MP38-05 DEFINING A COHORT OF MEN WHO MAY NOT REQUIRE REPEAT PROSTATE BIOPSY BASED ON PCA3 AND MRI: THE DOUBLE NEGATIVE EFFECT.
Bibliographic record
Abstract
You have accessJournal of UrologyProstate Cancer: Detection & Screening IV1 Apr 2017MP38-05 DEFINING A COHORT OF MEN WHO MAY NOT REQUIRE REPEAT PROSTATE BIOPSY BASED ON PCA3 AND MRI: THE DOUBLE NEGATIVE EFFECT. Nathan Perlis, Thamir Al-Kasab, Ardalan Ahmad, Estee Goldberg, Kamel Fadaak, Rashid Sayyid, Antonio Finelli, Girish Kulkarni, Alexandre Zlotta, Rob Hamilton, and Neil Fleshner Nathan PerlisNathan Perlis More articles by this author , Thamir Al-KasabThamir Al-Kasab More articles by this author , Ardalan AhmadArdalan Ahmad More articles by this author , Estee GoldbergEstee Goldberg More articles by this author , Kamel FadaakKamel Fadaak More articles by this author , Rashid SayyidRashid Sayyid More articles by this author , Antonio FinelliAntonio Finelli More articles by this author , Girish KulkarniGirish Kulkarni More articles by this author , Alexandre ZlottaAlexandre Zlotta More articles by this author , Rob HamiltonRob Hamilton More articles by this author , and Neil FleshnerNeil Fleshner More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.1158AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Prostate Cancer (PC) overdiagnosis and overtreatment is a major concern for clinicians and policy makers. Multiparametric MRI (mpMRI) and the PCA3 urine test aim to limit this by identifying fewer cases of indolent cancer and more clinically significant cases. We explore whether the utility of the tests can be maximized by combining them for a group of patients with previous prostate biopsies. METHODS We collected clinicopathologic data from all patients that underwent a urine PCA3 test from 2011 to June 2016 at the University Health Network at The University of Toronto in accordance with ethics committee approval. This included patients on active surveillance (AS) for low-risk PC and those without PC with previous negative biopsies and suspicion of occult, significant disease primarily based on rising PSA. We explored whether age, PSA, PCA3, mpMRI, DRE, family history and prostate size predicted for clinically significant prostate cancer on repeat biopsy as defined by Epstein criteria. We then stratified patients by mpMRI and PCA3 result to detect whether any particular combination of these test has exemplary negative predictive value (NPV) and considered the optimal sequence of tests. RESULTS 470 patients met inclusion criteria with median (IQR) age and PSA of 62.5 ng/mL (58-68) and 6.3 (4.6-8.8), respectively. PCA3 was abnormal (≥35) in 32.5% of cases. 18.8% of men had a positive family history and 5.6% had suspicious DRE. Epstein criteria or worse PC was identified in 26.3% of cases. In the multivariate model, only age (OR 1.08, 95%CI 1.01-1.16), mpMRI score 4 (OR 16.6, 95%CI 3.9-70.0) or 5 (OR 28.3, 95%CI 5.7-138), and PCA3 (OR 2.9, 95%CI 1.0-8.8) predicted for clinically significant PC on biopsy. No patients with a negative mpMRI and normal PCA3 test were found to have clinically significant PC on biopsy (0 of 26, 100% NPV for double negative test, p<0.0001). Using mpMRI as the initial test diminishes the number of overall tests (11 fewer tests per 100 patients), adds spatial information for targeted biopsy when available, but is more expensive than starting with PCA3 test for all patients. CONCLUSIONS Both PCA3 and mpMRI are useful tests for predicting clinically significant PC on repeat prostate biopsy. In the 1 of 6 patients in our cohort with double negative tests no clinically significant PC was found on biopsy, which raises the question whether biopsy can be avoided in this group altogether. This study is limited by its retrospective design and selection bias. A prospective trial at our centre is currently ongoing examining this question for patients on AS. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e485-e486 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Nathan Perlis More articles by this author Thamir Al-Kasab More articles by this author Ardalan Ahmad More articles by this author Estee Goldberg More articles by this author Kamel Fadaak More articles by this author Rashid Sayyid More articles by this author Antonio Finelli More articles by this author Girish Kulkarni More articles by this author Alexandre Zlotta More articles by this author Rob Hamilton More articles by this author Neil Fleshner More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.011 | 0.049 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.002 | 0.003 |
| Research integrity | 0.001 | 0.003 |
| Insufficient payload (model declined to judge) | 0.010 | 0.002 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".