Tomokazu Sazuka

Chiba University, Tiba, Chiba, Japan

Are you Tomokazu Sazuka?

Claim your profile

Publications (11)18.49 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Single-agent interferon (IFN) is no longer regarded as a standard option for first-line systemic treatment of metastatic renal cell carcinoma (RCC) in Western countries. However, some patients with favorable-risk RCC may still achieve complete and long-lasting remission in response to IFN treatment. The present study compared favorable-risk Japanese patients with metastatic RCC Japanese patients who had been treated with IFN or tyrosine kinase inhibitor (TKI) therapy as a first-line systemic therapy. From 1995 to 2014, a total of 48 patients with favorable risk as defined by the Memorial Sloan Kettering Cancer Center criteria who did not receive adjuvant systemic therapy were retrospectively enrolled in this study. We assessed the tumor response rate, progression-free survival (PFS), and overall survival (OS). The objective response rate for first-line therapy was 29% in the IFN group and 47% in the TKI group, but this difference did not reach the level of statistical significance. Median OS for IFN and TKI was 71 and 47 months, respectively (p=0.014). Median first-line PFS for IFN and TKI was 20 and 16 months, respectively (no significant difference). First-line IFN therapy did not prove inferior to TKI therapy in terms of OS according to metastatic sites. IFN is associated with a survival benefit in Japanese patients with favorable-risk metastatic RCC in the era of targeted therapy. Further prospective study is needed.
    Korean journal of urology 03/2015; 56(3):205-11. DOI:10.4111/kju.2015.56.3.205
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background The number of antihypertensive drug classes cannot accurately reflect the total consumption of antihypertensive drugs used to control blood pressure. The defined daily dose has been adopted to permit consumption analysis of many prescribed drugs. The aim of the present study was to assess postoperative changes in antihypertensive drug consumption in patients with primary aldosteronism using the defined daily dose as the unit of measurement. Methods This retrospective study included 110 Japanese patients who underwent unilateral laparoscopic adrenalectomy between 1995 and 2012. Antihypertensive drug doses were calculated according to the standard of the defined daily dose recommended by the World Health Organization to compare drug use. After assessing postoperative changes in antihypertensive drug consumption, univariate and multivariate analyses were performed to identify clinical predictors for a 75% or greater decrease in the defined daily dose. Results Consumption of antihypertensive drugs decreased postoperatively in 95.4% of patients. The median decrease in the defined daily dose was 76.8%. A postoperative decrease of 75% or greater in the defined daily dose was confirmed in 52.7% of patients. Multivariate analysis identified no medical history of cardiovascular disease, low body mass index, and short duration of hypertension as independent predictors of a postoperative decrease of 75% or greater in the defined daily dose. Conclusion The defined daily dose is a useful tool for assessing total changes in the consumption of antihypertensive drugs in patients with primary aldosteronism. Using the defined daily dose, clinicians could explain in detail to patients with primary aldosteronism the predicted postoperative change in antihypertensive drug consumption.
    03/2014; 189(4):e17. DOI:10.1016/j.juro.2013.02.1418
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background. The aim of this study was to determine concordance rates for prostatectomy specimens and transrectal needle biopsy samples in various areas of the prostate in order to assess diagnostic accuracy of the transrectal biopsy approach, especially for presurgical detection of cancer in the prostatic apex. Materials and Methods. From 2006 to 2011, 158 patients whose radical prostatectomy specimens had been evaluated were retrospectively enrolled in this study. Concordance rates for histopathology results of prostatectomy specimens and needle biopsy samples were evaluated in 8 prostatic sections (apex, middle, base, and transitional zones bilaterally) from 73 patients diagnosed at this institution, besides factors for detecting apex cancer in total 118 true positive and false negative apex cancers. Results. Prostate cancer was found most frequently (85%) in the apex of all patients. Of 584 histopathology sections, 153 (49%) from all areas were false negatives, as were 45% of apex biopsy samples. No readily available preoperative factors for detecting apex cancer were identified. Conclusions. In Japanese patients, the most frequent location of prostate cancer is in the apex. There is a high false negative rate for transrectal biopsy samples. To improve the detection rate, transperitoneal biopsy or more accurate imaging technology is needed.
