre-B lymphocyte protein 3 (VPREB3) is expressed during B-cell differentiation and in subsets of mature B-lymphocytes and is mainly found in bone marrow and lymphoid tissue germinative centers. So far, its function in B-cells remains to be clarified. The mRNA of VPREB3 was previously detected in aldosterone-producing adenomas (APA), however further information about this protein in human adrenocortical cells and tissues is currently unavailable. Therefore, in the present study we for the first time investigate the protein expression of VPREB3 in human adrenocortical tissues. In addition, we approach the previously suggested similarities in expression patterns of aldosterone-producing cells and Purkinje neurons. Immunohistochemical analysis of VPREB3 was performed in 13 non-pathological adrenals (NA), 6 adrenal glands with idiopathic hyperaldosteronism (IHA), 18 APA, 5 cortisol-producing adenomas (CPA) and 5 non-pathological human cerebellum specimens. The mRNA levels of VPREB3, steroidogenic-enzymes and other aldosterone biosynthesis markers were detected in 53 APA samples using real-time RT-PCR (qPCR) and compared to the clinical data of APA patients. In our results, the VPREB3 protein was diffusely detected in APA, partially or weakly detected in CPA, and immunolocalized in the zona glomerulosa of NA and IHA, as well as in the cytoplasm of cerebellar Purkinje cells. In APA, VPREB3 mRNA levels were significantly correlated to plasma aldosterone (P=0.026; R=0.30), KCNJ5 mutations (P=0.0061; mutated 34:19 wild-type), CYP11B2 (P<0.0001; R=0.65), Purkinje cell protein 4 (PCP4; P<0.0001; R=0.53) and voltage-dependent calcium channels CaV1.3 (P=0.023; R=0.31) and CaV3.2 (P=0.0019; R=0.42). Based on our data, we hypothesize a possible role for VPREB3 in aldosterone biosynthesis, and present ideas for future functional studies.
    Endocrine Pathology 04/2015; DOI:10.1007/s12022-015-9366-7 · 1.76 Impact Factor
  • Source
    The Journal of Urology 04/2015; 193(4):e1086-e1087. DOI:10.1016/j.juro.2015.02.1952 · 4.47 Impact Factor
  • Source
    The Journal of Urology 04/2015; 193(4):e18. DOI:10.1016/j.juro.2015.02.142 · 4.47 Impact Factor
  • Source
    The Journal of Urology 04/2015; 193(4):e743-e744. DOI:10.1016/j.juro.2015.02.2217 · 4.47 Impact Factor
  • The Journal of Urology 04/2015; 193(4):e937. DOI:10.1016/j.juro.2015.02.2694 · 4.47 Impact Factor
  • Source
    The Journal of Urology 04/2015; 193(4):e874. DOI:10.1016/j.juro.2015.02.2523 · 4.47 Impact Factor
  • Source
    The Journal of Urology 04/2015; 193(4):e81-e82. DOI:10.1016/j.juro.2015.02.289 · 4.47 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We previously reported the pharmacokinetic profile and preliminary tolerability of cabazitaxel in a phase I study in Japanese patients with metastatic castration-resistant prostate cancer (mCRPC). Here we report the final safety profile and anti-tumor activity of cabazitaxel in a larger population, including all patients enrolled in the expansion cohort of the study. Japanese patients with mCRPC previously treated with docetaxel received cabazitaxel intravenously every 3 weeks plus daily prednisolone. In patients treated with the maximum tolerated dose of 25 mg/m(2) we evaluated adverse events including treatment-related neutropenia, prostate-specific antigen (PSA) response and objective response. In total, 44 patients were treated with the maximum tolerated dose. The most frequent adverse events (any grade) were neutropenia (100 %), febrile neutropenia (54.5 %), fatigue (54.5 %), nausea (52.3 %) and diarrhea (50.0 %). There were no deaths due to treatment-related adverse events. Neutropenia with prior docetaxel did not appear to influence the probability of febrile neutropenia with cabazitaxel. Most patients received therapeutic granulocyte colony-stimulating factor (G-CSF; cycle 1: 86.4 %; cycle 2 or later: 81.8 %). In the efficacy population, two of 12 patients with measurable disease had partial response (objective response rate: 16.7 %), while 10 had stable disease. PSA response rate was 29.3 % (12/41 patients). Median time to PSA progression was 3.68 months (95 % confidence interval 1.35-4.63). In this heavily pretreated Japanese population, the occurrence of neutropenia and febrile neutropenia was high, suggesting G-CSF prophylaxis may be required as part of toxicity management. However, the efficacy of cabazitaxel was consistent with global studies. ClinicalTrials.gov identifier: NCT01324583.
