Y Arai

Kitasato University, Tokyo, Tokyo-to, Japan

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Publications (4)8.37 Total impact

  • Article: Prostate-specific antigen adjusted for total prostatic tumor volume as a predictor for outcome after radical prostatectomy.
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    ABSTRACT: The aim of this study was to investigate the potential prognostic value of preoperative serum prostate-specific antigen levels adjusted for total tumor volume (PSA-TTV density) for outcome following radical prostatectomy for prostate cancer by retrospective review in 268 patients. Lower PSA-TTV density was not only associated with a significantly higher risk for biological failure (bF), systemic failure and cancer death but also an independent predictor for bF (hazard ratio, 6.3). Therefore, these data suggest that there are subsets of prostate cancer with lower PSA secretion levels, and this phenotype is associated with a higher risk of failure after surgery.
    Prostate Cancer and Prostatic Diseases 02/2007; 10(1):60-5. · 2.42 Impact Factor
  • Article: Impact of biochemical failure on long-term clinical outcome after radical prostatectomy for prostate cancer in Japan.
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    ABSTRACT: Detailed information is needed to understand the impact of biochemical failure (bF) on long-term outcome after definitive therapy for prostate cancer. In all, 223 consecutive men treated with radical retropubic prostatectomy were followed and long-term clinical outcome was investigated. Pathological examination revealed more locally advanced tumors in this study compared with the typical cohorts seen in the Western series. The Cox proportional hazards model indicates pretreatment prostate-specific antigen levels and risk group stratification to be a significant predictors for bF (P<0.05), but not for overall survival. Seminal vesicle involvement was a significant predictor of systemic progression, cancer death and overall survival (P<0.05). Positive surgical margin and bF were also found to be independent predictors of overall survival (P<0.05). In contrast to reports from Western countries, this study found a significant correlation between bF after radical prostatectomy and overall survival. This may reflect years-later detection of prostate cancer in Japan compared with Western series. Biochemical failure may ultimately be translated into decreased overall survival after sufficient follow-up.
    Prostate Cancer and Prostatic Diseases 01/2004; 7(2):152-7. · 2.42 Impact Factor
  • Article: Treatment outcome by risk group after radical prostatectomy in Japanese men.
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    ABSTRACT: North American investigators have suggested the usefulness of risk-group stratification based on prostate-specific antigen (PSA), clinical stage and biopsy Gleason score for predicting the biochemical outcome of prostate cancer after radical prostatectomy. There have been no reports of the application of this stratification to early biochemical outcome after radical surgery in Japanese men. The study population consisted of 178 men treated with radical retropubic prostatectomy and bilateral pelvic lymph node dissection at Kitasato University Hospital (n = 110) and Kurashiki Central Hospital (n = 68) between October 1992 and May 1999. Pathologic and biochemical outcomes after radical prostatectomy were analyzed based on risk-group stratification. Risk groups were further analyzed according to detailed pathologic findings at biopsy. The median follow-up period for the 178 patients after radical surgery was 41.5 months (range, 2.0--82.0 months; mean, 40.9 months). Fifty-eight patients experienced PSA failure at a median of 8.0 months following surgery (range, 0.0--58.0). Risk-group stratification distinctly defined groups of pathologic findings in the radical prostatectomy specimens. The proportion of patients with PSA failure for low, intermediate and high-risk groups were 9.5%, 23.9% and 56.9%, respectively (P < 0.0001). Use of the number of cores with cancer and maximum cancer length in biopsy cores failed to improve risk stratification for PSA outcome in all risk groups. Risk-group stratification based on preoperative variables may significantly improve a physician's ability to counsel patients about PSA outcome after radical prostatectomy. Further improvement in risk stratification may call for use of variables other than the pathologic information in biopsy cores.
    International Journal of Urology 06/2001; 8(6):295-300. · 1.75 Impact Factor
  • Article: A study of pretreatment nomograms to predict pathological stage and biochemical recurrence after radical prostatectomy for clinically resectable prostate cancer in Japanese men.
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    ABSTRACT: Accurate pretreatment identification of the risks that prostate cancer has extended beyond the gland and that it will recur would significantly influence practice patterns. Preoperative nomograms to predict such risks have not been developed for the oriental male population. Construction of nomograms to predict preoperatively pathological outcome and early biochemical failure following radical prostatectomy in Japanese males was based on logistic regression analysis, with predicted probabilities and 95% confidence intervals for the final model being obtained by repeating the analysis on 1000 bootstrap samples from the original cohort. Prostate-specific antigen level, clinical stage and biopsy Gleason score contributed significantly to the prediction of pathological stage and of biochemical failure in the univariate analysis (p < 0.001). Combined use of these three variables predicted these treatment outcomes better than any single variable (p < 0.001). Nomograms combining these three variables to predict final pathological findings and early biochemical failure were then developed. The medians and 95% confidence intervals of the predicted probabilities are presented in the nomograms. This information enables clinicians to use their nomograms when counseling Japanese patients, leading to more informed treatment decisions and helping to identify those with a high risk of early biochemical failure. The nomograms may also be used to assure comparability of different treatment modalities in investigational trials.
    Japanese Journal of Clinical Oncology 02/2001; 31(2):74-81. · 1.78 Impact Factor