PD32-04 CAN CONFIRMATORY BIOPSY BE SKIPPED FOR ACTIVE SURVEILLANCE PATIENTS WITH NEGATIVE MRI FINDINGS AND A LOW NUMBER OF POSITIVE CORES ON DIAGNOSTIC BIOPSY? (2015)

You have accessJournal of UrologyProstate Cancer: Staging II1 Apr 2015PD32-04 CAN CONFIRMATORY BIOPSY BE SKIPPED FOR ACTIVE SURVEILLANCE PATIENTS WITH NEGATIVE MRI FINDINGS AND A LOW NUMBER OF POSITIVE CORES ON DIAGNOSTIC BIOPSY? Prassannah Satasivam, Biny Ying Poon, Hebert Alberto Vargas, Andrew Vickers, and James Eastham Prassannah SatasivamPrassannah Satasivam More articles by this author , Biny Ying PoonBiny Ying Poon More articles by this author , Hebert Alberto VargasHebert Alberto Vargas More articles by this author , Andrew VickersAndrew Vickers More articles by this author , and James EasthamJames Eastham More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.2115AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES MSKCC patients who are eligible for active surveillance (AS) on their initial diagnostic biopsy routinely receive an MRI as well as a confirmatory biopsy. We sought to determine whether the MRI result, in conjunction with the proportion of positive cores at initial biopsy, could predict the results of the confirmatory biopsy. If so, confirmatory biopsy might be avoided for men at low risk of reclassification. METHODS Our cohort included 444 patients who qualified for AS on initial findings from December 2007 to December 2013 and who received both an MRI and a confirmatory biopsy. We used logistic regression to assess whether the MRI result (no focal/dominant lesion vs focal/dominant lesion) and proportion of positive cores at initial biopsy could predict high-grade cancer (Gleason≥7) on confirmatory biopsy. We also performed decision curve analyses to assess if either of the logistic regression models would be clinically helpful. We assessed the decision curve analysis up to a threshold probability of 15% for high-grade cancer, which we considered the highest threshold for which a physician would forgo a confirmatory biopsy. RESULTS The median age was 62 years (IQR 56, 67) and 48% of patients were found to have a dominant or focal lesion on MRI. About 1 in 8 patients were found to have high-grade cancer on confirmatory biopsy, of whom 50 had 3+4, 6 had 4+3, 3 had Gleason 8 and 1 patient had Gleason 9 disease. MRI results and proportion of positive biopsy cores were significantly associated with high-grade cancer on confirmatory biopsy on both univariate and multivariable logistic regression (all p<0.05). When determining the need for confirmatory biopsy using a ten-fold cross-validated model, most clinicians and patients would derive the greatest net benefit when MRI results are used in conjunction with the proportion of positive cores at initial biopsy (AUC of 0.644), rather than positive cores alone (AUC of 0.601). For a threshold of 10%, this model would indicate confirmatory biopsies for 563 patients out of 1000 patients, of whom 101 would harbor high-grade disease (18%). Of the 437 not indicated for a confirmatory biopsy, 34 (8%) would harbor high-grade disease. CONCLUSIONS If externally validated, a model based on MRI in combination with the percentage positive cores on initial biopsy could be used to avoid confirmatory biopsy in some patients initiating AS. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e705-e706 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Prassannah Satasivam More articles by this author Biny Ying Poon More articles by this author Hebert Alberto Vargas More articles by this author Andrew Vickers More articles by this author James Eastham More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...