MP09-16 CONTEMPORARY MAPPING OF POST-PROSTATECTOMY PROSTATE CANCER RELAPSE WITH C-11 CHOLINE PET AND MULTIPARAMETRIC MRI

INTRODUCTION AND OBJECTIVES: The aim of this study was to develop and externally validate a novel model aimed at predicting cancer-specific mortality (CSM) after biochemical recurrence (BCR) among prostate cancer (PCa) patients treated with radical prostatectomy (RP) with or without adjuvant external beam radiotherapy (aRT) and/or hormonal therapy (aHT). METHODS: The development cohort included 689 consecutive PCa patients treated with RP between 1987 and 2011 at a single tertiary referral center. All men had a subsequent BCR, defined as 2 subsequent PSA valuesu003e0.2 ng/ml and rising. Multivariable competingrisks regression analyses tested the predictors of CSM after BCR for purpose of 5-year CSM nomogram development. Validation (2,000 bootstrap resamples) was internally tested. External validation was performed into a population of 6,734 PCa patients with BCR after treatment with RP treated at another tertiary referral center from 1987 to 2011. The predictive accuracy (PA) was quantified using the receiver operating characteristic-derived area under the curve and the calibration plot method. RESULTS: The 5-year CSM-free survival rate was 83.6% (CI: 79.6-87.2). At multivariable analyses, pathologic stage T3b or more (HR: 7.42; p1⁄40.008), pathologic Gleason score 8-10 (HR: 2.19; p1⁄40.003), lymph node invasion (HR: 3.57; p1⁄40.001), time to BCR (HR: 0.99; p1⁄40.03) and age at BCR (HR: 1.04; p1⁄40.04), were each significantly associated with the risk of CSM after BCR. The bootstrap-corrected PA was 87.4% (bootstrap 95% CI: 82.0-91.7%). External validation of our nomogram showed a good PA of 83.2%. Figure 1 shows the competing-risk nomogram CONCLUSIONS: We developed and externally validated the first nomogram for individual prediction of 5-year PCa-specific mortality after BCR, applicable to all contemporary patients who recur after RP, inclusive of those treated with adjuvant therapies. This accurate and generalizable tool could be useful for patient counseling, risk stratification, and in designing future randomized trials to determine the decision making process in the BCR patient population