    02/2013; 2013:705865. DOI:10.1155/2013/705865
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVES: To develop and to internally validate a novel nomogram for predicting the stone-free rate after transurethral ureterolithotripsy. METHODS: A total of 412 patients with 534 ureteral stones were treated with transurethral ureterolithotripsy using semi-rigid ureteroscopes. Treatment efficacy was evaluated 3 months after the procedure. Multivariate stepwise logistic regression analysis was used to identify independent predictors of being stone-free in the model-building set. A total of 427 stones (80% of 534) were randomly allocated for identification and statistical analysis to build the model, and the remaining 107 (20%) were used for cross-validation. A nomogram for the stone-free rate was developed based on the final logistic regression model. RESULTS: Stone length, number of stones, stone location and the presence of pyuria were independent factors related to the stone-free rate after transurethral ureterolithotripsy treatment, and these were used to develop a nomogram. In this nomogram, the area under the receiver operating characteristic curve was 0.7432 for the nomogram, 0.5641 for stone size, 0.5908 for the number of stones, 0.6594 for stone location and 0.6076 for pyuria. Validation using 20% of the data also achieved a reasonable predictive accuracy (area under the receiver operating characteristic curve = 0.682). CONCLUSIONS: The first nomogram for predicting the stone-free rate after transurethral ureterolithotripsy was developed. It has a reasonable predictive accuracy, and in combination with extracorporeal shock wave lithotripsy nomograms, it might be useful for deciding treatment methods.
    International Journal of Urology 11/2012; 20(6). DOI:10.1111/j.1442-2042.2012.03229.x · 1.80 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To examine the efficacy of an alpha-1 blocker and its correlation to structural alteration of the prostatic urethra and the loss of energy in the urine flow using a virtual urethra processed from an endoscopic video image. Video images of the prostatic urethra were recorded during cystourethroscopy in 11 patients with benign prostatic hyperplasia (BPH) before and after treatment with an alpha-1 blocker, naftopidil. The three-dimensional (3D) structure of the prostatic urethra was reproduced from video files. Fluid dynamic analysis and hydraulic energy calculations were performed using the "virtual" 3D urethral images. In 9 of 11 patients studied, an 11% improvement in the loss of energy (range, 1%-82%) was seen. Alpha-1 blocker treatment mediated the disappearance or decrease of the bulky vortex formation in seven patients, which led to an improved urinary stream. A positive correlation was found between improved energy loss and residual urine volume (P=0.0312). Alpha-1 blocker therapy led to a decreased energy loss in the urine flow in the prostatic urethra in relation to the improvement of clinical symptoms. The cystourethroscopy could be a tool to assess the urethral resistance in patients with BPH using image processing methodology.
    Journal of endourology / Endourological Society 04/2012; 26(9):1216-20. DOI:10.1089/end.2012.0078 · 2.10 Impact Factor
  • The Journal of Urology 04/2012; 187(4):e19. DOI:10.1016/j.juro.2012.02.088 · 3.75 Impact Factor
  • The Journal of Urology 04/2012; 187(4):e20–e21. DOI:10.1016/j.juro.2012.02.092 · 3.75 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to establish the discriminating accuracy of Kanao's pre-operative nomogram for renal cell carcinoma in predicting cause-specific survival among representative patients who underwent nephrectomy. Patients originated from two centers: Chiba University Hospital (n= 151) and Chiba Cancer Center (n = 91). We validated the predictive accuracy, which was assessed using Harrell's concordance-index. The concordance-index values were 0.692 and 0.834 for Chiba University Hospital and Chiba Cancer Center, respectively, although it was 0.822 for the combined data sets. Results of external validation were different at each cohort. We constructed calibration plots of Kanao's nomogram and confirmed the tendency at each institution. Inconsistency of results among two centers makes it difficult to reach a valid conclusion. Therefore, the predictive accuracy of Kanao's nomogram was not settled. Clinicians need to confirm the predictive accuracy of Kanao's nomogram and construct calibration plots when applying this nomogram to different patient populations.
