948 OPTIMAL TIMING OF EARLY VERSUS DELAYED ADJUVANT RADIOTHERAPY FOLLOWING RADICAL PROSTATECTOMY FOR LOCALLY ADVANCED PROSTATE CANCER

Abstract

You have accessJournal of UrologyProstate Cancer: Advanced III1 Apr 2012948 OPTIMAL TIMING OF EARLY VERSUS DELAYED ADJUVANT RADIOTHERAPY FOLLOWING RADICAL PROSTATECTOMY FOR LOCALLY ADVANCED PROSTATE CANCER Keith Kowalczyk, Xiangmei Gu, Paul Nguyen, Stuart Lipsitz, Hua-yin Yu, Sean Collins, and Jim Hu Keith KowalczykKeith Kowalczyk Washington, DC More articles by this author , Xiangmei GuXiangmei Gu Boston, MA More articles by this author , Paul NguyenPaul Nguyen Boston, MA More articles by this author , Stuart LipsitzStuart Lipsitz Boston, MA More articles by this author , Hua-yin YuHua-yin Yu Boston, MA More articles by this author , Sean CollinsSean Collins Washington, DC More articles by this author , and Jim HuJim Hu Boston, MA More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.1046AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Although post-prostatectomy adjuvant radiation therapy (ART) has shown survival benefits for >pT3 disease, optimal ART timing remains unknown as randomized controlled trials have used arbitrary cut-points based on study design. Using a population-based approach, we characterize outcomes of early vs. delayed ART as well as the optimal timing of ART following radical prostatectomy (RP) for locally advanced disease. METHODS Using Surveillance, Epidemiology, and End Results-Medicare data from 1995-2007, we identified 1056 men with >pT3N0 disease receiving early (<4 months post-RP, n=464) vs. delayed (4-12 months post-RP, n=592) ART following RP. Baseline demographic and tumor characteristics were recorded and compared. Propensity-score methods were used to compare overall mortality, prostate cancer-specific mortality (PCSM), bone-related events (defined as bone metastasis and/or pathologic fracture), and salvage hormonal therapy utilization (>12 months following initiation of ART). Additionally, we used the maximal statistic approach to determine time cut-points with most significant ART benefit. RESULTS Early vs. delayed ART was associated with improved PCSM (0.71 vs. 2.05 events per 100 person-years, p=0.024) for T3b disease and fewer bone-related events for T3a disease with negative margins (T3aNM, 0.92 vs. 2.50 events per 100 person-years, p=0.008). Administering ART >11 months post-RP for T3aNM (HR 15.6, p=0.022) and >6 months post-RP for T3b (HR 2.74, p=0.015) was associated with worse PCSM. Delaying ART >5 months for T3aNM (HR 2.52, p=0.005) and >7 months for T3a disease with positive margins (HR 2.26, p=0.007) was associated with increased bone-related events. CONCLUSIONS Initiating ART <6 months post-RP for T3b disease and <11 months post-RP for T3aNM disease is associated with improved PCSM. Early ART for T3a, regardless of margin status, is also associated with fewer bone-related events. Our population-based findings complement randomized trials designed with fixed ART timing, and aids providers and patients considering ART. Results of maximal statistic approach to calculate adjusted post-radical prostatectomy time cut-points when adjuvant radiation therapy has the most significant benefit Months Hazard Ratio p-value T3a NEGATIVE MARGIN Overall mortality 3 1.63 0.254 Prostate-cancer specific mortality 11 15.60 0.022 Bone-related events 5 2.52 0.005 Salvage hormonal therapy 4 1.78 0.039 T3a POSITIVE MARGIN Overall mortality 7 0.52 0.157 Prostate-cancer specific mortality 10 4.89 0.267 Bone-related events 7 2.25 0.007 Salvage hormonal therapy 4 1.57 0.093 T3b Overall mortality 12 7.34 0.318 Prostate-cancer specific mortality 6 2.74 0.015 Bone-related events 10 0.45 0.243 Salvage hormonal therapy 8 2.48 <0.001 T4 Overall mortality 3 0.38 0.013 Prostate-cancer specific mortality 6 6.10 0.021 Bone-related events 5 0.42 0.087 Salvage hormonal therapy 6 2.28 0.041 © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e386 Peer Review Report Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Keith Kowalczyk Washington, DC More articles by this author Xiangmei Gu Boston, MA More articles by this author Paul Nguyen Boston, MA More articles by this author Stuart Lipsitz Boston, MA More articles by this author Hua-yin Yu Boston, MA More articles by this author Sean Collins Washington, DC More articles by this author Jim Hu Boston, MA More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...