    International Journal of Clinical Oncology 03/2015; DOI:10.1007/s10147-015-0820-9 · 2.13 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Adrenal venous sampling is currently the only reliable method to distinguish unilateral from bilateral diseases in primary aldosteronism. In this study, we attempted to determine whether peripheral plasma levels of 18-oxocortisol (18oxoF) and 18-hydroxycortisol could contribute to the clinical differentiation between aldosteronoma and bilateral hyperaldosteronism in 234 patients with primary aldosteronism, including computed tomography (CT)-detectable aldosteronoma (n=113) and bilateral hyperaldosteronism (n=121), all of whom underwent CT and adrenal venous sampling. All aldosteronomas were surgically resected and the accuracy of diagnosis was clinically and histopathologically confirmed. 18oxoF and 18-hydroxycortisol were measured using liquid chromatography tandem mass spectrometry. Receiver operating characteristic analysis of 18oxoF discrimination of adenoma from hyperplasia demonstrated sensitivity/specificity of 0.83/0.99 at a cut-off value of 4.7 ng/dL, compared with that based on 18-hydroxycortisol (sensitivity/specificity: 0.62/0.96). 18oxoF levels above 6.1 ng/dL or of aldosterone >32.7 ng/dL were found in 95 of 113 patients with aldosteronoma (84%) but in none of 121 bilateral hyperaldosteronism, 30 of whom harbored CT-detectable unilateral nonfunctioning nodules in their adrenals. In addition, 18oxoF levels below 1.2 ng/dL, the lowest in aldosteronoma, were found 52 of the 121 (43%) patients with bilateral hyperaldosteronism. Further analysis of 27 patients with CT-undetectable micro aldosteronomas revealed that 8 of these 27 patients had CT-detectable contralateral adrenal nodules, the highest values of 18oxoF and aldosterone were 4.8 and 24.5 ng/dL, respectively, both below their cut-off levels indicated above. The peripheral plasma 18oxoF concentrations served not only to differentiate aldosteronoma but also could serve to avoid unnecessary surgery for nonfunctioning adrenocortical nodules concurrent with hyperplasia or microadenoma.
    Hypertension 03/2015; 65(5). DOI:10.1161/HYPERTENSIONAHA.114.04453 · 6.48 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Abscess of corpus cavernosum penis is a rare infection condition. A 69-year-old-man was referred toour hospital with gradual development of penis swelling. T2-weighted magnetic resonance imaging of the pelvis showed abscess formation in the corpus cavernosum. There was no apparent cause of his penile abscess from either history or clinical examination. Open drainage improved his clinical symptoms transiently. However, severe penile pain relapsed, and abscess progressively extended in the corpus cavernosum and spongiosum, necessitating total penectomy. The surgical specimen revealed intensive inflammation and his condition improved immediately after penectomy.
    Hinyokika kiyo. Acta urologica Japonica 03/2015; 61(3):109-114.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The optimal treatment for high-risk prostate cancer (Pca) remains to be established. We previously reported favorable biochemical recurrence-free survival (BRFS) in high-risk Pca patients treated with a neoadjuvant therapy comprising a luteinizing-hormone-releasing hormone (LHRH) agonist plus low dose estramustine phosphate (EMP) (LHRH+EMP) followed by radical prostatectomy (RP). In the present study, we used a retrospective design via propensity score matching to elucidate the clinical benefit of neoadjuvant LHRH+EMP for high-risk Pca. The Michinoku Urological Cancer Study Group database contained data for 1,268 consecutive Pca patients treated with RP alone at 4 institutions between April 2000 and March 2011 (RP alone group). In the RP alone group, we identified 386 high-risk Pca patients. The neoadjuvant LHRH+EMP group included 274 patients with high-risk Pca treated between September 2005 and November 2013 at Hirosaki University. Neoadjuvant LHRH+EMP therapy included LHRH and EMP administration at a dose of 280 mg/day for 6 months before RP. The outcome measures were overall survival (OS) and BRFS. The propensity score-matched analysis indicated 210 matched pairs from both groups. The 5-year BRFS rates were 90.4 and 65.8 % for the neoadjuvant LHRH+EMP and RP alone groups, respectively (P < 0.0001). The 5-year OS rates were 100 and 96.1 % for the neoadjuvant LHRH+EMP and RP alone groups, respectively (P = 0.110). Although the present study was not randomized, neoadjuvant LHRH+EMP therapy followed by RP appeared to reduce the risk of biochemical recurrence. A prospective randomized study is warranted to determine the clinical implications of the neoadjuvant therapy described here.
    International Journal of Clinical Oncology 02/2015; 20(5). DOI:10.1007/s10147-015-0802-y · 2.13 Impact Factor

Publication Stats

5k Citations
1,255.73 Total Impact Points


  • 2003–2015
    • Tohoku University
      • Department of Urology
  • 2014
    • Hirosaki University
      Khirosaki, Aomori, Japan
  • 2009
    • CSU Mentor
      Long Beach, California, United States
  • 2008
    • University of California, Los Angeles
      • Department of Urology
      Los Angeles, CA, United States
  • 1995–2007
    • Kurashiki Central Hospital
      Kurasiki, Okayama, Japan
  • 2001–2005
    • Kitasato University
      • Department of Urology
      Edo, Tōkyō, Japan
  • 2003–2004
    • Sendai University
      Sendai, Kagoshima, Japan
  • 2002
    • Kagawa University
      • Department of Urology
      Takaishi, Osaka-fu, Japan
    • Akita University
      Akita, Akita, Japan
  • 1989–1999
    • Kyoto University
      • Department of Urology
      Kioto, Kyōto, Japan