    Japanese Journal of Clinical Oncology 08/2011; 41(9):1147-51. DOI:10.1093/jjco/hyr101 · 1.75 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of the present study was to compare the accuracy of three prognostic models in predicting recurrence-free survival among Japanese patients who underwent nephrectomy for non-metastatic renal cell carcinoma (RCC). Patients originated from two centers: Chiba University Hospital (n = 152) and Chiba Cancer Center (n = 65). The following data were collected: age, sex, clinical presentation, Eastern Cooperative Oncology Group performance status, surgical technique, 1997 tumor-node-metastasis stage, clinical and pathological tumor size, histological subtype, disease recurrence, and progression. Three western models, including Yaycioglu's model, Cindolo's model and Kattan's nomogram, were used to predict recurrence-free survival. Predictive accuracy of these models were validated by using Harrell's concordance-index. Concordance-indexes were 0.795 and 0.745 for Kattan's nomogram, 0.700 and 0.634 for Yaycioglu's model, and 0.700 and 0.634 for Cindolo's model, respectively. Furthermore, the constructed calibration plots of Kattan's nomogram overestimated the predicted probability of recurrence-free survival after 5 years compared with the actual probability. Our findings suggest that despite working better than other predictive tools, Kattan's nomogram needs be used with caution when applied to Japanese patients who have undergone nephrectomy for non-metastatic RCC.
    International Journal of Urology 07/2011; 18(9):667-71. DOI:10.1111/j.1442-2042.2011.02812.x · 1.80 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The objective of the present study was to document the treatment efficacy and safety of sorafenib in Japanese patients with advanced renal cell carcinoma (RCC). A retrospective analysis of 50 consecutive patients with metastatic RCC between January 2005 and December 2009 was carried out. Patients received sorafenib after failed cytokine therapy or first-line sorafenib treatment. All received 400 mg of sorafenib orally twice daily. Five of 14 patients with bone metastases were also given bisphosphonates. Tumor response was evaluated every 1-2 months according to the Response Evaluation Criteria in Solid Tumors. Adverse events (AE) were evaluated at each visit during and after treatment, and were recorded according to the National Cancer Institute's Common Terminology Criteria for Adverse Events version 3.0. Dose modification of sorafenib was permitted if grade 3 or 4 AE occurred. Treatment continued until disease progression or treatment intolerance occurred. Partial response, and stable disease as best objective responses were observed in 11 (22%) and 23 (46%) patients, respectively. Median progression-free survival was 7.3 months and median overall survival was 11.9 months. All patients experienced AE and one or more grade 3/4 AE occurred in 43 of 50 (86%) patients. Although it requires close monitoring, sorafenib treatment seemed to be effective in the present study population.
    International Journal of Urology 09/2010; 17(9):811-5. DOI:10.1111/j.1442-2042.2010.02604.x · 1.80 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this study was to evaluate the efficacy and toxicities of the gemcitabine and paclitaxel combination regimen as second-line chemotherapy for patients with advanced or metastatic urothelial carcinoma (UC) who have previously been treated with platinum-based chemotherapy for the metastatic disease. Thirty-three patients with advanced or metastatic UC who had received platinum-based chemotherapy were treated with an outpatient gemcitabine and paclitaxel combination regimen. A dose of 180 mg/m(2) paclitaxel was administered by intravenous (IV) infusion on Day 1, and 1000 mg/m(2) gemcitabine was administered by IV on Days 1, 8 and 15.The course was repeated every 28 days. Patients were evaluated after every 2 cycles of therapy using computed tomography. Of the 33 patients enrolled in this study, 30 could be evaluated to determine treatment efficacy; 10 had an objective response [overall response rate: 33.3%, 95% confidence interval (CI), 19.2-51.2%]. The median overall survival was 11.3 months (95% CI, 7.2-13.6 months). The chemotherapy sensitivity differed with disease site. The response rates of lung and bone metastases were 27% and 14%, and the progressive disease (PD) rates of lung and bone metastases were 13% and 14%, respectively. On the other hand, the response rate of liver metastasis was 14%, and its PD rate was 57%. None of the patients (n = 3) with adrenal metastasis responded to this regimen. Toxicities were mild, and no life-threatening complications occurred. Gemcitabine and paclitaxel combination therapy is a tolerable and active regimen for patients with advanced UC after failure of platinum-based chemotherapy.
    Japanese Journal of Clinical Oncology 03/2009; 39(4):244-50. DOI:10.1093/jjco/hyp003 · 1.75 Impact Factor