Objective To evaluate the outcomes of T3 a prostate cancer with unfavorable prognostic factors treated with permanent interstitial brachytherapy combined with external radiotherapy and hormone therapy.Methods From January 2003 to December 2008,38 patients classified as T3 a prostate cancer with unfavorable prognostic factors were treated with trimodality therapy(brachytherapy + external radiotherapy + hormone therapy).The prescription dose of brachytherapy and external radiotherapy were 110 Gy and 45 Gy,respectively.The duration of hormone therapy was 2-3 years.The endpoints of this study included biochemical failure-free survival(BFFS),distant metastasis-free survival(DMFS),cancer-specific survival(CSS),and overall survival(OS).Survival curves were calculated using the Kaplan-Meier method.The Log-rank test was used to identify the prognostic predictors for univariate analysis.Results The median follow-up was 71 months.The serum pre-treatment prostate-specific antigen(PSA) level ranged from 10.0 to 99.8 ng/ml(mean 56.3 ng/ml),the Gleason score ranged from 5 to 9(median 8),and the percentage of positive biopsy cores ranged from 10% to 100%(mean 65%).The 5-year BFFS,DMFS,CSS,and OS rates were 44%,69%,82%,and 76%,respectively.All biochemical failures occurred within 40 months.The percentage of positive biopsy cores was significantly correlated with BFFS,DMFS,and OS(all P=0.000),and the Gleason score with DMFS(P=0.000) and OS(P=0.001).Conclusions T3 a prostate cancer with unfavorable prognostic factors presents not so optimistic outcome.Hormone therapy should be applied to prolong the biochemical progression-free or metastasis-free survival.The percentage of positive biopsy cores and the Gleason score are significant prognostic factors. Objective To evaluate the outcomes of T3 a prostate cancer with unfavorable prognostic factors treated with permanent interstitial brachytherapy combined with external radiotherapy and hormone therapy. Methods From January 2003 to December 2008, 38 patients classified as T3 a prostate cancer with unfavorable prognostic factors were treated with The dose of brachytherapy and external radiotherapy were 110 Gy and 45 Gy, respectively. The duration of hormone therapy was 2-3 years. endpoints of this study included biochemical failure-free survival (BFFS), distant metastasis-free survival (DMFS), cancer-specific survival (CSS), and overall survival (OS). Survival curves were calculated using the Kaplan-Meier method. prognostic predictors for univariate analysis. Results The median follow-up was 71 months. The serum pre-treatment prostate-specific antigen (PSA) level ranged from 10.0 to 99.8 ng / ml (mean 56.3 ng / ml), the Gleason score ranged from 5 to 9 (median 8), and the percentage of positive biopsy cores ranged from 10% to 100% (mean 65%). The 5 -year BFFS, DMFS, CSS, and OS rates were 44%, 69%, 82%, and 76%, respectively. All biochemical activity occurred occurred within 40 months. Percentage of positive biopsy cores was significantly correlated with BFFS, and OS (all P = 0.000), and the Gleason score with DMFS (P = 0.000) and OS (P = 0.001) .Conclusions T3 a prostate cancer with unfavorable prognostic factors presents not so optimistic outcome. Hormone therapy should be applied to prolong the biochemical progression-free or metastasis-free survival. The percentage of positive biopsy cores and the Gleason score are significant prognostic factors.