Impact of primary Gleason grade 4 on biochemical recurrence after permanent interstitial brachytherapy in Japanese patients with low- or intermediate-risk prostate cancer.

77 Background: To reveal a predictive factor for biochemical recurrence (BCR) after permanent prostate brachytherapy (PPB) using iodine-125 (125I) seed implantation in patients with localized prostate cancer classified as low or intermediate risk based on the National Comprehensive Cancer Network (NCCN) guidelines. Methods: From January 2004 to December 2009, consecutive 418 Japanese patients with clinically localized prostate cancer classified as low or intermediate risk based on the National Comprehensive Cancer Network (NCCN) guidelines were treated by PPB. The clinical factors including pathological data reviewed by central pathologist and follow-up data were prospectively collected. Kaplan-Meier and Cox regression analyses were used to assess the factors associated with BCR. Results: Median follow-up was 36.0 months. The 2, 3, 4 and 5-year BCR free rates using Phoenix definition were 98.3%, 96.0%, 91.6% and 87.0% respectively. On univariate analysis, primary Gleason grade 4 in biopsy specimen was str...