You have accessJournal of UrologyProstate Cancer: Localized: Radiation Therapy (PD08)1 Sep 2021PD08-11 SMALLER NUMBER OF BIOPSY CORES AT CANCER DIAGNOSIS IS ASSOCIATED WITH WORSE CLINICAL OUTCOME AFTER BRACHYTHERAPY MONOTHERAPY FOR LOCALIZED WHO PATHOLOGIC GRADE GROUP 1 OR 2 PROSTATE CANCER Yu Ozawa, Yasuto Yagi, Toru Nishiyama, Noriaki Santo, Ken Nakamura, Seiya Hattori, Tetsuo Monma, Jyunichi Shiraishi, Kazuhito Toya, Masanori Yorozu, and Shiro Saito Yu OzawaYu Ozawa More articles by this author , Yasuto YagiYasuto Yagi More articles by this author , Toru NishiyamaToru Nishiyama More articles by this author , Noriaki SantoNoriaki Santo More articles by this author , Ken NakamuraKen Nakamura More articles by this author , Seiya HattoriSeiya Hattori More articles by this author , Tetsuo MonmaTetsuo Monma More articles by this author , Jyunichi ShiraishiJyunichi Shiraishi More articles by this author , Kazuhito ToyaKazuhito Toya More articles by this author , Masanori YorozuMasanori Yorozu More articles by this author , and Shiro SaitoShiro Saito More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001976.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Smaller number of prostate biopsy cores at cancer diagnosis may underestimate pathological characteristics of prostate cancer (PCa). We summarize clinical outcomes of PCa after low does rate permanent seed implantation brachytherapy with iodine-125 (BT) as monotherapy, and determine the impact of the number of biopsy cores on long clinical outcomes. METHODS: For this single-center and retrospective study, we identified 1147 patients with localized WHO pathologic Grade Group 1 or 2 (Gleason score 3+3=6 or 3+4=7) PCa who underwent BT monotherapy between September 2003 and January 2014. All specimens of ultrasound guided trans-rectal or trans-perineal prostate biopsy were reviewed by urological pathologists in our institute. The primary outcome was biochemical recurrence (BCR) using the Phoenix definition. RESULTS: On Kaplan–Meier analysis for all patients with the median 9.1 (4.0-15.5) years follow-up, the 5- and 10-year BCR-free survival (BCRFS) rates were 97.6% and 95.6%, respectively. The median number of biopsy cores was 10 (2-33), and analysis of receiver operating characteristic (ROC) curves yielded the cutoff values of 0.85 for the number of biopsy cores (p <0.03; area under the curve 0.64, sensitivity 72.3%, specificity 53.4%). When it was used to classify patients, BCRFS rate was lower in smaller biopsy core group (≤9) than larger biopsy core group (≥10) on the log-rank analysis (p <0.02). The 5- and 10-year BCRFS rates were 96.6%, 93.8% in smaller biopsy core group, whereas 98.2%, 99.3% in larger biopsy core group. In addition to the number of biopsy cores, possible prognostic factors for BCR including PSA (ng/ml), clinical T stage, Grade Group, and neoadjuvant hormonal therapy were analyzed by multivariate Cox proportional hazard model. The result was that the number of biopsy cores (HR 0.87, 95% CI 0.80-0.96, p <0.01), clinical T2 (HR 2.82, 95% CI 1.62-4.92, p <0.01), and Grade Group 2 (HR 2.34, 95% CI 1.35-4.27, p <0.01) were associated with higher odds of BCR. CONCLUSIONS: Smaller number of biopsy cores at cancer diagnosis is the independent prognosis factor for BCR in WHO pathologic Grade Group 1 or 2 PCa with BT monotherapy. It may lead to underestimation of pathological characteristics and inadequate treatment. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e118-e118 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yu Ozawa More articles by this author Yasuto Yagi More articles by this author Toru Nishiyama More articles by this author Noriaki Santo More articles by this author Ken Nakamura More articles by this author Seiya Hattori More articles by this author Tetsuo Monma More articles by this author Jyunichi Shiraishi More articles by this author Kazuhito Toya More articles by this author Masanori Yorozu More articles by this author Shiro Saito More articles by this author Expand All Advertisement Loading ...